WorldWideScience

Sample records for human brain mri

  1. Human brain functional MRI and DTI visualization with virtual reality.

    Science.gov (United States)

    Chen, Bin; Moreland, John; Zhang, Jingyu

    2011-12-01

    Magnetic resonance diffusion tensor imaging (DTI) and functional MRI (fMRI) are two active research areas in neuroimaging. DTI is sensitive to the anisotropic diffusion of water exerted by its macromolecular environment and has been shown useful in characterizing structures of ordered tissues such as the brain white matter, myocardium, and cartilage. The diffusion tensor provides two new types of information of water diffusion: the magnitude and the spatial orientation of water diffusivity inside the tissue. This information has been used for white matter fiber tracking to review physical neuronal pathways inside the brain. Functional MRI measures brain activations using the hemodynamic response. The statistically derived activation map corresponds to human brain functional activities caused by neuronal activities. The combination of these two methods provides a new way to understand human brain from the anatomical neuronal fiber connectivity to functional activities between different brain regions. In this study, virtual reality (VR) based MR DTI and fMRI visualization with high resolution anatomical image segmentation and registration, ROI definition and neuronal white matter fiber tractography visualization and fMRI activation map integration is proposed. Rationale and methods for producing and distributing stereoscopic videos are also discussed.

  2. Parallel workflow tools to facilitate human brain MRI post-processing

    Directory of Open Access Journals (Sweden)

    Zaixu eCui

    2015-05-01

    Full Text Available Multi-modal magnetic resonance imaging (MRI techniques are widely applied in human brain studies. To obtain specific brain measures of interest from MRI datasets, a number of complex image post-processing steps are typically required. Parallel workflow tools have recently been developed, concatenating individual processing steps and enabling fully automated processing of raw MRI data to obtain the final results. These workflow tools are also designed to make optimal use of available computational resources and to support the parallel processing of different subjects or of independent processing steps for a single subject. Automated, parallel MRI post-processing tools can greatly facilitate relevant brain investigations and are being increasingly applied. In this review, we briefly summarize these parallel workflow tools and discuss relevant issues.

  3. MRI with intrathecal MRI gadolinium contrast medium administration: a possible method to assess glymphatic function in human brain

    International Nuclear Information System (INIS)

    Eide, Per Kristian; Ringstad, Geir

    2015-01-01

    Recently, the “glymphatic system” of the brain has been discovered in rodents, which is a paravascular, transparenchymal route for clearance of excess brain metabolites and distribution of compounds in the cerebrospinal fluid. It has already been demonstrated that intrathecally administered gadolinium (Gd) contrast medium distributes along this route in rats, but so far not in humans. A 27-year-old woman underwent magnetic resonance imaging (MRI) with intrathecal administration of gadobutrol, which distributed throughout her entire brain after 1 and 4.5 h. MRI with intrathecal Gd may become a tool to study glymphatic function in the human brain

  4. MRI with intrathecal MRI gadolinium contrast medium administration: a possible method to assess glymphatic function in human brain.

    Science.gov (United States)

    Eide, Per Kristian; Ringstad, Geir

    2015-11-01

    Recently, the "glymphatic system" of the brain has been discovered in rodents, which is a paravascular, transparenchymal route for clearance of excess brain metabolites and distribution of compounds in the cerebrospinal fluid. It has already been demonstrated that intrathecally administered gadolinium (Gd) contrast medium distributes along this route in rats, but so far not in humans. A 27-year-old woman underwent magnetic resonance imaging (MRI) with intrathecal administration of gadobutrol, which distributed throughout her entire brain after 1 and 4.5 h. MRI with intrathecal Gd may become a tool to study glymphatic function in the human brain.

  5. Mapping human whole-brain structural networks with diffusion MRI.

    Directory of Open Access Journals (Sweden)

    Patric Hagmann

    Full Text Available Understanding the large-scale structural network formed by neurons is a major challenge in system neuroscience. A detailed connectivity map covering the entire brain would therefore be of great value. Based on diffusion MRI, we propose an efficient methodology to generate large, comprehensive and individual white matter connectional datasets of the living or dead, human or animal brain. This non-invasive tool enables us to study the basic and potentially complex network properties of the entire brain. For two human subjects we find that their individual brain networks have an exponential node degree distribution and that their global organization is in the form of a small world.

  6. Simultaneous fMRI-PET of the opioidergic pain system in human brain

    DEFF Research Database (Denmark)

    Wey, Hsiao-Ying; Catana, Ciprian; Hooker, Jacob M

    2014-01-01

    distinct components of the blood oxygenation level dependent (BOLD) fMRI signal has not yet been shown. We obtained sixteen fMRI-PET data sets from eight healthy volunteers. Each subject participated in randomized order in a pain scan and a control (nonpainful pressure) scan on the same day. Dynamic PET......MRI and PET provide complementary information for studying brain function. While the potential use of simultaneous MRI/PET for clinical diagnostic and disease staging has been demonstrated recently; the biological relevance of concurrent functional MRI-PET brain imaging to dissect neurochemically...... data were acquired with an opioid radioligand, [(11)C]diprenorphine, to detect endogenous opioid releases in response to pain. BOLD fMRI data were collected at the same time to capture hemodynamic responses. In this simultaneous human fMRI-PET imaging study, we show co-localized responses in thalamus...

  7. Effects of hypoglycemia on human brain activation measured with fMRI.

    Science.gov (United States)

    Anderson, Adam W; Heptulla, Rubina A; Driesen, Naomi; Flanagan, Daniel; Goldberg, Philip A; Jones, Timothy W; Rife, Fran; Sarofin, Hedy; Tamborlane, William; Sherwin, Robert; Gore, John C

    2006-07-01

    Functional magnetic resonance imaging (fMRI) was used to measure the effects of acute hypoglycemia caused by passive sensory stimulation on brain activation. Visual stimulation was used to generate blood-oxygen-level-dependent (BOLD) contrast, which was monitored during hyperinsulinemic hypoglycemic and euglycemic clamp studies. Hypoglycemia (50 +/- 1 mg glucose/dl) decreased the fMRI signal relative to euglycemia in 10 healthy human subjects: the fractional signal change was reduced by 28 +/- 12% (P variations in blood glucose levels may modulate BOLD signals in the healthy brain.

  8. Mapping effective connectivity in the human brain with concurrent intracranial electrical stimulation and BOLD-fMRI.

    Science.gov (United States)

    Oya, Hiroyuki; Howard, Matthew A; Magnotta, Vincent A; Kruger, Anton; Griffiths, Timothy D; Lemieux, Louis; Carmichael, David W; Petkov, Christopher I; Kawasaki, Hiroto; Kovach, Christopher K; Sutterer, Matthew J; Adolphs, Ralph

    2017-02-01

    Understanding brain function requires knowledge of how one brain region causally influences another. This information is difficult to obtain directly in the human brain, and is instead typically inferred from resting-state fMRI. Here, we demonstrate the safety and scientific promise of a novel and complementary approach: concurrent electrical stimulation and fMRI (es-fMRI) at 3T in awake neurosurgical patients with implanted depth electrodes. We document the results of safety testing, actual experimental setup, and stimulation parameters, that safely and reliably evoke activation in distal structures through stimulation of amygdala, cingulate, or prefrontal cortex. We compare connectivity inferred from the evoked patterns of activation with that estimated from standard resting-state fMRI in the same patients: while connectivity patterns obtained with each approach are correlated, each method produces unique results. Response patterns were stable over the course of 11min of es-fMRI runs. COMPARISON WITH EXISTING METHOD: es-fMRI in awake humans yields unique information about effective connectivity, complementing resting-state fMRI. Although our stimulations were below the level of inducing any apparent behavioral or perceptual effects, a next step would be to use es-fMRI to modulate task performances. This would reveal the acute network-level changes induced by the stimulation that mediate the behavioral and cognitive effects seen with brain stimulation. es-fMRI provides a novel and safe approach for mapping effective connectivity in the human brain in a clinical setting, and will inform treatments for psychiatric and neurodegenerative disorders that use deep brain stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Human brain MRI at 500 MHz, scientific perspectives and technological challenges

    Science.gov (United States)

    Le Bihan, Denis; Schild, Thierry

    2017-03-01

    The understanding of the human brain is one of the main scientific challenges of the 21st century. In the early 2000s the French Alternative Energies and Atomic Energy Commission launched a program to conceive and build a ‘human brain explorer’, the first human MRI scanner operating at 11.7 T. This scanner was envisioned to be part of the ambitious French-German project Iseult, bridging together industrial and academic partners to push the limits of molecular neuroimaging, from mouse to man, using ultra-high field MRI. In this article we provide a summary of the main neuroscience and medical targets of the Iseult project, mainly to acquire within timescales compatible with human tolerances images at a scale of 100 μm at which everything remains to discover, and to create new approaches to develop new imaging biomarkers for specific neurological and psychiatric disorders. The system specifications, the technological challenges, in terms of magnet design, winding technology, cryogenics, quench protection, stability control, and the solutions which have been chosen to overcome them and build this outstanding instrument are provided. Lines of the research and development which will be necessary to fully exploit the potential of this and other UHF MRI scanners are also outlined.

  10. Functional MRI studies of acupuncture analgesia modulating within the human brain

    International Nuclear Information System (INIS)

    Hou Jinwen; Huang Weihao; Wang Qing; Feng Jingwei; Pu Yonglin; Gao Jiahong

    2002-01-01

    Objective: To evaluate the correlation between acupuncture analgesia and specific functional areas of the brain using functional magnetic resonance imaging (fMRI). Methods: Acupuncture stimulation was induced by manipulating acupuncture needle at the acupuncture point, large intestine 4 (LI 4, Hegu) on the right (dominant) hand of 8 healthy subjects. Functional MRI data were obtained from scanning the whole brain. A block-design paradigm was applied. Functional responses were established by students' group t-test analysis. Results: The data sets from 6 of 8 subjects were used in the study. Signal increases and signal decreases elicited by acupuncture stimulating were demonstrated in multiple brain regions. Signal increases in periaqueductal gray matter and ventral posterior nucleus of the left thalamus, and signal decreases in bilateral anterior cingulate cortex and bilateral occipital lobes were considered as the response to the acupuncture modulating within the human brain. Conclusion: The therapeutic effect of acupuncture analgesia was probably produced by the interaction of multiple brain structures of functional connectivity rather than through the activation of a single brain region

  11. Measurements of brain microstructure and connectivity with diffusion MRI

    Directory of Open Access Journals (Sweden)

    Ching-Po Lin

    2011-12-01

    Full Text Available By probing direction-dependent diffusivity of water molecules, diffusion MRI has shown its capability to reflect the microstructural tissue status and to estimate the neural orientation and pathways in the living brain. This approach has supplied novel insights into in-vivo human brain connections. By detecting the connection patterns, anatomical architecture and structural integrity between cortical regions or subcortical nuclei in the living human brain can be easily identified. It thus opens a new window on brain connectivity studies and disease processes. During the past years, there is a growing interest in exploring the connectivity patterns of the human brain. Specifically, the utilities of noninvasive neuroimaging data and graph theoretical analysis have provided important insights into the anatomical connections and topological pattern of human brain structural networks in vivo. Here, we review the progress of this important technique and the recent methodological and application studies utilizing graph theoretical approaches on brain structural networks with structural MRI and diffusion MRI.

  12. Integration of fMRI, NIROT and ERP for studies of human brain function.

    Science.gov (United States)

    Gore, John C; Horovitz, Silvina G; Cannistraci, Christopher J; Skudlarski, Pavel

    2006-05-01

    Different methods of assessing human brain function possess specific advantages and disadvantages compared to others, but it is believed that combining different approaches will provide greater information than can be obtained from each alone. For example, functional magnetic resonance imaging (fMRI) has good spatial resolution but poor temporal resolution, whereas the converse is true for electrophysiological recordings (event-related potentials or ERPs). In this review of recent work, we highlight a novel approach to combining these modalities in a manner designed to increase information on the origins and locations of the generators of specific ERPs and the relationship between fMRI and ERP signals. Near infrared imaging techniques have also been studied as alternatives to fMRI and can be readily integrated with simultaneous electrophysiological recordings. Each of these modalities may in principle be also used in so-called steady-state acquisitions in which the correlational structure of signals from the brain may be analyzed to provide new insights into brain function.

  13. D-BRAIN : Anatomically accurate simulated diffusion MRI brain data

    NARCIS (Netherlands)

    Perrone, Daniele; Jeurissen, Ben; Aelterman, Jan; Roine, Timo; Sijbers, Jan; Pizurica, Aleksandra; Leemans, Alexander; Philips, Wilfried

    2016-01-01

    Diffusion Weighted (DW) MRI allows for the non-invasive study of water diffusion inside living tissues. As such, it is useful for the investigation of human brain white matter (WM) connectivity in vivo through fiber tractography (FT) algorithms. Many DW-MRI tailored restoration techniques and FT

  14. Low-dimensional morphospace of topological motifs in human fMRI brain networks

    Directory of Open Access Journals (Sweden)

    Sarah E. Morgan

    2018-06-01

    Full Text Available We present a low-dimensional morphospace of fMRI brain networks, where axes are defined in a data-driven manner based on the network motifs. The morphospace allows us to identify the key variations in healthy fMRI networks in terms of their underlying motifs, and we observe that two principal components (PCs can account for 97% of the motif variability. The first PC of the motif distribution is correlated with efficiency and inversely correlated with transitivity. Hence this axis approximately conforms to the well-known economical small-world trade-off between integration and segregation in brain networks. Finally, we show that the economical clustering generative model proposed by Vértes et al. (2012 can approximately reproduce the motif morphospace of the real fMRI brain networks, in contrast to other generative models. Overall, the motif morphospace provides a powerful way to visualize the relationships between network properties and to investigate generative or constraining factors in the formation of complex human brain functional networks. Motifs have been described as the building blocks of complex networks. Meanwhile, a morphospace allows networks to be placed in a common space and can reveal the relationships between different network properties and elucidate the driving forces behind network topology. We combine the concepts of motifs and morphospaces to create the first motif morphospace of fMRI brain networks. Crucially, the morphospace axes are defined by the motifs, in a data-driven manner. We observe strong correlations between the networks’ positions in morphospace and their global topological properties, suggesting that motif morphospaces are a powerful way to capture the topology of networks in a low-dimensional space and to compare generative models of brain networks. Motif morphospaces could also be used to study other complex networks’ topologies.

  15. Unraveling the multiscale structural organization and connectivity of the human brain: the role of diffusion MRI

    Directory of Open Access Journals (Sweden)

    Matteo eBastiani

    2015-06-01

    Full Text Available The structural architecture and the anatomical connectivity of the human brain show different organizational principles at distinct spatial scales. Histological staining and light microscopy techniques have been widely used in classical neuroanatomical studies to unravel brain organization. Using such techniques is a laborious task performed on 2-dimensional histological sections by skilled anatomists possibly aided by semi-automated algorithms. With the recent advent of modern magnetic resonance imaging (MRI contrast mechanisms, cortical layers and columns can now be reliably identified and their structural properties quantified post mortem. These developments are allowing the investigation of neuroanatomical features of the brain at a spatial resolution that could be interfaced with that of histology. Diffusion MRI and tractography techniques, in particular, have been used to probe the architecture of both white and gray matter in three dimensions. Combined with mathematical network analysis, these techniques are increasingly influential in the investigation of the macro-, meso- and microscopic organization of brain connectivity and anatomy, both in vivo and ex vivo. Diffusion MRI-based techniques in combination with histology approaches can therefore support the endeavor of creating multimodal atlases that take into account the different spatial scales or levels on which the brain is organized. The aim of this review is to illustrate and discuss the structural architecture and the anatomical connectivity of the human brain at different spatial scales and how recently developed diffusion MRI techniques can help investigate these.

  16. MRI of 'brain death'

    International Nuclear Information System (INIS)

    Nishino, Shigeki; Itoh, Takahiko; Tuchida, Shohei; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira; Sanou, Kazuo.

    1990-01-01

    Magnetic resonance imaging (MRI) was undertaken for two patients who suffered from severe cerebrovascular diseases and were clinically brain dead. The MRI system we used was Resona (Yokogawa Medical Systems, superconductive system 0.5 T) and the CT apparatus was Toshiba TCT-300. Initial CT and MRI were undertaken as soon as possible after admission, and repeated sequentially. After diagnosis of brain death, we performed angiography to determine cerebral circulatory arrest, and MRI obtained at the same time was compared with the angiogram and CT. Case 1 was a 77-year-old man who was admitted in an unconscious state. CT and MRI on the second day after hospitalization revealed cerebellar infarction. He was diagnosed as brain dead on day 4. Case 2 was a 35-year-old man. When he was transferred to our hospital, he was in cardiorespiratory arrested. Cardiac resuscitation was successful but no spontaneous respiration appeared. CT and MRI on admission revealed right intracerebral hemorrhage. Angiography revealed cessation of contrast medium in intracranial vessels in both of the patients. We found no 'flow signal void sign' in the bilateral internal carotid and basilar arteries on MRI images in both cases after brain death. MRI, showing us the anatomical changes of the brain, clearly revealed brain herniations, even though only nuclear findings of 'brain tamponade' were seen on CT. But in Case 1, we could not see the infarct lesions in the cerebellum on MR images obtained after brain death. This phenomenon was caused by the whole brain ischemia masking the initial ischemic lesions. We concluded that MRI was useful not only the anatomical display of lesions and brain herniation with high contrast resolution but for obtaining information on cerebral circulation of brain death. (author)

  17. Optimizing full-brain coverage in human brain MRI through population distributions of brain size

    NARCIS (Netherlands)

    Mennes, M.; Jenkinson, M.; Valabregue, R.; Buitelaar, J.K.; Beckmann, C.F.; Smith, S.

    2014-01-01

    When defining an MRI protocol, brain researchers need to set multiple interdependent parameters that define repetition time (TR), voxel size, field-of-view (FOV), etc. Typically, researchers aim to image the full brain, making the expected FOV an important parameter to consider. Especially in 2D-EPI

  18. Learning Computational Models of Video Memorability from fMRI Brain Imaging.

    Science.gov (United States)

    Han, Junwei; Chen, Changyuan; Shao, Ling; Hu, Xintao; Han, Jungong; Liu, Tianming

    2015-08-01

    Generally, various visual media are unequally memorable by the human brain. This paper looks into a new direction of modeling the memorability of video clips and automatically predicting how memorable they are by learning from brain functional magnetic resonance imaging (fMRI). We propose a novel computational framework by integrating the power of low-level audiovisual features and brain activity decoding via fMRI. Initially, a user study experiment is performed to create a ground truth database for measuring video memorability and a set of effective low-level audiovisual features is examined in this database. Then, human subjects' brain fMRI data are obtained when they are watching the video clips. The fMRI-derived features that convey the brain activity of memorizing videos are extracted using a universal brain reference system. Finally, due to the fact that fMRI scanning is expensive and time-consuming, a computational model is learned on our benchmark dataset with the objective of maximizing the correlation between the low-level audiovisual features and the fMRI-derived features using joint subspace learning. The learned model can then automatically predict the memorability of videos without fMRI scans. Evaluations on publically available image and video databases demonstrate the effectiveness of the proposed framework.

  19. High-field fMRI unveils orientation columns in humans.

    Science.gov (United States)

    Yacoub, Essa; Harel, Noam; Ugurbil, Kâmil

    2008-07-29

    Functional (f)MRI has revolutionized the field of human brain research. fMRI can noninvasively map the spatial architecture of brain function via localized increases in blood flow after sensory or cognitive stimulation. Recent advances in fMRI have led to enhanced sensitivity and spatial accuracy of the measured signals, indicating the possibility of detecting small neuronal ensembles that constitute fundamental computational units in the brain, such as cortical columns. Orientation columns in visual cortex are perhaps the best known example of such a functional organization in the brain. They cannot be discerned via anatomical characteristics, as with ocular dominance columns. Instead, the elucidation of their organization requires functional imaging methods. However, because of insufficient sensitivity, spatial accuracy, and image resolution of the available mapping techniques, thus far, they have not been detected in humans. Here, we demonstrate, by using high-field (7-T) fMRI, the existence and spatial features of orientation- selective columns in humans. Striking similarities were found with the known spatial features of these columns in monkeys. In addition, we found that a larger number of orientation columns are devoted to processing orientations around 90 degrees (vertical stimuli with horizontal motion), whereas relatively similar fMRI signal changes were observed across any given active column. With the current proliferation of high-field MRI systems and constant evolution of fMRI techniques, this study heralds the exciting prospect of exploring unmapped and/or unknown columnar level functional organizations in the human brain.

  20. Brain entropy and human intelligence: A resting-state fMRI study

    Science.gov (United States)

    Calderone, Daniel; Morales, Leah J.

    2018-01-01

    Human intelligence comprises comprehension of and reasoning about an infinitely variable external environment. A brain capable of large variability in neural configurations, or states, will more easily understand and predict variable external events. Entropy measures the variety of configurations possible within a system, and recently the concept of brain entropy has been defined as the number of neural states a given brain can access. This study investigates the relationship between human intelligence and brain entropy, to determine whether neural variability as reflected in neuroimaging signals carries information about intellectual ability. We hypothesize that intelligence will be positively associated with entropy in a sample of 892 healthy adults, using resting-state fMRI. Intelligence is measured with the Shipley Vocabulary and WASI Matrix Reasoning tests. Brain entropy was positively associated with intelligence. This relation was most strongly observed in the prefrontal cortex, inferior temporal lobes, and cerebellum. This relationship between high brain entropy and high intelligence indicates an essential role for entropy in brain functioning. It demonstrates that access to variable neural states predicts complex behavioral performance, and specifically shows that entropy derived from neuroimaging signals at rest carries information about intellectual capacity. Future work in this area may elucidate the links between brain entropy in both resting and active states and various forms of intelligence. This insight has the potential to provide predictive information about adaptive behavior and to delineate the subdivisions and nature of intelligence based on entropic patterns. PMID:29432427

  1. Brain entropy and human intelligence: A resting-state fMRI study.

    Science.gov (United States)

    Saxe, Glenn N; Calderone, Daniel; Morales, Leah J

    2018-01-01

    Human intelligence comprises comprehension of and reasoning about an infinitely variable external environment. A brain capable of large variability in neural configurations, or states, will more easily understand and predict variable external events. Entropy measures the variety of configurations possible within a system, and recently the concept of brain entropy has been defined as the number of neural states a given brain can access. This study investigates the relationship between human intelligence and brain entropy, to determine whether neural variability as reflected in neuroimaging signals carries information about intellectual ability. We hypothesize that intelligence will be positively associated with entropy in a sample of 892 healthy adults, using resting-state fMRI. Intelligence is measured with the Shipley Vocabulary and WASI Matrix Reasoning tests. Brain entropy was positively associated with intelligence. This relation was most strongly observed in the prefrontal cortex, inferior temporal lobes, and cerebellum. This relationship between high brain entropy and high intelligence indicates an essential role for entropy in brain functioning. It demonstrates that access to variable neural states predicts complex behavioral performance, and specifically shows that entropy derived from neuroimaging signals at rest carries information about intellectual capacity. Future work in this area may elucidate the links between brain entropy in both resting and active states and various forms of intelligence. This insight has the potential to provide predictive information about adaptive behavior and to delineate the subdivisions and nature of intelligence based on entropic patterns.

  2. D-BRAIN : Anatomically accurate simulated diffusion MRI brain data

    OpenAIRE

    Perrone, Daniele; Jeurissen, Ben; Aelterman, Jan; Roine, Timo; Sijbers, Jan; Pizurica, Aleksandra; Leemans, Alexander; Philips, Wilfried

    2016-01-01

    Diffusion Weighted (DW) MRI allows for the non-invasive study of water diffusion inside living tissues. As such, it is useful for the investigation of human brain white matter (WM) connectivity in vivo through fiber tractography (FT) algorithms. Many DW-MRI tailored restoration techniques and FT algorithms have been developed. However, it is not clear how accurately these methods reproduce the WM bundle characteristics in real-world conditions, such as in the presence of noise, partial volume...

  3. Human brain imaging

    International Nuclear Information System (INIS)

    Kuhar, M.J.

    1987-01-01

    Just as there have been dramatic advances in the molecular biology of the human brain in recent years, there also have been remarkable advances in brain imaging. This paper reports on the development and broad application of microscopic imaging techniques which include the autoradiographic localization of receptors and the measurement of glucose utilization by autoradiography. These approaches provide great sensitivity and excellent anatomical resolution in exploring brain organization and function. The first noninvasive external imaging of receptor distributions in the living human brain was achieved by positron emission tomography (PET) scanning. Developments, techniques and applications continue to progress. Magnetic resonance imaging (MRI) is also becoming important. Its initial clinical applications were in examining the structure and anatomy of the brain. However, more recent uses, such as MRI spectroscopy, indicate the feasibility of exploring biochemical pathways in the brain, the metabolism of drugs in the brain, and also of examining some of these procedures at an anatomical resolution which is substantially greater than that obtainable by PET scanning. The issues will be discussed in greater detail

  4. Atlas of regional anatomy of the brain using MRI. With functional correlations

    International Nuclear Information System (INIS)

    Tamraz, J.C.

    2006-01-01

    The volume provides a unique review of the essential topographical anatomy of the brain from an MRI perspective, correlating high-quality anatomical plates with the corresponding high-resolution MRI images. The book includes a historical review of brain mapping and an analysis of the essential reference planes used for the study of the human brain. Subsequent chapters provide a detailed review of the sulcal and the gyral anatomy of the human cortex, guiding the reader through an interpretation of the individual brain atlas provided by high-resolution MRI. The relationship between brain structure and function is approached in a topographical fashion with analysis of the necessary imaging methodology and displayed anatomy. The central, perisylvian, mesial temporal and occipital areas receive special attention. Imaging of the core brain structures is included. An extensive coronal atlas concludes the book. (orig.)

  5. MRI of 'brain death'

    Energy Technology Data Exchange (ETDEWEB)

    Nishino, Shigeki; Itoh, Takahiko; Tuchida, Shohei; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira (Okayama Univ. (Japan). School of Medicine); Sanou, Kazuo

    1990-12-01

    Magnetic resonance imaging (MRI) was undertaken for two patients who suffered from severe cerebrovascular diseases and were clinically brain dead. The MRI system we used was Resona (Yokogawa Medical Systems, superconductive system 0.5 T) and the CT apparatus was Toshiba TCT-300. Initial CT and MRI were undertaken as soon as possible after admission, and repeated sequentially. After diagnosis of brain death, we performed angiography to determine cerebral circulatory arrest, and MRI obtained at the same time was compared with the angiogram and CT. Case 1 was a 77-year-old man who was admitted in an unconscious state. CT and MRI on the second day after hospitalization revealed cerebellar infarction. He was diagnosed as brain dead on day 4. Case 2 was a 35-year-old man. When he was transferred to our hospital, he was in cardiorespiratory arrested. Cardiac resuscitation was successful but no spontaneous respiration appeared. CT and MRI on admission revealed right intracerebral hemorrhage. Angiography revealed cessation of contrast medium in intracranial vessels in both of the patients. We found no 'flow signal void sign' in the bilateral internal carotid and basilar arteries on MRI images in both cases after brain death. MRI, showing us the anatomical changes of the brain, clearly revealed brain herniations, even though only nuclear findings of 'brain tamponade' were seen on CT. But in Case 1, we could not see the infarct lesions in the cerebellum on MR images obtained after brain death. This phenomenon was caused by the whole brain ischemia masking the initial ischemic lesions. We concluded that MRI was useful not only the anatomical display of lesions and brain herniation with high contrast resolution but for obtaining information on cerebral circulation of brain death. (author).

  6. Image processing techniques for quantification and assessment of brain MRI

    NARCIS (Netherlands)

    Kuijf, H.J.

    2013-01-01

    Magnetic resonance imaging (MRI) is a widely used technique to acquire digital images of the human brain. A variety of acquisition protocols is available to generate images in vivo and noninvasively, giving great opportunities to study the anatomy and physiology of the human brain. In my thesis,

  7. 7.0 tesla MRI brain white matter atlas. 2. ed.

    International Nuclear Information System (INIS)

    Cho, Zang-Hee

    2015-01-01

    Depicts the visualization of brain white matter with the latest 7.0 T MRI and TDI techniques. Represents a useful addition to brain research and clinical settings, such as the Human Connectome Project. Contains a wealth of exquisitely detailed color images. The introduction of techniques that permit visualization of the human nervous system is one of the foremost advances in neuroscience and brain-related research. Among the most recent significant developments in this respect are ultra-high field MRI and the image post-processing technique known as track density imaging (TDI). It is these techniques (including super-resolution TDI) which represent the two major components of 7.0 Tesla MRI - Brain White Matter Atlas. This second edition of the atlas has been revised and updated to fully reflect current application of these technological advancements in order to visualize the nervous system and the brain with the finest resolution and sensitivity. Exquisitely detailed color images offer neuroscientists, neurologists, and neurosurgeons a superb resource that will be of value both for the purpose of research and for the treatment of common brain diseases such as Alzheimer's disease and multiple sclerosis.

  8. 7.0 tesla MRI brain white matter atlas. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Zang-Hee (ed.) [Gachon Univ., Incheon (Korea, Republic of). Neuroscience Research Institute

    2015-04-01

    Depicts the visualization of brain white matter with the latest 7.0 T MRI and TDI techniques. Represents a useful addition to brain research and clinical settings, such as the Human Connectome Project. Contains a wealth of exquisitely detailed color images. The introduction of techniques that permit visualization of the human nervous system is one of the foremost advances in neuroscience and brain-related research. Among the most recent significant developments in this respect are ultra-high field MRI and the image post-processing technique known as track density imaging (TDI). It is these techniques (including super-resolution TDI) which represent the two major components of 7.0 Tesla MRI - Brain White Matter Atlas. This second edition of the atlas has been revised and updated to fully reflect current application of these technological advancements in order to visualize the nervous system and the brain with the finest resolution and sensitivity. Exquisitely detailed color images offer neuroscientists, neurologists, and neurosurgeons a superb resource that will be of value both for the purpose of research and for the treatment of common brain diseases such as Alzheimer's disease and multiple sclerosis.

  9. Brain venous pathologies: MRI findings

    International Nuclear Information System (INIS)

    Salvatico, Rosana; Gonzalez, Alejandro; Yanez, Paulina; Romero, Carlos; Trejo, Mariano; Lambre, Hector

    2006-01-01

    Purpose: To describe MRI findings of the different brain venous pathologies. Material and Methods: Between January 2002 and March 2004, 18 patients were studied 10 males and 8 females between 6 and 63 years old; with different brain venous pathologies. In all cases brain MRI were performed including morphological sequences with and without gadolinium injection and angiographic venous sequences. Results: 10 venous occlusions were found, 6 venous angiomas, and 2 presented varices secondary to arteriovenous dural fistula. Conclusion: Brain venous pathologies can appear in many different clinical contexts, with different prognosis and treatment. In all the cases brain MRI was the best imaging study to disclose typical morphologic abnormalities. (author) [es

  10. Recent applications of UHF-MRI in the study of human brain function and structure : a review

    NARCIS (Netherlands)

    Van der Zwaag, W.; Schäfer, Andreas; Marques, José P; Turner, R.; Trampel, Robert

    The increased availability of ultra-high-field (UHF) MRI has led to its application in a wide range of neuroimaging studies, which are showing promise in transforming fundamental approaches to human neuroscience. This review presents recent work on structural and functional brain imaging, at 7 T and

  11. Novel MRI methodology to detect human whole-brain connectivity changes after ingestion of fructose or glucose

    Science.gov (United States)

    Tsao, Sinchai; Wilkins, Bryce; Page, Kathleen A.; Singh, Manbir

    2012-03-01

    A novel MRI protocol has been developed to investigate the differential effects of glucose or fructose consumption on whole-brain functional brain connectivity. A previous study has reported a decrease in the fMRI blood oxygen level dependent (BOLD) signal of the hypothalamus following glucose ingestion, but due to technical limitations, was restricted to a single slice covering the hypothalamus, and thus unable to detect whole-brain connectivity. In another previous study, a protocol was devised to acquire whole-brain fMRI data following food intake, but only after restricting image acquisition to an MR sampling or repetition time (TR) of 20s, making the protocol unsuitable to detect functional connectivity above 0.025Hz. We have successfully implemented a continuous 36-min, 40 contiguous slices, whole-brain BOLD acquisition protocol on a 3T scanner with TR=4.5s to ensure detection of up to 0.1Hz frequencies for whole-brain functional connectivity analysis. Human data were acquired first with ingestion of water only, followed by a glucose or fructose drink within the scanner, without interrupting the scanning. Whole-brain connectivity was analyzed using standard correlation methodology in the 0.01-0.1 Hz range. The correlation coefficient differences between fructose and glucose ingestion among targeted regions were converted to t-scores using the water-only correlation coefficients as a null condition. Results show a dramatic increase in the hypothalamic connectivity to the hippocampus, amygdala, insula, caudate and the nucleus accumben for fructose over glucose. As these regions are known to be key components of the feeding and reward brain circuits, these results suggest a preference for fructose ingestion.

  12. Measurement of human advanced brain function in calculation processing using functional magnetic resonance imaging (fMRI)

    International Nuclear Information System (INIS)

    Hashida, Masahiro; Yamauchi, Syuichi; Wu, Jing-Long

    2001-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated the activated areas of the human brain related with calculation processing as an advanced function of the human brain. Furthermore, we investigated differences in activation between visual and auditory calculation processing. The eight subjects (all healthy men) were examined on a clinical MR unit (1.5 tesla) with a gradient echo-type EPI sequence. SPM99 software was used for data processing. Arithmetic problems were used for the visual stimulus (visual image) as well as for the auditory stimulus (audible voice). The stimuli were presented to the subjects as follows: no stimulation, presentation of random figures, and presentation of arithmetic problems. Activated areas of the human brain related with calculation processing were the inferior parietal lobule, middle frontal gyrus, and inferior frontal gyrus. Comparing the arithmetic problems with the presentation of random figures, we found that the activated areas of the human brain were not differently affected by visual and auditory systems. The areas activated in the visual and auditory experiments were observed at nearly the same place in the brain. It is possible to study advanced functions of the human brain such as calculation processing in a general clinical hospital when adequate tasks and methods of presentation are used. (author)

  13. Postmortem diffusion MRI of the human brainstem and thalamus for deep brain stimulator electrode localization

    Science.gov (United States)

    Calabrese, Evan; Hickey, Patrick; Hulette, Christine; Zhang, Jingxian; Parente, Beth; Lad, Shivanand P.; Johnson, G. Allan

    2015-01-01

    Deep brain stimulation (DBS) is an established surgical therapy for medically refractory tremor disorders including essential tremor (ET) and is currently under investigation for use in a variety of other neurologic and psychiatric disorders. There is growing evidence that the anti-tremor effects of DBS for ET are directly related to modulation of the dentatorubrothalamic tract (DRT), a white matter pathway that connects the cerebellum, red nucleus, and ventral intermediate nucleus of the thalamus. Emerging white matter targets for DBS, like the DRT, will require improved 3D reference maps of deep brain anatomy and structural connectivity for accurate electrode targeting. High-resolution diffusion MRI of postmortem brain specimens can provide detailed volumetric images of important deep brain nuclei and 3D reconstructions of white matter pathways with probabilistic tractography techniques. We present a high spatial and angular resolution diffusion MRI template of the postmortem human brainstem and thalamus with 3D reconstructions of the nuclei and white matter tracts involved in ET circuitry. We demonstrate accurate registration of these data to in vivo, clinical images from patients receiving DBS therapy, and correlate electrode proximity to tractography of the DRT with improvement of ET symptoms. PMID:26043869

  14. Measurement and imaging of brain function using MRI, MEG, and TMS

    International Nuclear Information System (INIS)

    Iramina, Keiji

    2008-01-01

    This paper reviews functional imaging techniques in neuroscience such as magnetic resonance imaging (MRI) functional MRI (fMRI), magnetoencephalogray (MEG), and transcranial magnetic stimulation (TMS). fMRI and MEG allow the neuronal activity of the brain to be measured non-invasively. MEG detects an electrical activity as neuronal activity, while, fMRI detects a hemodynamic response as neuronal activity. TMS is the application of a brief magnetic pulse or a train of pulses to the skull, which results in the induction of a local electric current in the underlying surface of the brain, thereby producing a localized axonal depolarization. As a non-invasive and effective method to make reversible lesions in the human brain, TMS has a long and successful history. All of these techniques have major potential for applications in the neuroscience and medicine. (author)

  15. Task-Related Edge Density (TED)-A New Method for Revealing Dynamic Network Formation in fMRI Data of the Human Brain.

    Science.gov (United States)

    Lohmann, Gabriele; Stelzer, Johannes; Zuber, Verena; Buschmann, Tilo; Margulies, Daniel; Bartels, Andreas; Scheffler, Klaus

    2016-01-01

    The formation of transient networks in response to external stimuli or as a reflection of internal cognitive processes is a hallmark of human brain function. However, its identification in fMRI data of the human brain is notoriously difficult. Here we propose a new method of fMRI data analysis that tackles this problem by considering large-scale, task-related synchronisation networks. Networks consist of nodes and edges connecting them, where nodes correspond to voxels in fMRI data, and the weight of an edge is determined via task-related changes in dynamic synchronisation between their respective times series. Based on these definitions, we developed a new data analysis algorithm that identifies edges that show differing levels of synchrony between two distinct task conditions and that occur in dense packs with similar characteristics. Hence, we call this approach "Task-related Edge Density" (TED). TED proved to be a very strong marker for dynamic network formation that easily lends itself to statistical analysis using large scale statistical inference. A major advantage of TED compared to other methods is that it does not depend on any specific hemodynamic response model, and it also does not require a presegmentation of the data for dimensionality reduction as it can handle large networks consisting of tens of thousands of voxels. We applied TED to fMRI data of a fingertapping and an emotion processing task provided by the Human Connectome Project. TED revealed network-based involvement of a large number of brain areas that evaded detection using traditional GLM-based analysis. We show that our proposed method provides an entirely new window into the immense complexity of human brain function.

  16. Task-Related Edge Density (TED-A New Method for Revealing Dynamic Network Formation in fMRI Data of the Human Brain.

    Directory of Open Access Journals (Sweden)

    Gabriele Lohmann

    Full Text Available The formation of transient networks in response to external stimuli or as a reflection of internal cognitive processes is a hallmark of human brain function. However, its identification in fMRI data of the human brain is notoriously difficult. Here we propose a new method of fMRI data analysis that tackles this problem by considering large-scale, task-related synchronisation networks. Networks consist of nodes and edges connecting them, where nodes correspond to voxels in fMRI data, and the weight of an edge is determined via task-related changes in dynamic synchronisation between their respective times series. Based on these definitions, we developed a new data analysis algorithm that identifies edges that show differing levels of synchrony between two distinct task conditions and that occur in dense packs with similar characteristics. Hence, we call this approach "Task-related Edge Density" (TED. TED proved to be a very strong marker for dynamic network formation that easily lends itself to statistical analysis using large scale statistical inference. A major advantage of TED compared to other methods is that it does not depend on any specific hemodynamic response model, and it also does not require a presegmentation of the data for dimensionality reduction as it can handle large networks consisting of tens of thousands of voxels. We applied TED to fMRI data of a fingertapping and an emotion processing task provided by the Human Connectome Project. TED revealed network-based involvement of a large number of brain areas that evaded detection using traditional GLM-based analysis. We show that our proposed method provides an entirely new window into the immense complexity of human brain function.

  17. MRI of the foetal brain

    International Nuclear Information System (INIS)

    Rich, P.; Jones, R.; Britton, J.; Foote, S.; Thilaganathan, B.

    2007-01-01

    Ultrasound examinations for foetal brain abnormalities have been a part of the routine antenatal screening programme in the UK for many years. In utero brain magnetic resonance imaging (MRI) is now being used increasingly successfully to clarify abnormal ultrasound findings, often resulting in a change of diagnosis or treatment plan. Interpretation requires an understanding of foetal brain development, malformations and acquired diseases. In this paper we will outline the technique of foetal MRI, relevant aspects of brain development and provide illustrated examples of foetal brain pathology

  18. New perspectives in EEG/MEG brain mapping and PET/fMRI neuroimaging of human pain.

    Science.gov (United States)

    Chen, A C

    2001-10-01

    With the maturation of EEG/MEG brain mapping and PET/fMRI neuroimaging in the 1990s, greater understanding of pain processing in the brain now elucidates and may even challenge the classical theory of pain mechanisms. This review scans across the cultural diversity of pain expression and modulation in man. It outlines the difficulties in defining and studying human pain. It then focuses on methods of studying the brain in experimental and clinical pain, the cohesive results of brain mapping and neuroimaging of noxious perception, the implication of pain research in understanding human consciousness and the relevance to clinical care as well as to the basic science of human psychophysiology. Non-invasive brain studies in man start to unveil the age-old puzzles of pain-illusion, hypnosis and placebo in pain modulation. The neurophysiological and neurohemodynamic brain measures of experimental pain can now largely satisfy the psychophysiologist's dream, unimaginable only a few years ago, of modelling the body-brain, brain-mind, mind-matter duality in an inter-linking 3-P triad: physics (stimulus energy); physiology (brain activities); and psyche (perception). For neuropsychophysiology greater challenges lie ahead: (a) how to integrate a cohesive theory of human pain in the brain; (b) what levels of analyses are necessary and sufficient; (c) what constitutes the structural organisation of the pain matrix; (d) what are the modes of processing among and across the sites of these structures; and (e) how can neural computation of these processes in the brain be carried out? We may envision that modular identification and delineation of the arousal-attention, emotion-motivation and perception-cognition neural networks of pain processing in the brain will also lead to deeper understanding of the human mind. Two foreseeable impacts on clinical sciences and basic theories from brain mapping/neuroimaging are the plausible central origin in persistent pain and integration of

  19. Task-Related Edge Density (TED)—A New Method for Revealing Dynamic Network Formation in fMRI Data of the Human Brain

    Science.gov (United States)

    Lohmann, Gabriele; Stelzer, Johannes; Zuber, Verena; Buschmann, Tilo; Margulies, Daniel; Bartels, Andreas; Scheffler, Klaus

    2016-01-01

    The formation of transient networks in response to external stimuli or as a reflection of internal cognitive processes is a hallmark of human brain function. However, its identification in fMRI data of the human brain is notoriously difficult. Here we propose a new method of fMRI data analysis that tackles this problem by considering large-scale, task-related synchronisation networks. Networks consist of nodes and edges connecting them, where nodes correspond to voxels in fMRI data, and the weight of an edge is determined via task-related changes in dynamic synchronisation between their respective times series. Based on these definitions, we developed a new data analysis algorithm that identifies edges that show differing levels of synchrony between two distinct task conditions and that occur in dense packs with similar characteristics. Hence, we call this approach “Task-related Edge Density” (TED). TED proved to be a very strong marker for dynamic network formation that easily lends itself to statistical analysis using large scale statistical inference. A major advantage of TED compared to other methods is that it does not depend on any specific hemodynamic response model, and it also does not require a presegmentation of the data for dimensionality reduction as it can handle large networks consisting of tens of thousands of voxels. We applied TED to fMRI data of a fingertapping and an emotion processing task provided by the Human Connectome Project. TED revealed network-based involvement of a large number of brain areas that evaded detection using traditional GLM-based analysis. We show that our proposed method provides an entirely new window into the immense complexity of human brain function. PMID:27341204

  20. Dynamic glucose enhanced (DGE) MRI for combined imaging of blood-brain barrier break down and increased blood volume in brain cancer.

    Science.gov (United States)

    Xu, Xiang; Chan, Kannie W Y; Knutsson, Linda; Artemov, Dmitri; Xu, Jiadi; Liu, Guanshu; Kato, Yoshinori; Lal, Bachchu; Laterra, John; McMahon, Michael T; van Zijl, Peter C M

    2015-12-01

    Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. Mice were inoculated orthotopically with human U87-EGFRvIII glioma cells. Time-resolved glucose signal changes were detected using chemical exchange saturation transfer (glucoCEST) MRI. Dynamic glucose enhanced (DGE) MRI was used to measure tissue response to an intravenous bolus of d-glucose. DGE images of mouse brains bearing human glioma showed two times higher and persistent changes in tumor compared with contralateral brain. Area-under-curve (AUC) analysis of DGE delineated blood vessels and tumor and had contrast comparable to the AUC determined using dynamic contrast enhanced (DCE) MRI with GdDTPA, both showing a significantly higher AUC in tumor than in brain (P blood volume and permeability with respect to normal brain. We expect DGE will provide a low-risk and less expensive alternative to DCE MRI for imaging cancer in vulnerable populations, such as children and patients with renal impairment. © 2015 Wiley Periodicals, Inc.

  1. Dynamic Glucose Enhanced (DGE) MRI for Combined Imaging of Blood Brain Barrier Break Down and Increased Blood Volume in Brain Cancer

    Science.gov (United States)

    Xu, Xiang; Chan, Kannie WY; Knutsson, Linda; Artemov, Dmitri; Xu, Jiadi; Liu, Guanshu; Kato, Yoshinori; Lal, Bachchu; Laterra, John; McMahon, Michael T.; van Zijl, Peter C.M.

    2015-01-01

    Purpose Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. Methods Mice were inoculated orthotopically with human U87-EGFRvIII glioma cells. Time-resolved glucose signal changes were detected using chemical exchange saturation transfer (glucoCEST) MRI. Dynamic glucose enhanced (DGE) MRI was used to measure tissue response to an intravenous bolus of d-glucose. Results DGE images of mouse brains bearing human glioma showed two times higher and persistent changes in tumor compared to contralateral brain. Area-under-curve (AUC) analysis of DGE delineated blood vessels and tumor and had contrast comparable to the AUC determined using dynamic contrast enhanced (DCE) MRI with GdDTPA, both showing a significantly higher AUC in tumor than in brain (pblood volume and permeability with respect to normal brain. We expect DGE will provide a low-risk and less expensive alternative to DCE MRI for imaging cancer in vulnerable populations, such as children and patients with renal impairment. PMID:26404120

  2. A Set of Functional Brain Networks for the Comprehensive Evaluation of Human Characteristics

    Directory of Open Access Journals (Sweden)

    Yul-Wan Sung

    2018-03-01

    Full Text Available Many human characteristics must be evaluated to comprehensively understand an individual, and measurements of the corresponding cognition/behavior are required. Brain imaging by functional MRI (fMRI has been widely used to examine brain function related to human cognition/behavior. However, few aspects of cognition/behavior of individuals or experimental groups can be examined through task-based fMRI. Recently, resting state fMRI (rs-fMRI signals have been shown to represent functional infrastructure in the brain that is highly involved in processing information related to cognition/behavior. Using rs-fMRI may allow diverse information about the brain through a single MRI scan to be obtained, as rs-fMRI does not require stimulus tasks. In this study, we attempted to identify a set of functional networks representing cognition/behavior that are related to a wide variety of human characteristics and to evaluate these characteristics using rs-fMRI data. If possible, these findings would support the potential of rs-fMRI to provide diverse information about the brain. We used resting-state fMRI and a set of 130 psychometric parameters that cover most human characteristics, including those related to intelligence and emotional quotients and social ability/skill. We identified 163 brain regions by VBM analysis using regression analysis with 130 psychometric parameters. Next, using a 163 × 163 correlation matrix, we identified functional networks related to 111 of the 130 psychometric parameters. Finally, we made an 8-class support vector machine classifiers corresponding to these 111 functional networks. Our results demonstrate that rs-fMRI signals contain intrinsic information about brain function related to cognition/behaviors and that this set of 111 networks/classifiers can be used to comprehensively evaluate human characteristics.

  3. Non-invasive, MRI-compatible fibreoptic device for functional near-IR reflectometry of human brain

    International Nuclear Information System (INIS)

    Sorvoja, H.S.S.; Myllylae, T S; Myllylae, Risto A; Kirillin, M Yu; Sergeeva, Ekaterina A; Elseoud, A A; Nikkinen, J; Tervonen, O; Kiviniemi, V

    2011-01-01

    A non-invasive device for measuring blood oxygen variations in human brain is designed, implemented, and tested for MRI compatibility. The device is based on principles of near-IR reflectometry; power LEDs serve as sources of probing radiation delivered to patient skin surface through optical fibres. Numerical Monte Carlo simulations of probing radiation propagation in a multilayer brain model are performed to evaluate signal levels at different source - detector separations at three operation wavelengths and an additional wavelength of 915 nm. It is shown that the device can be applied for brain activity studies using power LEDs operating at 830 and 915 nm, while employment of wavelength of 660 nm requires an increased probing power. Employment of the wavelength of 592 nm in the current configuration is unreasonable. (application of lasers and laser-optical methods in life sciences)

  4. Three-dimensional anisotropy contrast MRI and functional MRI of the human brain. Clinical application to assess pyramidal tract in patients with brain tumor and infarction

    International Nuclear Information System (INIS)

    Morikawa, Minoru; Kaminogo, Makio; Ishimaru, Hideki; Nakashima, Kazuaki; Kitagawa, Naoki; Ochi, Makoto; Hayashi, Kuniaki; Shibata, Shobu; Kabasawa, Hiroyuki

    2001-01-01

    We describe and evaluate the findings of three-dimensional anisotropy contrast MR axonography (3DAC MRX) and functional MRI (fMRI) in brain tumor and infarction. We obtained diffusion-weighted images (DWI) in 28 patients including 23 brain tumors and 15 acute infarctions located in or near pyramidal tract. Three anisotropic DWIs were transformed into graduations color-coded as red, green and blue, and then composed to form a combined color 3DAC MRX. We also performed functional MRI in 7 of the 28 patients and compared with cortical mapping of 3DAC MRX. 3DAC MRX with 23 brain tumors showed that the ipsilateral pyramidal tract was either discontinuous due to impaired anisotropy (n=8) or compressed due to mass effect (n=15). In 10 patients of acute infarction with motor impairment, pyramidal tract involvement was visually more conspicuous on 3DAC MRX compared to standard DWI. On functional MRI, hand motor activation was observed between blue vertical directional colors of pre- and post central gyrus. In conclusion, 3DAC MRX is a new noninvasive approach for visualization of the white matter neuronal tract and provides the information concerning pyramidal tract involvement. (author)

  5. Macroscopic networks in the human brain: mapping connectivity in healthy and damaged brains

    NARCIS (Netherlands)

    Nijhuis, E.H.J.

    2013-01-01

    The human brain contains a network of interconnected neurons. Recent advances in functional and structural in-vivo magnetic resonance neuroimaging (MRI) techniques have provided opportunities to model the networks of the human brain on a macroscopic scale. This dissertation investigates the

  6. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    International Nuclear Information System (INIS)

    Jung, Jin Ho; Choi, Yong; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun; Oh, Chang Hyun; Park, Hyun-wook; Kim, Kyung Min; Kim, Jong Guk

    2015-01-01

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  7. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun [Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 121-742 (Korea, Republic of); Oh, Chang Hyun; Park, Hyun-wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Kyung Min; Kim, Jong Guk [Korea Institute of Radiological and Medical Science, 75 Nowon-ro, Nowon-gu, Seoul 139-709 (Korea, Republic of)

    2015-05-15

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  8. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What ...

  9. A human brain atlas derived via n-cut parcellation of resting-state and task-based fMRI data.

    Science.gov (United States)

    James, George Andrew; Hazaroglu, Onder; Bush, Keith A

    2016-02-01

    The growth of functional MRI has led to development of human brain atlases derived by parcellating resting-state connectivity patterns into functionally independent regions of interest (ROIs). All functional atlases to date have been derived from resting-state fMRI data. But given that functional connectivity between regions varies with task, we hypothesized that an atlas incorporating both resting-state and task-based fMRI data would produce an atlas with finer characterization of task-relevant regions than an atlas derived from resting-state alone. To test this hypothesis, we derived parcellation atlases from twenty-nine healthy adult participants enrolled in the Cognitive Connectome project, an initiative to improve functional MRI's translation into clinical decision-making by mapping normative variance in brain-behavior relationships. Participants underwent resting-state and task-based fMRI spanning nine cognitive domains: motor, visuospatial, attention, language, memory, affective processing, decision-making, working memory, and executive function. Spatially constrained n-cut parcellation derived brain atlases using (1) all participants' functional data (Task) or (2) a single resting-state scan (Rest). An atlas was also derived from random parcellation for comparison purposes (Random). Two methods were compared: (1) a parcellation applied to the group's mean edge weights (mean), and (2) a two-stage approach with parcellation of individual edge weights followed by parcellation of mean binarized edges (two-stage). The resulting Task and Rest atlases had significantly greater similarity with each other (mean Jaccard indices JI=0.72-0.85) than with the Random atlases (JI=0.59-0.63; all pRest atlas similarity was greatest for the two-stage method (JI=0.85), which has been shown as more robust than the mean method; these atlases also better reproduced voxelwise seed maps of the left dorsolateral prefrontal cortex during rest and performing the n-back working memory

  10. Brain-wide pathway for waste clearance captured by contrast-enhanced MRI.

    Science.gov (United States)

    Iliff, Jeffrey J; Lee, Hedok; Yu, Mei; Feng, Tian; Logan, Jean; Nedergaard, Maiken; Benveniste, Helene

    2013-03-01

    The glymphatic system is a recently defined brain-wide paravascular pathway for cerebrospinal fluid (CSF) and interstitial fluid (ISF) exchange that facilitates efficient clearance of solutes and waste from the brain. CSF enters the brain along para-arterial channels to exchange with ISF, which is in turn cleared from the brain along para-venous pathways. Because soluble amyloid β clearance depends on glymphatic pathway function, we proposed that failure of this clearance system contributes to amyloid plaque deposition and Alzheimer's disease progression. Here we provide proof of concept that glymphatic pathway function can be measured using a clinically relevant imaging technique. Dynamic contrast-enhanced MRI was used to visualize CSF-ISF exchange across the rat brain following intrathecal paramagnetic contrast agent administration. Key features of glymphatic pathway function were confirmed, including visualization of para-arterial CSF influx and molecular size-dependent CSF-ISF exchange. Whole-brain imaging allowed the identification of two key influx nodes at the pituitary and pineal gland recesses, while dynamic MRI permitted the definition of simple kinetic parameters to characterize glymphatic CSF-ISF exchange and solute clearance from the brain. We propose that this MRI approach may provide the basis for a wholly new strategy to evaluate Alzheimer's disease susceptibility and progression in the live human brain.

  11. The role of MRI and CT of the brain in first episodes of psychosis

    International Nuclear Information System (INIS)

    Khandanpour, N.; Hoggard, N.; Connolly, D.J.A.

    2013-01-01

    Aim: To investigate whether imaging is associated with early detection of the organic causes of the first episode of psychosis (FEP). Materials and methods: Individuals with FEP but no neurological signs referred to a tertiary centre for cerebral magnetic resonance imaging (MRI) or computed tomography (CT) were reviewed retrospectively. Two groups were evaluated with either CT or MRI; the two groups were independent and no individual underwent both CT and MRI. Results: One hundred and twelve consecutive cerebral MRI and 204 consecutive CT examinations were identified. Three (2.7%) individuals had brain lesions [brain tumour and human immunodeficiency virus (HIV) encephalopathy] potentially accountable for the psychosis at MRI. Seventy patients (62.5%) had incidental brain lesions, such as cerebral atrophy, small vessel ischaemic changes, unruptured Circle of Willis aneurysm, cavernoma, and arachnoid cysts at MRI. Three patients (1.5%) had focal brain lesions (primary or secondary tumours) potentially accountable for the psychosis at CT. One hundred and thirty-three patients (65.2%) had incidental brain lesions unrelated to the psychosis on CT scan. There was no significant difference between MRI and CT imaging in detecting organic disease potentially responsible for FEP (p < 0.001). Conclusion: Routine MRI or CT imaging of the brain is unlikely to reveal disease leading to a significant change in management. MRI was comparable with CT in terms of diagnosis of both pathological and incidental cerebral lesions. Therefore, routine brain structural imaging of FEP in patients without focal neurology may not be routinely required and if imaging is requested then CT may function equally as well as MRI as the first-line investigation

  12. Brain regions with mirror properties: a meta-analysis of 125 human fMRI studies.

    Science.gov (United States)

    Molenberghs, Pascal; Cunnington, Ross; Mattingley, Jason B

    2012-01-01

    Mirror neurons in macaque area F5 fire when an animal performs an action, such as a mouth or limb movement, and also when the animal passively observes an identical or similar action performed by another individual. Brain-imaging studies in humans conducted over the last 20 years have repeatedly attempted to reveal analogous brain regions with mirror properties in humans, with broad and often speculative claims about their functional significance across a range of cognitive domains, from language to social cognition. Despite such concerted efforts, the likely neural substrates of these mirror regions have remained controversial, and indeed the very existence of a distinct subcategory of human neurons with mirroring properties has been questioned. Here we used activation likelihood estimation (ALE), to provide a quantitative index of the consistency of patterns of fMRI activity measured in human studies of action observation and action execution. From an initial sample of more than 300 published works, data from 125 papers met our strict inclusion and exclusion criteria. The analysis revealed 14 separate clusters in which activation has been consistently attributed to brain regions with mirror properties, encompassing 9 different Brodmann areas. These clusters were located in areas purported to show mirroring properties in the macaque, such as the inferior parietal lobule, inferior frontal gyrus and the adjacent ventral premotor cortex, but surprisingly also in regions such as the primary visual cortex, cerebellum and parts of the limbic system. Our findings suggest a core network of human brain regions that possess mirror properties associated with action observation and execution, with additional areas recruited during tasks that engage non-motor functions, such as auditory, somatosensory and affective components. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  13. Brain activation studies with PET and functional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yonekura, Yoshiharu [Fukui Medical Univ., Matsuoka (Japan). Biomedical Imaging Research Center; Sadato, Norihiro [Okazaki National Research Inst., Aichi (Japan). National Inst. for Physiological Sciences

    2002-01-01

    Application of PET and functional MRI in brain activation studies is reviewed. 3D-PET images obtained repeatedly after intravenous injection of about 370 MBq of H{sub 2}{sup 15}O can detect a faint blood flow change in the brain. Functional MRI can also detect the blood flow change in the brain due to blood oxygen level-dependent effect. Echo-planar imaging is popular in MRI with 1.5 or 3 T. Images are analyzed by statistical parametric mapping with correction of cerebral regions, anatomical normalization and statistics. PET data give the blood flow change by the H{sub 2}{sup 15}O incorporation into the brain and MRI data, by the scarce tissue oxygen consumption despite the change. Actual images during the cognition task-performance and of frequent artifacts are given. PET is suitable for studies of brain functions like sensibility and emotion and functional MRI, like cortex functions and clinical practices in identification of functional regions prior to surgery and evaluation of functional recovery of damaged brain. (K.H.)

  14. Brain activation studies with PET and functional MRI

    International Nuclear Information System (INIS)

    Yonekura, Yoshiharu; Sadato, Norihiro

    2002-01-01

    Application of PET and functional MRI in brain activation studies is reviewed. 3D-PET images obtained repeatedly after intravenous injection of about 370 MBq of H 2 15 O can detect a faint blood flow change in the brain. Functional MRI can also detect the blood flow change in the brain due to blood oxygen level-dependent effect. Echo-planar imaging is popular in MRI with 1.5 or 3 T. Images are analyzed by statistical parametric mapping with correction of cerebral regions, anatomical normalization and statistics. PET data give the blood flow change by the H 2 15 O incorporation into the brain and MRI data, by the scarce tissue oxygen consumption despite the change. Actual images during the cognition task-performance and of frequent artifacts are given. PET is suitable for studies of brain functions like sensibility and emotion and functional MRI, like cortex functions and clinical practices in identification of functional regions prior to surgery and evaluation of functional recovery of damaged brain. (K.H.)

  15. Brain MRI abnormalities in neuromyelitis optica

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fei, E-mail: feiwang1973@gmail.com [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Liu Yaou, E-mail: asiaeurope80@gmail.com [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Duan Yunyun, E-mail: duanyun2003@sohu.com [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Li Kuncheng, E-mail: kunchengli@yahoo.com.cn [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Education Ministry Key Laboratory for Neurodegenerative Disease, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China)

    2011-11-15

    Objective: The purpose of this study was to explore brain MRI findings in neuromyelitis optica (NMO) and to investigate specific brain lesions with respect to the localization of aquaporin-4 (AQP-4). Materials and methods: Forty admitted patients (36 women) who satisfied the 2006 criteria of Wingerchuk et al. for NMO were included in this study. All patients received a neurological examination and MRI scanning including brain and spinal cord. MRIs were classified as normal, nonspecific, multiple sclerosis-like, typical abnormalities. MS-like lesions were too few to satisfy the Barkhof et al. criteria for MS. Confluent lesions involving high AQP-4 regions were considered typical. Non-enhancing deep white matter lesions other than MS-like lesions or typical lesions were classified as nonspecific. Results: Brain MRI lesions were delineated in 12 patients (25%). Four patients (10%) had hypothalamus, brainstem or periventricle lesions. Six (15%) patients were nonspecific, and 2 (5%) patients had multiple sclerosis-like lesions. Conclusion: Brain MRIs are negative in most NMO, and brain lesions do not exclude the diagnosis of NMO. Hypothalamus, brainstem or periventricle lesions, corresponding to high sites of AQP-4 in the brain, are indicative of lesions of NMO.

  16. Brain MRI abnormalities in neuromyelitis optica

    International Nuclear Information System (INIS)

    Wang Fei; Liu Yaou; Duan Yunyun; Li Kuncheng

    2011-01-01

    Objective: The purpose of this study was to explore brain MRI findings in neuromyelitis optica (NMO) and to investigate specific brain lesions with respect to the localization of aquaporin-4 (AQP-4). Materials and methods: Forty admitted patients (36 women) who satisfied the 2006 criteria of Wingerchuk et al. for NMO were included in this study. All patients received a neurological examination and MRI scanning including brain and spinal cord. MRIs were classified as normal, nonspecific, multiple sclerosis-like, typical abnormalities. MS-like lesions were too few to satisfy the Barkhof et al. criteria for MS. Confluent lesions involving high AQP-4 regions were considered typical. Non-enhancing deep white matter lesions other than MS-like lesions or typical lesions were classified as nonspecific. Results: Brain MRI lesions were delineated in 12 patients (25%). Four patients (10%) had hypothalamus, brainstem or periventricle lesions. Six (15%) patients were nonspecific, and 2 (5%) patients had multiple sclerosis-like lesions. Conclusion: Brain MRIs are negative in most NMO, and brain lesions do not exclude the diagnosis of NMO. Hypothalamus, brainstem or periventricle lesions, corresponding to high sites of AQP-4 in the brain, are indicative of lesions of NMO.

  17. Brain Activity Associated with Emoticons: An fMRI Study

    Science.gov (United States)

    Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

    In this paper, we describe that brain activities associated with emoticons by using fMRI. In communication over a computer network, we use abstract faces such as computer graphics (CG) avatars and emoticons. These faces convey users' emotions and enrich their communications. However, the manner in which these faces influence the mental process is as yet unknown. The human brain may perceive the abstract face in an entirely different manner, depending on its level of reality. We conducted an experiment using fMRI in order to investigate the effects of emoticons. The results show that right inferior frontal gyrus, which associated with nonverbal communication, is activated by emoticons. Since the emoticons were created to reflect the real human facial expressions as accurately as possible, we believed that they would activate the right fusiform gyrus. However, this region was not found to be activated during the experiment. This finding is useful in understanding how abstract faces affect our behaviors and decision-making in communication over a computer network.

  18. A brain MRI atlas of the common squirrel monkey, Saimiri sciureus

    Science.gov (United States)

    Gao, Yurui; Schilling, Kurt G.; Khare, Shweta P.; Panda, Swetasudha; Choe, Ann S.; Stepniewska, Iwona; Li, Xia; Ding, Zhoahua; Anderson, Adam; Landman, Bennett A.

    2014-03-01

    The common squirrel monkey, Saimiri sciureus, is a New World monkey with functional and microstructural organization of central nervous system similar to that of humans. It is one of the most commonly used South American primates in biomedical research. Unlike its Old World macaque cousins, no digital atlases have described the organization of the squirrel monkey brain. Here, we present a multi-modal magnetic resonance imaging (MRI) atlas constructed from the brain of an adult female squirrel monkey. In vivo MRI acquisitions include high resolution T2 structural imaging and low resolution diffusion tensor imaging. Ex vivo MRI acquisitions include high resolution T2 structural imaging and high resolution diffusion tensor imaging. Cortical regions were manually annotated on the co-registered volumes based on published histological sections.

  19. Urea cycle disorders: brain MRI and neurological outcome.

    Science.gov (United States)

    Bireley, William R; Van Hove, Johan L K; Gallagher, Renata C; Fenton, Laura Z

    2012-04-01

    Urea cycle disorders encompass several enzyme deficiencies that can result in cerebral damage, with a wide clinical spectrum from asymptomatic to severe. The goal of this study was to correlate brain MRI abnormalities in urea cycle disorders with clinical neurological sequelae to evaluate whether MRI abnormalities can assist in guiding difficult treatment decisions. We performed a retrospective chart review of patients with urea cycle disorders and symptomatic hyperammonemia. Brain MRI images were reviewed for abnormalities that correlated with severity of clinical neurological sequelae. Our case series comprises six urea cycle disorder patients, five with ornithine transcarbamylase deficiency and one with citrullinemia type 1. The observed trend in distribution of brain MRI abnormalities as the severity of neurological sequelae increased was the peri-insular region first, extending into the frontal, parietal, temporal and, finally, the occipital lobes. There was thalamic restricted diffusion in three children with prolonged hyperammonemia. Prior to death, this site is typically reported to be spared in urea cycle disorders. The pattern and extent of brain MRI abnormalities correlate with clinical neurological outcome in our case series. This suggests that brain MRI abnormalities may assist in determining prognosis and helping clinicians with subsequent treatment decisions.

  20. Urea cycle disorders: brain MRI and neurological outcome

    Energy Technology Data Exchange (ETDEWEB)

    Bireley, William R. [University of Colorado, Department of Radiology, Aurora, CO (United States); Van Hove, Johan L.K. [University of Colorado, Department of Genetics and Inherited Metabolic Diseases, Aurora, CO (United States); Gallagher, Renata C. [Children' s Hospital Colorado, Department of Genetics and Inherited Metabolic Diseases, Aurora, CO (United States); Fenton, Laura Z. [Children' s Hospital Colorado, Department of Pediatric Radiology, Aurora, CO (United States)

    2012-04-15

    Urea cycle disorders encompass several enzyme deficiencies that can result in cerebral damage, with a wide clinical spectrum from asymptomatic to severe. The goal of this study was to correlate brain MRI abnormalities in urea cycle disorders with clinical neurological sequelae to evaluate whether MRI abnormalities can assist in guiding difficult treatment decisions. We performed a retrospective chart review of patients with urea cycle disorders and symptomatic hyperammonemia. Brain MRI images were reviewed for abnormalities that correlated with severity of clinical neurological sequelae. Our case series comprises six urea cycle disorder patients, five with ornithine transcarbamylase deficiency and one with citrullinemia type 1. The observed trend in distribution of brain MRI abnormalities as the severity of neurological sequelae increased was the peri-insular region first, extending into the frontal, parietal, temporal and, finally, the occipital lobes. There was thalamic restricted diffusion in three children with prolonged hyperammonemia. Prior to death, this site is typically reported to be spared in urea cycle disorders. The pattern and extent of brain MRI abnormalities correlate with clinical neurological outcome in our case series. This suggests that brain MRI abnormalities may assist in determining prognosis and helping clinicians with subsequent treatment decisions. (orig.)

  1. Urea cycle disorders: brain MRI and neurological outcome

    International Nuclear Information System (INIS)

    Bireley, William R.; Van Hove, Johan L.K.; Gallagher, Renata C.; Fenton, Laura Z.

    2012-01-01

    Urea cycle disorders encompass several enzyme deficiencies that can result in cerebral damage, with a wide clinical spectrum from asymptomatic to severe. The goal of this study was to correlate brain MRI abnormalities in urea cycle disorders with clinical neurological sequelae to evaluate whether MRI abnormalities can assist in guiding difficult treatment decisions. We performed a retrospective chart review of patients with urea cycle disorders and symptomatic hyperammonemia. Brain MRI images were reviewed for abnormalities that correlated with severity of clinical neurological sequelae. Our case series comprises six urea cycle disorder patients, five with ornithine transcarbamylase deficiency and one with citrullinemia type 1. The observed trend in distribution of brain MRI abnormalities as the severity of neurological sequelae increased was the peri-insular region first, extending into the frontal, parietal, temporal and, finally, the occipital lobes. There was thalamic restricted diffusion in three children with prolonged hyperammonemia. Prior to death, this site is typically reported to be spared in urea cycle disorders. The pattern and extent of brain MRI abnormalities correlate with clinical neurological outcome in our case series. This suggests that brain MRI abnormalities may assist in determining prognosis and helping clinicians with subsequent treatment decisions. (orig.)

  2. Brain Tumor Image Segmentation in MRI Image

    Science.gov (United States)

    Peni Agustin Tjahyaningtijas, Hapsari

    2018-04-01

    Brain tumor segmentation plays an important role in medical image processing. Treatment of patients with brain tumors is highly dependent on early detection of these tumors. Early detection of brain tumors will improve the patient’s life chances. Diagnosis of brain tumors by experts usually use a manual segmentation that is difficult and time consuming because of the necessary automatic segmentation. Nowadays automatic segmentation is very populer and can be a solution to the problem of tumor brain segmentation with better performance. The purpose of this paper is to provide a review of MRI-based brain tumor segmentation methods. There are number of existing review papers, focusing on traditional methods for MRI-based brain tumor image segmentation. this paper, we focus on the recent trend of automatic segmentation in this field. First, an introduction to brain tumors and methods for brain tumor segmentation is given. Then, the state-of-the-art algorithms with a focus on recent trend of full automatic segmentaion are discussed. Finally, an assessment of the current state is presented and future developments to standardize MRI-based brain tumor segmentation methods into daily clinical routine are addressed.

  3. Puberty and structural brain development in humans.

    Science.gov (United States)

    Herting, Megan M; Sowell, Elizabeth R

    2017-01-01

    Adolescence is a transitional period of physical and behavioral development between childhood and adulthood. Puberty is a distinct period of sexual maturation that occurs during adolescence. Since the advent of magnetic resonance imaging (MRI), human studies have largely examined neurodevelopment in the context of age. A breadth of animal findings suggest that sex hormones continue to influence the brain beyond the prenatal period, with both organizational and activational effects occurring during puberty. Given the animal evidence, human MRI research has also set out to determine how puberty may influence otherwise known patterns of age-related neurodevelopment. Here we review structural-based MRI studies and show that pubertal maturation is a key variable to consider in elucidating sex- and individual- based differences in patterns of human brain development. We also highlight the continuing challenges faced, as well as future considerations, for this vital avenue of research. Copyright © 2016. Published by Elsevier Inc.

  4. Utilizing 3D Printing Technology to Merge MRI with Histology: A Protocol for Brain Sectioning

    Science.gov (United States)

    Luciano, Nicholas J; Sati, Pascal; Nair, Govind; Guy, Joseph R; Ha, Seung-Kwon; Absinta, Martina; Chiang, Wen-Yang; Leibovitch, Emily C; Jacobson, Steven; Silva, Afonso C; Reich, Daniel S.

    2016-01-01

    Magnetic resonance imaging (MRI) allows for the delineation between normal and abnormal tissue on a macroscopic scale, sampling an entire tissue volume three-dimensionally. While MRI is an extremely sensitive tool for detecting tissue abnormalities, association of signal changes with an underlying pathological process is usually not straightforward. In the central nervous system, for example, inflammation, demyelination, axonal damage, gliosis, and neuronal death may all induce similar findings on MRI. As such, interpretation of MRI scans depends on the context, and radiological-histopathological correlation is therefore of the utmost importance. Unfortunately, traditional pathological sectioning of brain tissue is often imprecise and inconsistent, thus complicating the comparison between histology sections and MRI. This article presents novel methodology for accurately sectioning primate brain tissues and thus allowing precise matching between histology and MRI. The detailed protocol described in this article will assist investigators in applying this method, which relies on the creation of 3D printed brain slicers. Slightly modified, it can be easily implemented for brains of other species, including humans. PMID:28060281

  5. Utilizing 3D Printing Technology to Merge MRI with Histology: A Protocol for Brain Sectioning.

    Science.gov (United States)

    Luciano, Nicholas J; Sati, Pascal; Nair, Govind; Guy, Joseph R; Ha, Seung-Kwon; Absinta, Martina; Chiang, Wen-Yang; Leibovitch, Emily C; Jacobson, Steven; Silva, Afonso C; Reich, Daniel S

    2016-12-06

    Magnetic resonance imaging (MRI) allows for the delineation between normal and abnormal tissue on a macroscopic scale, sampling an entire tissue volume three-dimensionally. While MRI is an extremely sensitive tool for detecting tissue abnormalities, association of signal changes with an underlying pathological process is usually not straightforward. In the central nervous system, for example, inflammation, demyelination, axonal damage, gliosis, and neuronal death may all induce similar findings on MRI. As such, interpretation of MRI scans depends on the context, and radiological-histopathological correlation is therefore of the utmost importance. Unfortunately, traditional pathological sectioning of brain tissue is often imprecise and inconsistent, thus complicating the comparison between histology sections and MRI. This article presents novel methodology for accurately sectioning primate brain tissues and thus allowing precise matching between histology and MRI. The detailed protocol described in this article will assist investigators in applying this method, which relies on the creation of 3D printed brain slicers. Slightly modified, it can be easily implemented for brains of other species, including humans.

  6. Advance MRI for pediatric brain tumors with emphasis on clinical benefits

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Ra, Young Shin [Asan Medical Center, University of Ulsan College of Medicine, Seoul(Korea, Republic of)

    2017-01-15

    Conventional anatomic brain MRI is often limited in evaluating pediatric brain tumors, the most common solid tumors and a leading cause of death in children. Advanced brain MRI techniques have great potential to improve diagnostic performance in children with brain tumors and overcome diagnostic pitfalls resulting from diverse tumor pathologies as well as nonspecific or overlapped imaging findings. Advanced MRI techniques used for evaluating pediatric brain tumors include diffusion-weighted imaging, diffusion tensor imaging, functional MRI, perfusion imaging, spectroscopy, susceptibility-weighted imaging, and chemical exchange saturation transfer imaging. Because pediatric brain tumors differ from adult counterparts in various aspects, MRI protocols should be designed to achieve maximal clinical benefits in pediatric brain tumors. In this study, we review advanced MRI techniques and interpretation algorithms for pediatric brain tumors.

  7. Localization of spontaneous bursting neuronal activity in the preterm human brain with simultaneous EEG-fMRI.

    Science.gov (United States)

    Arichi, Tomoki; Whitehead, Kimberley; Barone, Giovanni; Pressler, Ronit; Padormo, Francesco; Edwards, A David; Fabrizi, Lorenzo

    2017-09-12

    Electroencephalographic recordings from the developing human brain are characterized by spontaneous neuronal bursts, the most common of which is the delta brush. Although similar events in animal models are known to occur in areas of immature cortex and drive their development, their origin in humans has not yet been identified. Here, we use simultaneous EEG-fMRI to localise the source of delta brush events in 10 preterm infants aged 32-36 postmenstrual weeks. The most frequent patterns were left and right posterior-temporal delta brushes which were associated in the left hemisphere with ipsilateral BOLD activation in the insula only; and in the right hemisphere in both the insular and temporal cortices. This direct measure of neural and hemodynamic activity shows that the insula, one of the most densely connected hubs in the developing cortex, is a major source of the transient bursting events that are critical for brain maturation.

  8. Connectome imaging for mapping human brain pathways.

    Science.gov (United States)

    Shi, Y; Toga, A W

    2017-09-01

    With the fast advance of connectome imaging techniques, we have the opportunity of mapping the human brain pathways in vivo at unprecedented resolution. In this article we review the current developments of diffusion magnetic resonance imaging (MRI) for the reconstruction of anatomical pathways in connectome studies. We first introduce the background of diffusion MRI with an emphasis on the technical advances and challenges in state-of-the-art multi-shell acquisition schemes used in the Human Connectome Project. Characterization of the microstructural environment in the human brain is discussed from the tensor model to the general fiber orientation distribution (FOD) models that can resolve crossing fibers in each voxel of the image. Using FOD-based tractography, we describe novel methods for fiber bundle reconstruction and graph-based connectivity analysis. Building upon these novel developments, there have already been successful applications of connectome imaging techniques in reconstructing challenging brain pathways. Examples including retinofugal and brainstem pathways will be reviewed. Finally, we discuss future directions in connectome imaging and its interaction with other aspects of brain imaging research.

  9. Brain anatomical networks in early human brain development.

    Science.gov (United States)

    Fan, Yong; Shi, Feng; Smith, Jeffrey Keith; Lin, Weili; Gilmore, John H; Shen, Dinggang

    2011-02-01

    Recent neuroimaging studies have demonstrated that human brain networks have economic small-world topology and modular organization, enabling efficient information transfer among brain regions. However, it remains largely unknown how the small-world topology and modular organization of human brain networks emerge and develop. Using longitudinal MRI data of 28 healthy pediatric subjects, collected at their ages of 1 month, 1 year, and 2 years, we analyzed development patterns of brain anatomical networks derived from morphological correlations of brain regional volumes. The results show that the brain network of 1-month-olds has the characteristically economic small-world topology and nonrandom modular organization. The network's cost efficiency increases with the brain development to 1 year and 2 years, so does the modularity, providing supportive evidence for the hypothesis that the small-world topology and the modular organization of brain networks are established during early brain development to support rapid synchronization and information transfer with minimal rewiring cost, as well as to balance between local processing and global integration of information. Copyright © 2010. Published by Elsevier Inc.

  10. Delineation of early brain development from fetuses to infants with diffusion MRI and beyond.

    Science.gov (United States)

    Ouyang, Minhui; Dubois, Jessica; Yu, Qinlin; Mukherjee, Pratik; Huang, Hao

    2018-04-12

    Dynamic macrostructural and microstructural changes take place from the mid-fetal stage to 2 years after birth. Delineating brain structural changes during this early developmental period provides new insights into the complicated processes of both typical brain development and the pathological mechanisms underlying various psychiatric and neurological disorders including autism, attention deficit hyperactivity disorder and schizophrenia. Decades of histological studies have identified strong spatial and functional gradients of maturation in human brain gray and white matter. The recent improvements in magnetic resonance imaging (MRI) techniques, especially diffusion MRI (dMRI), relaxometry imaging, and magnetization transfer imaging (MTI) have provided unprecedented opportunities to non-invasively quantify and map the early developmental changes at whole brain and regional levels. Here, we review the recent advances in understanding early brain structural development during the second half of gestation and the first two postnatal years using modern MR techniques. Specifically, we review studies that delineate the emergence and microstructural maturation of white matter tracts, as well as dynamic mapping of inhomogeneous cortical microstructural organization unique to fetuses and infants. These imaging studies converge into maturational curves of MRI measurements that are distinctive across different white matter tracts and cortical regions. Furthermore, contemporary models offering biophysical interpretations of the dMRI-derived measurements are illustrated to infer the underlying microstructural changes. Collectively, this review summarizes findings that contribute to charting spatiotemporally heterogeneous gray and white matter structural development, offering MRI-based biomarkers of typical brain development and setting the stage for understanding aberrant brain development in neurodevelopmental disorders. Copyright © 2018. Published by Elsevier Inc.

  11. MRI Evaluation and Safety in the Developing Brain

    Science.gov (United States)

    Tocchio, Shannon; Kline-Fath, Beth; Kanal, Emanuel; Schmithorst, Vincent J.; Panigrahy, Ashok

    2015-01-01

    Magnetic resonance imaging (MRI) evaluation of the developing brain has dramatically increased over the last decade. Faster acquisitions and the development of advanced MRI sequences such as magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI), perfusion imaging, functional MR imaging (fMRI), and susceptibility weighted imaging (SWI), as well as the use of higher magnetic field strengths has made MRI an invaluable tool for detailed evaluation of the developing brain. This article will provide an overview of the use and challenges associated with 1.5T and 3T static magnetic fields for evaluation of the developing brain. This review will also summarize the advantages, clinical challenges and safety concerns specifically related to MRI in the fetus and newborn, including the implications of increased magnetic field strength, logistics related to transporting and monitoring of neonates during scanning, sedation considerations and a discussion of current technologies such as MRI-conditional neonatal incubators and dedicated small-foot print neonatal intensive care unit (NICU) scanners. PMID:25743582

  12. Brain Activity and Human Unilateral Chewing

    Science.gov (United States)

    Quintero, A.; Ichesco, E.; Myers, C.; Schutt, R.; Gerstner, G.E.

    2012-01-01

    Brain mechanisms underlying mastication have been studied in non-human mammals but less so in humans. We used functional magnetic resonance imaging (fMRI) to evaluate brain activity in humans during gum chewing. Chewing was associated with activations in the cerebellum, motor cortex and caudate, cingulate, and brainstem. We also divided the 25-second chew-blocks into 5 segments of equal 5-second durations and evaluated activations within and between each of the 5 segments. This analysis revealed activation clusters unique to the initial segment, which may indicate brain regions involved with initiating chewing. Several clusters were uniquely activated during the last segment as well, which may represent brain regions involved with anticipatory or motor events associated with the end of the chew-block. In conclusion, this study provided evidence for specific brain areas associated with chewing in humans and demonstrated that brain activation patterns may dynamically change over the course of chewing sequences. PMID:23103631

  13. Cognition and brain abnormalities on MRI in pituitary patients

    International Nuclear Information System (INIS)

    Brummelman, Pauline; Sattler, Margriet G.A.; Meiners, Linda C.; Berg, Gerrit van den; Klauw, Melanie M. van der; Elderson, Martin F.; Dullaart, Robin P.F.; Koerts, Janneke; Werumeus Buning, Jorien; Tucha, Oliver; Wolffenbuttel, Bruce H.R.; Bergh, Alfons C.M. van den; Beek, André P. van

    2015-01-01

    Highlights: • Cognitive impairments are frequently observed in treated NFA patients. • NFA patients with cognitive impairments do not show brain abnormalities on MRI more frequently than patients without cognitive impairments. • The absence of brain abnormalities on brain MRI does not exclude impairments of cognition. - Abstract: Purpose: The extent to which cognitive dysfunction is related to specific brain abnormalities in patients treated for pituitary macroadenoma is unclear. Therefore, we compared brain abnormalities seen on Magnetic Resonance Imaging (MRI) in patients treated for nonfunctioning pituitary macroadenoma (NFA) with or without impairments in cognitive functioning. Methods: In this cross-sectional design, a cohort of 43 NFA patients was studied at the University Medical Center Groningen. White matter lesions (WMLs), cerebral atrophy, (silent) brain infarcts and abnormalities of the temporal lobes and hippocampi were assessed on pre-treatment and post-treatment MRI scans. Post-treatment cognitive examinations were performed using a verbal memory and executive functioning test. We compared our patient cohort with large reference populations representative of the Dutch population. Results: One or more impairments on both cognitive tests were frequently observed in treated NFA patients. No treatment effects were found with regard to the comparison between patients with and without impairments in executive functioning. Interestingly, in patients with one or more impairments on verbal memory function, treatment with radiotherapy had been given more frequently (74% in the impaired group versus 40% in the unimpaired group, P = 0.025). Patients with or without any brain abnormality on MRI did not differ in verbal memory or executive functioning. Conclusions: Brain abnormalities on MRI are not observed more frequently in treated NFA patients with impairments compared to NFA patients without impairments in verbal memory or executive functioning

  14. Cognition and brain abnormalities on MRI in pituitary patients

    Energy Technology Data Exchange (ETDEWEB)

    Brummelman, Pauline [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Sattler, Margriet G.A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen (Netherlands); Department of Radiation Oncology, Netherlands Cancer Institute – Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Meiners, Linda C. [Department of Radiology, University of Groningen, University Medical Center Groningen (Netherlands); Berg, Gerrit van den; Klauw, Melanie M. van der [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Elderson, Martin F. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); LifeLines Cohort Study and Biobank, University of Groningen, University Medical Center Groningen (Netherlands); Dullaart, Robin P.F. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Koerts, Janneke [Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen (Netherlands); Werumeus Buning, Jorien, E-mail: j.werumeus.buning@umcg.nl [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Tucha, Oliver [Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); LifeLines Cohort Study and Biobank, University of Groningen, University Medical Center Groningen (Netherlands); Bergh, Alfons C.M. van den [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen (Netherlands); Beek, André P. van, E-mail: a.p.van.beek@umcg.nl [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands)

    2015-02-15

    Highlights: • Cognitive impairments are frequently observed in treated NFA patients. • NFA patients with cognitive impairments do not show brain abnormalities on MRI more frequently than patients without cognitive impairments. • The absence of brain abnormalities on brain MRI does not exclude impairments of cognition. - Abstract: Purpose: The extent to which cognitive dysfunction is related to specific brain abnormalities in patients treated for pituitary macroadenoma is unclear. Therefore, we compared brain abnormalities seen on Magnetic Resonance Imaging (MRI) in patients treated for nonfunctioning pituitary macroadenoma (NFA) with or without impairments in cognitive functioning. Methods: In this cross-sectional design, a cohort of 43 NFA patients was studied at the University Medical Center Groningen. White matter lesions (WMLs), cerebral atrophy, (silent) brain infarcts and abnormalities of the temporal lobes and hippocampi were assessed on pre-treatment and post-treatment MRI scans. Post-treatment cognitive examinations were performed using a verbal memory and executive functioning test. We compared our patient cohort with large reference populations representative of the Dutch population. Results: One or more impairments on both cognitive tests were frequently observed in treated NFA patients. No treatment effects were found with regard to the comparison between patients with and without impairments in executive functioning. Interestingly, in patients with one or more impairments on verbal memory function, treatment with radiotherapy had been given more frequently (74% in the impaired group versus 40% in the unimpaired group, P = 0.025). Patients with or without any brain abnormality on MRI did not differ in verbal memory or executive functioning. Conclusions: Brain abnormalities on MRI are not observed more frequently in treated NFA patients with impairments compared to NFA patients without impairments in verbal memory or executive functioning

  15. Hand grips strength effect on motor function in human brain using fMRI: a pilot study

    International Nuclear Information System (INIS)

    Ismail, S S; Mohamad, M; Syazarina, S O; Nafisah, W Y

    2014-01-01

    Several methods of motor tasks for fMRI scanning have been evolving from simple to more complex tasks. Motor tasks on upper extremity were applied in order to excite the increscent of motor activation on contralesional and ipsilateral hemispheres in brain. The main objective of this study is to study the different conditions for motor tasks on upper extremity that affected the brain activation. Ten healthy right handed with normal vision (3 male and 7 female, age range=20-30 years, mean=24.6 years, SD=2.21) participated in this study. Prior to the scanning, participants were trained on hand grip tasks using rubber ball and pressure gauge tool outside the scanner. During fMRI session, a block design with 30-s task blocks and alternating 30-s rest periods was employed while participants viewed a computer screen via a back projection-mirror system and instructed to follow the instruction by gripping their hand with normal and strong grips using a rubber ball. Statistical Parametric mapping (SPM8) software was used to determine the brain activation. Both tasks activated the primary motor (M1), supplementary motor area (SMA), dorsal and ventral of premotor cortex area (PMA) in left hemisphere while in right hemisphere the area of primary motor (M1) somatosensory was activated. However, the comparison between both tasks revealed that the strong hand grip showed the higher activation at M1, PMA and SMA on left hemisphere and also the area of SMA on right hemisphere. Both conditions of motor tasks could provide insights the functional organization on human brain

  16. Hand grips strength effect on motor function in human brain using fMRI: a pilot study

    Science.gov (United States)

    Ismail, S. S.; Mohamad, M.; Syazarina, S. O.; Nafisah, W. Y.

    2014-11-01

    Several methods of motor tasks for fMRI scanning have been evolving from simple to more complex tasks. Motor tasks on upper extremity were applied in order to excite the increscent of motor activation on contralesional and ipsilateral hemispheres in brain. The main objective of this study is to study the different conditions for motor tasks on upper extremity that affected the brain activation. Ten healthy right handed with normal vision (3 male and 7 female, age range=20-30 years, mean=24.6 years, SD=2.21) participated in this study. Prior to the scanning, participants were trained on hand grip tasks using rubber ball and pressure gauge tool outside the scanner. During fMRI session, a block design with 30-s task blocks and alternating 30-s rest periods was employed while participants viewed a computer screen via a back projection-mirror system and instructed to follow the instruction by gripping their hand with normal and strong grips using a rubber ball. Statistical Parametric mapping (SPM8) software was used to determine the brain activation. Both tasks activated the primary motor (M1), supplementary motor area (SMA), dorsal and ventral of premotor cortex area (PMA) in left hemisphere while in right hemisphere the area of primary motor (M1) somatosensory was activated. However, the comparison between both tasks revealed that the strong hand grip showed the higher activation at M1, PMA and SMA on left hemisphere and also the area of SMA on right hemisphere. Both conditions of motor tasks could provide insights the functional organization on human brain.

  17. Neurospin Seminar: From the Proton to the Human Brain

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    From the Proton to the Human Brain Speaker: Prof Denis Le Bihan Abstract: The understanding of the human brain is one of the main scientific challenges of the 21st century. In the early 2000s the French Atomic Energy Commission (CEA) launched a program to conceive and build a “human brain explorer”, the first human MRI scanner operating at 11.7T. This scanner was envisioned to be part of the ambitious Iseult project, bridging together industrial and academic partners to push the limits of molecular neuroimaging, from mouse to man, using Ultra-High Field (UHF) MRI. In this seminar a summary of the main features of this magnet, and the neuroscience and medical targets of NeuroSpin where this outstanding instrument will be installed in 2017 will be surveyed. The unprecedented resolution and the new contrasts allowed by such UHF magnets, in combination with innovative concepts in physics and neurobiology, will allow to explore the human brain at a mesoscale at which everything remains to d...

  18. Information flow between interacting human brains: Identification, validation, and relationship to social expertise.

    Science.gov (United States)

    Bilek, Edda; Ruf, Matthias; Schäfer, Axel; Akdeniz, Ceren; Calhoun, Vince D; Schmahl, Christian; Demanuele, Charmaine; Tost, Heike; Kirsch, Peter; Meyer-Lindenberg, Andreas

    2015-04-21

    Social interactions are fundamental for human behavior, but the quantification of their neural underpinnings remains challenging. Here, we used hyperscanning functional MRI (fMRI) to study information flow between brains of human dyads during real-time social interaction in a joint attention paradigm. In a hardware setup enabling immersive audiovisual interaction of subjects in linked fMRI scanners, we characterize cross-brain connectivity components that are unique to interacting individuals, identifying information flow between the sender's and receiver's temporoparietal junction. We replicate these findings in an independent sample and validate our methods by demonstrating that cross-brain connectivity relates to a key real-world measure of social behavior. Together, our findings support a central role of human-specific cortical areas in the brain dynamics of dyadic interactions and provide an approach for the noninvasive examination of the neural basis of healthy and disturbed human social behavior with minimal a priori assumptions.

  19. High-resolution whole-brain diffusion MRI at 7T using radiofrequency parallel transmission.

    Science.gov (United States)

    Wu, Xiaoping; Auerbach, Edward J; Vu, An T; Moeller, Steen; Lenglet, Christophe; Schmitter, Sebastian; Van de Moortele, Pierre-François; Yacoub, Essa; Uğurbil, Kâmil

    2018-03-30

    Investigating the utility of RF parallel transmission (pTx) for Human Connectome Project (HCP)-style whole-brain diffusion MRI (dMRI) data at 7 Tesla (7T). Healthy subjects were scanned in pTx and single-transmit (1Tx) modes. Multiband (MB), single-spoke pTx pulses were designed to image sagittal slices. HCP-style dMRI data (i.e., 1.05-mm resolutions, MB2, b-values = 1000/2000 s/mm 2 , 286 images and 40-min scan) and data with higher accelerations (MB3 and MB4) were acquired with pTx. pTx significantly improved flip-angle detected signal uniformity across the brain, yielding ∼19% increase in temporal SNR (tSNR) averaged over the brain relative to 1Tx. This allowed significantly enhanced estimation of multiple fiber orientations (with ∼21% decrease in dispersion) in HCP-style 7T dMRI datasets. Additionally, pTx pulses achieved substantially lower power deposition, permitting higher accelerations, enabling collection of the same data in 2/3 and 1/2 the scan time or of more data in the same scan time. pTx provides a solution to two major limitations for slice-accelerated high-resolution whole-brain dMRI at 7T; it improves flip-angle uniformity, and enables higher slice acceleration relative to current state-of-the-art. As such, pTx provides significant advantages for rapid acquisition of high-quality, high-resolution truly whole-brain dMRI data. © 2018 International Society for Magnetic Resonance in Medicine.

  20. Practical MRI atlas of neonatal brain development

    International Nuclear Information System (INIS)

    Barkovich, A.J.; Truwit, C.L.

    1990-01-01

    This book is an anatomical reference for cranial magnetic resonance imaging (MRI) studies in neonates and infants. It contains 122 clear, sharp MRI scans and drawings showing changes in the normal appearance of the brain and skull during development. Sections of the atlas depict the major processes of maturation: brain myelination, development of the corpus callosum, development of the cranial bone marrow, and iron deposition in the brain. High-quality scans illustrate how these changes appear on magnetic resonance images during various stages of development

  1. Blood Flow and Brain Function: Investigations of neurovascular coupling using BOLD fMRI at 7 tesla

    NARCIS (Netherlands)

    Siero, J.C.W.

    2013-01-01

    The advent of ultra high field (7 tesla) MRI systems has opened the possibility to probe biological processes of the human body in great detail. Especially for studying brain function using BOLD fMRI there is a large benefit from the increased magnetic field strength. BOLD fMRI is the working horse

  2. Joint brain connectivity estimation from diffusion and functional MRI data

    Science.gov (United States)

    Chu, Shu-Hsien; Lenglet, Christophe; Parhi, Keshab K.

    2015-03-01

    Estimating brain wiring patterns is critical to better understand the brain organization and function. Anatomical brain connectivity models axonal pathways, while the functional brain connectivity characterizes the statistical dependencies and correlation between the activities of various brain regions. The synchronization of brain activity can be inferred through the variation of blood-oxygen-level dependent (BOLD) signal from functional MRI (fMRI) and the neural connections can be estimated using tractography from diffusion MRI (dMRI). Functional connections between brain regions are supported by anatomical connections, and the synchronization of brain activities arises through sharing of information in the form of electro-chemical signals on axon pathways. Jointly modeling fMRI and dMRI data may improve the accuracy in constructing anatomical connectivity as well as functional connectivity. Such an approach may lead to novel multimodal biomarkers potentially able to better capture functional and anatomical connectivity variations. We present a novel brain network model which jointly models the dMRI and fMRI data to improve the anatomical connectivity estimation and extract the anatomical subnetworks associated with specific functional modes by constraining the anatomical connections as structural supports to the functional connections. The key idea is similar to a multi-commodity flow optimization problem that minimizes the cost or maximizes the efficiency for flow configuration and simultaneously fulfills the supply-demand constraint for each commodity. In the proposed network, the nodes represent the grey matter (GM) regions providing brain functionality, and the links represent white matter (WM) fiber bundles connecting those regions and delivering information. The commodities can be thought of as the information corresponding to brain activity patterns as obtained for instance by independent component analysis (ICA) of fMRI data. The concept of information

  3. Brain microstructure mapping using quantitative and diffusion MRI

    International Nuclear Information System (INIS)

    Lebois, Alice

    2014-01-01

    This thesis is focused on the human brain microstructure mapping using quantitative and diffusion MRI. The T1/T2 quantitative imaging relies on sequences dedicated to the mapping of T1 and T2 relaxation times. Their variations within the tissue are linked to the presence of different water compartments defined by a specific organization of the tissue at the cell scale. Measuring these parameters can help, therefore, to better characterize the brain microstructure. The dMRI, on the other hand, explores the brownian motion of water molecules in the brain tissue, where the water molecules' movement is constrained by natural barriers, such as cell membranes. Thus, the information on their displacement carried by the dMRI signal gives access to the underlying cyto-architecture. Combination of these two modalities is, therefore, a promising way to probe the brain tissue microstructure. The main goal of the present thesis is to set up the methodology to study the microstructure of the white matter of the human brain in vivo. The first part includes the acquisition of a unique MRI database of 79 healthy subjects (the Archi/CONNECT), which includes anatomical high resolution data, relaxometry data, diffusion-weighted data at high spatio-angular resolution and functional data. This database has allowed us to build the first atlas of the anatomical connectivity of the healthy brain through the automatic segmentation of the major white matter bundles, providing an appropriate anatomical reference for the white matter to study individually the quantitative parameters along each fascicle, characterizing its microstructure organization. Emphasis was placed on the construction of the first atlas of the T1/T2 profiles along the major white matter pathways. The profiles of the T1 and T2 relaxation times were then correlated to the quantitative profiles computed from the diffusion MRI data (fractional anisotropy, radial and longitudinal diffusivities, apparent diffusion coefficient

  4. Increased expression of aquaporin-4 in human traumatic brain injury and brain tumors

    Institute of Scientific and Technical Information of China (English)

    HU Hua; YAO Hong-tian; ZHANG Wei-ping; ZHANG LEI; DING Wei; ZHANG Shi-hong; CHEN Zhong; WEI Er-qing

    2005-01-01

    Objective: To characterize the expression of aquaporin-4 (AQP4), one of the aquaporins (AQPs), in human brain specimens from patients with traumatic brain injury or brain tumors. Methods: Nineteen human brain specimens were obtained from the patients with traumatic brain injury, brain tumors, benign meningioma or early stage hemorrhagic stroke. MRI or CT imaging was used to assess brain edema. Hematoxylin and eosin staining were used to evaluate cell damage. Immunohistochemistry was used to detect the AQP4 expression. Results: AQP4 expression was increased from 15h to at least 8 d after injury. AQP4immunoreactivity was strong around astrocytomas, ganglioglioma and metastatic adenocarcinoma. However, AQP4 immunoreactivity was only found in the centers of astrocytomas and ganglioglioma, but not in metastatic adenocarcinoma derived from lung.Conclusion: AQP4 expression increases in human brains after traumatic brain injury, within brain-derived tumors, and around brain tumors.

  5. Scale-Free Brain-Wave Music from Simultaneously EEG and fMRI Recordings

    Science.gov (United States)

    Lu, Jing; Wu, Dan; Yang, Hua; Luo, Cheng; Li, Chaoyi; Yao, Dezhong

    2012-01-01

    In the past years, a few methods have been developed to translate human EEG to music. In 2009, PloS One 4 e5915, we developed a method to generate scale-free brainwave music where the amplitude of EEG was translated to music pitch according to the power law followed by both of them, the period of an EEG waveform is translated directly to the duration of a note, and the logarithm of the average power change of EEG is translated to music intensity according to the Fechner's law. In this work, we proposed to adopt simultaneously-recorded fMRI signal to control the intensity of the EEG music, thus an EEG-fMRI music is generated by combining two different and simultaneous brain signals. And most importantly, this approach further realized power law for music intensity as fMRI signal follows it. Thus the EEG-fMRI music makes a step ahead in reflecting the physiological process of the scale-free brain. PMID:23166768

  6. Scale-free brain-wave music from simultaneously EEG and fMRI recordings.

    Science.gov (United States)

    Lu, Jing; Wu, Dan; Yang, Hua; Luo, Cheng; Li, Chaoyi; Yao, Dezhong

    2012-01-01

    In the past years, a few methods have been developed to translate human EEG to music. In 2009, PloS One 4 e5915, we developed a method to generate scale-free brainwave music where the amplitude of EEG was translated to music pitch according to the power law followed by both of them, the period of an EEG waveform is translated directly to the duration of a note, and the logarithm of the average power change of EEG is translated to music intensity according to the Fechner's law. In this work, we proposed to adopt simultaneously-recorded fMRI signal to control the intensity of the EEG music, thus an EEG-fMRI music is generated by combining two different and simultaneous brain signals. And most importantly, this approach further realized power law for music intensity as fMRI signal follows it. Thus the EEG-fMRI music makes a step ahead in reflecting the physiological process of the scale-free brain.

  7. Advanced MRI techniques of the fetal brain

    International Nuclear Information System (INIS)

    Schoepf, V.; Dittrich, E.; Berger-Kulemann, V.; Kasprian, G.; Kollndorfer, K.; Prayer, D.

    2013-01-01

    Evaluation of the normal and pathological fetal brain. Magnetic resonance imaging (MRI). Advanced MRI of the fetal brain. Diffusion tensor imaging (DTI) is used in clinical practice, all other methods are used at a research level. Serving as standard methods in the future. Combined structural and functional data for all gestational ages will allow more specific insight into the developmental processes of the fetal brain. This gain of information will help provide a common understanding of complex spatial and temporal procedures of early morphological features and their impact on cognitive and sensory abilities. (orig.) [de

  8. Probing the brain with molecular fMRI.

    Science.gov (United States)

    Ghosh, Souparno; Harvey, Peter; Simon, Jacob C; Jasanoff, Alan

    2018-04-09

    One of the greatest challenges of modern neuroscience is to incorporate our growing knowledge of molecular and cellular-scale physiology into integrated, organismic-scale models of brain function in behavior and cognition. Molecular-level functional magnetic resonance imaging (molecular fMRI) is a new technology that can help bridge these scales by mapping defined microscopic phenomena over large, optically inaccessible regions of the living brain. In this review, we explain how MRI-detectable imaging probes can be used to sensitize noninvasive imaging to mechanistically significant components of neural processing. We discuss how a combination of innovative probe design, advanced imaging methods, and strategies for brain delivery can make molecular fMRI an increasingly successful approach for spatiotemporally resolved studies of diverse neural phenomena, perhaps eventually in people. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Insulin action in the human brain: evidence from neuroimaging studies.

    Science.gov (United States)

    Kullmann, S; Heni, M; Fritsche, A; Preissl, H

    2015-06-01

    Thus far, little is known about the action of insulin in the human brain. Nonetheless, recent advances in modern neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG), have made it possible to investigate the action of insulin in the brain in humans, providing new insights into the pathogenesis of brain insulin resistance and obesity. Using MEG, the clinical relevance of the action of insulin in the brain was first identified, linking cerebral insulin resistance with peripheral insulin resistance, genetic predisposition and weight loss success in obese adults. Although MEG is a suitable tool for measuring brain activity mainly in cortical areas, fMRI provides high spatial resolution for cortical as well as subcortical regions. Thus, the action of insulin can be detected within all eating behaviour relevant regions, which include regions deeply located within the brain, such as the hypothalamus, midbrain and brainstem, as well as regions within the striatum. In this review, we outline recent advances in the field of neuroimaging aiming to investigate the action of insulin in the human brain using different routes of insulin administration. fMRI studies have shown a significant insulin-induced attenuation predominantly in the occipital and prefrontal cortical regions and the hypothalamus, successfully localising insulin-sensitive brain regions in healthy, mostly normal-weight individuals. However, further studies are needed to localise brain areas affected by insulin resistance in obese individuals, which is an important prerequisite for selectively targeting brain insulin resistance in obesity. © 2015 British Society for Neuroendocrinology.

  10. Function-specific and Enhanced Brain Structural Connectivity Mapping via Joint Modeling of Diffusion and Functional MRI.

    Science.gov (United States)

    Chu, Shu-Hsien; Parhi, Keshab K; Lenglet, Christophe

    2018-03-16

    A joint structural-functional brain network model is presented, which enables the discovery of function-specific brain circuits, and recovers structural connections that are under-estimated by diffusion MRI (dMRI). Incorporating information from functional MRI (fMRI) into diffusion MRI to estimate brain circuits is a challenging task. Usually, seed regions for tractography are selected from fMRI activation maps to extract the white matter pathways of interest. The proposed method jointly analyzes whole brain dMRI and fMRI data, allowing the estimation of complete function-specific structural networks instead of interactively investigating the connectivity of individual cortical/sub-cortical areas. Additionally, tractography techniques are prone to limitations, which can result in erroneous pathways. The proposed framework explicitly models the interactions between structural and functional connectivity measures thereby improving anatomical circuit estimation. Results on Human Connectome Project (HCP) data demonstrate the benefits of the approach by successfully identifying function-specific anatomical circuits, such as the language and resting-state networks. In contrast to correlation-based or independent component analysis (ICA) functional connectivity mapping, detailed anatomical connectivity patterns are revealed for each functional module. Results on a phantom (Fibercup) also indicate improvements in structural connectivity mapping by rejecting false-positive connections with insufficient support from fMRI, and enhancing under-estimated connectivity with strong functional correlation.

  11. Prediction of standard-dose brain PET image by using MRI and low-dose brain [{sup 18}F]FDG PET images

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jiayin [School of Electronics Engineering, Huaihai Institute of Technology, Lianyungang, Jiangsu 222005, China and IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Gao, Yaozong [IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Shi, Feng [IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Lalush, David S. [Joint UNC-NCSU Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Lin, Weili [MRI Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Shen, Dinggang, E-mail: dgshen@med.unc.edu [IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and Department of Brain and Cognitive Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2015-09-15

    Purpose: Positron emission tomography (PET) is a nuclear medical imaging technology that produces 3D images reflecting tissue metabolic activity in human body. PET has been widely used in various clinical applications, such as in diagnosis of brain disorders. High-quality PET images play an essential role in diagnosing brain diseases/disorders. In practice, in order to obtain high-quality PET images, a standard-dose radionuclide (tracer) needs to be used and injected into a living body. As a result, it will inevitably increase the patient’s exposure to radiation. One solution to solve this problem is predicting standard-dose PET images using low-dose PET images. As yet, no previous studies with this approach have been reported. Accordingly, in this paper, the authors propose a regression forest based framework for predicting a standard-dose brain [{sup 18}F]FDG PET image by using a low-dose brain [{sup 18}F]FDG PET image and its corresponding magnetic resonance imaging (MRI) image. Methods: The authors employ a regression forest for predicting the standard-dose brain [{sup 18}F]FDG PET image by low-dose brain [{sup 18}F]FDG PET and MRI images. Specifically, the proposed method consists of two main steps. First, based on the segmented brain tissues (i.e., cerebrospinal fluid, gray matter, and white matter) in the MRI image, the authors extract features for each patch in the brain image from both low-dose PET and MRI images to build tissue-specific models that can be used to initially predict standard-dose brain [{sup 18}F]FDG PET images. Second, an iterative refinement strategy, via estimating the predicted image difference, is used to further improve the prediction accuracy. Results: The authors evaluated their algorithm on a brain dataset, consisting of 11 subjects with MRI, low-dose PET, and standard-dose PET images, using leave-one-out cross-validations. The proposed algorithm gives promising results with well-estimated standard-dose brain [{sup 18}F]FDG PET

  12. Prediction of standard-dose brain PET image by using MRI and low-dose brain ["1"8F]FDG PET images

    International Nuclear Information System (INIS)

    Kang, Jiayin; Gao, Yaozong; Shi, Feng; Lalush, David S.; Lin, Weili; Shen, Dinggang

    2015-01-01

    Purpose: Positron emission tomography (PET) is a nuclear medical imaging technology that produces 3D images reflecting tissue metabolic activity in human body. PET has been widely used in various clinical applications, such as in diagnosis of brain disorders. High-quality PET images play an essential role in diagnosing brain diseases/disorders. In practice, in order to obtain high-quality PET images, a standard-dose radionuclide (tracer) needs to be used and injected into a living body. As a result, it will inevitably increase the patient’s exposure to radiation. One solution to solve this problem is predicting standard-dose PET images using low-dose PET images. As yet, no previous studies with this approach have been reported. Accordingly, in this paper, the authors propose a regression forest based framework for predicting a standard-dose brain ["1"8F]FDG PET image by using a low-dose brain ["1"8F]FDG PET image and its corresponding magnetic resonance imaging (MRI) image. Methods: The authors employ a regression forest for predicting the standard-dose brain ["1"8F]FDG PET image by low-dose brain ["1"8F]FDG PET and MRI images. Specifically, the proposed method consists of two main steps. First, based on the segmented brain tissues (i.e., cerebrospinal fluid, gray matter, and white matter) in the MRI image, the authors extract features for each patch in the brain image from both low-dose PET and MRI images to build tissue-specific models that can be used to initially predict standard-dose brain ["1"8F]FDG PET images. Second, an iterative refinement strategy, via estimating the predicted image difference, is used to further improve the prediction accuracy. Results: The authors evaluated their algorithm on a brain dataset, consisting of 11 subjects with MRI, low-dose PET, and standard-dose PET images, using leave-one-out cross-validations. The proposed algorithm gives promising results with well-estimated standard-dose brain ["1"8F]FDG PET image and substantially

  13. Fear extinction in the human brain: A meta-analysis of fMRI studies in healthy participants.

    Science.gov (United States)

    Fullana, Miquel A; Albajes-Eizagirre, Anton; Soriano-Mas, Carles; Vervliet, Bram; Cardoner, Narcís; Benet, Olívia; Radua, Joaquim; Harrison, Ben J

    2018-05-01

    The study of fear extinction represents an important example of translational neuroscience in psychiatry and promises to improve the understanding and treatment of anxiety and fear-related disorders. We present the results of a set of meta-analyses of human fear extinction studies in healthy participants, conducted with functional magnetic resonance imaging (fMRI) and reporting whole-brain results. Meta-analyses of fear extinction learning primarily implicate consistent activation of brain regions linked to threat appraisal and experience, including the dorsal anterior cingulate and anterior insular cortices. An overlapping anatomical result was obtained from the meta-analysis of extinction recall studies, except when studies directly compared an extinguished threat stimulus to an unextinguished threat stimulus (instead of a safety stimulus). In this latter instance, more consistent activation was observed in dorsolateral and ventromedial prefrontal cortex regions, together with other areas including the hippocampus. While our results partially support the notion of a shared neuroanatomy between human and rodent models of extinction processes, they also encourage an expanded account of the neural basis of human fear extinction. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Physiological neuronal decline in healthy aging human brain - An in vivo study with MRI and short echo-time whole-brain (1)H MR spectroscopic imaging.

    Science.gov (United States)

    Ding, Xiao-Qi; Maudsley, Andrew A; Sabati, Mohammad; Sheriff, Sulaiman; Schmitz, Birte; Schütze, Martin; Bronzlik, Paul; Kahl, Kai G; Lanfermann, Heinrich

    2016-08-15

    Knowledge of physiological aging in healthy human brain is increasingly important for neuroscientific research and clinical diagnosis. To investigate neuronal decline in normal aging brain eighty-one healthy subjects aged between 20 and 70years were studied with MRI and whole-brain (1)H MR spectroscopic imaging. Concentrations of brain metabolites N-acetyl-aspartate (NAA), choline (Cho), total creatine (tCr), myo-inositol (mI), and glutamine+glutamate (Glx) in ratios to internal water, and the fractional volumes of brain tissue were estimated simultaneously in eight cerebral lobes and in cerebellum. Results demonstrated that an age-related decrease in gray matter volume was the largest contribution to changes in brain volume. Both lobar NAA and the fractional volume of gray matter (FVGM) decreased with age in all cerebral lobes, indicating that the decreased NAA was predominantly associated with decreased gray matter volume and neuronal density or metabolic activity. In cerebral white matter Cho, tCr, and mI increased with age in association with increased fractional volume, showing altered cellular membrane turn-over, energy metabolism, and glial activity in human aging white matter. In cerebellum tCr increased while brain tissue volume decreased with age, showing difference to cerebral aging. The observed age-related metabolic and microstructural variations suggest that physiological neuronal decline in aging human brain is associated with a reduction of gray matter volume and neuronal density, in combination with cellular aging in white matter indicated by microstructural alterations and altered energy metabolism in the cerebellum. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. PET/MRI for Oncologic Brain Imaging

    DEFF Research Database (Denmark)

    Rausch, Ivo; Rischka, Lucas; Ladefoged, Claes N

    2017-01-01

    The aim of this study was to compare attenuation-correction (AC) approaches for PET/MRI in clinical neurooncology.Methods:Forty-nine PET/MRI brain scans were included: brain tumor studies using18F-fluoro-ethyl-tyrosine (18F-FET) (n= 31) and68Ga-DOTANOC (n= 7) and studies of healthy subjects using18...... by Siemens Healthcare). As a reference, AC maps were derived from patient-specific CT images (CTref). PET data were reconstructed using standard settings after AC with all 4 AC methods. We report changes in diagnosis for all brain tumor patients and the following relative differences values (RDs...... of the whole brain and 10 anatomic regions segmented on MR images.Results:For brain tumor imaging (A and B), the standard PET-based diagnosis was not affected by any of the 3 MR-AC methods. For A, the average RDs of SUVmeanwere -10%, -4%, and -3% and of the VOIs 1%, 2%, and 7% for DIXON, UTE, and BD...

  16. MRI assessment of whole-brain structural changes in aging.

    Science.gov (United States)

    Guo, Hui; Siu, William; D'Arcy, Ryan Cn; Black, Sandra E; Grajauskas, Lukas A; Singh, Sonia; Zhang, Yunting; Rockwood, Kenneth; Song, Xiaowei

    2017-01-01

    One of the central features of brain aging is the accumulation of multiple age-related structural changes, which occur heterogeneously in individuals and can have immediate or potential clinical consequences. Each of these deficits can coexist and interact, producing both independent and additive impacts on brain health. Many of the changes can be visualized using MRI. To collectively assess whole-brain structural changes, the MRI-based Brain Atrophy and Lesion Index (BALI) has been developed. In this study, we validate this whole-brain health assessment approach using several clinical MRI examinations. Data came from three independent studies: the Alzheimer's Disease Neuroimaging Initiative Phase II (n=950; women =47.9%; age =72.7±7.4 years); the National Alzheimer's Coordinating Center (n=722; women =55.1%; age =72.7±9.9 years); and the Tianjin Medical University General Hospital Research database on older adults (n=170; women =60.0%; age =62.9±9.3 years). The 3.0-Tesla MRI scans were evaluated using the BALI rating scheme on the basis of T1-weighted (T1WI), T2-weighted (T2WI), T2-weighted fluid-attenuated inversion recovery (T2-FLAIR), and T2*-weighted gradient-recalled echo (T2*GRE) images. Atrophy and lesion changes were commonly seen in each MRI test. The BALI scores based on different sequences were highly correlated (Spearman r 2 >0.69; P age ( r 2 >0.29; P 26.48, P aging and dementia-related decline of structural brain health. Inclusion of additional MRI tests increased lesion differentiation. Further research is to integrate MRI tests for a clinical tool to aid the diagnosis and intervention of brain aging.

  17. MRI in ischemic brain diseases

    International Nuclear Information System (INIS)

    Steinbrich, W.; Friedmann, G.; Pawlik, G.; Boecher-Schwarz, H.G.; Heiss, W.D.

    1986-01-01

    The results of MRI and CT in 55 patients with brain infarcts were compared; in 26 of these cases an additional PET examination was obtained in order to study the regional glucose utilisation. MRI was superior to CT, demonstrating 11% more of the infarcts, particularly during the first 24 hours, in small lesions confined to the grey or subcortical white matter and in infratentorial ischemic lesion. On the other hand, only CT was able to show fresh hemorrhage, although MRI was the method of choice to demonstrate old blood collections. To characterise the follow up of an infarct, CT and MRI were similar, except the marginal contrast enhancement sometimes demonstrated by CT studies between the 2nd and 4th week after stroke event. PET was inferior to show details because of its poorer spatial resolution, but anyhow had a high sensitivity and provided additional informations concerning secondary inactivations of brain areas not directly damaged. Additionally PET was able to demonstrate areas of anaerobic glycolysis and lesions of diminished glucose utilisation in TIAs. Small areas of gliosis in the white matter of the cerebral hemispheres were frequently found in patients with cerebro-vascular diseases; they were best shown by MRI, but do not correlate with the extent of vascular stenoses or occlusions, shown by angiography. (orig) [de

  18. Hemisphere- and gender-related differences in small-world brain networks: a resting-state functional MRI study.

    Science.gov (United States)

    Tian, Lixia; Wang, Jinhui; Yan, Chaogan; He, Yong

    2011-01-01

    We employed resting-state functional MRI (R-fMRI) to investigate hemisphere- and gender-related differences in the topological organization of human brain functional networks. Brain networks were first constructed by measuring inter-regional temporal correlations of R-fMRI data within each hemisphere in 86 young, healthy, right-handed adults (38 males and 48 females) followed by a graph-theory analysis. The hemispheric networks exhibit small-world attributes (high clustering and short paths) that are compatible with previous results in the whole-brain functional networks. Furthermore, we found that compared with females, males have a higher normalized clustering coefficient in the right hemispheric network but a lower clustering coefficient in the left hemispheric network, suggesting a gender-hemisphere interaction. Moreover, we observed significant hemisphere-related differences in the regional nodal characteristics in various brain regions, such as the frontal and occipital regions (leftward asymmetry) and the temporal regions (rightward asymmetry), findings that are consistent with previous studies of brain structural and functional asymmetries. Together, our results suggest that the topological organization of human brain functional networks is associated with gender and hemispheres, and they provide insights into the understanding of functional substrates underlying individual differences in behaviors and cognition. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. MRI or not to MRI! Should brain MRI be a routine investigation in children with autistic spectrum disorders?

    Science.gov (United States)

    Zeglam, Adel M; Al-Ogab, Marwa F; Al-Shaftery, Thouraya

    2015-09-01

    To evaluate the routine usage of Magnetic Resonance Imaging (MRI) of brain and estimate the prevalence of brain abnormalities in children presenting to the Neurodevelopment Clinic of Al-Khadra Hospital (NDC-KH), Tripoli, Libya with autistic spectrum disorders (ASD). The records of all children with ASD presented to NDC-KH over 4-year period (from January 2009 to December 2012) were reviewed. All MRIs were acquired with a 1.5-T Philips (3-D T1, T2, FLAIR coronal and axial sequences). MRIs were reported to be normal, abnormal or no significant abnormalities by a consultant neuroradiologist. One thousand and seventy-five children were included in the study. Seven hundred and eighty-two children (72.7 %) had an MRI brain of whom 555 (71 %) were boys. 26 children (24 males and 2 females) (3.3 %) demonstrated MRI abnormalities (8 leukodystrophic changes, 4 periventricular leukomalacia, 3 brain atrophy, 2 tuberous sclerosis, 2 vascular changes, 1 pineoblastoma, 1 cerebellar angioma, 1 cerebellar hypoplasia, 3 agenesis of corpus callosum, 1 neuro-epithelial cyst). An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in children with autism. These results could contribute to further research into the pathogenesis of autistic spectrum disorder.

  20. Functional brain segmentation using inter-subject correlation in fMRI.

    Science.gov (United States)

    Kauppi, Jukka-Pekka; Pajula, Juha; Niemi, Jari; Hari, Riitta; Tohka, Jussi

    2017-05-01

    The human brain continuously processes massive amounts of rich sensory information. To better understand such highly complex brain processes, modern neuroimaging studies are increasingly utilizing experimental setups that better mimic daily-life situations. A new exploratory data-analysis approach, functional segmentation inter-subject correlation analysis (FuSeISC), was proposed to facilitate the analysis of functional magnetic resonance (fMRI) data sets collected in these experiments. The method provides a new type of functional segmentation of brain areas, not only characterizing areas that display similar processing across subjects but also areas in which processing across subjects is highly variable. FuSeISC was tested using fMRI data sets collected during traditional block-design stimuli (37 subjects) as well as naturalistic auditory narratives (19 subjects). The method identified spatially local and/or bilaterally symmetric clusters in several cortical areas, many of which are known to be processing the types of stimuli used in the experiments. The method is not only useful for spatial exploration of large fMRI data sets obtained using naturalistic stimuli, but also has other potential applications, such as generation of a functional brain atlases including both lower- and higher-order processing areas. Finally, as a part of FuSeISC, a criterion-based sparsification of the shared nearest-neighbor graph was proposed for detecting clusters in noisy data. In the tests with synthetic data, this technique was superior to well-known clustering methods, such as Ward's method, affinity propagation, and K-means ++. Hum Brain Mapp 38:2643-2665, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. Ultra-high field MRI: Advancing systems neuroscience towards mesoscopic human brain function

    NARCIS (Netherlands)

    Dumoulin, Serge O; Fracasso, A.; Van der Zwaag, W.; Siero, Jeroen C W; Petridou, Natalia

    2018-01-01

    Human MRI scanners at ultra-high magnetic field strengths of 7 T and higher are increasingly available to the neuroscience community. A key advantage brought by ultra-high field MRI is the possibility to increase the spatial resolution at which data is acquired, with little reduction in image

  2. [Introduction of neuroethics: out of clinic, beyond academia in human brain research].

    Science.gov (United States)

    Fukushi, Tamami; Sakura, Osamu

    2008-11-01

    Higher cognitive function in human brain is one of well-developed fields of neuroscience research in the 21st century. Especially functional magnetic resonance imaging (fMRI) and near infrared recording system have brought so many non-clinical researchers whose background is such as cognitive psychology, economics, politics, pedagogy, and so on, to the human brain mapping study. Authors have introduced the ethical issues related to incidental findings during the fMRI recording for non-clinical purpose, which is a typical problem derived from such expanded human brain research under non clinical condition, that is, neuroethics. In the present article we would introduce neuroethical issues in contexts of "out of clinic" and "beyond academia".

  3. Presurgical brain mapping of the language network in patients with brain tumors using resting-state fMRI: Comparison with task fMRI.

    Science.gov (United States)

    Sair, Haris I; Yahyavi-Firouz-Abadi, Noushin; Calhoun, Vince D; Airan, Raag D; Agarwal, Shruti; Intrapiromkul, Jarunee; Choe, Ann S; Gujar, Sachin K; Caffo, Brian; Lindquist, Martin A; Pillai, Jay J

    2016-03-01

    To compare language networks derived from resting-state fMRI (rs-fMRI) with task-fMRI in patients with brain tumors and investigate variables that affect rs-fMRI vs task-fMRI concordance. Independent component analysis (ICA) of rs-fMRI was performed with 20, 30, 40, and 50 target components (ICA20 to ICA50) and language networks identified for patients presenting for presurgical fMRI mapping between 1/1/2009 and 7/1/2015. 49 patients were analyzed fulfilling criteria for presence of brain tumors, no prior brain surgery, and adequate task-fMRI performance. Rs-vs-task-fMRI concordance was measured using Dice coefficients across varying fMRI thresholds before and after noise removal. Multi-thresholded Dice coefficient volume under the surface (DiceVUS) and maximum Dice coefficient (MaxDice) were calculated. One-way Analysis of Variance (ANOVA) was performed to determine significance of DiceVUS and MaxDice between the four ICA order groups. Age, Sex, Handedness, Tumor Side, Tumor Size, WHO Grade, number of scrubbed volumes, image intensity root mean square (iRMS), and mean framewise displacement (FD) were used as predictors for VUS in a linear regression. Artificial elevation of rs-fMRI vs task-fMRI concordance is seen at low thresholds due to noise. Noise-removed group-mean DiceVUS and MaxDice improved as ICA order increased, however ANOVA demonstrated no statistically significant difference between the four groups. Linear regression demonstrated an association between iRMS and DiceVUS for ICA30-50, and iRMS and MaxDice for ICA50. Overall there is moderate group level rs-vs-task fMRI language network concordance, however substantial subject-level variability exists; iRMS may be used to determine reliability of rs-fMRI derived language networks. © 2015 Wiley Periodicals, Inc.

  4. In vivo MRI of the fetal brain.

    Science.gov (United States)

    Girard, N; Raybaud, C; Dercole, C; Boubli, L; Chau, C; Cahen, S; Potier, A; Gamerre, M

    1993-01-01

    We report MRI of the brain in 45 fetuses; the findings were confirmed by pathological examination or postnatal neuroradiological studies. MRI necessitates medication to eliminate fetal motion; curare was injected into the umbilical cord, and MRI is therefore limited to cases in which umbilical cord puncture is indicated. T1-weighted images were obtained in axial, sagittal and coronal planes; the last of these were generally as the most useful as regards morphology. We demonstrated cerebral malformations (n = 13), brain haemorrhage (n = 1), a facial angioma (n = 1), a facial mass (n = 1), hydrocephalus (n = 5), unilateral ventricular enlargement (n = 1), atrophy (n = 4), a porencephalic cyst (n = 1) and normal appearances of the brain in 18 cases. Twenty-two of the fetuses were born alive, and the clinical and/or neuroradiological examination confirmed the antenatal findings. The diagnosis was also confirmed in 8 cases in which a neuropathological examination was possible.

  5. Clinical applications of 7 T MRI in the brain

    International Nuclear Information System (INIS)

    Kolk, Anja G. van der; Hendrikse, Jeroen; Zwanenburg, Jaco J.M.; Visser, Fredy; Luijten, Peter R.

    2013-01-01

    This review illustrates current applications and possible future directions of 7 Tesla (7 T) Magnetic Resonance Imaging (MRI) in the field of brain MRI, in clinical studies as well as clinical practice. With its higher signal-to-noise (SNR) and contrast-to-noise ratio (CNR) compared to lower field strengths, high resolution, contrast-rich images can be obtained of diverse pathologies, like multiple sclerosis (MS), brain tumours, aging-related changes and cerebrovascular diseases. In some of these diseases, additional pathophysiological information can be gained compared to lower field strengths. Because of clear depiction of small anatomical details, and higher lesion conspicuousness, earlier diagnosis and start of treatment of brain diseases may become possible. Furthermore, additional insight into the pathogenesis of brain diseases obtained with 7 T MRI could be the basis for new treatment developments. However, imaging at high field comes with several limitations, like inhomogeneous transmit fields, a higher specific absorption rate (SAR) and, currently, extensive contraindications for patient scanning. Future studies will be aimed at assessing the advantages and disadvantages of 7 T MRI over lower field strengths in light of clinical applications, specifically the additional diagnostic and prognostic value of 7 T MRI

  6. Clinical applications of 7 T MRI in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Kolk, Anja G. van der, E-mail: A.G.vanderKolk@umcutrecht.nl [Department of Radiology, University Medical Center Utrecht, Postbox 85500, 3508 GA Utrecht (Netherlands); Hendrikse, Jeroen, E-mail: J.Hendrikse@umcutrecht.nl [Department of Radiology, University Medical Center Utrecht, Postbox 85500, 3508 GA Utrecht (Netherlands); Zwanenburg, Jaco J.M., E-mail: J.J.M.Zwanenburg@umcutrecht.nl [Department of Radiology, University Medical Center Utrecht, Postbox 85500, 3508 GA Utrecht (Netherlands); Image Sciences Institute, University Medical Center Utrecht (Netherlands); Visser, Fredy, E-mail: F.Visser-2@umcutrecht.nl [Department of Radiology, University Medical Center Utrecht, Postbox 85500, 3508 GA Utrecht (Netherlands); Philips Healthcare, Best (Netherlands); Luijten, Peter R., E-mail: P.Luijten@umcutrecht.nl [Department of Radiology, University Medical Center Utrecht, Postbox 85500, 3508 GA Utrecht (Netherlands)

    2013-05-15

    This review illustrates current applications and possible future directions of 7 Tesla (7 T) Magnetic Resonance Imaging (MRI) in the field of brain MRI, in clinical studies as well as clinical practice. With its higher signal-to-noise (SNR) and contrast-to-noise ratio (CNR) compared to lower field strengths, high resolution, contrast-rich images can be obtained of diverse pathologies, like multiple sclerosis (MS), brain tumours, aging-related changes and cerebrovascular diseases. In some of these diseases, additional pathophysiological information can be gained compared to lower field strengths. Because of clear depiction of small anatomical details, and higher lesion conspicuousness, earlier diagnosis and start of treatment of brain diseases may become possible. Furthermore, additional insight into the pathogenesis of brain diseases obtained with 7 T MRI could be the basis for new treatment developments. However, imaging at high field comes with several limitations, like inhomogeneous transmit fields, a higher specific absorption rate (SAR) and, currently, extensive contraindications for patient scanning. Future studies will be aimed at assessing the advantages and disadvantages of 7 T MRI over lower field strengths in light of clinical applications, specifically the additional diagnostic and prognostic value of 7 T MRI.

  7. Quantitative Machine Learning Analysis of Brain MRI Morphology throughout Aging.

    Science.gov (United States)

    Shamir, Lior; Long, Joe

    2016-01-01

    While cognition is clearly affected by aging, it is unclear whether the process of brain aging is driven solely by accumulation of environmental damage, or involves biological pathways. We applied quantitative image analysis to profile the alteration of brain tissues during aging. A dataset of 463 brain MRI images taken from a cohort of 416 subjects was analyzed using a large set of low-level numerical image content descriptors computed from the entire brain MRI images. The correlation between the numerical image content descriptors and the age was computed, and the alterations of the brain tissues during aging were quantified and profiled using machine learning. The comprehensive set of global image content descriptors provides high Pearson correlation of ~0.9822 with the chronological age, indicating that the machine learning analysis of global features is sensitive to the age of the subjects. Profiling of the predicted age shows several periods of mild changes, separated by shorter periods of more rapid alterations. The periods with the most rapid changes were around the age of 55, and around the age of 65. The results show that the process of brain aging of is not linear, and exhibit short periods of rapid aging separated by periods of milder change. These results are in agreement with patterns observed in cognitive decline, mental health status, and general human aging, suggesting that brain aging might not be driven solely by accumulation of environmental damage. Code and data used in the experiments are publicly available.

  8. Development of Human Brain Structural Networks Through Infancy and Childhood

    Science.gov (United States)

    Huang, Hao; Shu, Ni; Mishra, Virendra; Jeon, Tina; Chalak, Lina; Wang, Zhiyue J.; Rollins, Nancy; Gong, Gaolang; Cheng, Hua; Peng, Yun; Dong, Qi; He, Yong

    2015-01-01

    During human brain development through infancy and childhood, microstructural and macrostructural changes take place to reshape the brain's structural networks and better adapt them to sophisticated functional and cognitive requirements. However, structural topological configuration of the human brain during this specific development period is not well understood. In this study, diffusion magnetic resonance image (dMRI) of 25 neonates, 13 toddlers, and 25 preadolescents were acquired to characterize network dynamics at these 3 landmark cross-sectional ages during early childhood. dMRI tractography was used to construct human brain structural networks, and the underlying topological properties were quantified by graph-theory approaches. Modular organization and small-world attributes are evident at birth with several important topological metrics increasing monotonically during development. Most significant increases of regional nodes occur in the posterior cingulate cortex, which plays a pivotal role in the functional default mode network. Positive correlations exist between nodal efficiencies and fractional anisotropy of the white matter traced from these nodes, while correlation slopes vary among the brain regions. These results reveal substantial topological reorganization of human brain structural networks through infancy and childhood, which is likely to be the outcome of both heterogeneous strengthening of the major white matter tracts and pruning of other axonal fibers. PMID:24335033

  9. Brain functional BOLD perturbation modelling for forward fMRI and inverse mapping

    Science.gov (United States)

    Robinson, Jennifer; Calhoun, Vince

    2018-01-01

    Purpose To computationally separate dynamic brain functional BOLD responses from static background in a brain functional activity for forward fMRI signal analysis and inverse mapping. Methods A brain functional activity is represented in terms of magnetic source by a perturbation model: χ = χ0 +δχ, with δχ for BOLD magnetic perturbations and χ0 for background. A brain fMRI experiment produces a timeseries of complex-valued images (T2* images), whereby we extract the BOLD phase signals (denoted by δP) by a complex division. By solving an inverse problem, we reconstruct the BOLD δχ dataset from the δP dataset, and the brain χ distribution from a (unwrapped) T2* phase image. Given a 4D dataset of task BOLD fMRI, we implement brain functional mapping by temporal correlation analysis. Results Through a high-field (7T) and high-resolution (0.5mm in plane) task fMRI experiment, we demonstrated in detail the BOLD perturbation model for fMRI phase signal separation (P + δP) and reconstructing intrinsic brain magnetic source (χ and δχ). We also provided to a low-field (3T) and low-resolution (2mm) task fMRI experiment in support of single-subject fMRI study. Our experiments show that the δχ-depicted functional map reveals bidirectional BOLD χ perturbations during the task performance. Conclusions The BOLD perturbation model allows us to separate fMRI phase signal (by complex division) and to perform inverse mapping for pure BOLD δχ reconstruction for intrinsic functional χ mapping. The full brain χ reconstruction (from unwrapped fMRI phase) provides a new brain tissue image that allows to scrutinize the brain tissue idiosyncrasy for the pure BOLD δχ response through an automatic function/structure co-localization. PMID:29351339

  10. Brain functional BOLD perturbation modelling for forward fMRI and inverse mapping.

    Science.gov (United States)

    Chen, Zikuan; Robinson, Jennifer; Calhoun, Vince

    2018-01-01

    To computationally separate dynamic brain functional BOLD responses from static background in a brain functional activity for forward fMRI signal analysis and inverse mapping. A brain functional activity is represented in terms of magnetic source by a perturbation model: χ = χ0 +δχ, with δχ for BOLD magnetic perturbations and χ0 for background. A brain fMRI experiment produces a timeseries of complex-valued images (T2* images), whereby we extract the BOLD phase signals (denoted by δP) by a complex division. By solving an inverse problem, we reconstruct the BOLD δχ dataset from the δP dataset, and the brain χ distribution from a (unwrapped) T2* phase image. Given a 4D dataset of task BOLD fMRI, we implement brain functional mapping by temporal correlation analysis. Through a high-field (7T) and high-resolution (0.5mm in plane) task fMRI experiment, we demonstrated in detail the BOLD perturbation model for fMRI phase signal separation (P + δP) and reconstructing intrinsic brain magnetic source (χ and δχ). We also provided to a low-field (3T) and low-resolution (2mm) task fMRI experiment in support of single-subject fMRI study. Our experiments show that the δχ-depicted functional map reveals bidirectional BOLD χ perturbations during the task performance. The BOLD perturbation model allows us to separate fMRI phase signal (by complex division) and to perform inverse mapping for pure BOLD δχ reconstruction for intrinsic functional χ mapping. The full brain χ reconstruction (from unwrapped fMRI phase) provides a new brain tissue image that allows to scrutinize the brain tissue idiosyncrasy for the pure BOLD δχ response through an automatic function/structure co-localization.

  11. Gadolinium-DTPA enhanced MRI of the brain

    International Nuclear Information System (INIS)

    Hosten, N.; Felix, R.

    1994-01-01

    The text reviews MRI findings in a variety of cerebral diseases. Advantages of Gadolinium-DTPA (Gd-DTPA) enhanced MRI over plain MRI and enhanced CT are discussed. Enhanced MRI is far superior to enhanced CT in the detection of meningeal tumor spread, meningeal inflammation, inflammatory lesions of the optic nerve, brain lesions in multiple sclerosis and infarction. Enhanced MRI is today the most sensitive diagnostic tool in hypophaseal adenomas. Also enhancement of gliomas is detected by MRI with higher sensitivity than by CT. Use Gd-DTPA allow to separate of vital tumor tissue from necrosis and edema, improve delineation of tumor extension and improve detection of lesions localized in gray matter

  12. Complex Trajectories of Brain Development in the Healthy Human Fetus.

    Science.gov (United States)

    Andescavage, Nickie N; du Plessis, Adre; McCarter, Robert; Serag, Ahmed; Evangelou, Iordanis; Vezina, Gilbert; Robertson, Richard; Limperopoulos, Catherine

    2017-11-01

    This study characterizes global and hemispheric brain growth in healthy human fetuses during the second half of pregnancy using three-dimensional MRI techniques. We studied 166 healthy fetuses that underwent MRI between 18 and 39 completed weeks gestation. We created three-dimensional high-resolution reconstructions of the brain and calculated volumes for left and right cortical gray matter (CGM), fetal white matter (FWM), deep subcortical structures (DSS), and the cerebellum. We calculated the rate of growth for each tissue class according to gestational age and described patterns of hemispheric growth. Each brain region demonstrated major increases in volume during the second half of gestation, the most pronounced being the cerebellum (34-fold), followed by FWM (22-fold), CGM (21-fold), and DSS (10-fold). The left cerebellar hemisphere, CGM, and DSS had larger volumes early in gestation, but these equalized by term. It has been increasingly recognized that brain asymmetry evolves throughout the human life span. Advanced quantitative MRI provides noninvasive measurements of early structural asymmetry between the left and right fetal brain that may inform functional and behavioral laterality differences seen in children and young adulthood. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Brain MRI findings of neuropsychiatric lupus

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang-Wook; Kwon, Bae Ju; Lee, Seung-Ro; Hahm, Chang-Kok; Moon, Won Jin; Jeon, Eui Yong; Bae, Sang-Chul [Hanyang Univ. School of Medicine, Seoul (Korea, Republic of)

    2000-12-01

    To evaluate the brain MRI findings in patients with neuropsychiatric lupus. In 26 patients (M:F = 2:24 ; aged 9-48 years) in whom the presence of systemic lupus erythematosus was clinically or pathologically proven and in whom neuropsychiatric lupus was also clinically diagnosed, the findings of brain MRI were retrospectively evaluated. MR images were analyzed with regard to the distribution, location, size and number of lesions due to cerebral ischemia or infarction, the presence of cerebral atrophy, and the extent and degree of brain parenchymal and intravascular enhancement. The most common MRI findings were lesions due to cerebral ischemia or infarction occurring in 18 patients (69%), and located within deep periventricular white matter (n=10), subcortical white matter (n=8), the cerebral cortex (n=7), basal ganglia (n=7), or brain stem or cerebellum (n=2). The lesions were single (n=3) or multiple (n=15), and in 17 patients were less than 1cm in diameter in regions other than the cerebral cortex. In six of these patients, lesions of 1-4cm in diameter in this region were combined, and one occurred in the cerebral cortex only. Cerebral atrophy was seen in 16 patients (62%), in ten of whom there was no past history of treatment with steroids for more than six months. In 15 patients (58%), contrast-enhanced MR image revealed diffuse enhancement of the basal ganglia or intravascular enhancement. In no case were MRI findings normal. The primary mainfestations of neuropsychiatric lupus are multifocal ischemia or infarctions in the cerebral cortex, and subcortical and deep white matter, and the cerebral atrophy. Contrast-enhanced MR images also demonstrated diffuse enhancement of the basal ganglia and intravascular enhancement, both thought to be related to the congestion due to the stagnation of cerebral blood flow.

  14. Brain MRI findings of neuropsychiatric lupus

    International Nuclear Information System (INIS)

    Kim, Jang-Wook; Kwon, Bae Ju; Lee, Seung-Ro; Hahm, Chang-Kok; Moon, Won Jin; Jeon, Eui Yong; Bae, Sang-Chul

    2000-01-01

    To evaluate the brain MRI findings in patients with neuropsychiatric lupus. In 26 patients (M:F = 2:24 ; aged 9-48 years) in whom the presence of systemic lupus erythematosus was clinically or pathologically proven and in whom neuropsychiatric lupus was also clinically diagnosed, the findings of brain MRI were retrospectively evaluated. MR images were analyzed with regard to the distribution, location, size and number of lesions due to cerebral ischemia or infarction, the presence of cerebral atrophy, and the extent and degree of brain parenchymal and intravascular enhancement. The most common MRI findings were lesions due to cerebral ischemia or infarction occurring in 18 patients (69%), and located within deep periventricular white matter (n=10), subcortical white matter (n=8), the cerebral cortex (n=7), basal ganglia (n=7), or brain stem or cerebellum (n=2). The lesions were single (n=3) or multiple (n=15), and in 17 patients were less than 1cm in diameter in regions other than the cerebral cortex. In six of these patients, lesions of 1-4cm in diameter in this region were combined, and one occurred in the cerebral cortex only. Cerebral atrophy was seen in 16 patients (62%), in ten of whom there was no past history of treatment with steroids for more than six months. In 15 patients (58%), contrast-enhanced MR image revealed diffuse enhancement of the basal ganglia or intravascular enhancement. In no case were MRI findings normal. The primary mainfestations of neuropsychiatric lupus are multifocal ischemia or infarctions in the cerebral cortex, and subcortical and deep white matter, and the cerebral atrophy. Contrast-enhanced MR images also demonstrated diffuse enhancement of the basal ganglia and intravascular enhancement, both thought to be related to the congestion due to the stagnation of cerebral blood flow

  15. The Application of MRI for Depiction of Subtle Blood Brain Barrier Disruption in Stroke

    OpenAIRE

    David Israeli, David Tanne, Dianne Daniels, David Last, Ran Shneor, David Guez, Efrat Landau, Yiftach Roth, Aharon Ocherashvilli, Mati Bakon, Chen Hoffman, Amit Weinberg, Talila Volk, Yael Mardor

    2011-01-01

    The development of imaging methodologies for detecting blood-brain-barrier (BBB) disruption may help predict stroke patient's propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI...

  16. The Application of MRI for Depiction of Subtle Blood Brain Barrier Disruption in Stroke

    OpenAIRE

    Israeli, David; Tanne, David; Daniels, Dianne; Last, David; Shneor, Ran; Guez, David; Landau, Efrat; Roth, Yiftach; Ocherashvilli, Aharon; Bakon, Mati; Hoffman, Chen; Weinberg, Amit; Volk, Talila; Mardor, Yael

    2010-01-01

    The development of imaging methodologies for detecting blood-brain-barrier (BBB) disruption may help predict stroke patient's propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI...

  17. High-resolution whole-brain DCE-MRI using constrained reconstruction: Prospective clinical evaluation in brain tumor patients

    International Nuclear Information System (INIS)

    Guo, Yi; Zhu, Yinghua; Lingala, Sajan Goud; Nayak, Krishna; Lebel, R. Marc; Shiroishi, Mark S.; Law, Meng

    2016-01-01

    Purpose: To clinically evaluate a highly accelerated T1-weighted dynamic contrast-enhanced (DCE) MRI technique that provides high spatial resolution and whole-brain coverage via undersampling and constrained reconstruction with multiple sparsity constraints. Methods: Conventional (rate-2 SENSE) and experimental DCE-MRI (rate-30) scans were performed 20 minutes apart in 15 brain tumor patients. The conventional clinical DCE-MRI had voxel dimensions 0.9 × 1.3 × 7.0 mm 3 , FOV 22 × 22 × 4.2 cm 3 , and the experimental DCE-MRI had voxel dimensions 0.9 × 0.9 × 1.9 mm 3 , and broader coverage 22 × 22 × 19 cm 3 . Temporal resolution was 5 s for both protocols. Time-resolved images and blood–brain barrier permeability maps were qualitatively evaluated by two radiologists. Results: The experimental DCE-MRI scans showed no loss of qualitative information in any of the cases, while achieving substantially higher spatial resolution and whole-brain spatial coverage. Average qualitative scores (from 0 to 3) were 2.1 for the experimental scans and 1.1 for the conventional clinical scans. Conclusions: The proposed DCE-MRI approach provides clinically superior image quality with higher spatial resolution and coverage than currently available approaches. These advantages may allow comprehensive permeability mapping in the brain, which is especially valuable in the setting of large lesions or multiple lesions spread throughout the brain.

  18. There is less MRI brain lesions and no characteristic MRI Brain findings in IIDDs patients with positive AQP4 serology among Malaysians.

    Science.gov (United States)

    Abdullah, Suhailah; Fadzli, Farhana; Ramli, Norlisah; Tan, Chong Tin

    2017-02-01

    The recently introduced International Consensus diagnostic criteria for diagnosis of neuromyelitis spectrum disorder include patients who are seronegative for AQP4 antibody. The criteria are dependent on typical MRI changes in the spinal cord, optic nerve and brain. This study aims to determine whether there are significant differences in the MRI brain images between AQP4 positive and negative patients with IIDDs. MRI brain of patients with a diagnosis of IIDDs presented to the Hospital from 2010 to 2015 was analysed. The MRI was assessed by 2 radiologists blinded to the AQP4 status, on features said to be typical of NMOSD and MS. Thirty nine patients fulfilled the criteria and were included in the study. They consisted of 19 AQP4 seropositive and 20 AQP4 seronegative patients. The mean age was older (37.0 vs. 28.8 years) among the AQP4 positive group. The majority of the patients were ethnic Chinese (72%), followed by the Malays and Indians. Those with AQP4 seropositive status generally has less brain lesions, and significantly less fulfilling the McDonald DIS criteria as compared to those with AQP4 seronegative status (15.8% vs. 60.0%, p=0.005). None of the seven cerebral MRI features highlighted in NMOSD 2015 diagnostic criteria, said to be characteristic of NMOSD was more common among the AQP4 positive patients. These features were in fact seen less frequently among the AQP4 seropositive patients. An example was the extensive hemispheric lesion seen in 10.5% of AQP4 seropositive patients vs. 45% of that AQP4 seronegative group. There was no characteristic MRI brain features in the Malaysian AQP4 seropositive IIDD patients versus those who are seronegative. This could be a reflection of ethnical difference. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Development of human brain structural networks through infancy and childhood.

    Science.gov (United States)

    Huang, Hao; Shu, Ni; Mishra, Virendra; Jeon, Tina; Chalak, Lina; Wang, Zhiyue J; Rollins, Nancy; Gong, Gaolang; Cheng, Hua; Peng, Yun; Dong, Qi; He, Yong

    2015-05-01

    During human brain development through infancy and childhood, microstructural and macrostructural changes take place to reshape the brain's structural networks and better adapt them to sophisticated functional and cognitive requirements. However, structural topological configuration of the human brain during this specific development period is not well understood. In this study, diffusion magnetic resonance image (dMRI) of 25 neonates, 13 toddlers, and 25 preadolescents were acquired to characterize network dynamics at these 3 landmark cross-sectional ages during early childhood. dMRI tractography was used to construct human brain structural networks, and the underlying topological properties were quantified by graph-theory approaches. Modular organization and small-world attributes are evident at birth with several important topological metrics increasing monotonically during development. Most significant increases of regional nodes occur in the posterior cingulate cortex, which plays a pivotal role in the functional default mode network. Positive correlations exist between nodal efficiencies and fractional anisotropy of the white matter traced from these nodes, while correlation slopes vary among the brain regions. These results reveal substantial topological reorganization of human brain structural networks through infancy and childhood, which is likely to be the outcome of both heterogeneous strengthening of the major white matter tracts and pruning of other axonal fibers. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Can fruits and vegetables be used as substitute phantoms for normal human brain tissues in magnetic resonance imaging?

    International Nuclear Information System (INIS)

    Teramoto, Daisuke; Ushioda, Yuichi; Sasaki, Ayaka; Sakurai Yuki; Nagahama, Hiroshi; Nakamura, Manami; Sugimori, Hiroyuki; Sakata, Motomichi

    2013-01-01

    Various custom-made phantoms designed to optimize magnetic resonance imaging (MRI) sequences have been created and subsequently reported in Japanese Society of Radiological Technology (JSRT). However, custom-made phantoms that correctly match the T 1 -value and T 2 -values of human brain tissue (gray matter and white matter) cannot be made easily or quickly. The aim of this project was to search for alternative materials, such as fruits and vegetables, for optimizing MRI sequences. The following eight fruits and vegetables were investigated: apple, tomato, melon, apple mango (Mangifera indica), banana, avocado, peach, and eggplant. Their potential was studied for use in modeling phantoms of normal human brain tissues. MRI (T 1 - and T 2 -weighted sequences) was performed on the human brain and the fruits and vegetables using various concentrations of contrast medium (gadolinium) in the same size tubes as the custom-made phantom. The authors compared the signal intensity (SI) in human brain tissue (gray matter and white matter) with that of the fruits and the custom-made phantom. The T 1 and T 2 values were measured for banana tissue and compared with those for human brain tissue in the literature. Our results indicated that banana tissue is similar to human brain tissue (both gray matter and white matter). Banana tissue can thus be employed as an alternative phantom for the human brain for the purpose of MRI. (author)

  1. Chediak-Higashi syndrome: brain MRI and MR spectroscopy manifestations

    International Nuclear Information System (INIS)

    Lolli, Valentina; Soto Ares, Gustavo; Pruvo, Jean-Pierre; Abou Chahla, Wadih; Jissendi-Tchofo, Patrice

    2015-01-01

    Chediak-Higashi syndrome is a rare inherited metabolic disorder characterized by partial oculocutaneous albinism, immunodeficiency, and neurological dysfunction. We present the brain magnetic resonance imaging (MRI) and MR spectroscopy (MRS) findings obtained during the accelerated phase of the disorder in an 8-year-old. The brain MRI manifestations at recurrences 15 months and 24 months later are reported as well. (orig.)

  2. Chediak-Higashi syndrome: brain MRI and MR spectroscopy manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Lolli, Valentina; Soto Ares, Gustavo; Pruvo, Jean-Pierre [Roger Salengro Hospital, CHRU, Neuroradiology Department, Lille (France); Abou Chahla, Wadih [Jeanne de Flandre Hospital, Pediatric Hematology and Oncology Department, Lille (France); Jissendi-Tchofo, Patrice [University Hospital Saint-Pierre, Radiology Department - Pediatric Neuroradiology Section, Brussels (Belgium)

    2015-08-15

    Chediak-Higashi syndrome is a rare inherited metabolic disorder characterized by partial oculocutaneous albinism, immunodeficiency, and neurological dysfunction. We present the brain magnetic resonance imaging (MRI) and MR spectroscopy (MRS) findings obtained during the accelerated phase of the disorder in an 8-year-old. The brain MRI manifestations at recurrences 15 months and 24 months later are reported as well. (orig.)

  3. Diffusion tractography of the subcortical auditory system in a postmortem human brain

    OpenAIRE

    Sitek, Kevin

    2017-01-01

    The subcortical auditory system is challenging to identify with standard human brain imaging techniques: MRI signal decreases toward the center of the brain as well as at higher resolution, both of which are necessary for imaging small brainstem auditory structures.Using high-resolution diffusion-weighted MRI, we asked:Can we identify auditory structures and connections in high-resolution ex vivo images?Which structures and connections can be mapped in vivo?

  4. MRI findings and diagnosis of brain echinococcus

    International Nuclear Information System (INIS)

    Miriguli Shayiti; Jia Wenxiao

    2010-01-01

    Objective: To study the characteristic findings of brain echinococcosis on MRI. Methods: The MRI findings of 18 patients with pathologically confirmed brain echinococcosis were retrospectively reviewed. Results: Among the patients, there were 9 cases of cystic echinococcosis and 9 cases of alveolar echinococcosis. In cystic echinococcosis, MRI revealed homogeneously hypointensity on T 1 WI and hyperintensity on T 2 WI, while it showed low signal intensity inside the cysts on FLAIR and DWI. In 6 cases of cystic echinococcosis, no edema was detected surrounding the lesions, while edema resulting from cyst rupture was found in 3 cases. The cystic walls were visible in 6 cases, obscure in 3 cases. The ruptured hydatid cysts in 3 cases showed slight ring enhancement. Alveolar echinococcosis appeared as multiple lesions with isointensity on T 1 WI and hypointensity on T 2 WI, surrounded by vasogenic edema. The 'charcoal-like' hypointensity and innumerous hyperintense bubbles of 1-10 mm in diameter inside the lesions on T 2 -weighted MR images were characteristic for lesions of alveolar echinococcosis. The lesions revealed hypointensity on DWI and showed irregular ring enhancement after injection of Gd-DTPA. Perfusion-weighted MR imaging revealed low relative cerebral blood volume. Conclusion: MRI can demonstrate lesions of brain echinococcosis accurately due to its advantages of multiorientation and multiparameter. It is clinically valuable. (authors)

  5. Fetal MRI of pathological brain development

    International Nuclear Information System (INIS)

    Brugger, P.C.; Prayer, D.

    2006-01-01

    Because of the superior tissue contrast, high spatial resolution, and multiplanar capabilities, fetal magnetic resonance imaging (MRI) can depict fetal brain pathologies with high accuracy. Pathological fetal brain development may result from malformations or acquired conditions. Differentiation of these etiologies is important with respect to managing the actual pregnancy or counseling future pregnancies. As a widened ventricular system is a common hallmark of both maldevelopment and acquired conditions, it may cause problems in the differential diagnosis. Fetal MRI can provide detailed morphological information, which allows refinement of the diagnosis of ventricular enlargement in a large number of cases. Systematic work-up of morphological details that may be recognized on MR images provides an approach for achieving a correct diagnosis in cases of ventricle enlargement. (orig.) [de

  6. Intrinsic functional brain architecture derived from graph theoretical analysis in the human fetus.

    Directory of Open Access Journals (Sweden)

    Moriah E Thomason

    Full Text Available The human brain undergoes dramatic maturational changes during late stages of fetal and early postnatal life. The importance of this period to the establishment of healthy neural connectivity is apparent in the high incidence of neural injury in preterm infants, in whom untimely exposure to ex-uterine factors interrupts neural connectivity. Though the relevance of this period to human neuroscience is apparent, little is known about functional neural networks in human fetal life. Here, we apply graph theoretical analysis to examine human fetal brain connectivity. Utilizing resting state functional magnetic resonance imaging (fMRI data from 33 healthy human fetuses, 19 to 39 weeks gestational age (GA, our analyses reveal that the human fetal brain has modular organization and modules overlap functional systems observed postnatally. Age-related differences between younger (GA <31 weeks and older (GA≥31 weeks fetuses demonstrate that brain modularity decreases, and connectivity of the posterior cingulate to other brain networks becomes more negative, with advancing GA. By mimicking functional principles observed postnatally, these results support early emerging capacity for information processing in the human fetal brain. Current technical limitations, as well as the potential for fetal fMRI to one day produce major discoveries about fetal origins or antecedents of neural injury or disease are discussed.

  7. MRI findings in primary brain lymphoma in immunocompetent patients

    Directory of Open Access Journals (Sweden)

    Saeed Nadhim Younis

    2017-08-01

    Full Text Available Background and objective: Primary brain lymphoma is an extranodal aggressive intracranial neoplasm of lymphocytic origin originating and confined to the brain parenchyma and meninges. It is rare in immune competent patients, but its incidence is increasing. This retrospective study was conducted to record the MRI features of primary brain lymphoma at the time of diagnosis in immunocompetent patients. Methods: Of the 450 patients diagnosed with the brain tumor during a period of five years from 2008 to 2013, the clinical features and MRI findings of 16 cases of pathologically proven to be non-Hodgkin’s lymphoma were studied. All the patients were tested negative for HIV and there was no history of immune suppression drugs or any other chronic illness. All the patients were examined with MRI observing the tumor location, multifocality, signal intensity in different sequences, enhancement patterns, peritumoral edema, the presence of hemorrhage and calcification. Results: Of the 16 patients, including the monofocal and multifocal cases, 30 lesions exhibited. The mean age at diagnosis was 53 years. Nine patients (56.25% found to have a multifocal disease. In more than 75% of lesions, MRI was hypo to iso signal on T1 and T2. Mild to moderate perilesional edema, strong contrast enhancement and restricted diffusion were seen in all cases. The hemorrhagic tumor was noticed in four lesions (13.3%. No calcification and no leptomeningeal lesions were noted. The MRI images in post steroid therapy were studied within one month of treatment. Tumour regression was noticed in 21/30 (70%, stable in 3/30 (10% and progressing in 6/30 (20%. Conclusion: MRI is a reliable imaging technique in the management of patients with primary brain lymphoma. Early accurate diagnosis is crucial to avoid the unnecessary operation and shift patients from extensive surgery to chemoradiotherapy.

  8. Measuring and manipulating brain connectivity with resting state functional connectivity magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS).

    Science.gov (United States)

    Fox, Michael D; Halko, Mark A; Eldaief, Mark C; Pascual-Leone, Alvaro

    2012-10-01

    Both resting state functional magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS) are increasingly popular techniques that can be used to non-invasively measure brain connectivity in human subjects. TMS shows additional promise as a method to manipulate brain connectivity. In this review we discuss how these two complimentary tools can be combined to optimally study brain connectivity and manipulate distributed brain networks. Important clinical applications include using resting state fcMRI to guide target selection for TMS and using TMS to modulate pathological network interactions identified with resting state fcMRI. The combination of TMS and resting state fcMRI has the potential to accelerate the translation of both techniques into the clinical realm and promises a new approach to the diagnosis and treatment of neurological and psychiatric diseases that demonstrate network pathology. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Whole brain functional connectivity in clinically isolated syndrome without conventional brain MRI lesions

    International Nuclear Information System (INIS)

    Liu, Yaou; Dai, Zhengjia; Duan, Yunyun; Huang, Jing; Ren, Zhuoqiong; Li, Kuncheng; Liu, Zheng; Dong, Huiqing; Shu, Ni; He, Yong; Vrenken, Hugo; Wattjes, Mike P.; Barkhof, Frederik

    2016-01-01

    To investigate brain functional connectivity (FC) alterations in patients with clinically isolated syndromes (CIS) presenting without conventional brain MRI lesions, and to identify the FC differences between the CIS patients who converted to multiple sclerosis (MS) and those not converted during a 5-year follow-up. We recruited 20 CIS patients without conventional brain lesions, 28 patients with MS and 28 healthy controls (HC). Normalized voxel-based functional connectivity strength (nFCS) was determined using resting-state fMRI (R-fMRI) and compared among groups. Furthermore, 5-years clinical follow-up of the CIS patients was performed to examine the differences in nFCS between converters and non-converters. Compared to HC, CIS patients showed significantly decreased nFCS in the visual areas and increased nFCS in several brain regions predominately in the temporal lobes. MS patients revealed more widespread higher nFCS especially in deep grey matter (DGM), compared to CIS and HC. In the four CIS patients converting to MS, significantly higher nFCS was found in right anterior cingulate gyrus (ACC) and fusiform gyrus (FG), compared to non-converted patients. We demonstrated both functional impairment and compensation in CIS by R-fMRI. nFCS alteration in ACC and FG seems to occur in CIS patients at risk of developing MS. (orig.)

  10. Human fMRI Reveals That Delayed Action Re-Recruits Visual Perception

    OpenAIRE

    Singhal, Anthony; Monaco, Simona; Kaufman, Liam D.; Culham, Jody C.

    2013-01-01

    Behavioral and neuropsychological research suggests that delayed actions rely on different neural substrates than immediate actions; however, the specific brain areas implicated in the two types of actions remain unknown. We used functional magnetic resonance imaging (fMRI) to measure human brain activation during delayed grasping and reaching. Specifically, we examined activation during visual stimulation and action execution separated by a 18-s delay interval in which subjects had to rememb...

  11. Can induced hypothermia be assured during brain MRI in neonates with hypoxic-ischemic encephalopathy?

    International Nuclear Information System (INIS)

    Wintermark, Pia; Labrecque, Michelle; Hansen, Anne; Warfield, Simon K.; DeHart, Stephanie

    2010-01-01

    Until now, brain MRIs in asphyxiated neonates who are receiving therapeutic hypothermia have been performed after treatment is complete. However, there is increasing interest in utilizing early brain MRI while hypothermia is still being provided to rapidly understand the degree of brain injury and possibly refine neuroprotective strategies. This study was designed to assess whether therapeutic hypothermia can be maintained while performing a brain MRI. Twenty MRI scans were obtained in 12 asphyxiated neonates while they were treated with hypothermia. The median difference between esophageal temperature on NICU departure and return was 0.1 C (range: -0.8 to 0.8 C). We found that therapeutic hypothermia can be safely and reproducibly maintained during a brain MRI. Hypothermia treatment should not prevent obtaining an early brain MRI if clinically indicated. (orig.)

  12. Can induced hypothermia be assured during brain MRI in neonates with hypoxic-ischemic encephalopathy?

    Energy Technology Data Exchange (ETDEWEB)

    Wintermark, Pia [Children' s Hospital Boston, Division of Newborn Medicine, Boston, MA (United States); Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); Montreal Children' s Hospital, Division of Newborn Medicine, Montreal, QC (Canada); Labrecque, Michelle; Hansen, Anne [Children' s Hospital Boston, Division of Newborn Medicine, Boston, MA (United States); Warfield, Simon K.; DeHart, Stephanie [Children' s Hospital Boston, Department of Radiology, Boston, MA (United States)

    2010-12-15

    Until now, brain MRIs in asphyxiated neonates who are receiving therapeutic hypothermia have been performed after treatment is complete. However, there is increasing interest in utilizing early brain MRI while hypothermia is still being provided to rapidly understand the degree of brain injury and possibly refine neuroprotective strategies. This study was designed to assess whether therapeutic hypothermia can be maintained while performing a brain MRI. Twenty MRI scans were obtained in 12 asphyxiated neonates while they were treated with hypothermia. The median difference between esophageal temperature on NICU departure and return was 0.1 C (range: -0.8 to 0.8 C). We found that therapeutic hypothermia can be safely and reproducibly maintained during a brain MRI. Hypothermia treatment should not prevent obtaining an early brain MRI if clinically indicated. (orig.)

  13. Extendable supervised dictionary learning for exploring diverse and concurrent brain activities in task-based fMRI.

    Science.gov (United States)

    Zhao, Shijie; Han, Junwei; Hu, Xintao; Jiang, Xi; Lv, Jinglei; Zhang, Tuo; Zhang, Shu; Guo, Lei; Liu, Tianming

    2018-06-01

    Recently, a growing body of studies have demonstrated the simultaneous existence of diverse brain activities, e.g., task-evoked dominant response activities, delayed response activities and intrinsic brain activities, under specific task conditions. However, current dominant task-based functional magnetic resonance imaging (tfMRI) analysis approach, i.e., the general linear model (GLM), might have difficulty in discovering those diverse and concurrent brain responses sufficiently. This subtraction-based model-driven approach focuses on the brain activities evoked directly from the task paradigm, thus likely overlooks other possible concurrent brain activities evoked during the information processing. To deal with this problem, in this paper, we propose a novel hybrid framework, called extendable supervised dictionary learning (E-SDL), to explore diverse and concurrent brain activities under task conditions. A critical difference between E-SDL framework and previous methods is that we systematically extend the basic task paradigm regressor into meaningful regressor groups to account for possible regressor variation during the information processing procedure in the brain. Applications of the proposed framework on five independent and publicly available tfMRI datasets from human connectome project (HCP) simultaneously revealed more meaningful group-wise consistent task-evoked networks and common intrinsic connectivity networks (ICNs). These results demonstrate the advantage of the proposed framework in identifying the diversity of concurrent brain activities in tfMRI datasets.

  14. Brain tumor segmentation using holistically nested neural networks in MRI images.

    Science.gov (United States)

    Zhuge, Ying; Krauze, Andra V; Ning, Holly; Cheng, Jason Y; Arora, Barbara C; Camphausen, Kevin; Miller, Robert W

    2017-10-01

    Gliomas are rapidly progressive, neurologically devastating, largely fatal brain tumors. Magnetic resonance imaging (MRI) is a widely used technique employed in the diagnosis and management of gliomas in clinical practice. MRI is also the standard imaging modality used to delineate the brain tumor target as part of treatment planning for the administration of radiation therapy. Despite more than 20 yr of research and development, computational brain tumor segmentation in MRI images remains a challenging task. We are presenting a novel method of automatic image segmentation based on holistically nested neural networks that could be employed for brain tumor segmentation of MRI images. Two preprocessing techniques were applied to MRI images. The N4ITK method was employed for correction of bias field distortion. A novel landmark-based intensity normalization method was developed so that tissue types have a similar intensity scale in images of different subjects for the same MRI protocol. The holistically nested neural networks (HNN), which extend from the convolutional neural networks (CNN) with a deep supervision through an additional weighted-fusion output layer, was trained to learn the multiscale and multilevel hierarchical appearance representation of the brain tumor in MRI images and was subsequently applied to produce a prediction map of the brain tumor on test images. Finally, the brain tumor was obtained through an optimum thresholding on the prediction map. The proposed method was evaluated on both the Multimodal Brain Tumor Image Segmentation (BRATS) Benchmark 2013 training datasets, and clinical data from our institute. A dice similarity coefficient (DSC) and sensitivity of 0.78 and 0.81 were achieved on 20 BRATS 2013 training datasets with high-grade gliomas (HGG), based on a two-fold cross-validation. The HNN model built on the BRATS 2013 training data was applied to ten clinical datasets with HGG from a locally developed database. DSC and sensitivity of

  15. Efficacy and toxicity in brain tumor treatment - quantitative Measurements using advanced MRI

    DEFF Research Database (Denmark)

    Ravn, Søren

    2016-01-01

    From the clinical introduction in the 1980s, MRI has grown to become an indispensable brain imaging modality, mainly due to its excellent ability to visualize soft tissues. Morphologically, T1- and T2-weighted brain tumor MRI have been part of routine diagnostic radiology for more than two decades...... with the introduction of magnets with higher field strength. Ongoing technical development has enabled a change from semiquantitative measurements to a true quantitative approach. This step is expected to have a great impact on the treatment of brain tumor patients in the future. The aim of this Ph.D. dissertation...... was to explore how different advanced MRI techniques could contribute to a higher degree of individualized treatment of brain tumor patients. The thesis is based on three studies in which advanced MRI is used to evaluate the possible role of fMRI in presurgical planning, Diffusion Tensor Imaging (DTI...

  16. Glucose Administration Enhances fMRI Brain Activation and Connectivity Related to Episodic Memory Encoding for Neutral and Emotional Stimuli

    Science.gov (United States)

    Parent, Marise B.; Krebs-Kraft, Desiree L.; Ryan, John P.; Wilson, Jennifer S.; Harenski, Carla; Hamann, Stephan

    2011-01-01

    Glucose enhances memory in a variety of species. In humans, glucose administration enhances episodic memory encoding, although little is known regarding the neural mechanisms underlying these effects. Here we examined whether elevating blood glucose would enhance functional MRI (fMRI) activation and connectivity in brain regions associated with…

  17. Intra-operative 3-T MRI for paediatric brain tumours: challenges and perspectives

    International Nuclear Information System (INIS)

    Abernethy, L.J.; Avula, S.; Hughes, G.M.; Wright, E.J.; Mallucci, C.L.

    2012-01-01

    MRI is the ideal modality for imaging intracranial tumours. Intraoperative MRI (ioMRI) makes it possible to obtain scans during a neurosurgical operation that can aid complete macroscopic tumour resection - a major prognostic factor in the majority of brain tumours in children. Intra-operative MRI can also help limit damage to normal brain tissue. It therefore has the potential to improve the survival of children with brain tumours and to minimise morbidity, including neurological deficits. The use of ioMRI is also likely to reduce the need for second look surgery, and may reduce the need for chemotherapy and radiotherapy. High-field MRI systems provide better anatomical information and also enable effective utilisation of advanced MRI techniques such as perfusion imaging, diffusion tensor imaging, and magnetic resonance spectroscopy. However, high-field ioMRI facilities require substantial capital investment, and careful planning is required for optimal benefit. Safe ioMRI requires meticulous attention to detail and rigorous application of magnetic field safety precautions. Interpretation of ioMRI can be challenging and requires experience and understanding of artefacts that are common in the intra-operative setting. (orig.)

  18. MRI abnormalities and related risk factors of the brain in patients with neuromyelitis optica

    International Nuclear Information System (INIS)

    Xiao Hui; Ma Lin; Lou Xin; Cai Youquan; Wang Yulin; Wang Yan; Wu Lei; Wu Weiping

    2011-01-01

    Objective: To investigate the MRI features of the brain in patients with neuromyelitis optica (NMO), and to evaluate the correlation between the brain abnormalities and related risk factors. Methods: Fifty-four patients with definite NMO according to 2006 Wingerchuk diagnosis criteria were enrolled in this study. MRI scanning of the brain was performed in these patients. Distribution and signal features of all the lesions were analyzed. A Logistic regression analysis was used to evaluate the risk factors of brain abnormalities. Results: Twenty-four NMO patients (44.4%) showed unremarkable findings and thirty (55.6%) showed abnormalities on brain MRI. Multiple and non-specific small lesions in the subcortical white matter and grey-white matter junction were the most frequent abnormalities on brain MRI (13/30, 43.3%). Typical lesion locations included corpus callosum, subependyma of ventricles, hypothalamus and brain stem. The lesions showed punctate, patchy and linear abnormal signals. Post-contrast MRI showed no abnormal enhancement in 16 cases. Logistic regression analysis showed that coexisting autoimmune disease or infection. history had correlations with abnormalities of the brain on MRI (OR=3.519, P<0.05). Conclusions: There was a high incidence of brain abnormalities in NMO. Subependymal white matter, corpus callosum, hypothalamus and brain stem were often involved in NMO. NMO patients with coexisting autoimmune disease and infection history had higher risk of brain abnormalities. (authors)

  19. Causal mapping of emotion networks in the human brain: Framework and initial findings.

    Science.gov (United States)

    Dubois, Julien; Oya, Hiroyuki; Tyszka, J Michael; Howard, Matthew; Eberhardt, Frederick; Adolphs, Ralph

    2017-11-13

    Emotions involve many cortical and subcortical regions, prominently including the amygdala. It remains unknown how these multiple network components interact, and it remains unknown how they cause the behavioral, autonomic, and experiential effects of emotions. Here we describe a framework for combining a novel technique, concurrent electrical stimulation with fMRI (es-fMRI), together with a novel analysis, inferring causal structure from fMRI data (causal discovery). We outline a research program for investigating human emotion with these new tools, and provide initial findings from two large resting-state datasets as well as case studies in neurosurgical patients with electrical stimulation of the amygdala. The overarching goal is to use causal discovery methods on fMRI data to infer causal graphical models of how brain regions interact, and then to further constrain these models with direct stimulation of specific brain regions and concurrent fMRI. We conclude by discussing limitations and future extensions. The approach could yield anatomical hypotheses about brain connectivity, motivate rational strategies for treating mood disorders with deep brain stimulation, and could be extended to animal studies that use combined optogenetic fMRI. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Imaging visual function of the human brain

    International Nuclear Information System (INIS)

    Marg, E.

    1988-01-01

    Imaging of human brain structure and activity with particular reference to visual function is reviewed along with methods of obtaining the data including computed tomographic (CT) scan, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET). The literature is reviewed and the potential for a new understanding of brain visual function is discussed. PET is reviewed from basic physical principles to the most recent visual brain findings with oxygen-15. It is shown that there is a potential for submillimeter localization of visual functions with sequentially different visual stimuli designed for the temporal separation of the responses. Single photon emission computed tomography (SPECT), a less expensive substitute for PET, is also discussed. MRS is covered from basic physical principles to the current state of the art of in vivo biochemical analysis. Future possible clinical applications are discussed. Improved understanding of the functional neural organization of vision and brain will open a window to maps and circuits of human brain function.119 references

  1. Quantitative Study of Longitudinal Relaxation (T 1) Contrast Mechanisms in Brain MRI

    Science.gov (United States)

    Jiang, Xu

    Longitudinal relaxation (T1) contrast in MRI is important for studying brain morphology and is widely used in clinical applications. Although MRI only detects signals from water hydrogen ( 1H) protons (WPs), T1 contrast is known to be influenced by other species of 1H protons, including those in macromolecules (MPs), such as lipids and proteins, through magnetization transfer (MT) between WPs and MPs. This complicates the use and quantification of T1 contrast for studying the underlying tissue composition and the physiology of the brain. MT contributes to T1 contrast to an extent that is generally dependent on MT kinetics, as well as the concentration and NMR spectral properties of MPs. However, the MP spectral properties and MT kinetics are both difficult to measure directly, as the signal from MPs is generally invisible to MRI. Therefore, to investigate MT kinetics and further quantify T1 contrast, we first developed a reliable way to indirectly measure the MP fraction and their exchange rate with WPs, with minimal dependence on the spectral properties of MPs. For this purpose, we used brief, highpower radiofrequency (RF) NMR excitation pulses to almost completely saturate the magnetization of MPs. Based on this, both MT kinetics and the contribution of MPs to T1 contrast through MT were studied. The thus obtained knowledge allowed us to subsequently infer the spectral properties of MPs by applying low-power, frequencyselective off-resonance RF pulses and measuring the offset-frequency dependent effect of MPs on the WP MRI signal. A two-pool exchange model was used in both cases to account for direct effects of the RF pulse on WP magnetization. Consistent with earlier works using MRI at low-field and post-mortem analysis of brain tissue, our novel measurement approach found that MPs constitute an up to 27% fraction of the total 1H protons in human brain white matter, and their spectrum follows a super-Lorentzian line with a T2 of 9.6+/-0.6 mus and a resonance

  2. Radiological study of the brain at various stages of human immunodeficiency virus infection: early development of brain atrophy

    International Nuclear Information System (INIS)

    Raininko, R.; Elovaara, I.; Virta, A.; Valanne, L.; Haltia, M.; Valle, S.L.

    1992-01-01

    One hundred and one persons infected with human immunodeficiency virus (HIV-1), in whom other central nervous system infections or diseases were excluded, underwent brain CT and/or MRI at various stages of HIV-1 infection: 29 were asymptomatic (ASX), 35 had lymphadenopathy syndrome (LAS), 17 had AIDS-related complex (ARC), and 20 had AIDS. A control group of 32 HIV-1-seronegative healthy persons underwent brain MRI. The most common finding was brain atrophy. The changes were bilateral and symmetrical, and they were more severe at later stages of infection. Non-specific small hyperintense foci were found on MRI in 13% of controls and 6-15% of the infected groups. Larger, diffuse, bilateral white matter infiltrates were detected in 4 demented patients with AIDS. Four patients with AIDS and 1 with LAS had focal hyperintense lesions in the internal capsules, lentiform nuclei or thalamus, often bilateral on MRI. One patient with AIDS examined with CT only, had low density in the lentiform nucleus. Loss of brain parenchyma can occur at an early stage of HIV-1 infection, and the atrophic process becomes more intense at later stages (ARC and AIDS). (orig./GDG)

  3. Wilson's disease: two treatment modalities. Correlations to pretreatment and posttreatment brain MRI

    International Nuclear Information System (INIS)

    Leiros da Costa, Maria do Desterro; Spitz, Mariana; Bacheschi, Luiz Alberto; Barbosa, Egberto Reis; Leite, Claudia Costa; Lucato, Leandro Tavares

    2009-01-01

    Brain magnetic resonance imaging (MRI) studies on Wilson's disease (WD) show lack of correlations between neurological and neuroimaging features. Long-term follow-up reports with sequential brain MRI in patients with neurological WD comparing different modalities of treatment are scarce. Eighteen patients with neurological WD underwent pretreatment and posttreatment brain MRI scans to evaluate the range of abnormalities and the evolution along these different periods. All patients underwent at least two MRI scans at different intervals, up to 11 years after the beginning of treatment. MRI findings were correlated with clinical picture, clinical severity, duration of neurological symptoms, and treatment with two different drugs. Patients were divided into two groups according to treatment: d-penicillamine (D-P), zinc (Zn), and Zn after the onset of severe intolerance to D-P. MRI scans before treatment showed, in all patients, hypersignal intensity lesions on T2- and proton-density-weighted images bilaterally and symmetrically at basal nuclei, thalamus, brain stem, cerebellum, brain cortex, and brain white matter. The most common neurological symptoms were: dysarthria, parkinsonism, dystonia, tremor, psychiatric disturbances, dysphagia, risus sardonicus, ataxia, chorea, and athetosis. From the neurological point of view, there was no difference on the evolution between the group treated exclusively with D-P and the one treated with Zn. Analysis of MRI scans with longer intervals after the beginning of treatment depicted a trend for neuroimaging worsening, without neurological correspondence, among patients treated with Zn. Neuroimaging pattern of evolution was more favorable for the group that received exclusively D-P. (orig.)

  4. In vitro MRI of brain development

    International Nuclear Information System (INIS)

    Rados, Marko; Judas, Milos; Kostovic, Ivica

    2006-01-01

    In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular zone. The basal ganglia showed an initial aggregation of cells. The most massive fiber system is in the hemispheric stalk, which is in continuity with thalamocortical fibers. During the mid-fetal period (15-22 postovulatory weeks), the typical fetal lamination pattern develops and the cerebral wall consists of the following zones: (a) a marginal zone (visible on MRI exclusively in the hippocampus); (b) the cortical plate with high cell-packing density and high MRI signal intensity; (c) the subplate zone, which is the most prominent zone rich in extracellular matrix and with a very low MRI signal intensity; (d) the intermediate zone (fetal 'white matter'); (e) the subventricular zone; (f) the periventricular fiber-rich zone; (g) the ventricular zone. The ganglionic eminence is still a very prominent structure with an intense proliferative activity. During the next period (22-26 postovulatory weeks), there is the developmental peak of transient MRI features, caused by the high content of hydrophyllic extracellular matrix in the subplate zone and the accumulation

  5. Comparison of two brain tumor-localizing MRI agent. GD-BOPTA and GD-DTPA. MRI and ICP study of rat brain tumor model

    International Nuclear Information System (INIS)

    Zhang, T.; Matsumura, A.; Yamamoto, T.; Yoshida, F.; Nose, T.

    2000-01-01

    In this study, we compared the behavior of Gd-BOPTA as a brain tumor selective contrast agent with Gd-DTPA in a common dose of 0.1 mmol/kg. We performed a MRI study using those two agent as contrast material, and we measured tissue Gd-concentrations by ICP-AES. As a result, Gd-BOPTA showed a better MRI enhancement in brain tumor. ICP showed significantly greater uptake of Gd-BOPTA in tumor samples, at all time course peaked at 5 minutes after administration, Gd being retained for a longer time in brain tumor till 2 hours, without rapid elimination as Gd-DTPA. We conclude that Gd-BOPTA is a new useful contrast material for MR imaging in brain tumor and an effective absorption agent for neutron capture therapy for further research. (author)

  6. Decerebrate posturing following traumatic brain injury: MRI findings and their diagnostic value

    International Nuclear Information System (INIS)

    Woischneck, D.; Skalej, M.; Firsching, R.; Kapapa, T.

    2015-01-01

    Aim: To determine the pathomorphological and clinical background to decerebrate posturing in humans following serious traumatic brain injury. Materials and methods: One hundred and twenty patients who had been unconscious for more than 24 h underwent diagnostic MRI within 8 days after trauma. The presence of decerebrate rigidity as the clinical parameter was correlated to MRI findings, such as traumatic lesions in defined brain areas. Significance was presumed as p < 0.05. Results: On the day of MRI 43 (36%) patients exhibited decerebrate posturing: 19 (23%) cases were unilateral and 24 (77%) bilateral. There was a significant correlation between midbrain lesions and the presence of rigidity. If a midbrain lesion was found in the absence of pontine lesions, decerebrate rigidity could be concluded (p < 0.05). There was no significant correlation to the rigidity in the case of midbrain lesions accompanied by pontine lesions, and no correlation to the rigidity could be detected for other regions of the brain. Both the occurrence of decerebrate posturing and the detection of brainstem lesions at MRI correlated with the Glasgow Outcome Scale. The combination of both parameters improved the probability of predicting the outcome. Conclusion: The rate of decerebrate posturing increases significantly in the presence of midbrain lesions. The presence of pontine lesions appears to be of secondary importance. The chances of predicting the Glasgow Outcome Scale are improved by the combination of clinical information (decerebrate posturing) and radiological parameters (type of brainstem lesion). - Highlights: • The pathomorphology of decerebrate posturing after TBI is not known for certain. • Midbrain lesions on MRI were correlated significantly to decerebrate posturing. • A combination of decerebrate posturing and brainstem lesions predict poor outcome

  7. Preliminary evaluation of a brain PET insertable to MRI

    International Nuclear Information System (INIS)

    Cho, Gyuseng; Choi, Yong; Lee, Jae Sung; An, Hyun Joon; Jung, Jin Ho; Park, Hyun Wook; Oh, Chang Hyun; Park, Kyeongjin; Lim, Kyung Taek; Cho, Minsik; Sul, Woo Suk; Kim, Hyoungtaek; Kim, Hyunduk

    2014-01-01

    There is a new trend of the medical image that diagnoses a brain disease as like Alzheimer dementia. The first qualified candidate is a PET-MRI fusion modality because MRI is a more powerful anatomic diagnosis tool than other modalities. In our study, in order to solve the high magnetic field from MRI, the development was consisted with four main items such as photo-sensor, PET scanner, MRI head-coil and attenuation correction algorithm development.

  8. Preliminary evaluation of a brain PET insertable to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyuseng [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 South (Korea, Republic of); Choi, Yong [Department of Electronic Engineering, Sogang University, Seoul, 121-742 South (Korea, Republic of); Lee, Jae Sung; An, Hyun Joon [Department of Nuclear Medicine, Seoul National University, Seoul, 110-744 South (Korea, Republic of); Jung, Jin Ho [Department of Electronic Engineering, Sogang University, Seoul, 121-742 South (Korea, Republic of); Park, Hyun Wook; Oh, Chang Hyun; Park, Kyeongjin; Lim, Kyung Taek; Cho, Minsik [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 South (Korea, Republic of); Sul, Woo Suk [National NanoFab Center, Deajeon, 305-806 South (Korea, Republic of); Kim, Hyoungtaek; Kim, Hyunduk [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 South (Korea, Republic of)

    2014-07-29

    There is a new trend of the medical image that diagnoses a brain disease as like Alzheimer dementia. The first qualified candidate is a PET-MRI fusion modality because MRI is a more powerful anatomic diagnosis tool than other modalities. In our study, in order to solve the high magnetic field from MRI, the development was consisted with four main items such as photo-sensor, PET scanner, MRI head-coil and attenuation correction algorithm development.

  9. Seizure-induced brain lesions: A wide spectrum of variably reversible MRI abnormalities

    International Nuclear Information System (INIS)

    Cianfoni, A.; Caulo, M.; Cerase, A.; Della Marca, G.; Falcone, C.; Di Lella, G.M.; Gaudino, S.; Edwards, J.; Colosimo, C.

    2013-01-01

    Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention

  10. Seizure-induced brain lesions: A wide spectrum of variably reversible MRI abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Cianfoni, A., E-mail: acianfoni@hotmail.com [Neuroradiology, Neurocenter of Italian Switzerland–Ospedale regionale Lugano, Via Tesserete 46, Lugano, 6900, CH (Switzerland); Caulo, M., E-mail: caulo@unich.it [Department of Neuroscience and Imaging, University of Chieti, Via dei Vestini 33, 6610 Chieti. Italy (Italy); Cerase, A., E-mail: alfonsocerase@gmail.com [Unit of Neuroimaging and Neurointervention NINT, Department of Neurological and Sensorineural Sciences, Azienda Ospedaliera Universitaria Senese, Policlinico “Santa Maria alle Scotte”, V.le Bracci 16, Siena (Italy); Della Marca, G., E-mail: dellamarca@rm.unicatt.it [Neurology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Falcone, C., E-mail: carlo_falc@libero.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Di Lella, G.M., E-mail: gdilella@rm.unicatt.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Gaudino, S., E-mail: sgaudino@sirm.org [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Edwards, J., E-mail: edwardjc@musc.edu [Neuroscience Dept., Medical University of South Carolina, 96J Lucas st, 29425, Charleston, SC (United States); Colosimo, C., E-mail: colosimo@rm.unicatt.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy)

    2013-11-01

    Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention.

  11. Unmasking Language Lateralization in Human Brain Intrinsic Activity

    Science.gov (United States)

    McAvoy, Mark; Mitra, Anish; Coalson, Rebecca S.; d'Avossa, Giovanni; Keidel, James L.; Petersen, Steven E.; Raichle, Marcus E.

    2016-01-01

    Lateralization of function is a fundamental feature of the human brain as exemplified by the left hemisphere dominance of language. Despite the prominence of lateralization in the lesion, split-brain and task-based fMRI literature, surprisingly little asymmetry has been revealed in the increasingly popular functional imaging studies of spontaneous fluctuations in the fMRI BOLD signal (so-called resting-state fMRI). Here, we show the global signal, an often discarded component of the BOLD signal in resting-state studies, reveals a leftward asymmetry that maps onto regions preferential for semantic processing in left frontal and temporal cortex and the right cerebellum and a rightward asymmetry that maps onto putative attention-related regions in right frontal, temporoparietal, and parietal cortex. Hemispheric asymmetries in the global signal resulted from amplitude modulation of the spontaneous fluctuations. To confirm these findings obtained from normal, healthy, right-handed subjects in the resting-state, we had them perform 2 semantic processing tasks: synonym and numerical magnitude judgment and sentence comprehension. In addition to establishing a new technique for studying lateralization through functional imaging of the resting-state, our findings shed new light on the physiology of the global brain signal. PMID:25636911

  12. Anisotropic Diffusion based Brain MRI Segmentation and 3D Reconstruction

    Directory of Open Access Journals (Sweden)

    M. Arfan Jaffar

    2012-06-01

    Full Text Available In medical field visualization of the organs is very imperative for accurate diagnosis and treatment of any disease. Brain tumor diagnosis and surgery also required impressive 3D visualization of the brain to the radiologist. Detection and 3D reconstruction of brain tumors from MRI is a computationally time consuming and error-prone task. Proposed system detects and presents a 3D visualization model of the brain and tumor inside which greatly helps the radiologist to effectively diagnose and analyze the brain tumor. We proposed a multi-phase segmentation and visualization technique which overcomes the many problems of 3D volume segmentation methods like lake of fine details. In this system segmentation is done in three different phases which reduces the error chances. The system finds contours for skull, brain and tumor. These contours are stacked over and two novel methods are used to find the 3D visualization models. The results of these techniques, particularly of interpolation based, are impressive. Proposed system is tested against publically available data set [41] and MRI datasets available from MRI aamp; CT center Rawalpindi, Pakistan [42].

  13. Diagnostic value of low-field MRI for acute poisoning brain injury

    International Nuclear Information System (INIS)

    Dang Lianrong; He Qinyi

    2012-01-01

    Objective: To investigate the value of low-field MIR in diagnosis of acute CO poisoning brain injury. Methods: The brain MIR and clinical data of 110 patients with acute CO poisoning brain injury confirmed by clinical examination were retrospectively analyzed. Results: Long T1 and T2 signal intensity was showed on MRI in cerebral hemispheres and globus pallidus symmetrically. There were three basic types of MIR manifestations, white matter of brain type, globus pallidus type and brain mixed type. Conclusions: MRI could be used for confirming the degree and range of acute CO poisoning brain injury. It has important clinical value in the diagnosis, staging and prognosis of patients with acute CO poisoning brain injury. (authors)

  14. Progesterone mediates brain functional connectivity changes during the menstrual cycle - A pilot resting state MRI study

    Directory of Open Access Journals (Sweden)

    Katrin eArelin

    2015-02-01

    Full Text Available The growing interest in intrinsic brain organization has sparked various innovative approaches to generating comprehensive connectivity-based maps of the human brain. Prior reports point to a sexual dimorphism of the structural and functional human connectome. However, it is uncertain whether subtle changes in sex hormones, as occur during the monthly menstrual cycle, substantially impact the functional architecture of the female brain. Here, we performed eigenvector centrality (EC mapping in 32 longitudinal resting state fMRI scans of a single healthy subject without oral contraceptive use, across four menstrual cycles, and assessed estrogen and progesterone levels. To investigate associations between cycle-dependent hormones and brain connectivity, we performed correlation analyses between the EC maps and the respective hormone levels. On the whole brain level, we found a significant positive correlation between progesterone and EC in the bilateral DLPFC and bilateral sensorimotor cortex. In a secondary region-of-interest analysis, we detected a progesterone-modulated increase in functional connectivity of both bilateral DLPFC and bilateral sensorimotor cortex with the hippocampus. Our results suggest that the menstrual cycle substantially impacts intrinsic functional connectivity, particularly in brain areas associated with contextual memory-regulation, such as the hippocampus. These findings are the first to link the subtle hormonal fluctuations that occur during the menstrual cycle, to significant changes in regional functional connectivity in the hippocampus in a longitudinal design, given the limitation of data acquisition in a single subject. Our study demonstrates the feasibility of such a longitudinal rs-fMRI design and illustrates a means of creating a personalized map of the human brain by integrating potential mediators of brain states, such as menstrual cycle phase.

  15. Combined MRI and MRS improves pre-therapeutic diagnoses of pediatric brain tumors over MRI alone

    Energy Technology Data Exchange (ETDEWEB)

    Shiroishi, Mark S.; Nelson, Marvin D. [Children' s Hospital Los Angeles/Keck School of Medicine of USC, Department of Radiology, Los Angeles, CA (United States); Panigrahy, Ashok [Children' s Hospital Los Angeles/Keck School of Medicine of USC, Department of Radiology, Los Angeles, CA (United States); Children' s Hospital of Pittsburgh of University of Pittsburgh Medical Center, Department of Pediatric Radiology, Pittsburgh, PA (United States); Moore, Kevin R. [Primary Children' s Medical Center, Department of Radiology, Salt Lake City, UT (United States); Gilles, Floyd H. [Children' s Hospital Los Angeles/Keck School of Medicine of USC, Department of Pathology, Los Angeles, CA (United States); Gonzalez-Gomez, Ignacio [All Children' s Hospital, Department of Pathology, St. Petersburg, FL (United States); Blueml, Stefan [Children' s Hospital Los Angeles/Keck School of Medicine of USC, Department of Radiology, Los Angeles, CA (United States); Rudi Schulte Research Institute, Santa Barbara, CA (United States)

    2015-09-15

    The specific goal of this study was to determine whether the inclusion of MRS had a measureable and positive impact on the accuracy of pre-surgical MR examinations of untreated pediatric brain tumors over that of MRI alone in clinical practice. Final imaging reports of 120 pediatric patients with newly detected brain tumors who underwent combined MRI/MRS examinations were retrospectively reviewed. Final pathology was available in all cases. Group A comprised 60 subjects studied between June 2001 and January 2005, when MRS was considered exploratory and radiologists utilized only conventional MRI to arrive at a diagnosis. For group B, comprising 60 subjects studied between January 2005 and March 2008, the radiologists utilized information from both MRI and MRS. Furthermore, radiologists revisited group A (blind review, time lapse >4 years) to determine whether the additional information from MRS would have altered their interpretation. Sixty-three percent of patients in group A were diagnosed correctly, whereas in 10 % the report was partially correct with the final tumor type mentioned (but not mentioned as most likely tumor), while in 27 % of cases the reports were wrong. For group B, the diagnoses were correct in 87 %, partially correct in 5 %, and incorrect in 8 % of the cases, which is a significant improvement (p < 0.005). Re-review of combined MRI and MRS of group A resulted 87 % correct, 7 % partially correct, and 7 % incorrect diagnoses, which is a significant improvement over the original diagnoses (p < 0.05). Adding MRS to conventional MRI significantly improved diagnostic accuracy in preoperative pediatric patients with untreated brain tumors. (orig.)

  16. Combined MRI and MRS improves pre-therapeutic diagnoses of pediatric brain tumors over MRI alone

    International Nuclear Information System (INIS)

    Shiroishi, Mark S.; Nelson, Marvin D.; Panigrahy, Ashok; Moore, Kevin R.; Gilles, Floyd H.; Gonzalez-Gomez, Ignacio; Blueml, Stefan

    2015-01-01

    The specific goal of this study was to determine whether the inclusion of MRS had a measureable and positive impact on the accuracy of pre-surgical MR examinations of untreated pediatric brain tumors over that of MRI alone in clinical practice. Final imaging reports of 120 pediatric patients with newly detected brain tumors who underwent combined MRI/MRS examinations were retrospectively reviewed. Final pathology was available in all cases. Group A comprised 60 subjects studied between June 2001 and January 2005, when MRS was considered exploratory and radiologists utilized only conventional MRI to arrive at a diagnosis. For group B, comprising 60 subjects studied between January 2005 and March 2008, the radiologists utilized information from both MRI and MRS. Furthermore, radiologists revisited group A (blind review, time lapse >4 years) to determine whether the additional information from MRS would have altered their interpretation. Sixty-three percent of patients in group A were diagnosed correctly, whereas in 10 % the report was partially correct with the final tumor type mentioned (but not mentioned as most likely tumor), while in 27 % of cases the reports were wrong. For group B, the diagnoses were correct in 87 %, partially correct in 5 %, and incorrect in 8 % of the cases, which is a significant improvement (p < 0.005). Re-review of combined MRI and MRS of group A resulted 87 % correct, 7 % partially correct, and 7 % incorrect diagnoses, which is a significant improvement over the original diagnoses (p < 0.05). Adding MRS to conventional MRI significantly improved diagnostic accuracy in preoperative pediatric patients with untreated brain tumors. (orig.)

  17. Functional MRI brain imaging studies using the Contact Heat Evoked Potential Stimulator (CHEPS in a human volunteer topical capsaicin pain model

    Directory of Open Access Journals (Sweden)

    Shenoy R

    2011-10-01

    Full Text Available Ravikiran Shenoy1, Katherine Roberts1, Anastasia Papadaki2, Donald McRobbie2, Maarten Timmers3, Theo Meert3, Praveen Anand11Peripheral Neuropathy Unit, Hammersmith Hospital, Imperial College London; 2Imaging Sciences Department, Charing Cross Hospital, London, United Kingdom; 3Johnson and Johnson Pharmaceutical Research and Development, Beerse, BelgiumAbstract: Acute application of topical capsaicin produces spontaneous burning and stinging pain similar to that seen in some neuropathic states, with local hyperalgesia. Use of capsaicin applied topically or injected intradermally has been described as a model for neuropathic pain, with patterns of activation in brain regions assessed using functional magnetic resonance imaging (fMRI and positron emission tomography. The Contact Heat Evoked Potential Stimulator (CHEPS is a noninvasive clinically practical method of stimulating cutaneous A-delta nociceptors. In this study, topical capsaicin (1% was applied to the left volar forearm for 15 minutes of twelve adult healthy human volunteers. fMRI scans and a visual analog pain score were recorded during CHEPS stimulation precapsaicin and postcapsaicin application. Following capsaicin application there was a significant increase in visual analog scale (mean ± standard error of the mean; precapsaicin 26.4 ± 5.3; postcapsaicin 48.9 ± 6.0; P < 0.0001. fMRI demonstrated an overall increase in areas of activation, with a significant increase in the contralateral insular signal (mean ± standard error of the mean; precapsaicin 0.434 ± 0.03; postcapsaicin 0.561 ± 0.07; P = 0.047. The authors of this paper recently published a study in which CHEPS-evoked A-delta cerebral potential amplitudes were found to be decreased postcapsaicin application. In patients with neuropathic pain, evoked pain and fMRI brain responses are typically increased, while A-delta evoked potential amplitudes are decreased. The protocol of recording fMRI following CHEPS stimulation

  18. Graph theoretical analysis and application of fMRI-based brain network in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    LIU Xue-na

    2012-08-01

    Full Text Available Alzheimer's disease (AD, a progressive neurodegenerative disease, is clinically characterized by impaired memory and many other cognitive functions. However, the pathophysiological mechanisms underlying the disease are not thoroughly understood. In recent years, using functional magnetic resonance imaging (fMRI as well as advanced graph theory based network analysis approach, several studies of patients with AD suggested abnormal topological organization in both global and regional properties of functional brain networks, specifically, as demonstrated by a loss of small-world network characteristics. These studies provide novel insights into the pathophysiological mechanisms of AD and could be helpful in developing imaging biomarkers for disease diagnosis. In this paper we introduce the essential concepts of complex brain networks theory, and review recent advances of the study on human functional brain networks in AD, especially focusing on the graph theoretical analysis of small-world network based on fMRI. We also propound the existent problems and research orientation.

  19. Isointense infant brain MRI segmentation with a dilated convolutional neural network

    OpenAIRE

    Moeskops, Pim; Pluim, Josien P. W.

    2017-01-01

    Quantitative analysis of brain MRI at the age of 6 months is difficult because of the limited contrast between white matter and gray matter. In this study, we use a dilated triplanar convolutional neural network in combination with a non-dilated 3D convolutional neural network for the segmentation of white matter, gray matter and cerebrospinal fluid in infant brain MR images, as provided by the MICCAI grand challenge on 6-month infant brain MRI segmentation.

  20. A population MRI brain template and analysis tools for the macaque.

    Science.gov (United States)

    Seidlitz, Jakob; Sponheim, Caleb; Glen, Daniel; Ye, Frank Q; Saleem, Kadharbatcha S; Leopold, David A; Ungerleider, Leslie; Messinger, Adam

    2018-04-15

    The use of standard anatomical templates is common in human neuroimaging, as it facilitates data analysis and comparison across subjects and studies. For non-human primates, previous in vivo templates have lacked sufficient contrast to reliably validate known anatomical brain regions and have not provided tools for automated single-subject processing. Here we present the "National Institute of Mental Health Macaque Template", or NMT for short. The NMT is a high-resolution in vivo MRI template of the average macaque brain generated from 31 subjects, as well as a neuroimaging tool for improved data analysis and visualization. From the NMT volume, we generated maps of tissue segmentation and cortical thickness. Surface reconstructions and transformations to previously published digital brain atlases are also provided. We further provide an analysis pipeline using the NMT that automates and standardizes the time-consuming processes of brain extraction, tissue segmentation, and morphometric feature estimation for anatomical scans of individual subjects. The NMT and associated tools thus provide a common platform for precise single-subject data analysis and for characterizations of neuroimaging results across subjects and studies. Copyright © 2017 ElsevierCompany. All rights reserved.

  1. Emerging role of functional brain MRI in low-grade glioma surgery

    DEFF Research Database (Denmark)

    Friismose, Ancuta; Traise, Peter; Markovic, Ljubo

    Learning objectives 1. To describe the use of functional MRI (fMRI) in cranial surgery planning for patients with low-grade gliomas (LGG). 2. To show the increasing importance of fMRI in the clinical setting. Background LGG include brain tumors classified by the World Health Organization as grade I...... be used to map eloquent cortex areas, thus minimizing postoperative deficits and improving surgical performance. Findings and procedure details Patients diagnosed with low-grade gliomas located in eloquent brain areas undergo fMRI prior to surgery. The exams are performed on a 3T MR system (Achieva TX....... Language comprehension and visual tasks can be added to visualize Wernicke’s area or the visual cortex. Diffusion tensor imaging (DTI) is used to map nerve tract course relative to the tumour. Conclusion FMRI has proven its clinical utility in locating eloquent brain areas with relation to tumor site...

  2. Automated selection of brain regions for real-time fMRI brain-computer interfaces

    Science.gov (United States)

    Lührs, Michael; Sorger, Bettina; Goebel, Rainer; Esposito, Fabrizio

    2017-02-01

    Objective. Brain-computer interfaces (BCIs) implemented with real-time functional magnetic resonance imaging (rt-fMRI) use fMRI time-courses from predefined regions of interest (ROIs). To reach best performances, localizer experiments and on-site expert supervision are required for ROI definition. To automate this step, we developed two unsupervised computational techniques based on the general linear model (GLM) and independent component analysis (ICA) of rt-fMRI data, and compared their performances on a communication BCI. Approach. 3 T fMRI data of six volunteers were re-analyzed in simulated real-time. During a localizer run, participants performed three mental tasks following visual cues. During two communication runs, a letter-spelling display guided the subjects to freely encode letters by performing one of the mental tasks with a specific timing. GLM- and ICA-based procedures were used to decode each letter, respectively using compact ROIs and whole-brain distributed spatio-temporal patterns of fMRI activity, automatically defined from subject-specific or group-level maps. Main results. Letter-decoding performances were comparable to supervised methods. In combination with a similarity-based criterion, GLM- and ICA-based approaches successfully decoded more than 80% (average) of the letters. Subject-specific maps yielded optimal performances. Significance. Automated solutions for ROI selection may help accelerating the translation of rt-fMRI BCIs from research to clinical applications.

  3. 99mTc-HMPAO Brain SPECT in Seizure Disorder: Comparison Brain SPECT, MRI / CT and EEG

    International Nuclear Information System (INIS)

    Yang, Hyung In; Im, Ju Hyuk; Choi, Chang Woon; Lee, Dong Soo; Chung, June Key; No, Jae Kyu; Lee, Myung Chul; Koh, Chang Soon

    1994-01-01

    We studied 115 patients with seizure who had been performed brain SPECT brain MRI of CT and EEG. To evaluate the pattern of brain SPECT in seizure patients 28 of them had secondary epilepsies, 87 had primary epilepsies. In primary epilepsies, 42 were generalized seizure and 45 were partial seizure. The causes of secondary epilepsies were congenital malformation, cerebromalacia, cerebral infarction ultiple sclerosis, AV-malformation. granuloma and etc, in order. In 28 secondary epilepsies, 25 of them, brain SPECT lesions was concordant with MRI or CT lesions. 3 were disconcordant. The brain SPECT findings of generalized seizure were normal in 22 patients, diffuse irregular decreased perfusion in 8, decreased in frontal cortex in 4. temporal in 5 and frontotemporal in 3. In 45 partial seizure, 19 brain SPECT were concordant with EEG (42.4%).

  4. Automated processing pipeline for neonatal diffusion MRI in the developing Human Connectome Project.

    Science.gov (United States)

    Bastiani, Matteo; Andersson, Jesper L R; Cordero-Grande, Lucilio; Murgasova, Maria; Hutter, Jana; Price, Anthony N; Makropoulos, Antonios; Fitzgibbon, Sean P; Hughes, Emer; Rueckert, Daniel; Victor, Suresh; Rutherford, Mary; Edwards, A David; Smith, Stephen M; Tournier, Jacques-Donald; Hajnal, Joseph V; Jbabdi, Saad; Sotiropoulos, Stamatios N

    2018-05-28

    The developing Human Connectome Project is set to create and make available to the scientific community a 4-dimensional map of functional and structural cerebral connectivity from 20 to 44 weeks post-menstrual age, to allow exploration of the genetic and environmental influences on brain development, and the relation between connectivity and neurocognitive function. A large set of multi-modal MRI data from fetuses and newborn infants is currently being acquired, along with genetic, clinical and developmental information. In this overview, we describe the neonatal diffusion MRI (dMRI) image processing pipeline and the structural connectivity aspect of the project. Neonatal dMRI data poses specific challenges, and standard analysis techniques used for adult data are not directly applicable. We have developed a processing pipeline that deals directly with neonatal-specific issues, such as severe motion and motion-related artefacts, small brain sizes, high brain water content and reduced anisotropy. This pipeline allows automated analysis of in-vivo dMRI data, probes tissue microstructure, reconstructs a number of major white matter tracts, and includes an automated quality control framework that identifies processing issues or inconsistencies. We here describe the pipeline and present an exemplar analysis of data from 140 infants imaged at 38-44 weeks post-menstrual age. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Fast periodic stimulation (FPS): a highly effective approach in fMRI brain mapping.

    Science.gov (United States)

    Gao, Xiaoqing; Gentile, Francesco; Rossion, Bruno

    2018-03-03

    Defining the neural basis of perceptual categorization in a rapidly changing natural environment with low-temporal resolution methods such as functional magnetic resonance imaging (fMRI) is challenging. Here, we present a novel fast periodic stimulation (FPS)-fMRI approach to define face-selective brain regions with natural images. Human observers are presented with a dynamic stream of widely variable natural object images alternating at a fast rate (6 images/s). Every 9 s, a short burst of variable face images contrasting with object images in pairs induces an objective face-selective neural response at 0.111 Hz. A model-free Fourier analysis achieves a twofold increase in signal-to-noise ratio compared to a conventional block-design approach with identical stimuli and scanning duration, allowing to derive a comprehensive map of face-selective areas in the ventral occipito-temporal cortex, including the anterior temporal lobe (ATL), in all individual brains. Critically, periodicity of the desired category contrast and random variability among widely diverse images effectively eliminates the contribution of low-level visual cues, and lead to the highest values (80-90%) of test-retest reliability in the spatial activation map yet reported in imaging higher level visual functions. FPS-fMRI opens a new avenue for understanding brain function with low-temporal resolution methods.

  6. MRI Brain Tumor Segmentation Methods- A Review

    OpenAIRE

    Gursangeet, Kaur; Jyoti, Rani

    2016-01-01

    Medical image processing and its segmentation is an active and interesting area for researchers. It has reached at the tremendous place in diagnosing tumors after the discovery of CT and MRI. MRI is an useful tool to detect the brain tumor and segmentation is performed to carry out the useful portion from an image. The purpose of this paper is to provide an overview of different image segmentation methods like watershed algorithm, morphological operations, neutrosophic sets, thresholding, K-...

  7. Different brain activation under left and right ventricular stimulation: an fMRI study in anesthetized rats.

    Science.gov (United States)

    Suzuki, Hideaki; Sumiyoshi, Akira; Kawashima, Ryuta; Shimokawa, Hiroaki

    2013-01-01

    Myocardial ischemia in the anterior wall of the left ventricule (LV) and in the inferior wall and/or right ventricle (RV) shows different manifestations that can be explained by the different innervations of cardiac afferent nerves. However, it remains unclear whether information from different areas of the heart, such as the LV and RV, are differently processed in the brain. In this study, we investigated the brain regions that process information from the LV or RV using cardiac electrical stimulation and functional magnetic resonance imaging (fMRI) in anesthetized rats because the combination of these two approaches cannot be used in humans. An electrical stimulation catheter was inserted into the LV or RV (n = 12 each). Brain fMRI scans were recorded during LV or RV stimulation (9 Hz and 0.3 ms width) over 10 blocks consisting of alternating periods of 2 mA for 30 sec followed by 0.2 mA for 60 sec. The validity of fMRI signals was confirmed by first and second-level analyses and temporal profiles. Increases in fMRI signals were observed in the anterior cingulate cortex and the right somatosensory cortex under LV stimulation. In contrast, RV stimulation activated the right somatosensory cortex, which was identified more anteriorly compared with LV stimulation but did not activate the anterior cingulate cortex. This study provides the first evidence for differences in brain activation under LV and RV stimulation. These different brain processes may be associated with different clinical manifestations between anterior wall and inferoposterior wall and/or RV myocardial ischemia.

  8. A case of brain SLE: MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Soon; Kim, Seung Min [Wonju College of Medicine, Yonsei University, Wonju (Korea, Republic of)

    1992-01-15

    Systemic lupus erythematosus(SLE) is an autoimmune disease characterized by multisystem involvement including central nervous system and various neurologic symptoms. The authors experienced a case of brain SLE and report MRI and other neuroimaging findings.

  9. Gender similarities and differences in brain activation strategies: Voxel-based meta-analysis on fMRI studies.

    Science.gov (United States)

    AlRyalat, Saif Aldeen

    2017-01-01

    Gender similarities and differences have long been a matter of debate in almost all human research, especially upon reaching the discussion about brain functions. This large scale meta-analysis was performed on functional MRI studies. It included more than 700 active brain foci from more than 70 different experiments to study gender related similarities and differences in brain activation strategies for three of the main brain functions: Visual-spatial cognition, memory, and emotion. Areas that are significantly activated by both genders (i.e. core areas) for the tested brain function are mentioned, whereas those areas significantly activated exclusively in one gender are the gender specific areas. During visual-spatial cognition task, and in addition to the core areas, males significantly activated their left superior frontal gyrus, compared with left superior parietal lobule in females. For memory tasks, several different brain areas activated by each gender, but females significantly activated two areas from the limbic system during memory retrieval tasks. For emotional task, males tend to recruit their bilateral prefrontal regions, whereas females tend to recruit their bilateral amygdalae. This meta-analysis provides an overview based on functional MRI studies on how males and females use their brain.

  10. 123I-iomazenil brain receptor SPECT in focal epilepsy. In comparison with 99mTc-HMPAO brain SPECT, MRI and Video/EEG monitoring

    International Nuclear Information System (INIS)

    Xu Hao; Wang Tongge; Huang Li; Michael Cordes

    1998-01-01

    Purpose: To evaluate the clinical value of 123 I-Iomazenil brain receptor SPECT in diagnosis of focal epilepsy in comparison with 99m Tc-HMPAO brain SPECT, MRI and Video/EEG monitoring. Methods 123 I-Iomazenil brain receptor SPECT was performed on 40 patients with focal epilepsy. The results were compared with those obtained by 99m Tc-HMPAO brain SPECT, MRI and Video/EEG monitoring. Results: In 40 patients, the sensitivity of Video/EEG monitoring for localization of epileptogenic area was 95% (38/40). The sensitivity of 123 I-iomazenil brain receptor SPECT, 99m Tc-HMPAO brain SPECT and MRI for localization of epileptogenic area compared with Video/EEG monitoring ('gold standard') was 65.8%(25/38), 55.3%(21/38) and 47.4%(18/38), respectively. The localization of epileptogenic area with 123 I-Iomazenil brain receptor SPECT was in concordance with Video/EEG monitoring in 20 patients, 99m Tc-HMPAO brain SPECT in 15 patients and MRI in 16 patients, respectively. The sensitivity of 123 I-Iomazenil brain receptor SPECT combined with MRI for localization of epileptogenic area was 84.2%(32/38). Conclusions: 123 I-Iomazenil brain receptor SPECT is a useful method in detecting and localizing epileptogenic area. The combination of 123 I-Iomazenil brain receptor SPECT and MRI has a high sensitivity for detecting epileptogenic area

  11. MRI of Mouse Models for Gliomas Shows Similarities to Humans and Can Be Used to Identify Mice for Preclinical Trials

    Directory of Open Access Journals (Sweden)

    Jason A. Koutcher

    2002-01-01

    Full Text Available Magnetic resonance imaging (MRI has been utilized for screening and detecting brain tumors in mice based upon their imaging characteristics appearance and their pattern of enhancement. Imaging of these tumors reveals many similarities to those observed in humans with identical pathology. Specifically, high-grade murine gliomas have histologic characteristics of glioblastoma multiforme (GBM with contrast enhancement after intravenous administration of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA, implying disruption of the blood-brain barrier in these tumors. In contrast, low-grade murine oligodendrogliomas do not reveal contrast enhancement, similar to human tumors. MRI can be used to identify mice with brain neoplasms as inclusion criteria in preclinical trials.

  12. Functional connectivity analysis of the brain network using resting-state fMRI

    International Nuclear Information System (INIS)

    Hayashi, Toshihiro

    2011-01-01

    Spatial patterns of spontaneous fluctuations in blood oxygenation level-dependent (BOLD) signals reflect the underlying neural architecture. The study of the brain network based on these self-organized patterns is termed resting-state functional MRI (fMRI). This review article aims at briefly reviewing a basic concept of this technology and discussing its implications for neuropsychological studies. First, the technical aspects of resting-state fMRI, including signal sources, physiological artifacts, image acquisition, and analytical methods such as seed-based correlation analysis and independent component analysis, are explained, followed by a discussion on the major resting-state networks, including the default mode network. In addition, the structure-function correlation studied using diffuse tensor imaging and resting-state fMRI is briefly discussed. Second, I have discussed the reservations and potential pitfalls of 2 major imaging methods: voxel-based lesion-symptom mapping and task fMRI. Problems encountered with voxel-based lesion-symptom mapping can be overcome by using resting-state fMRI and evaluating undamaged brain networks in patients. Regarding task fMRI in patients, I have also emphasized the importance of evaluating the baseline brain activity because the amplitude of activation in BOLD fMRI is hard to interpret as the same baseline cannot be assumed for both patient and normal groups. (author)

  13. Imaging brain microstructure with diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C; Dyrby, Tim B; Nilsson, Markus

    2018-01-01

    This article gives an overview of microstructure imaging of the brain with diffusion MRI and reviews the state of the art. The microstructure-imaging paradigm aims to estimate and map microscopic properties of tissue using a model that links these properties to the voxel scale MR signal. Imaging ...

  14. Unexplained mental retardation: is brain MRI useful?

    Energy Technology Data Exchange (ETDEWEB)

    Decobert, Fabrice; Merzoug, Valerie; Kalifa, Gabriel; Adamsbaum, Catherine [Saint Vincent de Paul Hospital, Department of Radiology, 75674 Paris Cedex 14 (France); Grabar, Sophie [Cochin Hospital, Department of Biostatistics and Medical Information, Paris (France); Ponsot, Gerard [Saint Vincent de Paul Hospital, Department of Neuropaediatrics, Paris (France); Des Portes, Vincent [Saint Vincent de Paul Hospital, Department of Neuropaediatrics, Paris (France); Debrousse Hospital, Department of Neuropaediatrics, Lyon (France)

    2005-06-01

    Mental retardation (MR), defined as an IQ below 70, is a frequent cause of consultation in paediatrics. To evaluate the yield of brain MRI in the diagnostic work-up of unexplained MR in children. Patients and methods: The MRI features and clinical data of 100 patients (age 1-18 years) affected with non-progressive MR of unknown origin were compared to an age-matched control group (n=100). Two radiologists conducted an independent review of the MRI scans. Univariate and multivariate analyses showed a higher incidence of brain anomalies in the MR group than in the control group (53 vs 17, OR=5.7 [2.9-11.1]), for signal abnormalities within the periventricular white matter (OR=20.3 [2.6-155.3]), lateral ventricular dilatation (OR=15.6 [2.0-124]), mild corpus callosum abnormalities (shortness, atrophy) (OR=6.8 [1.8-25.6]) and subtle cerebellar abnormalities, including fissure enlargement (OR=5.2 [1.1-26.2]). The diagnostic value of MRI abnormalities was considered good in 5% of patients (Alexander disease n=1, diffuse cortical malformation n=1, leukomalacia n=1, vermian agenesis n=1, commissural agenesis n=1), and weak in 48% of patients, in whom non-specific abnormalities did not lead to a diagnosis. Some clinical features resulted in a significantly higher percentage of abnormal MRI scans: abnormal neurological examination (82% vs 47%, P=0.008), abnormal skull circumference (66% vs 49%, P=0.04). Motor delay was associated with cerebellar abnormalities (P=0.01). (orig.)

  15. Unexplained mental retardation: is brain MRI useful?

    International Nuclear Information System (INIS)

    Decobert, Fabrice; Merzoug, Valerie; Kalifa, Gabriel; Adamsbaum, Catherine; Grabar, Sophie; Ponsot, Gerard; Des Portes, Vincent

    2005-01-01

    Mental retardation (MR), defined as an IQ below 70, is a frequent cause of consultation in paediatrics. To evaluate the yield of brain MRI in the diagnostic work-up of unexplained MR in children. Patients and methods: The MRI features and clinical data of 100 patients (age 1-18 years) affected with non-progressive MR of unknown origin were compared to an age-matched control group (n=100). Two radiologists conducted an independent review of the MRI scans. Univariate and multivariate analyses showed a higher incidence of brain anomalies in the MR group than in the control group (53 vs 17, OR=5.7 [2.9-11.1]), for signal abnormalities within the periventricular white matter (OR=20.3 [2.6-155.3]), lateral ventricular dilatation (OR=15.6 [2.0-124]), mild corpus callosum abnormalities (shortness, atrophy) (OR=6.8 [1.8-25.6]) and subtle cerebellar abnormalities, including fissure enlargement (OR=5.2 [1.1-26.2]). The diagnostic value of MRI abnormalities was considered good in 5% of patients (Alexander disease n=1, diffuse cortical malformation n=1, leukomalacia n=1, vermian agenesis n=1, commissural agenesis n=1), and weak in 48% of patients, in whom non-specific abnormalities did not lead to a diagnosis. Some clinical features resulted in a significantly higher percentage of abnormal MRI scans: abnormal neurological examination (82% vs 47%, P=0.008), abnormal skull circumference (66% vs 49%, P=0.04). Motor delay was associated with cerebellar abnormalities (P=0.01). (orig.)

  16. Brain CT and MRI findings in fat embolism syndrome

    International Nuclear Information System (INIS)

    Suzuki, Shin; Hayashi, Takaki; Ri, Kyoshichi

    1996-01-01

    To elucidate brain CT and MRI findings in fat embolism syndrome (FES), we retrospectively analyzed images from 5 patients with FES during the acute and subacute stages. Brain CT examinations demonstrated brain edema in 2 patients and transient spotty low density lesions in 2 patients. Three patients showed no abnormalities. Brain MRI, however, showed brain abnormalities in all patients during the acute stages. These were revealed as spotty high signal intensity lesions on T2WI, and some showed low intensity on T1WI. These spotty lesions were considered to reflect edematous fluid occurring as a result of the unique pathophysiological condition of FES. While the spotty high signal intensity lesions on T2WI were distributed in the cerebrum, cerebellum, brain stem, thalamus, basal ganglia, internal capsule and corpus callosum, cerebral and cerebellar spotty lesions were characteristically located along the boundary zones of the major vascular territories. This characteristic location might be induced by a hypoxic brain condition in FES because the numerous fat globules present in this condition can block entire brain capillaries. This characteristic signal location on T2WI is a useful indicator for differentiating FES from the primary intra-axial brain injury in patients with multifocal trauma. (author)

  17. MRI brain findings in ephedrone encephalopathy associated with manganese abuse: Single-center perspective

    International Nuclear Information System (INIS)

    Poniatowska, Renata; Lusawa, Małgorzata; Skierczyńska, Agnieszka; Makowicz, Grzegorz; Habrat, Bogusław; Sienkiewicz-Jarosz, Halina

    2014-01-01

    Manganese (Mn) is a well-known toxic agent causing symptoms of parkinsonism in employees of certain branches of industry. Home production of a psychostimulant ephedrone (methcathinone), involving the use of potassium permanganate, became a new cause of intoxications in Poland. This article presents clinical symptoms, initial brain MRI findings and characteristics of changes observed in follow-up examinations in 4 patients with manganese intoxication associated with intravenous administration of ephedrone. All patients in our case series presented symptoms of parkinsonism. T1-WI MRI revealed high intensity signal in globi pallidi in all patients; hyperintense lesions in midbrain were observed in three patients, while lesions located in cerebellar hemispheres and pituitary gland in just one patient. The reduction of signal intensity in the affected brain structures was observed in follow-up studies, with no significant improvement in clinical symptoms. Brain MRI is helpful in the assessment of distribution as well as dynamics of changes in ephedrone encephalopathy. Regression of signal intensity changes visible in brain MRI is not associated with clinical condition improvement. Although brain MRI findings are not characteristic for ephedrone encephalopathy, they may contribute to diagnosing this condition

  18. Fetal brain volumetry through MRI volumetric reconstruction and segmentation

    Science.gov (United States)

    Estroff, Judy A.; Barnewolt, Carol E.; Connolly, Susan A.; Warfield, Simon K.

    2013-01-01

    Purpose Fetal MRI volumetry is a useful technique but it is limited by a dependency upon motion-free scans, tedious manual segmentation, and spatial inaccuracy due to thick-slice scans. An image processing pipeline that addresses these limitations was developed and tested. Materials and methods The principal sequences acquired in fetal MRI clinical practice are multiple orthogonal single-shot fast spin echo scans. State-of-the-art image processing techniques were used for inter-slice motion correction and super-resolution reconstruction of high-resolution volumetric images from these scans. The reconstructed volume images were processed with intensity non-uniformity correction and the fetal brain extracted by using supervised automated segmentation. Results Reconstruction, segmentation and volumetry of the fetal brains for a cohort of twenty-five clinically acquired fetal MRI scans was done. Performance metrics for volume reconstruction, segmentation and volumetry were determined by comparing to manual tracings in five randomly chosen cases. Finally, analysis of the fetal brain and parenchymal volumes was performed based on the gestational age of the fetuses. Conclusion The image processing pipeline developed in this study enables volume rendering and accurate fetal brain volumetry by addressing the limitations of current volumetry techniques, which include dependency on motion-free scans, manual segmentation, and inaccurate thick-slice interpolation. PMID:20625848

  19. Novel whole brain segmentation and volume estimation using quantitative MRI

    International Nuclear Information System (INIS)

    West, J.; Warntjes, J.B.M.; Lundberg, P.

    2012-01-01

    Brain segmentation and volume estimation of grey matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) are important for many neurological applications. Volumetric changes are observed in multiple sclerosis (MS), Alzheimer's disease and dementia, and in normal aging. A novel method is presented to segment brain tissue based on quantitative magnetic resonance imaging (qMRI) of the longitudinal relaxation rate R 1 , the transverse relaxation rate R 2 and the proton density, PD. Previously reported qMRI values for WM, GM and CSF were used to define tissues and a Bloch simulation performed to investigate R 1 , R 2 and PD for tissue mixtures in the presence of noise. Based on the simulations a lookup grid was constructed to relate tissue partial volume to the R 1 -R 2 -PD space. The method was validated in 10 healthy subjects. MRI data were acquired using six resolutions and three geometries. Repeatability for different resolutions was 3.2% for WM, 3.2% for GM, 1.0% for CSF and 2.2% for total brain volume. Repeatability for different geometries was 8.5% for WM, 9.4% for GM, 2.4% for CSF and 2.4% for total brain volume. We propose a new robust qMRI-based approach which we demonstrate in a patient with MS. (orig.)

  20. Novel whole brain segmentation and volume estimation using quantitative MRI

    Energy Technology Data Exchange (ETDEWEB)

    West, J. [Linkoeping University, Radiation Physics, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden); Linkoeping University, Center for Medical Imaging Science and Visualization (CMIV), Linkoeping (Sweden); SyntheticMR AB, Linkoeping (Sweden); Warntjes, J.B.M. [Linkoeping University, Center for Medical Imaging Science and Visualization (CMIV), Linkoeping (Sweden); SyntheticMR AB, Linkoeping (Sweden); Linkoeping University and Department of Clinical Physiology UHL, County Council of Oestergoetland, Clinical Physiology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden); Lundberg, P. [Linkoeping University, Center for Medical Imaging Science and Visualization (CMIV), Linkoeping (Sweden); Linkoeping University and Department of Radiation Physics UHL, County Council of Oestergoetland, Radiation Physics, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden); Linkoeping University and Department of Radiology UHL, County Council of Oestergoetland, Radiology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping (Sweden)

    2012-05-15

    Brain segmentation and volume estimation of grey matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) are important for many neurological applications. Volumetric changes are observed in multiple sclerosis (MS), Alzheimer's disease and dementia, and in normal aging. A novel method is presented to segment brain tissue based on quantitative magnetic resonance imaging (qMRI) of the longitudinal relaxation rate R{sub 1}, the transverse relaxation rate R{sub 2} and the proton density, PD. Previously reported qMRI values for WM, GM and CSF were used to define tissues and a Bloch simulation performed to investigate R{sub 1}, R{sub 2} and PD for tissue mixtures in the presence of noise. Based on the simulations a lookup grid was constructed to relate tissue partial volume to the R{sub 1}-R{sub 2}-PD space. The method was validated in 10 healthy subjects. MRI data were acquired using six resolutions and three geometries. Repeatability for different resolutions was 3.2% for WM, 3.2% for GM, 1.0% for CSF and 2.2% for total brain volume. Repeatability for different geometries was 8.5% for WM, 9.4% for GM, 2.4% for CSF and 2.4% for total brain volume. We propose a new robust qMRI-based approach which we demonstrate in a patient with MS. (orig.)

  1. Development of BOLD signal hemodynamic responses in the human brain

    NARCIS (Netherlands)

    Arichi, T.; Varela, M.; Melendez-Calderon, A.; Allievi, A.; Merchant, N.; Tusor, N.; Counsell, S.J.; Burdet, E.; Beckmann, Christian; Edwards, A.D.

    2012-01-01

    In the rodent brain the hemodynamic response to a brief external stimulus changes significantly during development. Analogous changes in human infants would complicate the determination and use of the hemodynamic response function (HRF) for functional magnetic resonance imaging (fMRI) in developing

  2. Measuring and manipulating brain connectivity with resting state functional connectivity magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS)

    OpenAIRE

    Fox, Michael D.; Halko, Mark A.; Eldaief, Mark C.; Pascual-Leone, Alvaro

    2012-01-01

    Both resting state functional magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS) are increasingly popular techniques that can be used to non-invasively measure brain connectivity in human subjects. TMS shows additional promise as a method to manipulate brain connectivity. In this review we discuss how these two complimentary tools can be combined to optimally study brain connectivity and manipulate distributed brain networks. Important clinical applications include...

  3. A Dirichlet process mixture model for brain MRI tissue classification.

    Science.gov (United States)

    Ferreira da Silva, Adelino R

    2007-04-01

    Accurate classification of magnetic resonance images according to tissue type or region of interest has become a critical requirement in diagnosis, treatment planning, and cognitive neuroscience. Several authors have shown that finite mixture models give excellent results in the automated segmentation of MR images of the human normal brain. However, performance and robustness of finite mixture models deteriorate when the models have to deal with a variety of anatomical structures. In this paper, we propose a nonparametric Bayesian model for tissue classification of MR images of the brain. The model, known as Dirichlet process mixture model, uses Dirichlet process priors to overcome the limitations of current parametric finite mixture models. To validate the accuracy and robustness of our method we present the results of experiments carried out on simulated MR brain scans, as well as on real MR image data. The results are compared with similar results from other well-known MRI segmentation methods.

  4. The application of MRI for depiction of subtle blood brain barrier disruption in stroke.

    Science.gov (United States)

    Israeli, David; Tanne, David; Daniels, Dianne; Last, David; Shneor, Ran; Guez, David; Landau, Efrat; Roth, Yiftach; Ocherashvilli, Aharon; Bakon, Mati; Hoffman, Chen; Weinberg, Amit; Volk, Talila; Mardor, Yael

    2010-12-26

    The development of imaging methodologies for detecting blood-brain-barrier (BBB) disruption may help predict stroke patient's propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI at relatively long delays (~15 minutes) after contrast injection and subtracting from them images acquired immediately after contrast administration. In addition, the relatively long delays allow for acquisition of high resolution images resulting in high resolution BBB disruption maps. The sensitivity is further increased by image preprocessing with corrections for intensity variations and with whole body (rigid+elastic) registration. Since only two separate time points are required, the time between the two acquisitions can be used for acquiring routine clinical data, keeping the total imaging time to a minimum. A proof of concept study was performed in 34 patients with ischemic stroke and 2 patients with brain metastases undergoing high resolution T1-weighted MRI acquired at 3 time points after contrast injection. The MR images were pre-processed and subtracted to produce BBB disruption maps. BBB maps of patients with brain metastases and ischemic stroke presented different patterns of BBB opening. The significant advantage of the long extravasation time was demonstrated by a dynamic-contrast-enhancement study performed continuously for 18 min. The high sensitivity of our methodology enabled depiction of clear BBB disruption in 27% of the stroke patients who did not have abnormalities on conventional contrast-enhanced MRI. In 36% of the patients, who had abnormalities detectable by conventional MRI, the BBB disruption volumes were significantly larger in the maps than in

  5. Novel frontiers in ultra-structural and molecular MRI of the brain.

    Science.gov (United States)

    Duyn, Jeff H; Koretsky, Alan P

    2011-08-01

    Recent developments in the MRI of the brain continue to expand its use in basic and clinical neuroscience. This review highlights some areas of recent progress. Higher magnetic field strengths and improved signal detectors have allowed improved visualization of the various properties of the brain, facilitating the anatomical definition of function-specific areas and their connections. For example, by sensitizing the MRI signal to the magnetic susceptibility of tissue, it is starting to become possible to reveal the laminar structure of the cortex and identify millimeter-scale fiber bundles. Using exogenous contrast agents, and innovative ways to manipulate contrast, it is becoming possible to highlight specific fiber tracts and cell populations. These techniques are bringing us closer to understanding the evolutionary blueprint of the brain, improving the detection and characterization of disease, and help to guide treatment. Recent MRI techniques are leading to more detailed and more specific contrast in the study of the brain.

  6. Development of PET insert for simultaneous PET/MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jiwoong; Choi, Yong; Jung, Jin Ho; Kim, Sangsu; Im, Ki Chun; Lim, Hyun Keong [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Oh, Changheun; Park, HyunWook; Cho, Gyuseong [Departments of Electrical Engineering and Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2014-07-29

    Recently, there has been great interest on the development of combined PET/MR, which is a useful tool for both functional and anatomic imaging. The purpose of this study was to develop a MR compatible PET insert for simultaneous PET and MR imaging of human brain and to evaluate the performance of the hybrid PET-MRI. The PET insert consisted of 18 detector blocks arranged in a ring of 390 mm diameter with 60 mm axial FOV. Each detector block was composed of 4 × 4 matrix of detector modules, each of which consisted of a 4 × 4 array LYSO coupled to a 4 × 4 GAPD array. The PET gantry was shielded with gold-plated conductive fabric tapes. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuits (PDCs) and then transferred to FPGA-embedded DAQ modules. The PDCs and DAQ modules were enclosed in an aluminum box and located at the rear of the MR bore inside MRI room. 3-T human MRIs of two different vendors were used to evaluate the MR compatibility of developed PET insert. No significant changes of the PET performance and the homogeneity of MR images caused by the non-compatibility of PET-MRI were observed with the 2 different MRIs. The signal intensities of MR images were slightly degraded (<3.6%) with the both MRI systems. The difference between independently and simultaneously acquired PET images of brain phantom was negligibly small (<4.3%). High quality simultaneous brain PET and MRI of 3 normal volunteers were successfully acquired. Experimental results indicate that the high performance compact and lightweight PET insert for hybrid PET/MRI, which could be utilized with the MRI from various manufactures, can be developed using GAPD arrays and charge signal transmission method proposed in this study.

  7. Perfusion kinetics in human brain tumor with DCE-MRI derived model and CFD analysis.

    Science.gov (United States)

    Bhandari, A; Bansal, A; Singh, A; Sinha, N

    2017-07-05

    Cancer is one of the leading causes of death all over the world. Among the strategies that are used for cancer treatment, the effectiveness of chemotherapy is often hindered by factors such as irregular and non-uniform uptake of drugs inside tumor. Thus, accurate prediction of drug transport and deposition inside tumor is crucial for increasing the effectiveness of chemotherapeutic treatment. In this study, a computational model of human brain tumor is developed that incorporates dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) data into a voxelized porous media model. The model takes into account realistic transport and perfusion kinetics parameters together with realistic heterogeneous tumor vasculature and accurate arterial input function (AIF), which makes it patient specific. The computational results for interstitial fluid pressure (IFP), interstitial fluid velocity (IFV) and tracer concentration show good agreement with the experimental results. The computational model can be extended further for predicting the deposition of chemotherapeutic drugs in tumor environment as well as selection of the best chemotherapeutic drug for a specific patient. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Low-frequency hippocampal-cortical activity drives brain-wide resting-state functional MRI connectivity.

    Science.gov (United States)

    Chan, Russell W; Leong, Alex T L; Ho, Leon C; Gao, Patrick P; Wong, Eddie C; Dong, Celia M; Wang, Xunda; He, Jufang; Chan, Ying-Shing; Lim, Lee Wei; Wu, Ed X

    2017-08-15

    The hippocampus, including the dorsal dentate gyrus (dDG), and cortex engage in bidirectional communication. We propose that low-frequency activity in hippocampal-cortical pathways contributes to brain-wide resting-state connectivity to integrate sensory information. Using optogenetic stimulation and brain-wide fMRI and resting-state fMRI (rsfMRI), we determined the large-scale effects of spatiotemporal-specific downstream propagation of hippocampal activity. Low-frequency (1 Hz), but not high-frequency (40 Hz), stimulation of dDG excitatory neurons evoked robust cortical and subcortical brain-wide fMRI responses. More importantly, it enhanced interhemispheric rsfMRI connectivity in various cortices and hippocampus. Subsequent local field potential recordings revealed an increase in slow oscillations in dorsal hippocampus and visual cortex, interhemispheric visual cortical connectivity, and hippocampal-cortical connectivity. Meanwhile, pharmacological inactivation of dDG neurons decreased interhemispheric rsfMRI connectivity. Functionally, visually evoked fMRI responses in visual regions also increased during and after low-frequency dDG stimulation. Together, our results indicate that low-frequency activity robustly propagates in the dorsal hippocampal-cortical pathway, drives interhemispheric cortical rsfMRI connectivity, and mediates visual processing.

  9. High-resolution functional MRI of the human amygdala at 7 T

    Energy Technology Data Exchange (ETDEWEB)

    Sladky, Ronald, E-mail: ronald.sladky@meduniwien.ac.at [MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna (Austria); Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna (Austria); Baldinger, Pia; Kranz, Georg S. [Department of Psychiatry and Psychotherapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna (Austria); Tröstl, Jasmin [MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna (Austria); Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna (Austria); Höflich, Anna; Lanzenberger, Rupert [Department of Psychiatry and Psychotherapy, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna (Austria); Moser, Ewald [MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna (Austria); Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna (Austria); Windischberger, Christian, E-mail: christian.windischberger@meduniwien.ac.at [MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna (Austria); Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna (Austria)

    2013-05-15

    Functional magnetic resonance imaging (fMRI) has become the primary non-invasive method for investigating the human brain function. With an increasing number of ultra-high field MR systems worldwide possibilities of higher spatial and temporal resolution in combination with increased sensitivity and specificity are expected to advance detailed imaging of distinct cortical brain areas and subcortical structures. One target region of particular importance to applications in psychiatry and psychology is the amygdala. However, ultra-high field magnetic resonance imaging of these ventral brain regions is a challenging endeavor that requires particular methodological considerations. Ventral brain areas are particularly prone to signal losses arising from strong magnetic field inhomogeneities along susceptibility borders. In addition, physiological artifacts from respiration and cardiac action cause considerable fluctuations in the MR signal. Here we show that, despite these challenges, fMRI data from the amygdala may be obtained with high temporal and spatial resolution combined with increased signal-to-noise ratio. Maps of neural activation during a facial emotion discrimination paradigm at 7 T are presented and clearly show the gain in percental signal change compared to 3 T results, demonstrating the potential benefits of ultra-high field functional MR imaging also in ventral brain areas.

  10. High-resolution functional MRI of the human amygdala at 7 T

    International Nuclear Information System (INIS)

    Sladky, Ronald; Baldinger, Pia; Kranz, Georg S.; Tröstl, Jasmin; Höflich, Anna; Lanzenberger, Rupert; Moser, Ewald; Windischberger, Christian

    2013-01-01

    Functional magnetic resonance imaging (fMRI) has become the primary non-invasive method for investigating the human brain function. With an increasing number of ultra-high field MR systems worldwide possibilities of higher spatial and temporal resolution in combination with increased sensitivity and specificity are expected to advance detailed imaging of distinct cortical brain areas and subcortical structures. One target region of particular importance to applications in psychiatry and psychology is the amygdala. However, ultra-high field magnetic resonance imaging of these ventral brain regions is a challenging endeavor that requires particular methodological considerations. Ventral brain areas are particularly prone to signal losses arising from strong magnetic field inhomogeneities along susceptibility borders. In addition, physiological artifacts from respiration and cardiac action cause considerable fluctuations in the MR signal. Here we show that, despite these challenges, fMRI data from the amygdala may be obtained with high temporal and spatial resolution combined with increased signal-to-noise ratio. Maps of neural activation during a facial emotion discrimination paradigm at 7 T are presented and clearly show the gain in percental signal change compared to 3 T results, demonstrating the potential benefits of ultra-high field functional MR imaging also in ventral brain areas

  11. Automatic Semantic Segmentation of Brain Gliomas from MRI Images Using a Deep Cascaded Neural Network.

    Science.gov (United States)

    Cui, Shaoguo; Mao, Lei; Jiang, Jingfeng; Liu, Chang; Xiong, Shuyu

    2018-01-01

    Brain tumors can appear anywhere in the brain and have vastly different sizes and morphology. Additionally, these tumors are often diffused and poorly contrasted. Consequently, the segmentation of brain tumor and intratumor subregions using magnetic resonance imaging (MRI) data with minimal human interventions remains a challenging task. In this paper, we present a novel fully automatic segmentation method from MRI data containing in vivo brain gliomas. This approach can not only localize the entire tumor region but can also accurately segment the intratumor structure. The proposed work was based on a cascaded deep learning convolutional neural network consisting of two subnetworks: (1) a tumor localization network (TLN) and (2) an intratumor classification network (ITCN). The TLN, a fully convolutional network (FCN) in conjunction with the transfer learning technology, was used to first process MRI data. The goal of the first subnetwork was to define the tumor region from an MRI slice. Then, the ITCN was used to label the defined tumor region into multiple subregions. Particularly, ITCN exploited a convolutional neural network (CNN) with deeper architecture and smaller kernel. The proposed approach was validated on multimodal brain tumor segmentation (BRATS 2015) datasets, which contain 220 high-grade glioma (HGG) and 54 low-grade glioma (LGG) cases. Dice similarity coefficient (DSC), positive predictive value (PPV), and sensitivity were used as evaluation metrics. Our experimental results indicated that our method could obtain the promising segmentation results and had a faster segmentation speed. More specifically, the proposed method obtained comparable and overall better DSC values (0.89, 0.77, and 0.80) on the combined (HGG + LGG) testing set, as compared to other methods reported in the literature. Additionally, the proposed approach was able to complete a segmentation task at a rate of 1.54 seconds per slice.

  12. Assessment of brain metastases by means of dynamic susceptibility contrast enhanced MRI

    International Nuclear Information System (INIS)

    Knopp, M.; Wenz, F.; Debus, J.; Hentrich, H.R.

    2002-01-01

    Full text: To assess if pre therapeutic measurements of regional cerebral blood flow (rCBF) and volume (rCVB) are able to predict the response of brain metastases to radiation therapy and to assess the influence of radiosurgery on rCBF and rCBV on brain metastases and normal surrounding tissue. We examined 25 patients with brain metastases prior to high dose radiosurgery with conventional T1 and T2 weighted MRI and dynamic susceptibility contrast enhanced MRI (DSC MRI). For DSC MRI 55 T2*w GE images of two sections were acquired after bolus administration of 0.1 mmol/kg gadoteridol (ProHance) for the simultaneous measurement of brain feeding arteries and brain tissue. This allowed an absolute quantification of rCBF and rCBV. Follow-up examinations were performed 6 weeks and 3 months after radiotherapy and the acquired perfusion data were related to a 3 point scale of treatment outcome. Radiosurgery was performed by a linear accelerator with a 80% isodose of 18-20 Gv. For treatment planning the heads of the patients were immobilized by a cask mask to avoid head movement. DSC MRI was able to assess perfusion data in all patients. Higher pre therapeutic rCBV seems to predict a poor treatment outcome. After radiosurgery patients with tumor remission and stable disease presented a decrease of rCBV over time regardless of temporary tumor volume increase. Patients with tumor progression at the 3 month followup presented an increase of rCBV. Effects on normal surrounding tissue could not be observed. DSC MRI using Gadoteridol allows the non-invasive assessment of rCBV and rCBF of brain metastases and its changes due to radiosurgery. The method may also be able to predict treatment outcome. Furthermore radiofrequency effects on surrounding unaffected tissue can be monitored. Copyright (2002) Blackwell Science Pty Ltd

  13. Deep Learning for Brain MRI Segmentation: State of the Art and Future Directions.

    Science.gov (United States)

    Akkus, Zeynettin; Galimzianova, Alfiia; Hoogi, Assaf; Rubin, Daniel L; Erickson, Bradley J

    2017-08-01

    Quantitative analysis of brain MRI is routine for many neurological diseases and conditions and relies on accurate segmentation of structures of interest. Deep learning-based segmentation approaches for brain MRI are gaining interest due to their self-learning and generalization ability over large amounts of data. As the deep learning architectures are becoming more mature, they gradually outperform previous state-of-the-art classical machine learning algorithms. This review aims to provide an overview of current deep learning-based segmentation approaches for quantitative brain MRI. First we review the current deep learning architectures used for segmentation of anatomical brain structures and brain lesions. Next, the performance, speed, and properties of deep learning approaches are summarized and discussed. Finally, we provide a critical assessment of the current state and identify likely future developments and trends.

  14. {sup 99m}Tc-HMPAO Brain SPECT in Seizure Disorder: Comparison Brain SPECT, MRI / CT and EEG

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hyung In [Kyunghee University Hospital, Seoul (Korea, Republic of); Im, Ju Hyuk; Choi, Chang Woon; Lee, Dong Soo; Chung, June Key; No, Jae Kyu; Lee, Myung Chul; Koh, Chang Soon [Seoul National University Hospital, Seoul (Korea, Republic of)

    1994-03-15

    We studied 115 patients with seizure who had been performed brain SPECT brain MRI of CT and EEG. To evaluate the pattern of brain SPECT in seizure patients 28 of them had secondary epilepsies, 87 had primary epilepsies. In primary epilepsies, 42 were generalized seizure and 45 were partial seizure. The causes of secondary epilepsies were congenital malformation, cerebromalacia, cerebral infarction ultiple sclerosis, AV-malformation. granuloma and etc, in order. In 28 secondary epilepsies, 25 of them, brain SPECT lesions was concordant with MRI or CT lesions. 3 were disconcordant. The brain SPECT findings of generalized seizure were normal in 22 patients, diffuse irregular decreased perfusion in 8, decreased in frontal cortex in 4. temporal in 5 and frontotemporal in 3. In 45 partial seizure, 19 brain SPECT were concordant with EEG (42.4%).

  15. Combining fMRI and behavioral measures to examine the process of human learning.

    Science.gov (United States)

    Karuza, Elisabeth A; Emberson, Lauren L; Aslin, Richard N

    2014-03-01

    Prior to the advent of fMRI, the primary means of examining the mechanisms underlying learning were restricted to studying human behavior and non-human neural systems. However, recent advances in neuroimaging technology have enabled the concurrent study of human behavior and neural activity. We propose that the integration of behavioral response with brain activity provides a powerful method of investigating the process through which internal representations are formed or changed. Nevertheless, a review of the literature reveals that many fMRI studies of learning either (1) focus on outcome rather than process or (2) are built on the untested assumption that learning unfolds uniformly over time. We discuss here various challenges faced by the field and highlight studies that have begun to address them. In doing so, we aim to encourage more research that examines the process of learning by considering the interrelation of behavioral measures and fMRI recording during learning. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Current status and future role of brain PET/MRI in clinical and research settings

    Energy Technology Data Exchange (ETDEWEB)

    Werner, P.; Barthel, H.; Sabri, O. [University Hospital Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Drzezga, A. [University Hospital Cologne, Department of Nuclear Medicine, Koeln (Germany)

    2015-01-09

    Hybrid PET/MRI systematically offers a complementary combination of two modalities that has often proven itself superior to the single modality approach in the diagnostic work-up of many neurological and psychiatric diseases. Emerging PET tracers, technical advances in multiparametric MRI and obvious workflow advantages may lead to a significant improvement in the diagnosis of dementia disorders, neurooncological diseases, epilepsy and neurovascular diseases using PET/MRI. Moreover, simultaneous PET/MRI is well suited to complex studies of brain function in which fast fluctuations of brain signals (e.g. related to task processing or in response to pharmacological interventions) need to be monitored on multiple levels. Initial simultaneous studies have already demonstrated that these complementary measures of brain function can provide new insights into the functional and structural organization of the brain. (orig.)

  17. Current status and future role of brain PET/MRI in clinical and research settings

    International Nuclear Information System (INIS)

    Werner, P.; Barthel, H.; Sabri, O.; Drzezga, A.

    2015-01-01

    Hybrid PET/MRI systematically offers a complementary combination of two modalities that has often proven itself superior to the single modality approach in the diagnostic work-up of many neurological and psychiatric diseases. Emerging PET tracers, technical advances in multiparametric MRI and obvious workflow advantages may lead to a significant improvement in the diagnosis of dementia disorders, neurooncological diseases, epilepsy and neurovascular diseases using PET/MRI. Moreover, simultaneous PET/MRI is well suited to complex studies of brain function in which fast fluctuations of brain signals (e.g. related to task processing or in response to pharmacological interventions) need to be monitored on multiple levels. Initial simultaneous studies have already demonstrated that these complementary measures of brain function can provide new insights into the functional and structural organization of the brain. (orig.)

  18. EKG-based detection of deep brain stimulation in fMRI studies.

    Science.gov (United States)

    Fiveland, Eric; Madhavan, Radhika; Prusik, Julia; Linton, Renee; Dimarzio, Marisa; Ashe, Jeffrey; Pilitsis, Julie; Hancu, Ileana

    2018-04-01

    To assess the impact of synchronization errors between the assumed functional MRI paradigm timing and the deep brain stimulation (DBS) on/off cycling using a custom electrocardiogram-based triggering system METHODS: A detector for measuring and predicting the on/off state of cycling deep brain stimulation was developed and tested in six patients in office visits. Three-electrode electrocardiogram measurements, amplified by a commercial bio-amplifier, were used as input for a custom electronics box (e-box). The e-box transformed the deep brain stimulation waveforms into transistor-transistor logic pulses, recorded their timing, and propagated it in time. The e-box was used to trigger task-based deep brain stimulation functional MRI scans in 5 additional subjects; the impact of timing accuracy on t-test values was investigated in a simulation study using the functional MRI data. Following locking to each patient's individual waveform, the e-box was shown to predict stimulation onset with an average absolute error of 112 ± 148 ms, 30 min after disconnecting from the patients. The subsecond accuracy of the e-box in predicting timing onset is more than adequate for our slow varying, 30-/30-s on/off stimulation paradigm. Conversely, the experimental deep brain stimulation onset prediction accuracy in the absence of the e-box, which could be off by as much as 4 to 6 s, could significantly decrease activation strength. Using this detector, stimulation can be accurately synchronized to functional MRI acquisitions, without adding any additional hardware in the MRI environment. Magn Reson Med 79:2432-2439, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  19. Body growth and brain development in premature babies: an MRI study

    International Nuclear Information System (INIS)

    Tzarouchi, Loukia C.; Zikou, Anastasia; Kosta, Paraskevi; Argyropoulou, Maria I.; Drougia, Aikaterini; Andronikou, Styliani; Astrakas, Loukas G.

    2014-01-01

    Prematurity and intrauterine growth restriction are associated with neurodevelopmental disabilities. To assess the relationship between growth status and regional brain volume (rBV) and white matter microstructure in premature babies at around term-equivalent age. Premature infants (n= 27) of gestational age (GA): 29.8 ± 2.1 weeks, with normal brain MRI scans were studied at corrected age: 41.2 ± 1.4 weeks. The infants were divided into three groups: 1) appropriate for GA at birth and at the time of MRI (AGA), 2) small for GA at birth with catch-up growth at the time of MRI (SGA a ) and 3) small for GA at birth with failure of catch-up growth at the time of MRI (SGA b ). The T1-weighted images were segmented into 90 rBVs using the SPM8/IBASPM and differences among groups were assessed. Fractional anisotropy (FA) was measured bilaterally in 15 fiber tracts and its relationship to GA and somatometric measurements was explored. Lower rBV was observed in SGA b in superior and anterior brain areas. A positive correlation was demonstrated between FA and head circumference and body weight. Body weight was the only significant predictor for FA (P< 0.05). In premature babies, catch-up growth is associated with regional brain volume catch-up at around term-equivalent age, starting from the brain areas maturing first. Body weight seems to be a strong predictor associated with WM microstructure in brain areas related to attention, language, cognition, memory and executing functioning. (orig.)

  20. Body growth and brain development in premature babies: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Tzarouchi, Loukia C.; Zikou, Anastasia; Kosta, Paraskevi; Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece); Drougia, Aikaterini; Andronikou, Styliani [University of Ioannina, Intensive Care Unit, Child Health Department, Medical School, Ioannina (Greece); Astrakas, Loukas G. [University of Ioannina, Department of Medical Physics, Medical School, Ioannina (Greece)

    2014-03-15

    Prematurity and intrauterine growth restriction are associated with neurodevelopmental disabilities. To assess the relationship between growth status and regional brain volume (rBV) and white matter microstructure in premature babies at around term-equivalent age. Premature infants (n= 27) of gestational age (GA): 29.8 ± 2.1 weeks, with normal brain MRI scans were studied at corrected age: 41.2 ± 1.4 weeks. The infants were divided into three groups: 1) appropriate for GA at birth and at the time of MRI (AGA), 2) small for GA at birth with catch-up growth at the time of MRI (SGA{sub a}) and 3) small for GA at birth with failure of catch-up growth at the time of MRI (SGA{sub b}). The T1-weighted images were segmented into 90 rBVs using the SPM8/IBASPM and differences among groups were assessed. Fractional anisotropy (FA) was measured bilaterally in 15 fiber tracts and its relationship to GA and somatometric measurements was explored. Lower rBV was observed in SGA{sub b} in superior and anterior brain areas. A positive correlation was demonstrated between FA and head circumference and body weight. Body weight was the only significant predictor for FA (P< 0.05). In premature babies, catch-up growth is associated with regional brain volume catch-up at around term-equivalent age, starting from the brain areas maturing first. Body weight seems to be a strong predictor associated with WM microstructure in brain areas related to attention, language, cognition, memory and executing functioning. (orig.)

  1. Wilson's disease: two treatment modalities. Correlations to pretreatment and posttreatment brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Leiros da Costa, Maria do Desterro [Federal University of Paraiba, Movement Disorders Unit, Paraiba (Brazil); Spitz, Mariana; Bacheschi, Luiz Alberto; Barbosa, Egberto Reis [University of Sao Paulo, Movement Disorders Unit, Sao Paulo (Brazil); Leite, Claudia Costa; Lucato, Leandro Tavares [University of Sao Paulo, Department of Radiology, Sao Paulo (Brazil)

    2009-10-15

    Brain magnetic resonance imaging (MRI) studies on Wilson's disease (WD) show lack of correlations between neurological and neuroimaging features. Long-term follow-up reports with sequential brain MRI in patients with neurological WD comparing different modalities of treatment are scarce. Eighteen patients with neurological WD underwent pretreatment and posttreatment brain MRI scans to evaluate the range of abnormalities and the evolution along these different periods. All patients underwent at least two MRI scans at different intervals, up to 11 years after the beginning of treatment. MRI findings were correlated with clinical picture, clinical severity, duration of neurological symptoms, and treatment with two different drugs. Patients were divided into two groups according to treatment: d-penicillamine (D-P), zinc (Zn), and Zn after the onset of severe intolerance to D-P. MRI scans before treatment showed, in all patients, hypersignal intensity lesions on T2- and proton-density-weighted images bilaterally and symmetrically at basal nuclei, thalamus, brain stem, cerebellum, brain cortex, and brain white matter. The most common neurological symptoms were: dysarthria, parkinsonism, dystonia, tremor, psychiatric disturbances, dysphagia, risus sardonicus, ataxia, chorea, and athetosis. From the neurological point of view, there was no difference on the evolution between the group treated exclusively with D-P and the one treated with Zn. Analysis of MRI scans with longer intervals after the beginning of treatment depicted a trend for neuroimaging worsening, without neurological correspondence, among patients treated with Zn. Neuroimaging pattern of evolution was more favorable for the group that received exclusively D-P. (orig.)

  2. Driving and driven architectures of directed small-world human brain functional networks.

    Directory of Open Access Journals (Sweden)

    Chaogan Yan

    Full Text Available Recently, increasing attention has been focused on the investigation of the human brain connectome that describes the patterns of structural and functional connectivity networks of the human brain. Many studies of the human connectome have demonstrated that the brain network follows a small-world topology with an intrinsically cohesive modular structure and includes several network hubs in the medial parietal regions. However, most of these studies have only focused on undirected connections between regions in which the directions of information flow are not taken into account. How the brain regions causally influence each other and how the directed network of human brain is topologically organized remain largely unknown. Here, we applied linear multivariate Granger causality analysis (GCA and graph theoretical approaches to a resting-state functional MRI dataset with a large cohort of young healthy participants (n = 86 to explore connectivity patterns of the population-based whole-brain functional directed network. This directed brain network exhibited prominent small-world properties, which obviously improved previous results of functional MRI studies showing weak small-world properties in the directed brain networks in terms of a kernel-based GCA and individual analysis. This brain network also showed significant modular structures associated with 5 well known subsystems: fronto-parietal, visual, paralimbic/limbic, subcortical and primary systems. Importantly, we identified several driving hubs predominantly located in the components of the attentional network (e.g., the inferior frontal gyrus, supplementary motor area, insula and fusiform gyrus and several driven hubs predominantly located in the components of the default mode network (e.g., the precuneus, posterior cingulate gyrus, medial prefrontal cortex and inferior parietal lobule. Further split-half analyses indicated that our results were highly reproducible between two

  3. MRI of perinatal brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Mary; Allsop, Joanna [Imperial College, Robert Steiner MR Unit, Perinatal Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, London (United Kingdom); Martinez Biarge, Miriam [La Paz University Hospital, Dept of Neonatology, Madrid (Spain); Counsell, Serena [Imperial College, Robert Steiner MR Unit, Neonatal Medicine, MRC Clinical Sciences Centre, Hammersmith Hospital, London (United Kingdom); Cowan, Frances [Imperial College, Dept of Paediatrics, Hammersmith Hospital, London (United Kingdom)

    2010-06-15

    MRI is invaluable in assessing the neonatal brain following suspected perinatal injury. Good quality imaging requires adaptations to both the hardware and the sequences used for adults or older children. The perinatal and postnatal details often predict the pattern of lesions sustained and should be available to aid interpretation of the imaging findings. Perinatal lesions, the pattern of which can predict neurodevelopmental outcome, are at their most obvious on conventional imaging between 1 and 2 weeks from birth. Very early imaging during the first week may be useful to make management decisions in ventilated neonates but brain abnormalities may still be subtle using conventional sequences. Diffusion-weighted imaging (DWI) is very useful for the early identification of ischaemic tissue in the neonatal brain but may underestimate the final extent of injury, particularly basal ganglia and thalamic lesions. MR imaging is an excellent predictor of outcome following perinatal brain injury and can therefore be used as a biomarker in interventional trials designed to reduce injury and improve neurodevelopmental outcome. (orig.)

  4. MRI of perinatal brain injury

    International Nuclear Information System (INIS)

    Rutherford, Mary; Allsop, Joanna; Martinez Biarge, Miriam; Counsell, Serena; Cowan, Frances

    2010-01-01

    MRI is invaluable in assessing the neonatal brain following suspected perinatal injury. Good quality imaging requires adaptations to both the hardware and the sequences used for adults or older children. The perinatal and postnatal details often predict the pattern of lesions sustained and should be available to aid interpretation of the imaging findings. Perinatal lesions, the pattern of which can predict neurodevelopmental outcome, are at their most obvious on conventional imaging between 1 and 2 weeks from birth. Very early imaging during the first week may be useful to make management decisions in ventilated neonates but brain abnormalities may still be subtle using conventional sequences. Diffusion-weighted imaging (DWI) is very useful for the early identification of ischaemic tissue in the neonatal brain but may underestimate the final extent of injury, particularly basal ganglia and thalamic lesions. MR imaging is an excellent predictor of outcome following perinatal brain injury and can therefore be used as a biomarker in interventional trials designed to reduce injury and improve neurodevelopmental outcome. (orig.)

  5. Magnetic resonance imaging (MRI) of liver and brain in haematologic-organic patients with fever of unknown origin

    International Nuclear Information System (INIS)

    Heussel, C.P.; Kauczor, H.U.; Poguntke, M.; Schadmand-Fischer, S.; Mildenberger, P.; Thelen, M.; Heussel, G.

    1998-01-01

    To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin. Material and Methods: Twenty liver MRI (T 2 -TSE, T 2 -HASTE, T 1 -FLASH±Gd dynamic) and 16 brain MRI (T 2 -TSE, FLAIR, T 1 -TSE±Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up. Results: suspected organ system. Comparison with clinical follow-up. Results: A focus was detected in 11/20 liver MRI. Candidiasis (n=3), mycobacteriosis (n=2), relapse of haematological disease (n=3), graft versus host disease (n=1), non-clarified (n=2). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follo-wup. In brain MRI, 3/16 showed a focus (toxoplasmosis, aspergillosis, mastoiditis). Clinical indication for an infectious involvement of the brain was found in 4/16 cases 2--5 months after initially normal brain MRI. No suspicion of an infectious involvement of brain was present in the remaining 9/16 cases. Conclusion: In case of fever of unknown origin and suspicion of liver involvement, MRI of the liver should be performed due to data given in literature and its sensitivity of 100%. Because of the delayed detectability of cerebral manifestations, in cases of persisting suspicion even a previously normal MRI of the brain should be repeated. (orig.) [de

  6. A multi-atlas based method for automated anatomical Macaca fascicularis brain MRI segmentation and PET kinetic extraction.

    Science.gov (United States)

    Ballanger, Bénédicte; Tremblay, Léon; Sgambato-Faure, Véronique; Beaudoin-Gobert, Maude; Lavenne, Franck; Le Bars, Didier; Costes, Nicolas

    2013-08-15

    MRI templates and digital atlases are needed for automated and reproducible quantitative analysis of non-human primate PET studies. Segmenting brain images via multiple atlases outperforms single-atlas labelling in humans. We present a set of atlases manually delineated on brain MRI scans of the monkey Macaca fascicularis. We use this multi-atlas dataset to evaluate two automated methods in terms of accuracy, robustness and reliability in segmenting brain structures on MRI and extracting regional PET measures. Twelve individual Macaca fascicularis high-resolution 3DT1 MR images were acquired. Four individual atlases were created by manually drawing 42 anatomical structures, including cortical and sub-cortical structures, white matter regions, and ventricles. To create the MRI template, we first chose one MRI to define a reference space, and then performed a two-step iterative procedure: affine registration of individual MRIs to the reference MRI, followed by averaging of the twelve resampled MRIs. Automated segmentation in native space was obtained in two ways: 1) Maximum probability atlases were created by decision fusion of two to four individual atlases in the reference space, and transformation back into the individual native space (MAXPROB)(.) 2) One to four individual atlases were registered directly to the individual native space, and combined by decision fusion (PROPAG). Accuracy was evaluated by computing the Dice similarity index and the volume difference. The robustness and reproducibility of PET regional measurements obtained via automated segmentation was evaluated on four co-registered MRI/PET datasets, which included test-retest data. Dice indices were always over 0.7 and reached maximal values of 0.9 for PROPAG with all four individual atlases. There was no significant mean volume bias. The standard deviation of the bias decreased significantly when increasing the number of individual atlases. MAXPROB performed better when increasing the number of

  7. Custom fit 3D-printed brain holders for comparison of histology with MRI in marmosets.

    Science.gov (United States)

    Guy, Joseph R; Sati, Pascal; Leibovitch, Emily; Jacobson, Steven; Silva, Afonso C; Reich, Daniel S

    2016-01-15

    MRI has the advantage of sampling large areas of tissue and locating areas of interest in 3D space in both living and ex vivo systems, whereas histology has the ability to examine thin slices of ex vivo tissue with high detail and specificity. Although both are valuable tools, it is currently difficult to make high-precision comparisons between MRI and histology due to large differences inherent to the techniques. A method combining the advantages would be an asset to understanding the pathological correlates of MRI. 3D-printed brain holders were used to maintain marmoset brains in the same orientation during acquisition of ex vivo MRI and pathologic cutting of the tissue. The results of maintaining this same orientation show that sub-millimeter, discrete neuropathological features in marmoset brain consistently share size, shape, and location between histology and ex vivo MRI, which facilitates comparison with serial imaging acquired in vivo. Existing methods use computational approaches sensitive to data input in order to warp histologic images to match large-scale features on MRI, but the new method requires no warping of images, due to a preregistration accomplished in the technique, and is insensitive to data formatting and artifacts in both MRI and histology. The simple method of using 3D-printed brain holders to match brain orientation during pathologic sectioning and MRI acquisition enables rapid and precise comparison of small features seen on MRI to their underlying histology. Published by Elsevier B.V.

  8. Our Faces in the Dog's Brain: Functional Imaging Reveals Temporal Cortex Activation during Perception of Human Faces.

    Directory of Open Access Journals (Sweden)

    Laura V Cuaya

    Full Text Available Dogs have a rich social relationship with humans. One fundamental aspect of it is how dogs pay close attention to human faces in order to guide their behavior, for example, by recognizing their owner and his/her emotional state using visual cues. It is well known that humans have specific brain regions for the processing of other human faces, yet it is unclear how dogs' brains process human faces. For this reason, our study focuses on describing the brain correlates of perception of human faces in dogs using functional magnetic resonance imaging (fMRI. We trained seven domestic dogs to remain awake, still and unrestrained inside an MRI scanner. We used a visual stimulation paradigm with block design to compare activity elicited by human faces against everyday objects. Brain activity related to the perception of faces changed significantly in several brain regions, but mainly in the bilateral temporal cortex. The opposite contrast (i.e., everyday objects against human faces showed no significant brain activity change. The temporal cortex is part of the ventral visual pathway, and our results are consistent with reports in other species like primates and sheep, that suggest a high degree of evolutionary conservation of this pathway for face processing. This study introduces the temporal cortex as candidate to process human faces, a pillar of social cognition in dogs.

  9. Diffusion MRI of the neonate brain: acquisition, processing and analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pannek, Kerstin [University of Queensland, Centre for Clinical Research, Brisbane (Australia); University of Queensland, School of Medicine, Brisbane (Australia); University of Queensland, Centre for Advanced Imaging, Brisbane (Australia); Guzzetta, Andrea [IRCCS Stella Maris, Department of Developmental Neuroscience, Calambrone Pisa (Italy); Colditz, Paul B. [University of Queensland, Centre for Clinical Research, Brisbane (Australia); University of Queensland, Perinatal Research Centre, Brisbane (Australia); Rose, Stephen E. [University of Queensland, Centre for Clinical Research, Brisbane (Australia); University of Queensland, Centre for Advanced Imaging, Brisbane (Australia); University of Queensland Centre for Clinical Research, Royal Brisbane and Women' s Hospital, Brisbane (Australia)

    2012-10-15

    Diffusion MRI (dMRI) is a popular noninvasive imaging modality for the investigation of the neonate brain. It enables the assessment of white matter integrity, and is particularly suited for studying white matter maturation in the preterm and term neonate brain. Diffusion tractography allows the delineation of white matter pathways and assessment of connectivity in vivo. In this review, we address the challenges of performing and analysing neonate dMRI. Of particular importance in dMRI analysis is adequate data preprocessing to reduce image distortions inherent to the acquisition technique, as well as artefacts caused by head movement. We present a summary of techniques that should be used in the preprocessing of neonate dMRI data, and demonstrate the effect of these important correction steps. Furthermore, we give an overview of available analysis techniques, ranging from voxel-based analysis of anisotropy metrics including tract-based spatial statistics (TBSS) to recently developed methods of statistical analysis addressing issues of resolving complex white matter architecture. We highlight the importance of resolving crossing fibres for tractography and outline several tractography-based techniques, including connectivity-based segmentation, the connectome and tractography mapping. These techniques provide powerful tools for the investigation of brain development and maturation. (orig.)

  10. Sex beyond the genitalia: The human brain mosaic

    Science.gov (United States)

    Joel, Daphna; Berman, Zohar; Tavor, Ido; Wexler, Nadav; Gaber, Olga; Stein, Yaniv; Shefi, Nisan; Pool, Jared; Urchs, Sebastian; Margulies, Daniel S.; Liem, Franziskus; Hänggi, Jürgen; Jäncke, Lutz; Assaf, Yaniv

    2015-01-01

    Whereas a categorical difference in the genitals has always been acknowledged, the question of how far these categories extend into human biology is still not resolved. Documented sex/gender differences in the brain are often taken as support of a sexually dimorphic view of human brains (“female brain” or “male brain”). However, such a distinction would be possible only if sex/gender differences in brain features were highly dimorphic (i.e., little overlap between the forms of these features in males and females) and internally consistent (i.e., a brain has only “male” or only “female” features). Here, analysis of MRIs of more than 1,400 human brains from four datasets reveals extensive overlap between the distributions of females and males for all gray matter, white matter, and connections assessed. Moreover, analyses of internal consistency reveal that brains with features that are consistently at one end of the “maleness-femaleness” continuum are rare. Rather, most brains are comprised of unique “mosaics” of features, some more common in females compared with males, some more common in males compared with females, and some common in both females and males. Our findings are robust across sample, age, type of MRI, and method of analysis. These findings are corroborated by a similar analysis of personality traits, attitudes, interests, and behaviors of more than 5,500 individuals, which reveals that internal consistency is extremely rare. Our study demonstrates that, although there are sex/gender differences in the brain, human brains do not belong to one of two distinct categories: male brain/female brain. PMID:26621705

  11. Structural MRI markers of brain aging early after ischemic stroke.

    Science.gov (United States)

    Werden, Emilio; Cumming, Toby; Li, Qi; Bird, Laura; Veldsman, Michele; Pardoe, Heath R; Jackson, Graeme; Donnan, Geoffrey A; Brodtmann, Amy

    2017-07-11

    To examine associations between ischemic stroke, vascular risk factors, and MRI markers of brain aging. Eighty-one patients (mean age 67.5 ± 13.1 years, 31 left-sided, 61 men) with confirmed first-ever (n = 66) or recurrent (n = 15) ischemic stroke underwent 3T MRI scanning within 6 weeks of symptom onset (mean 26 ± 9 days). Age-matched controls (n = 40) completed identical testing. Multivariate regression analyses examined associations between group membership and MRI markers of brain aging (cortical thickness, total brain volume, white matter hyperintensity [WMH] volume, hippocampal volume), normalized against intracranial volume, and the effects of vascular risk factors on these relationships. First-ever stroke was associated with smaller hippocampal volume ( p = 0.025) and greater WMH volume ( p = 0.004) relative to controls. Recurrent stroke was in turn associated with smaller hippocampal volume relative to both first-ever stroke ( p = 0.017) and controls ( p = 0.001). These associations remained significant after adjustment for age, sex, education, and, in stroke patients, infarct volume. Total brain volume was not significantly smaller in first-ever stroke patients than in controls ( p = 0.056), but the association became significant after further adjustment for atrial fibrillation ( p = 0.036). Cortical thickness and brain volumes did not differ as a function of stroke type, infarct volume, or etiology. Brain structure is likely to be compromised before ischemic stroke by vascular risk factors. Smaller hippocampal and total brain volumes and increased WMH load represent proxies for underlying vascular brain injury. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  12. Integrating histology and MRI in the first digital brain of common squirrel monkey, Saimiri sciureus

    Science.gov (United States)

    Sun, Peizhen; Parvathaneni, Prasanna; Schilling, Kurt G.; Gao, Yurui; Janve, Vaibhav; Anderson, Adam; Landman, Bennett A.

    2015-03-01

    This effort is a continuation of development of a digital brain atlas of the common squirrel monkey, Saimiri sciureus, a New World monkey with functional and microstructural organization of central nervous system similar to that of humans. Here, we present the integration of histology with multi-modal magnetic resonance imaging (MRI) atlas constructed from the brain of an adult female squirrel monkey. The central concept of this work is to use block face photography to establish an intermediate common space in coordinate system which preserves the high resolution in-plane resolution of histology while enabling 3-D correspondence with MRI. In vivo MRI acquisitions include high resolution T2 structural imaging (300 μm isotropic) and low resolution diffusion tensor imaging (600 um isotropic). Ex vivo MRI acquisitions include high resolution T2 structural imaging and high resolution diffusion tensor imaging (both 300 μm isotropic). Cortical regions were manually annotated on the co-registered volumes based on published histological sections in-plane. We describe mapping of histology and MRI based data of the common squirrel monkey and construction of a viewing tool that enable online viewing of these datasets. The previously descried atlas MRI is used for its deformation to provide accurate conformation to the MRI, thus adding information at the histological level to the MRI volume. This paper presents the mapping of single 2D image slice in block face as a proof of concept and this can be extended to map the atlas space in 3D coordinate system as part of the future work and can be loaded to an XNAT system for further use.

  13. Brain-to-brain hyperclassification reveals action-specific motor mapping of observed actions in humans.

    Science.gov (United States)

    Smirnov, Dmitry; Lachat, Fanny; Peltola, Tomi; Lahnakoski, Juha M; Koistinen, Olli-Pekka; Glerean, Enrico; Vehtari, Aki; Hari, Riitta; Sams, Mikko; Nummenmaa, Lauri

    2017-01-01

    Seeing an action may activate the corresponding action motor code in the observer. It remains unresolved whether seeing and performing an action activates similar action-specific motor codes in the observer and the actor. We used novel hyperclassification approach to reveal shared brain activation signatures of action execution and observation in interacting human subjects. In the first experiment, two "actors" performed four types of hand actions while their haemodynamic brain activations were measured with 3-T functional magnetic resonance imaging (fMRI). The actions were videotaped and shown to 15 "observers" during a second fMRI experiment. Eleven observers saw the videos of one actor, and the remaining four observers saw the videos of the other actor. In a control fMRI experiment, one of the actors performed actions with closed eyes, and five new observers viewed these actions. Bayesian canonical correlation analysis was applied to functionally realign observers' and actors' fMRI data. Hyperclassification of the seen actions was performed with Bayesian logistic regression trained on actors' data and tested with observers' data. Without the functional realignment, between-subjects accuracy was at chance level. With the realignment, the accuracy increased on average by 15 percentage points, exceeding both the chance level and the accuracy without functional realignment. The highest accuracies were observed in occipital, parietal and premotor cortices. Hyperclassification exceeded chance level also when the actor did not see her own actions. We conclude that the functional brain activation signatures underlying action execution and observation are partly shared, yet these activation signatures may be anatomically misaligned across individuals.

  14. Cerebrospinal fluid volumetric MRI mapping as a simple measurement for evaluating brain atrophy

    DEFF Research Database (Denmark)

    De Vis, J B; Zwanenburg, J J; van der Kleij, L A

    2016-01-01

    OBJECTIVES: To assess whether volumetric cerebrospinal fluid (CSF) MRI can be used as a surrogate for brain atrophy assessment and to evaluate how the T2 of the CSF relates to brain atrophy. METHODS: Twenty-eight subjects [mean age 64 (sd 2) years] were included; T1-weighted and CSF MRI were......) and medial temporal lobe atrophy (MTA)] was evaluated. RESULTS: Relative total, peripheral subarachnoidal, and ventricular VCSF increased significantly with increased scores on the GCA and MTA (R = 0.83, 0.78 and 0.78 and R = 0.72, 0.62 and 0.86). Total, peripheral subarachnoidal, and ventricular T2...... be a marker of neurodegenerative disease. KEY POINTS: • A 1:11 min CSF MRI volumetric sequence can evaluate brain atrophy. • CSF MRI provides accurate atrophy assessment without partial volume effects. • CSF MRI data can be processed quickly without user interaction. • The measured T 2 of the CSF is related...

  15. The power of using functional fMRI on small rodents to study brain pharmacology and disease

    OpenAIRE

    Jonckers, Elisabeth; Shah, Disha; Hamaide, Julie; Verhoye, Marleen; Van der Linden, Annemie

    2015-01-01

    Abstract: Functional magnetic resonance imaging (fMRI) is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD) fMRI techniques, including resting state (rsfMRI), stimulus-evoked (st-fMRI), and pharmacological MRI (phMRI). Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sen...

  16. Brain activity modification produced by a single radioelectric asymmetric brain stimulation pulse: a new tool for neuropsychiatric treatments. Preliminary fMRI study

    Directory of Open Access Journals (Sweden)

    Castagna A

    2011-10-01

    Full Text Available Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna1 1Department of Neuro-Psycho-Physio Pathology, Rinaldi Fontani Institute, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, Italy Purpose: Radioelectric asymmetric brain stimulation technology with its treatment protocols has shown efficacy in various psychiatric disorders. The aim of this work was to highlight the mechanisms by which these positive effects are achieved. The current study was conducted to determine whether a single 500-millisecond radioelectric asymmetric conveyor (REAC brain stimulation pulse (BSP, applied to the ear, can effect a modification of brain activity that is detectable using functional magnetic resonance imaging (fMRI. Methods: Ten healthy volunteers, six females and four males, underwent fMRI during a simple finger-tapping motor task before and after receiving a single 500-millisecond REAC-BSP. Results: The fMRI results indicate that the average variation in task-induced encephalic activation patterns is lower in subjects following the single REAC pulse. Conclusion: The current report demonstrates that a single REAC-BSP is sufficient to modulate brain activity in awake subjects, able to be measured using fMRI. These initial results open new perspectives into the understanding of the effects of weak and brief radio pulses upon brain activity, and provide the basis for further indepth studies using REAC-BSP and fMRI. Keywords: fMRI, brain stimulation, brain modulation, REAC, neuropsychiatric treatments

  17. Creating probabilistic maps of the face network in the adolescent brain: A multi-centre functional MRI study

    International Nuclear Information System (INIS)

    Tahmasebi, Amir M.; Mareckova, Klara; Artiges, Eric; Martinot, Jean-Luc; Banaschewski, Tobias; Barker, Gareth J.; Loth, Eva; Schumann, Gunter; Bruehl, Ruediger; Ittermann, Bernd; Buchel, Christian; Conrod, Patricia J.; Flor, Herta; Strohle, Andreas; Garavan, Hugh; Gallinat, Jurgen; Heinz, Andreas; Poline, Jean-Baptiste; Rietschel, Marcella; Smolka, Michael N.; Paus, Tomas

    2012-01-01

    Large-scale magnetic resonance (MR) studies of the human brain offer unique opportunities for identifying genetic and environmental factors shaping the human brain. Here, we describe a dataset collected in the context of a multi-centre study of the adolescent brain, namely the IMAGEN Study. We focus on one of the functional paradigms included in the project to probe the brain network underlying processing of ambiguous and angry faces. Using functional MR (fMRI) data collected in 1,110 adolescents, we constructed probabilistic maps of the neural network engaged consistently while viewing the ambiguous or angry faces; 21 brain regions responding to faces with high probability were identified. We were also able to address several methodological issues, including the minimal sample size yielding a stable location of a test region, namely the fusiform face area (FFA), as well as the effect of acquisition site (eight sites) and scanner (four manufacturers) on the location and magnitude of the fMRI response to faces in the FFA. Finally, we provided a comparison between male and female adolescents in terms of the effect sizes of sex differences in brain response to the ambiguous and angry faces in the 21 regions of interest. Overall, we found a stronger neural response to the ambiguous faces in several cortical regions, including the fusiform face area, in female (vs. male) adolescents, and a slightly stronger response to the angry faces in the amygdala of male (vs. female) adolescents. (authors)

  18. Pre-clinical testing of a phased array ultrasound system for MRI-guided noninvasive surgery of the brain--a primate study.

    Science.gov (United States)

    Hynynen, Kullervo; McDannold, Nathan; Clement, Greg; Jolesz, Ferenc A; Zadicario, Eyal; Killiany, Ron; Moore, Tara; Rosen, Douglas

    2006-08-01

    MRI-guided and monitored focused ultrasound thermal surgery of brain through intact skull was tested in three rhesus monkeys. The aim of this study was to determine the amount of skull heating in an animal model with a head shape similar to that of a human. The ultrasound beam was generated by a 512 channel phased array system (Exablate 3000, InSightec, Haifa, Israel) that was integrated within a 1.5-T MR-scanner. The skin was pre-cooled by degassed temperature controlled water circulating between the array surface and the skin. Skull surface temperature was measured with invasive thermocouple probes. The results showed that by applying surface cooling the skin and skull surface can be protected, and that the brain surface temperature becomes the limiting factor. The MRI thermometry was shown to be useful in detecting the tissue temperature distribution next to the bone, and it should be used to monitor the brain surface temperature. The acoustic intensity values during the 20 s sonications were adequate for thermal ablation in the human brain provided that surface cooling is used.

  19. Do spotty high intensity regions found in basal ganglia on MRI T2-weighted brain images of elderly subjects indicate gliosis? Comparison of brain MRI T2-weighted images of elderly subjects and necropsy brain

    International Nuclear Information System (INIS)

    Murai, Hiroshi; Hattori, Hideyuki; Matsumoto, Masayuki

    2001-01-01

    Spotty high intensity regions are frequently found on the MRI T2-weighted brain images (T2WI) of elderly people. High intensity regions with a diameter of 3 mm or less have been considered as expanded perivascular space with no pathological implications on radiological diagnosis. However, its morphometrical basis is not clear. We examined the character of the spotty regions using brain MRI of brain screening subjects, and studied morphometrically arteriolosclerosis and perivascular tissue damage using necropsy brains of subjects aged 65 years and over. The size, number and location of the spotty high intensity regions were examined using the brain MRI of 109 T2WI which is used for brain screening at Kanazawa Medical University Hospital. The frontal lobe, temporal lobe, parietal lobe, hippocampus, midbrain and basal ganglia were sampled from 15 subjects aged 65 years and over, and the tissue sections were processed for HE stain, Elastica van Gieson stain and immunostaining with GFAP. We took photographs of brain arterioli and surrounding parenchyma with a digital telescope camera and the degree of arterioscleosis and tissue damage were assessed by measurements with an image analyzer. Spotty high intensity regions on T2WI with a diameter of 3 mm or less were observed in 95.5% subjects aged 65 years and over. 69.4% spotty region was observed in basal ganglia. There was a significant correlation between age and size. In morphometrical examination, at the basal ganglia, the density of GFAP-positive astrocytes in the perivascular tissue had a significant positive correlation with the proportional thickness of the adventitia, which is an index of arteriosclerosis, and a significant negative correlation with the size of the perivascular space. The results suggested that the spotty regions in the brain MRI of elderly people do not represent dilatations of the perivascular space, but is mild brain damage caused by arteriosclerosis. (author)

  20. Neonatal brain MRI: how reliable is the radiologist's eye?

    Energy Technology Data Exchange (ETDEWEB)

    Morel, B. [A. Trousseau Hospital APHP, Pediatric Radiology, Paris (France); LTCI, CNRS, Telecom ParisTech, Universite Paris-Saclay, Paris (France); Antoni, G.; Teglas, J.P. [INSERM, CESP Centre for Research in Epidemiology and Population Health, U1018, Reproduction and Child Development, Villejuif (France); Bloch, I. [LTCI, CNRS, Telecom ParisTech, Universite Paris-Saclay, Paris (France); Adamsbaum, C. [Paris Sud University, Pediatric Radiology Department Bicetre Hospital APHP, Faculty of Medicine, Paris (France)

    2016-02-15

    White matter (WM) analysis in neonatal brain magnetic resonance imaging (MRI) is challenging, as demonstrated by the issue of diffuse excessive high signal intensity (DEHSI). We evaluated the reliability of the radiologist's eye in this context. Three experienced observers graded the WM signal intensity on axial T2-weighted 1.5T images from 60 different premature newborns on 2 occasions 4 weeks apart with a semi-quantitative classification under identical viewing conditions. The intra- and inter-observer correlation coefficients were fair to moderate (Fleiss' kappa between 0.21 and 0.60). This is a serious limitation of which we need to be aware, as it can lead to contradictory conclusions in the challenging context of term-equivalent age brain MRI in premature infants. These results highlight the need for a semiautomatic tool to help in objectively analyzing MRI signal intensity in the neonatal brain. (orig.)

  1. In vitro delineation of human brain-stem anatomy using a small resonator: correlation with macroscopic and histological findings

    International Nuclear Information System (INIS)

    Maeurer, J.; Mitrovic, T.; Knollmann, F.D.; Luedtke, E.; Requardt

    1996-01-01

    Our purpose was to investigate the potential of an experimental animal coil using a commercial MRI unit to delineate the anatomical structure of the human brain stem. Three formaldehyde-fixed brain-stem specimens were examined by MRI and sectioned perpendicular to their longitudinal axis. The images were compared with gross anatomy and myelin-stained histological sections. Fibre tracts and nuclei which were not evident on examination of the unstained specimen were readily identified by MRI. Due to its inherent grey/white matter contrast, MRI with a high-resolution coil delineates anatomical structures in a way comparable to the myelin-stained histological sections. However, pigmented structures, readily visible on examination of the unstained specimen were discernible on neither MRI nor on myelin-stained sections. The excellent anatomical detail and grey/white matter contrast provided by these images could make MRI a useful adjunct to the pathologist investigating brain disease. (orig.)

  2. Functional MRI in human motor control studies and clinical applications

    International Nuclear Information System (INIS)

    Toma, Keiichiro

    2002-01-01

    Functional magnetic resonance imaging (fMRI) has been a useful tool for the noninvasive mapping of brain function associated with various motor and cognitive tasks. Because fMRI is based on the blood oxygenation level dependent (BOLD) effect, it does not directly record neural activity. With the fMRI technique, distinguishing BOLD signals creased by cortical projection neurons from those created by intracortical neurons appears to be difficult. Two major experimental designs are used in fMRI studies: block designs and event-related designs. Block-designed fMRI presupposes the steady state of regional cerebral blood flow and has been applied to examinations of brain activation caused by tasks requiring sustained or repetitive movements. By contrast, the more recently developed event-related fMRI with time resolution of a few seconds allows the mapping of brain activation associated with a single movement according to the transient aspects of the hemodynamic response. Increasing evidence suggests that multiple motor areas are engaged in a networked manner to execute various motor acts. In order to understand functional brain maps, it is important that one understands sequential and parallel organizations of anatomical connections between multiple motor areas. In fMRI studies of complex motor tasks, elementary parameters such as movement length, force, velocity, acceleration and frequency should be controlled, because inconsistency in those parameters may alter the extent and intensity of motor cortical activation, confounding interpretation of the findings obtained. In addition to initiation of movements, termination of movements plays an important role in the successful achievement of complex movements. Brain areas exclusively related to the termination of movements have been, for the first time, uncovered with an event-related fMRI technique. We propose the application of fMRI to the elucidation of the pathophysiology of movement disorders, particularly dystonia

  3. Functional MRI in human motor control studies and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Toma, Keiichiro [Kyoto Univ. (Japan). Graduate School of Medicine; Nakai, Toshiharu [Inst. of Biomedical Research and Innovation, Kobe (Japan)

    2002-07-01

    Functional magnetic resonance imaging (fMRI) has been a useful tool for the noninvasive mapping of brain function associated with various motor and cognitive tasks. Because fMRI is based on the blood oxygenation level dependent (BOLD) effect, it does not directly record neural activity. With the fMRI technique, distinguishing BOLD signals creased by cortical projection neurons from those created by intracortical neurons appears to be difficult. Two major experimental designs are used in fMRI studies: block designs and event-related designs. Block-designed fMRI presupposes the steady state of regional cerebral blood flow and has been applied to examinations of brain activation caused by tasks requiring sustained or repetitive movements. By contrast, the more recently developed event-related fMRI with time resolution of a few seconds allows the mapping of brain activation associated with a single movement according to the transient aspects of the hemodynamic response. Increasing evidence suggests that multiple motor areas are engaged in a networked manner to execute various motor acts. In order to understand functional brain maps, it is important that one understands sequential and parallel organizations of anatomical connections between multiple motor areas. In fMRI studies of complex motor tasks, elementary parameters such as movement length, force, velocity, acceleration and frequency should be controlled, because inconsistency in those parameters may alter the extent and intensity of motor cortical activation, confounding interpretation of the findings obtained. In addition to initiation of movements, termination of movements plays an important role in the successful achievement of complex movements. Brain areas exclusively related to the termination of movements have been, for the first time, uncovered with an event-related fMRI technique. We propose the application of fMRI to the elucidation of the pathophysiology of movement disorders, particularly dystonia

  4. Intraoperative MRI in pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choudhri, Asim F. [Le Bonheur Children' s Hospital, Department of Radiology, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Siddiqui, Adeel [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Klimo, Paul; Boop, Frederick A. [University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Semmes-Murphey Neurologic and Spine Institute, Memphis, TN (United States); St. Jude Children' s Hospital, Division of Neurosurgery, Department of Surgery, Memphis, TN (United States)

    2015-09-15

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. (orig.)

  5. Intraoperative MRI in pediatric brain tumors

    International Nuclear Information System (INIS)

    Choudhri, Asim F.; Siddiqui, Adeel; Klimo, Paul; Boop, Frederick A.

    2015-01-01

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. (orig.)

  6. Development of Spatial and Verbal Working Memory Capacity in the Human Brain

    Science.gov (United States)

    Thomason, Moriah E.; Race, Elizabeth; Burrows, Brittany; Whitfield-Gabrieli, Susan; Glover, Gary H.; Gabrieli, John D. E.

    2009-01-01

    A core aspect of working memory (WM) is the capacity to maintain goal-relevant information in mind, but little is known about how this capacity develops in the human brain. We compared brain activation, via fMRI, between children (ages 7-12 years) and adults (ages 20-29 years) performing tests of verbal and spatial WM with varying amounts (loads)…

  7. Hidden Markov event sequence models: toward unsupervised functional MRI brain mapping.

    Science.gov (United States)

    Faisan, Sylvain; Thoraval, Laurent; Armspach, Jean-Paul; Foucher, Jack R; Metz-Lutz, Marie-Noëlle; Heitz, Fabrice

    2005-01-01

    Most methods used in functional MRI (fMRI) brain mapping require restrictive assumptions about the shape and timing of the fMRI signal in activated voxels. Consequently, fMRI data may be partially and misleadingly characterized, leading to suboptimal or invalid inference. To limit these assumptions and to capture the broad range of possible activation patterns, a novel statistical fMRI brain mapping method is proposed. It relies on hidden semi-Markov event sequence models (HSMESMs), a special class of hidden Markov models (HMMs) dedicated to the modeling and analysis of event-based random processes. Activation detection is formulated in terms of time coupling between (1) the observed sequence of hemodynamic response onset (HRO) events detected in the voxel's fMRI signal and (2) the "hidden" sequence of task-induced neural activation onset (NAO) events underlying the HROs. Both event sequences are modeled within a single HSMESM. The resulting brain activation model is trained to automatically detect neural activity embedded in the input fMRI data set under analysis. The data sets considered in this article are threefold: synthetic epoch-related, real epoch-related (auditory lexical processing task), and real event-related (oddball detection task) fMRI data sets. Synthetic data: Activation detection results demonstrate the superiority of the HSMESM mapping method with respect to a standard implementation of the statistical parametric mapping (SPM) approach. They are also very close, sometimes equivalent, to those obtained with an "ideal" implementation of SPM in which the activation patterns synthesized are reused for analysis. The HSMESM method appears clearly insensitive to timing variations of the hemodynamic response and exhibits low sensitivity to fluctuations of its shape (unsustained activation during task). Real epoch-related data: HSMESM activation detection results compete with those obtained with SPM, without requiring any prior definition of the expected

  8. Segmentation and Visualisation of Human Brain Structures

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Roger

    2003-10-01

    In this thesis the focus is mainly on the development of segmentation techniques for human brain structures and of the visualisation of such structures. The images of the brain are both anatomical images (magnet resonance imaging (MRI) and autoradiography) and functional images that show blood flow (functional magnetic imaging (fMRI), positron emission tomography (PET), and single photon emission tomography (SPECT)). When working with anatomical images, the structures segmented are visible as different parts of the brain, e.g. the brain cortex, the hippocampus, or the amygdala. In functional images, the activity or the blood flow that be seen. Grey-level morphology methods are used in the segmentations to make tissue types in the images more homogenous and minimise difficulties with connections to outside tissue. A method for automatic histogram thresholding is also used. Furthermore, there are binary operations such as logic operation between masks and binary morphology operations. The visualisation of the segmented structures uses either surface rendering or volume rendering. For the visualisation of thin structures, surface rendering is the better choice since otherwise some voxels might be missed. It is possible to display activation from a functional image on the surface of a segmented cortex. A new method for autoradiographic images has been developed, which integrates registration, background compensation, and automatic thresholding to get faster and more reliable results than the standard techniques give.

  9. Segmentation and Visualisation of Human Brain Structures

    International Nuclear Information System (INIS)

    Hult, Roger

    2003-01-01

    In this thesis the focus is mainly on the development of segmentation techniques for human brain structures and of the visualisation of such structures. The images of the brain are both anatomical images (magnet resonance imaging (MRI) and autoradiography) and functional images that show blood flow (functional magnetic imaging (fMRI), positron emission tomography (PET), and single photon emission tomography (SPECT)). When working with anatomical images, the structures segmented are visible as different parts of the brain, e.g. the brain cortex, the hippocampus, or the amygdala. In functional images, the activity or the blood flow that be seen. Grey-level morphology methods are used in the segmentations to make tissue types in the images more homogenous and minimise difficulties with connections to outside tissue. A method for automatic histogram thresholding is also used. Furthermore, there are binary operations such as logic operation between masks and binary morphology operations. The visualisation of the segmented structures uses either surface rendering or volume rendering. For the visualisation of thin structures, surface rendering is the better choice since otherwise some voxels might be missed. It is possible to display activation from a functional image on the surface of a segmented cortex. A new method for autoradiographic images has been developed, which integrates registration, background compensation, and automatic thresholding to get faster and more reliable results than the standard techniques give

  10. Custom Fit 3D-Printed Brain Holders for Comparison of Histology with MRI in Marmosets

    Science.gov (United States)

    Guy, Joseph R.; Sati, Pascal; Leibovitch, Emily; Jacobson, Steven; Silva, Afonso C.; Reich, Daniel S.

    2015-01-01

    Background MRI has the advantage of sampling large areas of tissue and locating areas of interest in 3D space in both living and ex vivo systems, whereas histology has the ability to examine thin slices of ex vivo tissue with high detail and specificity. Although both are valuable tools, it is currently difficult to make high-precision comparisons between MRI and histology due to large differences inherent to the techniques. A method combining the advantages would be an asset to understanding the pathological correlates of MRI. New Method 3D-printed brain holders were used to maintain marmoset brains in the same orientation during acquisition of ex vivo MRI and pathologic cutting of the tissue. Results The results of maintaining this same orientation show that sub-millimeter, discrete neuropathological features in marmoset brain consistently share size, shape, and location between histology and ex vivo MRI, which facilitates comparison with serial imaging acquired in vivo. Comparison with Existing Methods Existing methods use computational approaches sensitive to data input in order to warp histologic images to match large-scale features on MRI, but the new method requires no warping of images, due to a preregistration accomplished in the technique, and is insensitive to data formatting and artifacts in both MRI and histology. Conclusions The simple method of using 3D-printed brain holders to match brain orientation during pathologic sectioning and MRI acquisition enables rapid and precise comparison of small features seen on MRI to their underlying histology. PMID:26365332

  11. Homocysteine and brain atrophy on MRI of non-demented elderly

    NARCIS (Netherlands)

    den Heijer, T; Vermeer, SE; Clarke, R; Oudkerk, M; Koudstaal, PJ; Hofman, A; Breteler, MMB

    Patients with Alzheimer's disease have higher plasma homocysteine levels than controls, but it is uncertain whether higher plasma homocysteine levels are involved in the early pathogenesis of the disease. Hippocampal, amygdalar and global brain atrophy on brain MRI have been proposed as early

  12. Role of mitochondrial calcium uptake homeostasis in resting state fMRI brain networks.

    Science.gov (United States)

    Kannurpatti, Sridhar S; Sanganahalli, Basavaraju G; Herman, Peter; Hyder, Fahmeed

    2015-11-01

    Mitochondrial Ca(2+) uptake influences both brain energy metabolism and neural signaling. Given that brain mitochondrial organelles are distributed in relation to vascular density, which varies considerably across brain regions, we hypothesized different physiological impacts of mitochondrial Ca(2+) uptake across brain regions. We tested the hypothesis by monitoring brain "intrinsic activity" derived from the resting state functional MRI (fMRI) blood oxygen level dependent (BOLD) fluctuations in different functional networks spanning the somatosensory cortex, caudate putamen, hippocampus and thalamus, in normal and perturbed mitochondrial Ca(2+) uptake states. In anesthetized rats at 11.7 T, mitochondrial Ca(2+) uptake was inhibited or enhanced respectively by treatments with Ru360 or kaempferol. Surprisingly, mitochondrial Ca(2+) uptake inhibition by Ru360 and enhancement by kaempferol led to similar dose-dependent decreases in brain-wide intrinsic activities in both the frequency domain (spectral amplitude) and temporal domain (resting state functional connectivity; RSFC). The fact that there were similar dose-dependent decreases in the frequency and temporal domains of the resting state fMRI-BOLD fluctuations during mitochondrial Ca(2+) uptake inhibition or enhancement indicated that mitochondrial Ca(2+) uptake and its homeostasis may strongly influence the brain's functional organization at rest. Interestingly, the resting state fMRI-derived intrinsic activities in the caudate putamen and thalamic regions saturated much faster with increasing dosage of either drug treatment than the drug-induced trends observed in cortical and hippocampal regions. Regional differences in how the spectral amplitude and RSFC changed with treatment indicate distinct mitochondrion-mediated spontaneous neuronal activity coupling within the various RSFC networks determined by resting state fMRI. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Multidimensional MRI-CT atlas of the naked mole-rat brain

    Directory of Open Access Journals (Sweden)

    Fumiko eSeki

    2013-12-01

    Full Text Available Naked mole-rats have a variety of distinctive features such as the organisation of a hierarchical society (known as eusociality, extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI, which generates high contrast images of fibre structures, can characterise unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography (CT were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualisation of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  14. Using human brain activity to guide machine learning.

    Science.gov (United States)

    Fong, Ruth C; Scheirer, Walter J; Cox, David D

    2018-03-29

    Machine learning is a field of computer science that builds algorithms that learn. In many cases, machine learning algorithms are used to recreate a human ability like adding a caption to a photo, driving a car, or playing a game. While the human brain has long served as a source of inspiration for machine learning, little effort has been made to directly use data collected from working brains as a guide for machine learning algorithms. Here we demonstrate a new paradigm of "neurally-weighted" machine learning, which takes fMRI measurements of human brain activity from subjects viewing images, and infuses these data into the training process of an object recognition learning algorithm to make it more consistent with the human brain. After training, these neurally-weighted classifiers are able to classify images without requiring any additional neural data. We show that our neural-weighting approach can lead to large performance gains when used with traditional machine vision features, as well as to significant improvements with already high-performing convolutional neural network features. The effectiveness of this approach points to a path forward for a new class of hybrid machine learning algorithms which take both inspiration and direct constraints from neuronal data.

  15. The usefulness of brain MRI and CT in the clinical practice of epilepsia

    Energy Technology Data Exchange (ETDEWEB)

    Horita, Hideki [Jikei Univ., Komae, Tokyo (Japan). Daisan Hospital; Maekawa, Kihei

    1995-09-01

    This study was conducted to clarify the usefulness of brain MRI and CT in the clinical practice of epilepsy. The subjects were 100 epileptic child patients (average age, 13.2{+-}8.2 years) who underwent brain MRI, including 93 patients who also underwent brain CT. Twenty-two abnormal findings were obtained by MRI and 25 by CT. Thirty-nine patients who had complications such as mental retardation, cerebral palsy, or the overlapping disorders showed abnormal findings in a significantly high incidence. No significant correlations existed between the presence or absence of abnormal findings and the disease course after seizures. Patients with symptomatic localization-related epilepsies or cryptogenic and symptomatic generalized epilepsies showed abnormal findings in a significantly high incidence and unfavorable disease course after seizures. In 10 of 28 patients who showed abnormal findings, the abnormal finding site on images were correlated to the focus site on electroencephalograms. In conclusion, brain MRI and CT are essential in the clinical practice of epilepsy, however, we should notice the limitation of these methods. (Y.S.).

  16. The usefulness of brain MRI and CT in the clinical practice of epilepsia

    International Nuclear Information System (INIS)

    Horita, Hideki; Maekawa, Kihei.

    1995-01-01

    This study was conducted to clarify the usefulness of brain MRI and CT in the clinical practice of epilepsy. The subjects were 100 epileptic child patients (average age, 13.2±8.2 years) who underwent brain MRI, including 93 patients who also underwent brain CT. Twenty-two abnormal findings were obtained by MRI and 25 by CT. Thirty-nine patients who had complications such as mental retardation, cerebral palsy, or the overlapping disorders showed abnormal findings in a significantly high incidence. No significant correlations existed between the presence or absence of abnormal findings and the disease course after seizures. Patients with symptomatic localization-related epilepsies or cryptogenic and symptomatic generalized epilepsies showed abnormal findings in a significantly high incidence and unfavorable disease course after seizures. In 10 of 28 patients who showed abnormal findings, the abnormal finding site on images were correlated to the focus site on electroencephalograms. In conclusion, brain MRI and CT are essential in the clinical practice of epilepsy, however, we should notice the limitation of these methods. (Y.S.)

  17. MRI of the brain and craniocervical junction in Morquio's disease

    International Nuclear Information System (INIS)

    Hughes, D.G.; Chadderton, R.D.; Cowie, R.A.; Wraith, J.E.; Jenkins, J.P.R.

    1997-01-01

    We reviewed MRI of the brain and cervical spine in 11 patients with Morquio's disease. No abnormality was seen in the brain. The odontoid peg was abnormal in all patients, with varying degrees of cord compression due to an anterior soft tissue mass and indentation by the posterior arch of the atlas. The degree of cord compression was more marked than suggested by the symptoms and signs. We recommend MRI of the cervical spine in children with Morquio's disease before the development of neurological symptoms, to optimise the timing and type of surgical intervention. (orig.). With 5 figs., 2 tabs

  18. Implications of oxidative stress in the brain plasticity originated by fasting: a BOLD-fMRI study.

    Science.gov (United States)

    Belaïch, Rachida; Boujraf, Saïd; Benzagmout, Mohammed; Magoul, Rabia; Maaroufi, Mustapha; Tizniti, Siham

    2017-11-01

    and the maximum intensity of BOLD signal in the activated area M1 was determined for all studied volunteers. The current study allowed measuring regional brain volumes and neural network activity before and during an extended period of fasting using BOLD-fMRI. This demonstrated and confirmed the impact of fasting on human brain structure and function. Further studies are required to elucidate mechanisms and enable direct inference of a diet-induced OS effect on the brain.

  19. Tuberous sclerosis: diffusion MRI findings in the brain

    International Nuclear Information System (INIS)

    Sener, R.N.

    2002-01-01

    Diffusion MRI has mainly been used for detection of acute ischemia, and for distinction of cytotoxic and vasogenic edema. We applied diffusion MRI in patients with tuberous sclerosis in order to evaluate diffusion imaging characteristics of parenchymal changes. Five children with known tuberous sclerosis were included in this study. The MRI examinations were performed on a 1.5-T MR unit. Diffusion MRI was obtained using the echo-planar imaging sequence. Apparent diffusion coefficient (ADC) values from the abnormal brain parenchyma were calculated directly from automatically generated ADC maps. Seven normal children were available for comparison. In this control group the mean ADC value of the normal white matter was 0.84±0.12 x 10 -3 mm 2 /s. In tuberous sclerosis patients the mean ADC value of the white matter hamartomas (n=20) was apparently high (1.52±0.24 x 10 -3 mm 2 /s) compared with that of normal white matter. The ADC value of calcified hamartomas was ''zero''. The ADC value within a giant cell tumor was 0.89 x 10 -3 mm 2 /s, similar to that of normal cerebral white matter. The ADC maps were superior to b=1000 s/mm 2 (true diffusion) images with respect to lesion evaluation, and they provided mathematical information on tissue integrity. With respect to detection of the exact numbers and sizes of the parenchymal hamartomas fluid-attenuated inversion recovery images were superior to ADC maps. It is believed that diffusion MRI can be useful in evaluation of various parenchymal changes associated with tuberous sclerosis. Further studies on tuberous sclerosis, and on various brain lesions, would provide increasing data on this relatively new MRI sequence. (orig.)

  20. Direct Electrical Stimulation in the Human Brain Disrupts Melody Processing.

    Science.gov (United States)

    Garcea, Frank E; Chernoff, Benjamin L; Diamond, Bram; Lewis, Wesley; Sims, Maxwell H; Tomlinson, Samuel B; Teghipco, Alexander; Belkhir, Raouf; Gannon, Sarah B; Erickson, Steve; Smith, Susan O; Stone, Jonathan; Liu, Lynn; Tollefson, Trenton; Langfitt, John; Marvin, Elizabeth; Pilcher, Webster H; Mahon, Bradford Z

    2017-09-11

    Prior research using functional magnetic resonance imaging (fMRI) [1-4] and behavioral studies of patients with acquired or congenital amusia [5-8] suggest that the right posterior superior temporal gyrus (STG) in the human brain is specialized for aspects of music processing (for review, see [9-12]). Intracranial electrical brain stimulation in awake neurosurgery patients is a powerful means to determine the computations supported by specific brain regions and networks [13-21] because it provides reversible causal evidence with high spatial resolution (for review, see [22, 23]). Prior intracranial stimulation or cortical cooling studies have investigated musical abilities related to reading music scores [13, 14] and singing familiar songs [24, 25]. However, individuals with amusia (congenitally, or from a brain injury) have difficulty humming melodies but can be spared for singing familiar songs with familiar lyrics [26]. Here we report a detailed study of a musician with a low-grade tumor in the right temporal lobe. Functional MRI was used pre-operatively to localize music processing to the right STG, and the patient subsequently underwent awake intraoperative mapping using direct electrical stimulation during a melody repetition task. Stimulation of the right STG induced "music arrest" and errors in pitch but did not affect language processing. These findings provide causal evidence for the functional segregation of music and language processing in the human brain and confirm a specific role of the right STG in melody processing. VIDEO ABSTRACT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Parametric fMRI analysis of visual encoding in the human medial temporal lobe.

    Science.gov (United States)

    Rombouts, S A; Scheltens, P; Machielson, W C; Barkhof, F; Hoogenraad, F G; Veltman, D J; Valk, J; Witter, M P

    1999-01-01

    A number of functional brain imaging studies indicate that the medial temporal lobe system is crucially involved in encoding new information into memory. However, most studies were based on differences in brain activity between encoding of familiar vs. novel stimuli. To further study the underlying cognitive processes, we applied a parametric design of encoding. Seven healthy subjects were instructed to encode complex color pictures into memory. Stimuli were presented in a parametric fashion at different rates, thus representing different loads of encoding. Functional magnetic resonance imaging (fMRI) was used to assess changes in brain activation. To determine the number of pictures successfully stored into memory, recognition scores were determined afterwards. During encoding, brain activation occurred in the medial temporal lobe, comparable to the results obtained by others. Increasing the encoding load resulted in an increase in the number of successfully stored items. This was reflected in a significant increase in brain activation in the left lingual gyrus, in the left and right parahippocampal gyrus, and in the right inferior frontal gyrus. This study shows that fMRI can detect changes in brain activation during variation of one aspect of higher cognitive tasks. Further, it strongly supports the notion that the human medial temporal lobe is involved in encoding novel visual information into memory.

  2. Topological isomorphisms of human brain and financial market networks

    Directory of Open Access Journals (Sweden)

    Petra E Vértes

    2011-09-01

    Full Text Available Although metaphorical and conceptual connections between the human brain and the financial markets have often been drawn, rigorous physical or mathematical underpinnings of this analogy remain largely unexplored. Here, we apply a statistical and graph theoretic approach to the study of two datasets - the timeseries of 90 stocks from the New York Stock Exchange over a three-year period, and the fMRI-derived timeseries acquired from 90 brain regions over the course of a 10 min-long functional MRI scan of resting brain function in healthy volunteers. Despite the many obvious substantive differences between these two datasets, graphical analysis demonstrated striking commonalities in terms of global network topological properties. Both the human brain and the market networks were non-random, small-world, modular, hierarchical systems with fat-tailed degree distributions indicating the presence of highly connected hubs. These properties could not be trivially explained by the univariate time series statistics of stock price returns. This degree of topological isomorphism suggests that brains and markets can be regarded broadly as members of the same family of networks. The two systems, however, were not topologically identical. The financial market was more efficient and more modular - more highly optimised for information processing - than the brain networks; but also less robust to systemic disintegration as a result of hub deletion. We conclude that the conceptual connections between brains and markets are not merely metaphorical; rather these two information processing systems can be rigorously compared in the same mathematical language and turn out often to share important topological properties in common to some degree. There will be interesting scientific arbitrage opportunities in further work at the graph theoretically-mediated interface between systems neuroscience and the statistical physics of financial markets.

  3. Topological isomorphisms of human brain and financial market networks.

    Science.gov (United States)

    Vértes, Petra E; Nicol, Ruth M; Chapman, Sandra C; Watkins, Nicholas W; Robertson, Duncan A; Bullmore, Edward T

    2011-01-01

    Although metaphorical and conceptual connections between the human brain and the financial markets have often been drawn, rigorous physical or mathematical underpinnings of this analogy remain largely unexplored. Here, we apply a statistical and graph theoretic approach to the study of two datasets - the time series of 90 stocks from the New York stock exchange over a 3-year period, and the fMRI-derived time series acquired from 90 brain regions over the course of a 10-min-long functional MRI scan of resting brain function in healthy volunteers. Despite the many obvious substantive differences between these two datasets, graphical analysis demonstrated striking commonalities in terms of global network topological properties. Both the human brain and the market networks were non-random, small-world, modular, hierarchical systems with fat-tailed degree distributions indicating the presence of highly connected hubs. These properties could not be trivially explained by the univariate time series statistics of stock price returns. This degree of topological isomorphism suggests that brains and markets can be regarded broadly as members of the same family of networks. The two systems, however, were not topologically identical. The financial market was more efficient and more modular - more highly optimized for information processing - than the brain networks; but also less robust to systemic disintegration as a result of hub deletion. We conclude that the conceptual connections between brains and markets are not merely metaphorical; rather these two information processing systems can be rigorously compared in the same mathematical language and turn out often to share important topological properties in common to some degree. There will be interesting scientific arbitrage opportunities in further work at the graph-theoretically mediated interface between systems neuroscience and the statistical physics of financial markets.

  4. Three-dimensional brain mapping using fMRI

    International Nuclear Information System (INIS)

    Fukunaga, Masaki; Tanaka, Chuzo; Umeda, Masahiro; Ebisu, Toshihiko; Aoki, Ichio; Higuchi, Toshihiro; Naruse, Shoji.

    1997-01-01

    Functional mapping of the activated brain, the location and extent of the activated area were determined, during motor tasks and sensory stimulation using fMRI superimposed on 3D anatomical MRI. Twelve volunteers were studied. The fMR images were acquired using a 2D gradient echo echo planar imaging sequence. The 3D anatomical MR images of the whole brain were acquired using a conventional 3D gradient echo sequence. Motor tasks were sequential opposition of fingers, clenching a hand and elbow flexion. Somatosensory stimulation were administered by scrubbing the palm and sole with a washing sponge. Visual stimulation consisted of full visual field stimulation. Data were analyzed by the cross-correlation method. Transversal fMR images and anatomical images were reconstructed using both volume-, surface-rendering methods, and reconstructed for coronal and sagittal sections. Activated areas were expressed using the three primary colors. Motor tasks activated the contralateral primary motor area (M1), the primary somatosensory area (S1) and the supplementary motor area (SMA). Somatosensory tasks activated the contralateral S1, M1 and secondary sensory area (S2). Activated areas during full visual field stimulation was observed in the bilateral occipital lobe, including both the primary cortex. Three-dimensional brain mapping allowed visualization of the anatomical location and extent of the activated brain during both motor task and sensory stimulation. Using this method we could obtain a functional map similar to the Penfield's schema. (author)

  5. Pediatric MRI

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Study of Normal Brain Development is a longitudinal study using anatomical MRI, diffusion tensor imaging (DTI), and MR spectroscopy (MRS) to map pediatric...

  6. Evaluation of MRI sequences for quantitative T1 brain mapping

    Science.gov (United States)

    Tsialios, P.; Thrippleton, M.; Glatz, A.; Pernet, C.

    2017-11-01

    T1 mapping constitutes a quantitative MRI technique finding significant application in brain imaging. It allows evaluation of contrast uptake, blood perfusion, volume, providing a more specific biomarker of disease progression compared to conventional T1-weighted images. While there are many techniques for T1-mapping there is a wide range of reported T1-values in tissues, raising the issue of protocols reproducibility and standardization. The gold standard for obtaining T1-maps is based on acquiring IR-SE sequence. Widely used alternative sequences are IR-SE-EPI, VFA (DESPOT), DESPOT-HIFI and MP2RAGE that speed up scanning and fitting procedures. A custom MRI phantom was used to assess the reproducibility and accuracy of the different methods. All scans were performed using a 3T Siemens Prisma scanner. The acquired data processed using two different codes. The main difference was observed for VFA (DESPOT) which grossly overestimated T1 relaxation time by 214 ms [126 270] compared to the IR-SE sequence. MP2RAGE and DESPOT-HIFI sequences gave slightly shorter time than IR-SE (~20 to 30ms) and can be considered as alternative and time-efficient methods for acquiring accurate T1 maps of the human brain, while IR-SE-EPI gave identical result, at a cost of a lower image quality.

  7. Brain MRI findings of carbon disulfide poisoning

    International Nuclear Information System (INIS)

    Cha, Joo Hee; Kim, Mi Jung; Yim, Sang Hyuk; Kim, Sam Soo; Han, Heon; Kim, Rok Ho

    2002-01-01

    To evaluate the findings of brain MRI in patients with carbon disulfide poisoning. Ninety-one patients who had suffered carbon disulfide poisoning [male:female=87:4; age, 32-74 (mean 53.3) years] were included in this study. To determine the extent of white matter hyperintensity (Grade 0-V) and lacunar infarction, T2-weighted MR imaging of the brain was performed. T2-weighted images depicted white matter hyperintensity in 70 patients (76.9%) and lacunar infarcts in 27 (29.7%). In these patients, the prevalent findings at T2-weighted MR imaging of the brain were white matter hyperintensity and lacunar infarcts. Disturbance of the cardiovascular system by carbon disulfide might account for these results

  8. How Does Your Brain See “Living” Circles: A Study of Animacy and Intention Using fMRI

    Directory of Open Access Journals (Sweden)

    P McAleer

    2011-04-01

    Full Text Available It is widely reported that the perception of animacy can occur from simple displays of moving shapes with participants attributing such qualities as goals, beliefs, and intentions. Furthermore, via neuroimaging studies, a network of brain areas, including regions of the temporal and frontal lobes, has been shown to process the percept. However, problems exist that prevent the bridging of fMRI studies on the perception of animacy and intention in shapes to the same percept of human movement. First, the issue of prior displays being poorly controlled in terms of low-level visual cues blurs the actual root of the effect. Second, the general use of synthetically generated displays and their relationship to actual human movement: a problem previously addressed in behavioural studies via a systematic reduction of live visual footage of human actors. Therefore, we propose experiments that incorporate both synthetically generated animacy stimuli and displays derived from human motion. Following the classic Tremoulet and Feldman displays, stimuli are created that allow for manipulation of animacy and intent whilst controlling low-level visual cues. These displays are then used in a whole-brain fMRI study to locate neural regions sensitive to the perception of animacy and intention. Finally, within these regions, a region-of-interest analysis is performed to examine the change in brain activation from viewing animacy displays derived from human movement with varying intent (eg, chasing or following. This study develops the relationship between previous animacy literature and the real-world perception of intent.

  9. Revealing topological organization of human brain functional networks with resting-state functional near infrared spectroscopy.

    Science.gov (United States)

    Niu, Haijing; Wang, Jinhui; Zhao, Tengda; Shu, Ni; He, Yong

    2012-01-01

    The human brain is a highly complex system that can be represented as a structurally interconnected and functionally synchronized network, which assures both the segregation and integration of information processing. Recent studies have demonstrated that a variety of neuroimaging and neurophysiological techniques such as functional magnetic resonance imaging (MRI), diffusion MRI and electroencephalography/magnetoencephalography can be employed to explore the topological organization of human brain networks. However, little is known about whether functional near infrared spectroscopy (fNIRS), a relatively new optical imaging technology, can be used to map functional connectome of the human brain and reveal meaningful and reproducible topological characteristics. We utilized resting-state fNIRS (R-fNIRS) to investigate the topological organization of human brain functional networks in 15 healthy adults. Brain networks were constructed by thresholding the temporal correlation matrices of 46 channels and analyzed using graph-theory approaches. We found that the functional brain network derived from R-fNIRS data had efficient small-world properties, significant hierarchical modular structure and highly connected hubs. These results were highly reproducible both across participants and over time and were consistent with previous findings based on other functional imaging techniques. Our results confirmed the feasibility and validity of using graph-theory approaches in conjunction with optical imaging techniques to explore the topological organization of human brain networks. These results may expand a methodological framework for utilizing fNIRS to study functional network changes that occur in association with development, aging and neurological and psychiatric disorders.

  10. Brain MRI findings of spontaneous intracranial hypotension

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Kyu; Byun, Woo Mok; Cho, Jae Ho; Cho Kil Ho; Hwang, Mi Soo; Park, Bok Hwan [Yeungnam Univ. College of Medicine, Taegu (Korea, Republic of); Joo, Yang Gu [Keimyoung Univ. College of Medicine, Taegu (Korea, Republic of); Lee, Sang Jin [Soonchunhyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-09-01

    To evaluate brain MRI findings of spontaneous intracranial hypotension. A retrospective review of MRI findings was conducted on six patients with clinically proven spontaneous intracranial hypotension; no patient had a history of previous spinal puncture. Follow-up MRI was available in two patients, and to detect CSF leakage, radio-nuclide cisternography(n=3D5), myelography(n=3D1), and MR myelography(n=3D1) were performed. On contrast-enhanced T1WI, diffuse dural enhancement was seen in all cases, subdural hematoma or hygroma was seen in four cases, pituitary gland prominence in four, dural sinus dilatation in four, downward displacement of the cerebellar tonsil in two, downward displacement of the iter in one, and suprasellar and prepontine cistern effacement in two. In no patient was abnormal CSF leakage found. Although dural enhancement, as seen on MRI, is not specific, diffuse enhancement of the dura mater accompanied by subdural hematoma, hygroma, pituitary gland prominence, dural sinus dilatation, downward displacement of the cerebellar tonsil, or suprasellar and prepontine cistern effacement can strongly suggest intracranial hypotension.=20.

  11. Change in brain and lesion volumes after CEE therapies: the WHIMS-MRI studies.

    Science.gov (United States)

    Coker, Laura H; Espeland, Mark A; Hogan, Patricia E; Resnick, Susan M; Bryan, R Nick; Robinson, Jennifer G; Goveas, Joseph S; Davatzikos, Christos; Kuller, Lewis H; Williamson, Jeff D; Bushnell, Cheryl D; Shumaker, Sally A

    2014-02-04

    To determine whether smaller brain volumes in older women who had completed Women's Health Initiative (WHI)-assigned conjugated equine estrogen-based hormone therapy (HT), reported by WHI Memory Study (WHIMS)-MRI, correspond to a continuing increased rate of atrophy an average of 6.1 to 7.7 years later in WHIMS-MRI2. A total of 1,230 WHI participants were contacted: 797 (64.8%) consented, and 729 (59%) were rescanned an average of 4.7 years after the initial MRI scan. Mean annual rates of change in total brain volume, the primary outcome, and rates of change in ischemic lesion volumes, the secondary outcome, were compared between treatment groups using mixed-effect models with adjustment for trial, clinical site, age, intracranial volumes, and time between MRI measures. Total brain volume decreased an average of 3.22 cm(3)/y in the active arm and 3.07 cm(3)/y in the placebo arm (p = 0.53). Total ischemic lesion volumes increased in both arms at a rate of 0.12 cm(3)/y (p = 0.88). Conjugated equine estrogen-based postmenopausal HT, previously assigned at WHI baseline, did not affect rates of decline in brain volumes or increases in brain lesion volumes during the 4.7 years between the initial and follow-up WHIMS-MRI studies. Smaller frontal lobe volumes were observed as persistent group differences among women assigned to active HT compared with placebo. Women with a history of cardiovascular disease treated with active HT, compared with placebo, had higher rates of accumulation in white matter lesion volume and total brain lesion volume. Further study may elucidate mechanisms that explain these findings.

  12. Anisotropic Diffusion based Brain MRI Segmentation and 3D Reconstruction

    OpenAIRE

    M. Arfan Jaffar; Sultan Zia; Ghaznafar Latif; AnwarM. Mirza; Irfan Mehmood; Naveed Ejaz; Sung Wook Baik

    2012-01-01

    In medical field visualization of the organs is very imperative for accurate diagnosis and treatment of any disease. Brain tumor diagnosis and surgery also required impressive 3D visualization of the brain to the radiologist. Detection and 3D reconstruction of brain tumors from MRI is a computationally time consuming and error-prone task. Proposed system detects and presents a 3D visualization model of the brain and tumor inside which greatly helps the radiologist to effectively diagnose and ...

  13. Spatial Mapping of Structural and Connectional Imaging Data for the Developing Human Brain with Diffusion Tensor Imaging

    Science.gov (United States)

    Ouyang, Austin; Jeon, Tina; Sunkin, Susan M.; Pletikos, Mihovil; Sedmak, Goran; Sestan, Nenad; Lein, Ed S.; Huang, Hao

    2014-01-01

    During human brain development from fetal stage to adulthood, the white matter (WM) tracts undergo dramatic changes. Diffusion tensor imaging (DTI), a widely used magnetic resonance imaging (MRI) modality, offers insight into the dynamic changes of WM fibers as these fibers can be noninvasively traced and three-dimensionally (3D) reconstructed with DTI tractography. The DTI and conventional T1 weighted MRI images also provide sufficient cortical anatomical details for mapping the cortical regions of interests (ROIs). In this paper, we described basic concepts and methods of DTI techniques that can be used to trace major WM tracts noninvasively from fetal brain of 14 postconceptional weeks (pcw) to adult brain. We applied these techniques to acquire DTI data and trace, reconstruct and visualize major WM tracts during development. After categorizing major WM fiber bundles into five unique functional tract groups, namely limbic, brain stem, projection, commissural and association tracts, we revealed formation and maturation of these 3D reconstructed WM tracts of the developing human brain. The structural and connectional imaging data offered by DTI provides the anatomical backbone of transcriptional atlas of the developing human brain. PMID:25448302

  14. Spatial mapping of structural and connectional imaging data for the developing human brain with diffusion tensor imaging.

    Science.gov (United States)

    Ouyang, Austin; Jeon, Tina; Sunkin, Susan M; Pletikos, Mihovil; Sedmak, Goran; Sestan, Nenad; Lein, Ed S; Huang, Hao

    2015-02-01

    During human brain development from fetal stage to adulthood, the white matter (WM) tracts undergo dramatic changes. Diffusion tensor imaging (DTI), a widely used magnetic resonance imaging (MRI) modality, offers insight into the dynamic changes of WM fibers as these fibers can be noninvasively traced and three-dimensionally (3D) reconstructed with DTI tractography. The DTI and conventional T1 weighted MRI images also provide sufficient cortical anatomical details for mapping the cortical regions of interests (ROIs). In this paper, we described basic concepts and methods of DTI techniques that can be used to trace major WM tracts noninvasively from fetal brain of 14 postconceptional weeks (pcw) to adult brain. We applied these techniques to acquire DTI data and trace, reconstruct and visualize major WM tracts during development. After categorizing major WM fiber bundles into five unique functional tract groups, namely limbic, brain stem, projection, commissural and association tracts, we revealed formation and maturation of these 3D reconstructed WM tracts of the developing human brain. The structural and connectional imaging data offered by DTI provides the anatomical backbone of transcriptional atlas of the developing human brain. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Functional brain activation differences in stuttering identified with a rapid fMRI sequence

    Science.gov (United States)

    Kraft, Shelly Jo; Choo, Ai Leen; Sharma, Harish; Ambrose, Nicoline G.

    2011-01-01

    The purpose of this study was to investigate whether brain activity related to the presence of stuttering can be identified with rapid functional MRI (fMRI) sequences that involved overt and covert speech processing tasks. The long-term goal is to develop sensitive fMRI approaches with developmentally appropriate tasks to identify deviant speech motor and auditory brain activity in children who stutter closer to the age at which recovery from stuttering is documented. Rapid sequences may be preferred for individuals or populations who do not tolerate long scanning sessions. In this report, we document the application of a picture naming and phoneme monitoring task in three minute fMRI sequences with adults who stutter (AWS). If relevant brain differences are found in AWS with these approaches that conform to previous reports, then these approaches can be extended to younger populations. Pairwise contrasts of brain BOLD activity between AWS and normally fluent adults indicated the AWS showed higher BOLD activity in the right inferior frontal gyrus (IFG), right temporal lobe and sensorimotor cortices during picture naming and and higher activity in the right IFG during phoneme monitoring. The right lateralized pattern of BOLD activity together with higher activity in sensorimotor cortices is consistent with previous reports, which indicates rapid fMRI sequences can be considered for investigating stuttering in younger participants. PMID:22133409

  16. Brain MRI findings in infants with primary congenital glaucoma

    International Nuclear Information System (INIS)

    Dai, A. Ibrahym; Saygili, O.

    2007-01-01

    Congenital glaucoma appears in the first months of life, eventually at birth. Isolated congenital glaucoma is characterized by minor malformations of the irido-corneal angle of the anterior chamber of the eye. Clinical manifestations include tearing, photophobia and enlargement of the globe appearing in the first months of life. Imaging technology such as optical coherence tomography and measurement of central corneal thickness may play an important role in the assessment of children with suspected or known glaucoma. However, no MRI findings of the CNS in patients with primary congenital glaucoma (PCG) were reported in the literature. The purpose of this study was to investigate MRI findings of the brain in infants with PCG. We reviewed the radiological and histopathological and clinical characteristics of infants with primary congenital glaucoma. The records of 17 patients with PCG were reviewed and the MRIs of the brain and associated manifestations were analyzed. Three patients with PCG had abnormal MRI findings suggesting agenesis of the corpus callosum. Two infants had delayed myelinization of the brain. Significant abnormal optic nerve excavation and increased corneal diameters in 2 patients with delayed myelinization may suggest that intraocular pressure can be more striking and more severe, revealing a close relationship with PCG and abnormal myelinization in white matter. Studies with more patients are needed to confirm these results. (author)

  17. An Automated and Intelligent Medical Decision Support System for Brain MRI Scans Classification.

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal Siddiqui

    Full Text Available A wide interest has been observed in the medical health care applications that interpret neuroimaging scans by machine learning systems. This research proposes an intelligent, automatic, accurate, and robust classification technique to classify the human brain magnetic resonance image (MRI as normal or abnormal, to cater down the human error during identifying the diseases in brain MRIs. In this study, fast discrete wavelet transform (DWT, principal component analysis (PCA, and least squares support vector machine (LS-SVM are used as basic components. Firstly, fast DWT is employed to extract the salient features of brain MRI, followed by PCA, which reduces the dimensions of the features. These reduced feature vectors also shrink the memory storage consumption by 99.5%. At last, an advanced classification technique based on LS-SVM is applied to brain MR image classification using reduced features. For improving the efficiency, LS-SVM is used with non-linear radial basis function (RBF kernel. The proposed algorithm intelligently determines the optimized values of the hyper-parameters of the RBF kernel and also applied k-fold stratified cross validation to enhance the generalization of the system. The method was tested by 340 patients' benchmark datasets of T1-weighted and T2-weighted scans. From the analysis of experimental results and performance comparisons, it is observed that the proposed medical decision support system outperformed all other modern classifiers and achieves 100% accuracy rate (specificity/sensitivity 100%/100%. Furthermore, in terms of computation time, the proposed technique is significantly faster than the recent well-known methods, and it improves the efficiency by 71%, 3%, and 4% on feature extraction stage, feature reduction stage, and classification stage, respectively. These results indicate that the proposed well-trained machine learning system has the potential to make accurate predictions about brain abnormalities

  18. The capability of high field MRI in demonstrating post-mortem fetal brains at different gestational age

    International Nuclear Information System (INIS)

    Zhang Zhonghe; Liu Shuwei; Lin Xiangtao; Gen Hequn; Teng Gaojun; Fang Fang; Zang Fengchao; Yu Taifei; Zhao Bin

    2009-01-01

    Objective: To study the capability of high field MRI in demonstrating the post-mortem fetal brains at different gestational age (GA). Methods: One hundred and eight post-mortem fetal brains of 14-40 weeks GA were evaluated by 3.0 T MRI. Eleven brains of 14 to 27 weeks GA with good 3.0 T MRI images were chosen and scanned by 7.0 T MRI. The developing sulci, layered structures of fetal cerebral cortex and basal nuclei were evaluated on MRI of different Tesla (3.0 T and 7.0 T) and their results analyzed. Results: On T 1 WI of 3.0 T MRI, the layered structures of fetal cerebral cortex were present at 14 weeks GA, the sulci were more accurately identified after 16 weeks GA. The basal nuclei were clearly distinguishable after 20 weeks CA, and these structures were better visualized as the GA increased. On T 2 WI of 7.0 T MRI, the sulci, layered structures of fetal cerebral cortex and basal nuclei were shown more clearly at the same GA when compared to 3.0 T, especially the sulci at the early developmental stages. Conclusions: T 1 WI of 3.0 T MRI could show the developing structures of post-mortem fetal brain well, but the T 2 WI of 7.0 T MRI were comparatively better. (authors)

  19. MRI findings of radiation encephalopathy of brain stem after radiotherapy for nasopharyngeal cancer

    International Nuclear Information System (INIS)

    Liang Changhong; Li Guoye; Huang Biao; Huang Meiping; Zheng Junhui; Tan Shaoheng; Zeng Qiongxin

    1998-01-01

    Purpose: To study MRI findings and clinical manifestation of radiation encephalopathy (RE) of brain stem. Methods: MRI findings and clinical symptoms in 51 patients with RE of brain stem after radiotherapy for nasopharyngeal cancer were reviewed. Results: Clinical symptoms included number weakness or paralysis in the limbs and symptoms of damaged cranial nerves. All lesions appeared hypo- or iso-intense on spin echo(SE) T 1 -weighted images and inhomogeneous and mixed hyper- and iso-intense on Turbo spin echo (TSE) T 2 -weighted images. The lesions were located in mesencephalon, pons, medulla, basilar part of pons, basilar part of pons and medulla oblongata in 2,7,3,9 and 30 patients respectively. The enhancement patterns included irregular rings in 39 patients, spotty in 3 and no enhancement in 9 patients. Mass effect was minimal in all patients. On follow-up MRI, the lesions disappeared in 4 patients, did not change in size and shape in 8 patients and enlarged in 2 patients. Conclusion: MRI could demonstrate the characteristic findings of RE of brain stem. MRI findings sometimes are not consistent with the clinical symptoms

  20. Visceral fat is associated with brain structure independent of human immunodeficiency virus infection status.

    Science.gov (United States)

    Lake, Jordan E; Popov, Mikhail; Post, Wendy S; Palella, Frank J; Sacktor, Ned; Miller, Eric N; Brown, Todd T; Becker, James T

    2017-06-01

    The combined effects of human immunodeficiency virus (HIV), obesity, and elevated visceral adipose tissue (VAT) on brain structure are unknown. In a cross-sectional analysis of Multicenter AIDS Cohort Study (MACS) participants, we determined associations between HIV serostatus, adiposity, and brain structure. Men (133 HIV+, 84 HIV-) in the MACS Cardiovascular 2 and magnetic resonance imaging (MRI) sub-studies with CT-quantified VAT and whole brain MRI measured within 1 year were assessed. Voxel-based morphometry analyzed brain volumes. Men were stratified by elevated (eVAT, ≥100cm 2 ) or "normal" (nVAT, 25 kg/m 2 , smaller gray and white matter volumes, and larger cerebrospinal fluid volume than nVAT men. In multivariate analysis, hypertension, higher adiponectin, higher interleukin-6, age, diabetes mellitus, higher body mass index, and eVAT were associated with brain atrophy (p central nervous system effects may be amplified in this population.

  1. Evidence for Functional Networks within the Human Brain's White Matter.

    Science.gov (United States)

    Peer, Michael; Nitzan, Mor; Bick, Atira S; Levin, Netta; Arzy, Shahar

    2017-07-05

    brain. However, most fMRI studies ignored a major part of the brain, the white-matter, discarding signals from it as arising from noise. Here we use resting-state fMRI data from 176 subjects to show that signals from the human white-matter contain meaningful information. We identify 12 functional networks composed of interacting long-distance white-matter tracts. Moreover, we show that these networks are highly correlated to resting-state gray-matter networks, highlighting their functional role. Our findings enable reinterpretation of many existing fMRI datasets, and suggest a new way to explore the white-matter role in cognition and its disturbances in neuropsychiatric disorders. Copyright © 2017 the authors 0270-6474/17/376394-14$15.00/0.

  2. Brain MRI and SPECT in the diagnosis of early neurological involvement in Wilson's disease

    International Nuclear Information System (INIS)

    Piga, Mario; Satta, Loredana; Serra, Alessandra; Loi, Gianluigi; Murru, Alessandra; Demelia, Luigi; Sias, Alessandro; Marrosu, Francesco

    2008-01-01

    To evaluate the impact of brain MRI and single-photon emission computed tomography (SPECT) in early detection of central nervous system abnormalities in patients affected by Wilson's disease (WD) with or without neurological involvement. Out of 25 consecutive WD patients, 13 showed hepatic involvement, ten hepatic and neurological manifestations, and twp hepatic, neurological, and psychiatric symptoms, including mainly movement disorders, major depression, and psychosis. Twenty-four healthy, age-gender matched subjects served as controls. All patients underwent brain MRI and 99m Tc-ethyl-cysteinate dimer (ECD) SPECT before starting specific therapy. Voxel-by-voxel analyses were performed using statistical parametric mapping to compare differences in 99m Tc-ECD brain uptake between the two groups. Brain MRI showed T2-weighted hyperintensities in seven patients (28%), six of whom were affected by hepatic and neurological forms. Brain perfusion SPECT showed pathological data in 19 patients (76%), revealing diffuse or focal hypoperfusion in superior frontal (Brodmann area (BA) 6), prefrontal (BA 9), parietal (BA 40), and occipital (BA 18, BA 39) cortices in temporal gyri (BA 37, BA 21) and in caudatus and putamen. Moreover, hepatic involvement was detected in nine subjects; eight presented both hepatic and neurological signs, while two exhibited WD-correlated hepatic, neurological, and psychiatric alterations. All but one patient with abnormal MRI matched with abnormal ECD SPECT. Pathologic MRI findings were obtained in six out of ten patients with hepatic and neurological involvement while abnormal ECD SPECT was revealed in eight patients. Both patients with hepatic, neurological, and psychiatric involvement displayed abnormal ECD SPECT and one displayed an altered MRI. These findings suggest that ECD SPECT might be useful in detecting early brain damage in WD, not only in the perspective of assessing and treating motor impairment but also in evaluating better the

  3. Restoring susceptibility induced MRI signal loss in rat brain at 9.4 T: A step towards whole brain functional connectivity imaging.

    Directory of Open Access Journals (Sweden)

    Rupeng Li

    Full Text Available The aural cavity magnetic susceptibility artifact leads to significant echo planar imaging (EPI signal dropout in rat deep brain that limits acquisition of functional connectivity fcMRI data. In this study, we provide a method that recovers much of the EPI signal in deep brain. Needle puncture introduction of a liquid-phase fluorocarbon into the middle ear allows acquisition of rat fcMRI data without signal dropout. We demonstrate that with seeds chosen from previously unavailable areas, including the amygdala and the insular cortex, we are able to acquire large scale networks, including the limbic system. This tool allows EPI-based neuroscience and pharmaceutical research in rat brain using fcMRI that was previously not feasible.

  4. Digital atlas of fetal brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Teresa; Weinberger, E. [Department of Radiology, Seattle Children' s Hospital, Seattle, WA (United States); Matesan, Manuela [University of Washington, Department of Radiology, Seattle, WA (United States); Bulas, Dorothy I. [Division of Diagnostic Imaging and Radiology, Children' s National Medical Center, Washington, DC (United States)

    2010-02-15

    Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C, permits linked scrolling and resizing the images. Simultaneous comparison of varying gestational ages is permissible. Fetal brain images across gestational ages 18 to 37 weeks are provided as an interactive digital atlas and are available for free download. Improved interpretation of fetal brain abnormalities can be facilitated by the use of digital atlas cataloging of the normal changes throughout fetal development. Here we provide a description of the atlas and a discussion of normal fetal brain development. (orig.)

  5. Digital atlas of fetal brain MRI

    International Nuclear Information System (INIS)

    Chapman, Teresa; Weinberger, E.; Matesan, Manuela; Bulas, Dorothy I.

    2010-01-01

    Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C, permits linked scrolling and resizing the images. Simultaneous comparison of varying gestational ages is permissible. Fetal brain images across gestational ages 18 to 37 weeks are provided as an interactive digital atlas and are available for free download. Improved interpretation of fetal brain abnormalities can be facilitated by the use of digital atlas cataloging of the normal changes throughout fetal development. Here we provide a description of the atlas and a discussion of normal fetal brain development. (orig.)

  6. Brain CT and MRI findings of a long-term case of subacute sclerosing panencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Aoshiba, Kazunori; Ota, Kohei; Komatsuzaki, Satoshi; Kobayashi, Itsuro; Maruyama, Shoichi

    1987-11-01

    Our study involved a long-term case (ten years) of subacute sclerosing panencephalitis. The case began with a 23 year-old experiencing visual deterioration. During the course of his illness, amnesia, autism and abnormal behavior were observed without any myoclonus. On the electroencephalogram, periodic synclonous discharge was shown in the early stage of his illness and subsequently disappeared. The brain CT and the MRI disclosed diffuse lesions in both cortical and subcortical areas of the cerebral hemispheres. The location and spread of lesions were more clearly revealed by the MRI than the brain CT. These findings suggest that the MRI is more useful than the brain CT in the diagnosis of subacute sclerosing panencephalitis.

  7. Brain CT and MRI findings of a long-term case of subacute sclerosing panencephalitis

    International Nuclear Information System (INIS)

    Aoshiba, Kazunori; Ota, Kohei; Komatsuzaki, Satoshi; Kobayashi, Itsuro; Maruyama, Shoichi

    1987-01-01

    Our study involved a long-term case (ten years) of subacute sclerosing panencephalitis. The case began with a 23 year-old experiencing visual deterioration. During the course of his illness, amnesia, autism and abnormal behavior were observed without any myoclonus. On the electroencephalogram, periodic synclonous discharge was shown in the early stage of his illness and subsequently disappeared. The brain CT and the MRI disclosed diffuse lesions in both cortical and subcortical areas of the cerebral hemispheres. The location and spread of lesions were more clearly revealed by the MRI than the brain CT. These findings suggest that the MRI is more useful than the brain CT in the diagnosis of subacute sclerosing panencephalitis. (author)

  8. A correlation of clinical, MRI and brain SPECT in dementia

    International Nuclear Information System (INIS)

    Shelley, S.; Indirani, M.; Gokhale, S.; Anirudhan, N.; Sivakumar, M.R.; Jaganathan, K.

    2004-01-01

    Background: Dementia is a clinical syndrome characterised by acquired impairment in multiple neuropsycologic and behavior domains including memory, language, speech, visuospatial ability, cognition and mood/personality. Dementia produces deficits in perfusion reflecting decreased metabolic needs. Neuroimaging techniques help in determining whether the cognitive symptoms are organic and in which pattern of cognitive loss the patient may evolve. AIM: To differentiate various types of Dementia, based on the regional perfusion abnormalities seen in Brain SPECT and correlate this with Clinical and MRI findings. Material and methods: Patients suffering from memory impairment and memory loss were referred to our department for Brain SPECT as a part of work up for Dementia. They had undergone a detailed clinical examination, psychometry, mini mental status examination (MMSE), memory/cognitive testing and an MRI. Brain SPECT was done after injecting Tc 99m ECD (Ethylene Cysteinate Dimer ) and imaging after 45 minutes. The images obtained were reconstructed in a conventional way. The various patterns of perfusion abnormalities seen in the SPECT images was studied and correlated with MRI and clinical findings. The patients were thus classified as having Multi Infarct Dementia, Alzheimer's disease, Fronto-Temporal Dementia and Mixed variety. Results: Twenty One Patients were included in our study from February 2003 to February 2004. The mean age of the patients was 73 years ( 37 to 81). 15 were males and 6 were females. Out of 21 patients, 12 had Multi Infarct Dementia, 4 had Alzheimer's disease, 1 had Fronto- Temporal Dementia and 4 had Mixed variety. Conclusion: Brain SPECT aids in substantiating the clinical findings and in correlation with MRI helps in distinguishing various types of Dementia and thus has prognostic implications and helps in instituting early appropriate treatment to the patient. In our study, the majority of the patients have Multi Infarct Dementia

  9. Hypomelanosis of Ito and brain abnormalities: MRI findings and literature review

    International Nuclear Information System (INIS)

    Steiner, J.; Adamsbaum, C.; Desguerres, I.; Lalande, G.; Raynaud, F.; Ponsot, G.; Kalifa, G.

    1996-01-01

    We report the results of a 14-year retrospective study of brain MRI abnormalities in 12 pediatric patients presenting with hypomelanosis of Ito (HI). Miscellaneous brain abnormalities were found: one patient had a medulloblastoma, three had cortical malformations, and five demonstrated ''minor'' abnormalities such as dilated Virchow-Robin spaces or brain atrophy. We emphasize the polymorphism of brain abnormalities associated with HI. (orig.). With 5 figs., 1 tab

  10. Brain Activity Unique to Orgasm in Women: An fMRI Analysis.

    Science.gov (United States)

    Wise, Nan J; Frangos, Eleni; Komisaruk, Barry R

    2017-11-01

    Although the literature on imaging of regional brain activity during sexual arousal in women and men is extensive and largely consistent, that on orgasm is relatively limited and variable, owing in part to the methodologic challenges posed by variability in latency to orgasm in participants and head movement. To compare brain activity at orgasm (self- and partner-induced) with that at the onset of genital stimulation, immediately before the onset of orgasm, and immediately after the cessation of orgasm and to upgrade the methodology for obtaining and analyzing functional magnetic resonance imaging (fMRI) findings. Using fMRI, we sampled equivalent time points across female participants' variable durations of stimulation and orgasm in response to self- and partner-induced clitoral stimulation. The first 20-second epoch of orgasm was contrasted with the 20-second epochs at the beginning of stimulation and immediately before and after orgasm. Separate analyses were conducted for whole-brain and brainstem regions of interest. For a finer-grained analysis of the peri-orgasm phase, we conducted a time-course analysis on regions of interest. Head movement was minimized to a mean less than 1.3 mm using a custom-fitted thermoplastic whole-head and neck brace stabilizer. Ten women experienced orgasm elicited by self- and partner-induced genital stimulation in a Siemens 3-T Trio fMRI scanner. Brain activity gradually increased leading up to orgasm, peaked at orgasm, and then decreased. We found no evidence of deactivation of brain regions leading up to or during orgasm. The activated brain regions included sensory, motor, reward, frontal cortical, and brainstem regions (eg, nucleus accumbens, insula, anterior cingulate cortex, orbitofrontal cortex, operculum, right angular gyrus, paracentral lobule, cerebellum, hippocampus, amygdala, hypothalamus, ventral tegmental area, and dorsal raphe). Insight gained from the present findings could provide guidance toward a rational basis

  11. Quantifying anisotropy and fiber orientation in human brain histological sections

    Directory of Open Access Journals (Sweden)

    Matthew D Budde

    2013-02-01

    Full Text Available Diffusion weighted imaging (DWI has provided unparalleled insight into the microscopic structure and organization of the central nervous system. Diffusion tensor imaging (DTI and other models of the diffusion MRI signal extract microstructural properties of tissues with relevance to the normal and injured brain. Despite the prevalence of such techniques and applications, accurate and large-scale validation has proven difficult, particularly in the human brain. In this report, human brain sections obtained from a digital public brain bank were employed to quantify anisotropy and fiber orientation using structure tensor analysis. The derived maps depict the intricate complexity of white matter fibers at a resolution not attainable with current DWI experiments. Moreover, the effects of multiple fiber bundles (i.e. crossing fibers and intravoxel fiber dispersion were demonstrated. Examination of the cortex and hippocampal regions validated specific features of previous in vivo and ex vivo DTI studies of the human brain. Despite the limitation to two dimensions, the resulting images provide a unique depiction of white matter organization at resolutions currently unattainable with DWI. The method of analysis may be used to validate tissue properties derived from DTI and alternative models of the diffusion signal.

  12. Hemorrhage detection in MRI brain images using images features

    Science.gov (United States)

    Moraru, Luminita; Moldovanu, Simona; Bibicu, Dorin; Stratulat (Visan), Mirela

    2013-11-01

    The abnormalities appear frequently on Magnetic Resonance Images (MRI) of brain in elderly patients presenting either stroke or cognitive impairment. Detection of brain hemorrhage lesions in MRI is an important but very time-consuming task. This research aims to develop a method to extract brain tissue features from T2-weighted MR images of the brain using a selection of the most valuable texture features in order to discriminate between normal and affected areas of the brain. Due to textural similarity between normal and affected areas in brain MR images these operation are very challenging. A trauma may cause microstructural changes, which are not necessarily perceptible by visual inspection, but they could be detected by using a texture analysis. The proposed analysis is developed in five steps: i) in the pre-processing step: the de-noising operation is performed using the Daubechies wavelets; ii) the original images were transformed in image features using the first order descriptors; iii) the regions of interest (ROIs) were cropped from images feature following up the axial symmetry properties with respect to the mid - sagittal plan; iv) the variation in the measurement of features was quantified using the two descriptors of the co-occurrence matrix, namely energy and homogeneity; v) finally, the meaningful of the image features is analyzed by using the t-test method. P-value has been applied to the pair of features in order to measure they efficacy.

  13. The maternal brain and its plasticity in humans

    Science.gov (United States)

    Kim, Pilyoung; Strathearn, Lane; Swain, James E.

    2015-01-01

    Early mother-infant relationships play important roles in infants’ optimal development. New mothers undergo neurobiological changes that support developing mother-infant relationships regardless of great individual differences in those relationships. In this article, we review the neural plasticity in human mothers’ brains based on functional magnetic resonance imaging (fMRI) studies. First, we review the neural circuits that are involved in establishing and maintaining mother-infant relationships. Second, we discuss early postpartum factors (e.g., birth and feeding methods, hormones, and parental sensitivity) that are associated with individual differences in maternal brain neuroplasticity. Third, we discuss abnormal changes in the maternal brain related to psychopathology (i.e., postpartum depression, posttraumatic stress disorder, substance abuse) and potential brain remodeling associated with interventions. Last, we highlight potentially important future research directions to better understand normative changes in the maternal brain and risks for abnormal changes that may disrupt early mother-infant relationships. PMID:26268151

  14. Leptomeningeal enhancement on preoperative brain MRI in patients with glioblastoma and its clinical impact.

    Science.gov (United States)

    Kim, Hakyoung; Lim, Do Hoon; Kim, Tae Gyu; Lee, Jung-Il; Nam, Do-Hyun; Seol, Ho Jun; Kong, Doo-Sik; Choi, Jung Won; Suh, Yeon-Lim; Kim, Sung Tae

    2018-02-23

    Leptomeningeal enhancement (LME) on preoperative brain magnetic resonance imaging (MRI) does not always indicate leptomeningeal seeding (LMS). With Stupp's regimen, authors have treated glioblastoma patients with LME on preoperative brain MRI but here we tried to find the clinical impact of LME. From 2005 to 2015, 290 patients with glioblastoma have been treated with Stupp's regimen at Samsung Medical Center. Among these, 33 patients showed LME on preoperative brain MRI. We compared the clinical outcomes between the patients with or without LME on preoperative brain MRI and analyzed the clinical results according to changes of LME at following MRI. The median survival was 23 months, and 2-year overall survival (OS) and disease-free survival (DFS) rate was 46.3% and 19.6%, respectively. Prognostic factors for OS and DFS were Karnofsky performance status, extent of resection and adjuvant chemotherapy. MGMT promoter methylation status was a significant prognostic factor for DFS. However, LME was not a significant prognostic factor for OS (P = 0.156) or DFS (P = 0.193). Among the 33 patients with LME on preoperative MRI, 21 (63.6%) showed persistent LME at the next MRI. A statistically significant difference in 2-year survival was evident between patients with and without persistent LME (OS, 17.3% and 70.1%, respectively, P = 0.044; DFS, 5.3% and 54.0%, respectively, P = 0.006). The most common pattern of failure was local recurrence. However, patients with persistent LME displayed a higher incidence of LMS than patients without LME. LME on preoperative brain MRI did not affect the clinical results in glioblastoma patients treated with the Stupp's regimen. However, persistence of LME was associated with poor survival and high possibility of LMS. For these patients, the postoperative adjuvant treatment should focus on palliative aim or more aggressive treatment scheme should be followed to overcome the disastrous results. © 2018 John Wiley & Sons Australia, Ltd.

  15. Digital atlas of fetal brain MRI.

    Science.gov (United States)

    Chapman, Teresa; Matesan, Manuela; Weinberger, Ed; Bulas, Dorothy I

    2010-02-01

    Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C#, permits linked scrolling and resizing the images. Simultaneous comparison of varying gestational ages is permissible. Fetal brain images across gestational ages 18 to 37 weeks are provided as an interactive digital atlas and are available for free download from http://radiology.seattlechildrens.org/teaching/fetal_brain . Improved interpretation of fetal brain abnormalities can be facilitated by the use of digital atlas cataloging of the normal changes throughout fetal development. Here we provide a description of the atlas and a discussion of normal fetal brain development.

  16. The brain's silent messenger: using selective attention to decode human thought for brain-based communication.

    Science.gov (United States)

    Naci, Lorina; Cusack, Rhodri; Jia, Vivian Z; Owen, Adrian M

    2013-05-29

    The interpretation of human thought from brain activity, without recourse to speech or action, is one of the most provoking and challenging frontiers of modern neuroscience. In particular, patients who are fully conscious and awake, yet, due to brain damage, are unable to show any behavioral responsivity, expose the limits of the neuromuscular system and the necessity for alternate forms of communication. Although it is well established that selective attention can significantly enhance the neural representation of attended sounds, it remains, thus far, untested as a response modality for brain-based communication. We asked whether its effect could be reliably used to decode answers to binary (yes/no) questions. Fifteen healthy volunteers answered questions (e.g., "Do you have brothers or sisters?") in the fMRI scanner, by selectively attending to the appropriate word ("yes" or "no"). Ninety percent of the answers were decoded correctly based on activity changes within the attention network. The majority of volunteers conveyed their answers with less than 3 min of scanning, suggesting that this technique is suited for communication in a reasonable amount of time. Formal comparison with the current best-established fMRI technique for binary communication revealed improved individual success rates and scanning times required to detect responses. This novel fMRI technique is intuitive, easy to use in untrained participants, and reliably robust within brief scanning times. Possible applications include communication with behaviorally nonresponsive patients.

  17. Reliability of semiquantitative 18F-FDG PET parameters derived from simultaneous brain PET/MRI: A feasibility study

    International Nuclear Information System (INIS)

    Jena, Amarnath; Taneja, Sangeeta; Goel, Reema; Renjen, Pushpendranath; Negi, Pradeep

    2014-01-01

    Purpose: Simultaneous brain PET/MRI faces an important issue of validation of accurate MRI based attenuation correction (AC) method for precise quantitation of brain PET data unlike in PET/CT systems where the use of standard, validated CT based AC is routinely available. The aim of this study was to investigate the feasibility of evaluation of semiquantitative 18 F-FDG PET parameters derived from simultaneous brain PET/MRI using ultrashort echo time (UTE) sequences for AC and to assess their agreement with those obtained from PET/CT examination. Methods: Sixteen patients (age range 18–73 years; mean age 49.43 (19.3) years; 13 men 3 women) underwent simultaneous brain PET/MRI followed immediately by PET/CT. Quantitative analysis of brain PET images obtained from both studies was undertaken using Scenium v.1 brain analysis software package. Twenty ROIs for various brain regions were system generated and 6 semiquantitative parameters including maximum standardized uptake value (SUV max), SUV mean, minimum SUV (SUV min), minimum standard deviation (SD min), maximum SD (SD max) and SD from mean were calculated for both sets of PET data for each patient. Intra-class correlation coefficients (ICCs) were determined to assess agreement between the various semiquantitative parameters for the two PET data sets. Results: Intra-class co-relation between the two PET data sets for SUV max, SUV mean and SD max was highly significant (p < 0.00) for all the 20 predefined brain regions with ICC > 0.9. SD from mean was also found to be statistically significant for all the predefined brain regions with ICC > 0.8. However, SUV max and SUV mean values obtained from PET/MRI were significantly lower compared to those of PET/CT for all the predefined brain regions. Conclusion: PET quantitation accuracy using the MRI based UTE sequences for AC in simultaneous brain PET/MRI is reliable in a clinical setting, being similar to that obtained using PET/CT

  18. Simultaneous MRI and PET imaging of a rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Raylman, Raymond R [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Majewski, Stan [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Lemieux, Susan K [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Velan, S Sendhil [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Kross, Brian [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Popov, Vladimir [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Smith, Mark F [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Weisenberger, Andrew G [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Zorn, Carl [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Marano, Gary D [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States)

    2006-12-21

    Multi-modality imaging is rapidly becoming a valuable tool in the diagnosis of disease and in the development of new drugs. Functional images produced with PET fused with anatomical structure images created by MRI will allow the correlation of form with function. Our group is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode. Each MRI-PET detector module consists of an array of LSO detector elements coupled through a long fibre optic light guide to a single Hamamatsu flat panel position-sensitive photomultiplier tube (PSPMT). The use of light guides allows the PSPMTs to be positioned outside the bore of a 3T MRI scanner where the magnetic field is relatively small. To test the device, simultaneous MRI and PET images of the brain of a male Sprague Dawley rat injected with FDG were successfully obtained. The images revealed no noticeable artefacts in either image set. Future work includes the construction of a full ring PET scanner, improved light guides and construction of a specialized MRI coil to permit higher quality MRI imaging.

  19. Simultaneous MRI and PET imaging of a rat brain

    International Nuclear Information System (INIS)

    Raylman, Raymond R; Majewski, Stan; Lemieux, Susan K; Velan, S Sendhil; Kross, Brian; Popov, Vladimir; Smith, Mark F; Weisenberger, Andrew G; Zorn, Carl; Marano, Gary D

    2006-01-01

    Multi-modality imaging is rapidly becoming a valuable tool in the diagnosis of disease and in the development of new drugs. Functional images produced with PET fused with anatomical structure images created by MRI will allow the correlation of form with function. Our group is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode. Each MRI-PET detector module consists of an array of LSO detector elements coupled through a long fibre optic light guide to a single Hamamatsu flat panel position-sensitive photomultiplier tube (PSPMT). The use of light guides allows the PSPMTs to be positioned outside the bore of a 3T MRI scanner where the magnetic field is relatively small. To test the device, simultaneous MRI and PET images of the brain of a male Sprague Dawley rat injected with FDG were successfully obtained. The images revealed no noticeable artefacts in either image set. Future work includes the construction of a full ring PET scanner, improved light guides and construction of a specialized MRI coil to permit higher quality MRI imaging

  20. MRI/MRA evaluation of sickle cell disease of the brain

    International Nuclear Information System (INIS)

    Zimmerman, Robert A.

    2005-01-01

    Sickle cell disease is a major cause of pediatric stroke. Understanding the disease that affects the brain as infarctions, both clinically apparent and silent, requires an understanding of how the blood vessels are affected, the way in which both the brain and the blood vessels are imaged by MRI and MRA and the mechanism of injury. (orig.)

  1. Topological organization of the human brain functional connectome across the lifespan

    Directory of Open Access Journals (Sweden)

    Miao Cao

    2014-01-01

    Full Text Available Human brain function undergoes complex transformations across the lifespan. We employed resting-state functional MRI and graph-theory approaches to systematically chart the lifespan trajectory of the topological organization of human whole-brain functional networks in 126 healthy individuals ranging in age from 7 to 85 years. Brain networks were constructed by computing Pearson's correlations in blood-oxygenation-level-dependent temporal fluctuations among 1024 parcellation units followed by graph-based network analyses. We observed that the human brain functional connectome exhibited highly preserved non-random modular and rich club organization over the entire age range studied. Further quantitative analyses revealed linear decreases in modularity and inverted-U shaped trajectories of local efficiency and rich club architecture. Regionally heterogeneous age effects were mainly located in several hubs (e.g., default network, dorsal attention regions. Finally, we observed inverse trajectories of long- and short-distance functional connections, indicating that the reorganization of connectivity concentrates and distributes the brain's functional networks. Our results demonstrate topological changes in the whole-brain functional connectome across nearly the entire human lifespan, providing insights into the neural substrates underlying individual variations in behavior and cognition. These results have important implications for disease connectomics because they provide a baseline for evaluating network impairments in age-related neuropsychiatric disorders.

  2. Brain changes following four weeks of unimanual motor training: Evidence from fMRI-guided diffusion MRI tractography.

    Science.gov (United States)

    Reid, Lee B; Sale, Martin V; Cunnington, Ross; Mattingley, Jason B; Rose, Stephen E

    2017-09-01

    We have reported reliable changes in behavior, brain structure, and function in 24 healthy right-handed adults who practiced a finger-thumb opposition sequence task with their left hand for 10 min daily, over 4 weeks. Here, we extend these findings by using diffusion MRI to investigate white-matter changes in the corticospinal tract, basal-ganglia, and connections of the dorsolateral prefrontal cortex. Twenty-three participant datasets were available with pre-training and post-training scans. Task performance improved in all participants (mean: 52.8%, SD: 20.0%; group P right caudate nucleus (4.9%; P left nucleus accumbens (-1.3%; P right corticospinal tract (mean 3.28%; P left corticospinal tract did not show any changes. FA also increased in white matter connections between the right middle frontal gyrus and both right caudate nucleus (17/22 participants; P right supplementary motor area (18/22 participants; P left (non-trained) hemisphere. In combination with our functional and structural findings, this study provides detailed, multifocal evidence for widespread neuroplastic changes in the human brain resulting from motor training. Hum Brain Mapp 38:4302-4312, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Location of core diagnostic information across various sequences in brain MRI and implications for efficiency of MRI scanner utilization.

    Science.gov (United States)

    Sharma, Aseem; Chatterjee, Arindam; Goyal, Manu; Parsons, Matthew S; Bartel, Seth

    2015-04-01

    Targeting redundancy within MRI can improve its cost-effective utilization. We sought to quantify potential redundancy in our brain MRI protocols. In this retrospective review, we aggregated 207 consecutive adults who underwent brain MRI and reviewed their medical records to document clinical indication, core diagnostic information provided by MRI, and its clinical impact. Contributory imaging abnormalities constituted positive core diagnostic information whereas absence of imaging abnormalities constituted negative core diagnostic information. The senior author selected core sequences deemed sufficient for extraction of core diagnostic information. For validating core sequences selection, four readers assessed the relative ease of extracting core diagnostic information from the core sequences. Potential redundancy was calculated by comparing the average number of core sequences to the average number of sequences obtained. Scanning had been performed using 9.4±2.8 sequences over 37.3±12.3 minutes. Core diagnostic information was deemed extractable from 2.1±1.1 core sequences, with an assumed scanning time of 8.6±4.8 minutes, reflecting a potential redundancy of 74.5%±19.1%. Potential redundancy was least in scans obtained for treatment planning (14.9%±25.7%) and highest in scans obtained for follow-up of benign diseases (81.4%±12.6%). In 97.4% of cases, all four readers considered core diagnostic information to be either easily extractable from core sequences or the ease to be equivalent to that from the entire study. With only one MRI lacking clinical impact (0.48%), overutilization did not seem to contribute to potential redundancy. High potential redundancy that can be targeted for more efficient scanner utilization exists in brain MRI protocols.

  4. Mapping the human brain during a specific Vojta's tactile input: the ipsilateral putamen's role.

    Science.gov (United States)

    Sanz-Esteban, Ismael; Calvo-Lobo, Cesar; Ríos-Lago, Marcos; Álvarez-Linera, Juan; Muñoz-García, Daniel; Rodríguez-Sanz, David

    2018-03-01

    A century of research in human brain parcellation has demonstrated that different brain areas are associated with functional tasks. New neuroscientist perspectives to achieve the parcellation of the human brain have been developed to know the brain areas activation and its relationship with different stimuli. This descriptive study aimed to compare brain regions activation by specific tactile input (STI) stimuli according to the Vojta protocol (STI-group) to a non-STI stimulation (non-STI-group). An exploratory functional magnetic resonance imaging (fMRI) study was performed. The 2 groups of participants were passively stimulated by an expert physical therapist using the same paradigm structure, although differing in the place of stimulation. The stimulation was presented to participants using a block design in all cases. A sample of 16 healthy participants, 5 men and 11 women, with mean age 31.31 ± 8.13 years was recruited. Indeed, 12 participants were allocated in the STI-group and 4 participants in the non-STI-group. fMRI was used to map the human brain in vivo while these tactile stimuli were being applied. Data were analyzed using a general linear model in SPM12 implemented in MATLAB. Differences between groups showed a greater activation in the right cortical areas (temporal and frontal lobes), subcortical regions (thalamus, brainstem, and basal nuclei), and in the cerebellum (anterior lobe). STI-group had specific difference brain activation areas, such as the ipsilateral putamen. Future studies should study clinical implications in neurorehabilitation patients.

  5. Localisation of the brain in fetal MRI using bundled SIFT features.

    Science.gov (United States)

    Keraudren, Kevin; Kyriakopoulou, Vanessa; Rutherford, Mary; Hajnal, Joseph V; Rueckert, Daniel

    2013-01-01

    Fetal MRI is a rapidly emerging diagnostic imaging tool. Its main focus is currently on brain imaging, but there is a huge potential for whole body studies. We propose a method for accurate and robust localisation of the fetal brain in MRI when the image data is acquired as a stack of 2D slices misaligned due to fetal motion. We first detect possible brain locations in 2D images with a Bag-of-Words model using SIFT features aggregated within Maximally Stable Extremal Regions (called bundled SIFT), followed by a robust fitting of an axis-aligned 3D box to the selected regions. We rely on prior knowledge of the fetal brain development to define size and shape constraints. In a cross-validation experiment, we obtained a median error distance of 5.7mm from the ground truth and no missed detection on a database of 59 fetuses. This 2D approach thus allows a robust detection even in the presence of substantial fetal motion.

  6. An audit of clinical practice, referral patterns, and appropriateness of clinical indications for brain MRI examinations: A single-centre study in Ghana.

    Science.gov (United States)

    Piersson, A D; Nunoo, G; Gorleku, P N

    2018-05-01

    The aim of this study was to investigate current brain MRI practice, pattern of brain MRI requests, and their appropriateness using the American College of Radiology (ACR) Appropriateness Criteria. We used direct observation and questionnaires to obtain data concerning routine brain MRI practice. We then retrospectively analyzed (i) demographic characteristics, (ii) clinical history, and (iii) appropriateness of brain MRI requests against published criteria. All patients were administered the screening questionnaire; however, no reviews were undertaken directly with patients, and no signature of the radiographer was recorded. Apart from routine brain protocol, there were dedicated protocols for epilepsy and stroke. Brain MRI images from 161 patients (85 Males; 76 Females) were analyzed. The age group with most brain MRI requests were from 26 to 45 year olds. The commonest four clinical indications for imaging were brain tumour, headache, seizure, and stroke. Using the ACR Appropriateness Criteria, almost 43% of the brain MRI scans analyzed were found to be "usually appropriate", 38% were "maybe appropriate" and 19% were categorized as "usually not appropriate". There was knowledge gap with regards to MRI safety in local practice, thus there is the utmost need for MRI safety training. Data on the commonest indications for performing brain MRI in this study should be used to inform local neuroradiological practice. Dedicated stroke and epilepsy MRI protocols require additional sequences i.e. MRA and 3D T1 volume acquisition, respectively. The ACR Appropriateness Criteria is recommended for use by the referring practitioners to improve appropriateness of brain MRI requests. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  7. MRI of normal fetal brain development

    International Nuclear Information System (INIS)

    Prayer, Daniela; Kasprian, Gregor; Krampl, Elisabeth; Ulm, Barbara; Witzani, Linde; Prayer, Lucas; Brugger, Peter C.

    2006-01-01

    Normal fetal brain maturation can be studied by in vivo magnetic resonance imaging (MRI) from the 18th gestational week (GW) to term, and relies primarily on T2-weighted and diffusion-weighted (DW) sequences. These maturational changes must be interpreted with a knowledge of the histological background and the temporal course of the respective developmental steps. In addition, MR presentation of developing and transient structures must be considered. Signal changes associated with maturational processes can mainly be ascribed to the following changes in tissue composition and organization, which occur at the histological level: (1) a decrease in water content and increasing cell-density can be recognized as a shortening of T1- and T2-relaxation times, leading to increased T1-weighted and decreased T2-weighted intensity, respectively; (2) the arrangement of microanatomical structures to create a symmetrical or asymmetrical environment, leading to structural differences that may be demonstrated by DW-anisotropy; (3) changes in non-structural qualities, such as the onset of a membrane potential in premyelinating axons. The latter process also influences the appearance of a structure on DW sequences. Thus, we will review the in vivo MR appearance of different maturational states of the fetal brain and relate these maturational states to anatomical, histological, and in vitro MRI data. Then, the development of the cerebral cortex, white matter, temporal lobe, and cerebellum will be reviewed, and the MR appearance of transient structures of the fetal brain will be shown. Emphasis will be placed on the appearance of the different structures with the various sequences. In addition, the possible utility of dynamic fetal sequences in assessing spontaneous fetal movements is discussed

  8. MRI of normal fetal brain development

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, Daniela [Department of Radiodiagnostics, Medical University of Vienna, Vienna (Austria)]. E-mail: Daniela.prayer@meduniwien.ac.at; Kasprian, Gregor [Department of Radiodiagnostics, Medical University of Vienna, Vienna (Austria); Krampl, Elisabeth [Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna (Austria); Ulm, Barbara [Department of Prenatal Diagnosis, Medical University of Vienna, Vienna (Austria); Witzani, Linde [Department of Radiodiagnostics, Medical University of Vienna, Vienna (Austria); Prayer, Lucas [Diagnosezentrum Urania, Vienna (Austria); Brugger, Peter C. [Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna (Austria)

    2006-02-15

    Normal fetal brain maturation can be studied by in vivo magnetic resonance imaging (MRI) from the 18th gestational week (GW) to term, and relies primarily on T2-weighted and diffusion-weighted (DW) sequences. These maturational changes must be interpreted with a knowledge of the histological background and the temporal course of the respective developmental steps. In addition, MR presentation of developing and transient structures must be considered. Signal changes associated with maturational processes can mainly be ascribed to the following changes in tissue composition and organization, which occur at the histological level: (1) a decrease in water content and increasing cell-density can be recognized as a shortening of T1- and T2-relaxation times, leading to increased T1-weighted and decreased T2-weighted intensity, respectively; (2) the arrangement of microanatomical structures to create a symmetrical or asymmetrical environment, leading to structural differences that may be demonstrated by DW-anisotropy; (3) changes in non-structural qualities, such as the onset of a membrane potential in premyelinating axons. The latter process also influences the appearance of a structure on DW sequences. Thus, we will review the in vivo MR appearance of different maturational states of the fetal brain and relate these maturational states to anatomical, histological, and in vitro MRI data. Then, the development of the cerebral cortex, white matter, temporal lobe, and cerebellum will be reviewed, and the MR appearance of transient structures of the fetal brain will be shown. Emphasis will be placed on the appearance of the different structures with the various sequences. In addition, the possible utility of dynamic fetal sequences in assessing spontaneous fetal movements is discussed.

  9. Evaluation of Brain and Cervical MRI Abnormality Rates in Patients With Systemic Lupus Erythematosus With or Without Neurological Manifestations

    International Nuclear Information System (INIS)

    Harirchian, Mohammad Hossein; Saberi, Hazhir; Najafizadeh, Seyed Reza; Hashemi, Seyed Ali

    2011-01-01

    Central nervous system (CNS) involvement has been observed in 14-80% of patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is an appropriate method for evaluating CNS involvement in these patients. Clinical manifestations and MRI findings of CNS lupus should be differentiated from other mimicking diseases such as multiple sclerosis (MS). The aim of this study was to evaluate the prevalence and extent of brain and cervical cord MRI lesions of lupus patients. The relationship between neurological signs and symptoms and MRI findings were evaluated as well. Fifty SLE patients who had been referred to the rheumatology clinic of our hospital within 2009 were included in a cross sectional study. All patients fulfilled the revised 1981 American College of Rheumatology (ACR) criteria for SLE. We evaluated the neurological signs and symptoms and brain and cervical MRI findings in these patients. Forty-one patients (82%) were female and nine (18%) were male. The mean age was 30.1 ± 9.3 years. Twenty eight (56%) patients had an abnormal brain MRI. No one showed any abnormality in the cervical MRI. The lesions in 20 patients were similar to demyelinative plaques. Seventeen patients with abnormal brain MRI were neurologically asymptomatic. There was only a significant relationship between neurological motor manifestations and brain MRI abnormal findings. Unlike the brain, cervical MRI abnormality and especially asymptomatic cord involvement in MRI is quite rare in SLE patients. This finding may be helpful to differentiate SLE from other CNS disorders such as MS

  10. Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI.

    Science.gov (United States)

    Colas, Jaron T; Pauli, Wolfgang M; Larsen, Tobias; Tyszka, J Michael; O'Doherty, John P

    2017-10-01

    Prediction-error signals consistent with formal models of "reinforcement learning" (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models-namely, "actor/critic" models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning.

  11. Real-time motion analytics during brain MRI improve data quality and reduce costs.

    Science.gov (United States)

    Dosenbach, Nico U F; Koller, Jonathan M; Earl, Eric A; Miranda-Dominguez, Oscar; Klein, Rachel L; Van, Andrew N; Snyder, Abraham Z; Nagel, Bonnie J; Nigg, Joel T; Nguyen, Annie L; Wesevich, Victoria; Greene, Deanna J; Fair, Damien A

    2017-11-01

    Head motion systematically distorts clinical and research MRI data. Motion artifacts have biased findings from many structural and functional brain MRI studies. An effective way to remove motion artifacts is to exclude MRI data frames affected by head motion. However, such post-hoc frame censoring can lead to data loss rates of 50% or more in our pediatric patient cohorts. Hence, many scanner operators collect additional 'buffer data', an expensive practice that, by itself, does not guarantee sufficient high-quality MRI data for a given participant. Therefore, we developed an easy-to-setup, easy-to-use Framewise Integrated Real-time MRI Monitoring (FIRMM) software suite that provides scanner operators with head motion analytics in real-time, allowing them to scan each subject until the desired amount of low-movement data has been collected. Our analyses show that using FIRMM to identify the ideal scan time for each person can reduce total brain MRI scan times and associated costs by 50% or more. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Adversarial training and dilated convolutions for brain MRI segmentation

    NARCIS (Netherlands)

    Moeskops, P.; Veta, M.; Lafarge, M.W.; Eppenhof, K.A.J.; Pluim, J.P.W.

    2017-01-01

    Convolutional neural networks (CNNs) have been applied to various automatic image segmentation tasks in medical image analysis, including brain MRI segmentation. Generative adversarial networks have recently gained popularity because of their power in generating images that are difficult to

  13. Sexual differences of human brain

    Directory of Open Access Journals (Sweden)

    Masoud Pezeshki Rad

    2014-04-01

    Full Text Available During the last decades there has been an increasing interest in studying the differences between males and females. These differences extend from behavioral to cognitive to micro- and macro- neuro-anatomical aspects of human biology. There have been many methods to evaluate these differences and explain their determinants. The most studied cause of this dimorphism is the prenatal sex hormones and their organizational effect on brain and behavior. However, there have been new and recent attentions to hormone's activational influences in puberty and also the effects of genomic imprinting. In this paper, we reviewed the sex differences of brain, the evidences for possible determinants of these differences and also the methods that have been used to discover them. We reviewed the most conspicuous findings with specific attention to macro-anatomical differences based on Magnetic Resonance Imaging (MRI data. We finally reviewed the findings and the many opportunities for future studies.

  14. CT and MRI imaging of the brain in MELAS syndrome.

    Science.gov (United States)

    Pauli, Wojciech; Zarzycki, Artur; Krzyształowski, Adam; Walecka, Anna

    2013-07-01

    MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes) is a rare, multisystem disorder which belongs to a group of mitochondrial metabolic diseases. As other diseases in this group, it is inherited in the maternal line. In this report, we discussed a case of a 10-year-old girl with clinical and radiological picture of MELAS syndrome. We would like to describe characteristic radiological features of MELAS syndrome in CT, MRI and MR spectroscopy of the brain and differential diagnosis. The rarity of this disorder and the complexity of its clinical presentation make MELAS patients among the most difficult to diagnose. Brain imaging studies require a wide differential diagnosis, primarily to distinguish between MELAS and ischemic stroke. Particularly helpful are the MRI and MR spectroscopy techniques.

  15. CT and MRI imaging of the brain in MELAS syndrome

    International Nuclear Information System (INIS)

    Pauli, Wojciech; Zarzycki, Artur; Krzyształowski, Adam; Walecka, Anna

    2013-01-01

    MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes) is a rare, multisystem disorder which belongs to a group of mitochondrial metabolic diseases. As other diseases in this group, it is inherited in the maternal line. In this report, we discussed a case of a 10-year-old girl with clinical and radiological picture of MELAS syndrome. We would like to describe characteristic radiological features of MELAS syndrome in CT, MRI and MR spectroscopy of the brain and differential diagnosis. The rarity of this disorder and the complexity of its clinical presentation make MELAS patients among the most difficult to diagnose. Brain imaging studies require a wide differential diagnosis, primarily to distinguish between MELAS and ischemic stroke. Particularly helpful are the MRI and MR spectroscopy techniques

  16. The brain MRI classification problem from wavelets perspective

    Science.gov (United States)

    Bendib, Mohamed M.; Merouani, Hayet F.; Diaba, Fatma

    2015-02-01

    Haar and Daubechies 4 (DB4) are the most used wavelets for brain MRI (Magnetic Resonance Imaging) classification. The former is simple and fast to compute while the latter is more complex and offers a better resolution. This paper explores the potential of both of them in performing Normal versus Pathological discrimination on the one hand, and Multiclassification on the other hand. The Whole Brain Atlas is used as a validation database, and the Random Forest (RF) algorithm is employed as a learning approach. The achieved results are discussed and statistically compared.

  17. Neuroanatomical Markers of Social Hierarchy Recognition in Humans: A Combined ERP/MRI Study.

    Science.gov (United States)

    Santamaría-García, Hernando; Burgaleta, Miguel; Sebastián-Gallés, Nuria

    2015-07-29

    Social hierarchy is an ubiquitous principle of social organization across animal species. Although some progress has been made in our understanding of how humans infer hierarchical identity, the neuroanatomical basis for perceiving key social dimensions of others remains unexplored. Here, we combined event-related potentials and structural MRI to reveal the neuroanatomical substrates of early status recognition. We designed a covertly simulated hierarchical setting in which participants performed a task either with a superior or with an inferior player. Participants showed higher amplitude in the N170 component when presented with a picture of a superior player compared with an inferior player. Crucially, the magnitude of this effect correlated with brain morphology of the posterior cingulate cortex, superior temporal gyrus, insula, fusiform gyrus, and caudate nucleus. We conclude that early recognition of social hierarchies relies on the structural properties of a network involved in the automatic recognition of social identity. Humans can perceive social hierarchies very rapidly, an ability that is key for social interactions. However, some individuals are more sensitive to hierarchical information than others. Currently, it is unknown how brain structure supports such fast-paced processes of social hierarchy perception and their individual differences. Here, we addressed this issue for the first time by combining the high temporal resolution of event-related potentials (ERPs) and the high spatial resolution of structural MRI. This methodological approach allowed us to unveil a novel association between ERP neuromarkers of social hierarchy perception and the morphology of several cortical and subcortical brain regions typically assumed to play a role in automatic processes of social cognition. Our results are a step forward in our understanding of the human social brain. Copyright © 2015 the authors 0270-6474/15/3510843-08$15.00/0.

  18. MRI evaluation and functional assessment of brain injury after hypoxic ischemia in neonatal mice.

    Science.gov (United States)

    Adén, Ulrika; Dahlberg, Viktoria; Fredholm, Bertil B; Lai, Li-Ju; Chen, Zhengguan; Bjelke, Börje

    2002-05-01

    Severe perinatal asphyxia is an important cause of brain injury in the newborn infant. We examined early events after hypoxic ischemia (HI) in the 7-day-old mouse brain by MRI and related them to long-term functional effects and histopathology in the same animals at 4 to 5 weeks of age. HI was induced in 7-day-old CD1 mice by exposure to 8% oxygen for 30 minutes after occlusion of the left common carotid artery. The resulting unilateral focal lesion was evaluated in vivo by MRI (T2 maps and apparent diffusion coefficient maps) at 3, 6, and 24 hours and 5 days after hypoxia. Locomotion and sensorimotor function were analyzed after 3 weeks. Four weeks after HI, the mice were killed, and cresyl violet-stained brain sections were examined morphologically. A decrease in apparent diffusion coefficient values in cortex on the affected side was found at 3 hours after HI. T2 values were significantly increased after 6 hours and remained so for 5 days. Maximal size of the lesion was attained at 3 to 6 hours after HI and declined thereafter. Animals with MRI-detected lesions had decreased forward locomotion, performed worse than controls in the beam-walking test, and showed a unilateral hypotrophy in the cresyl violet-stained brain sections 4 weeks later. The temporal progression of the damage after HI in 7-day-old mice differs from that of the adult brain as judged by MRI. The early lesions detected by MRI were related to functional impairments for these mice in near-adult life.

  19. Dynamic multi-coil technique (DYNAMITE) shimming for echo-planar imaging of the human brain at 7 Tesla.

    Science.gov (United States)

    Juchem, Christoph; Umesh Rudrapatna, S; Nixon, Terence W; de Graaf, Robin A

    2015-01-15

    Gradient-echo echo-planar imaging (EPI) is the primary method of choice in functional MRI and other methods relying on fast MRI to image brain activation and connectivity. However, the high susceptibility of EPI towards B0 magnetic field inhomogeneity poses serious challenges. Conventional magnetic field shimming with low-order spherical harmonic (SH) functions is capable of compensating shallow field distortions, but performs poorly for global brain shimming or on specific areas with strong susceptibility-induced B0 distortions such as the prefrontal cortex (PFC). Excellent B0 homogeneity has been demonstrated recently in the human brain at 7 Tesla with the DYNAmic Multi-coIl TEchnique (DYNAMITE) for magnetic field shimming (J Magn Reson (2011) 212:280-288). Here, we report the benefits of DYNAMITE shimming for multi-slice EPI and T2* mapping. A standard deviation of 13Hz was achieved for the residual B0 distribution in the human brain at 7 Tesla with DYNAMITE shimming and was 60% lower compared to conventional shimming that employs static zero through third order SH shapes. The residual field inhomogeneity with SH shimming led to an average 8mm shift at acquisition parameters commonly used for fMRI and was reduced to 1.5-3mm with DYNAMITE shimming. T2* values obtained from the prefrontal and temporal cortices with DYNAMITE shimming were 10-50% longer than those measured with SH shimming. The reduction of the confounding macroscopic B0 field gradients with DYNAMITE shimming thereby promises improved access to the relevant microscopic T2* effects. The combination of high spatial resolution and DYNAMITE shimming allows largely artifact-free EPI and T2* mapping throughout the brain, including prefrontal and temporal lobe areas. DYNAMITE shimming is expected to critically benefit a wide range of MRI applications that rely on excellent B0 magnetic field conditions including EPI-based fMRI to study various cognitive processes and assessing large-scale brain connectivity

  20. Dynamic Multi-Coil Technique (DYNAMITE) Shimming for Echo-Planar Imaging of the Human Brain at 7 Tesla

    Science.gov (United States)

    Juchem, Christoph; Rudrapatna, S. Umesh; Nixon, Terence W.; de Graaf, Robin A.

    2014-01-01

    Gradient-echo echo-planar imaging (EPI) is the primary method of choice in functional MRI and other methods relying on fast MRI to image brain activation and connectivity. However, the high susceptibility of EPI towards B0 magnetic field inhomogeneity poses serious challenges. Conventional magnetic field shimming with low-order spherical harmonic (SH) functions is capable of compensating shallow field distortions, but performs poorly for global brain shimming or on specific areas with strong susceptibility-induced B0 distortions such as the prefrontal cortex (PFC). Excellent B0 homogeneity has been demonstrated recently in the human brain at 7 Tesla with the DYNAmic Multi-coIl TEchnique (DYNAMITE) for magnetic field shimming (Juchem et al., J Magn Reson (2011) 212:280-288). Here, we report the benefits of DYNAMITE shimming for multi-slice EPI and T2* mapping. A standard deviation of 13 Hz was achieved for the residual B0 distribution in the human brain at 7 Tesla with DYNAMITE shimming and was 60% lower compared to conventional shimming that employs static zero through third order SH shapes. The residual field inhomogeneity with SH shimming led to an average 8 mm shift at acquisition parameters commonly used for fMRI and was reduced to 1.5-3 mm with DYNAMITE shimming. T2* values obtained from the prefrontal and temporal cortices with DYNAMITE shimming were 10-50% longer than those measured with SH shimming. The reduction of the confounding macroscopic B0 field gradients with DYNAMITE shimming thereby promises improved access to the relevant microscopic T2* effects. The combination of high spatial resolution and DYNAMITE shimming allows largely artifact-free EPI and T2* mapping throughout the brain, including prefrontal and temporal lobe areas. DYNAMITE shimming is expected to critically benefit a wide range of MRI applications that rely on excellent B0 magnetic field conditions including EPI-based fMRI to study various cognitive processes and assessing large

  1. Persistent lesion hyperintensity on brain diffusion-weighted MRI is an early sign of intravascular lymphoma.

    Science.gov (United States)

    Kageyama, Takashi; Yamanaka, Haruo; Nakamura, Fumihiko; Suenaga, Toshihiko

    2017-06-08

    A 63-year-old man presented with right-sided hemianopia and unsteady gait. Brain MRI revealed multiple hyperintense infarct-like lesions on diffusion-weighted images (DWI). Hyperintensity persisted in some of these lesions even after 6 weeks, although his symptoms were ameliorated then. The patient developed episodic dizziness and a transient event of apraxia at 18 weeks after the first episode. Brain MRI revealed additional hyperintense lesions on DWI, which persisted even after 7 weeks. Eventually, the patient manifested cauda equina syndrome 39 weeks after the first episode. Brain MRI showed the presence of new lesions in addition to the persistent hyperintense lesions on DWI over 21 weeks in the right frontal lobe. Based on laboratory findings and the pathological assessment of bone marrow and random skin biopsies, the patient was diagnosed with intravascular lymphoma (IVL). Persistent hyperintense lesions on DWI of brain MRI may precede the clinical exacerbation of IVL. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. Abnormal baseline brain activity in patients with neuromyelitis optica: A resting-state fMRI study

    International Nuclear Information System (INIS)

    Liu Yaou; Liang Peipeng; Duan Yunyun; Jia Xiuqin; Wang Fei; Yu Chunshui; Qin Wen; Dong Huiqing; Ye Jing; Li Kuncheng

    2011-01-01

    Purpose: Recent immunopathologic and MRI findings suggest that tissue damage in neuromyelitis optica (NMO) is not limited to spinal cord and optic nerve, but also in brain. Baseline brain activity can reveal the brain functional changes to the tissue damages and give clues to the pathophysiology of NMO, however, it has never been explored by resting-state functional MRI (fMRI). We used regional amplitude of low frequency fluctuation (ALFF) as an index in resting-state fMRI to investigate how baseline brain activity changes in patients with NMO. Methods: Resting-state fMRIs collected from seventeen NMO patients and seventeen age- and sex-matched normal controls were compared to investigate the ALFF difference between the two groups. The relationships between ALFF in regions with significant group differences and the EDSS (Expanded Disability Status Scale), disease duration were further explored. Results: Our results showed that NMO patients had significantly decreased ALFF in precuneus, posterior cingulate cortex (PCC) and lingual gyrus; and increased ALFF in middle frontal gyrus, caudate nucleus and thalamus, compared to normal controls. Moderate negative correlations were found between the EDSS and ALFF in the left middle frontal gyrus (r = -0.436, p = 0.040) and the left caudate (r = -0.542, p = 0.012). Conclusion: The abnormal baseline brain activity shown by resting-state fMRI in NMO is relevant to cognition, visual and motor systems. It implicates a complex baseline brain status of both functional impairments and adaptations caused by tissue damages in these systems, which gives clues to the pathophysiology of NMO.

  3. Abnormal baseline brain activity in patients with neuromyelitis optica: A resting-state fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yaou [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Liang Peipeng [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); International WIC institute, Beijing University of Technology, Beijing 100024 (China); Duan Yunyun; Jia Xiuqin; Wang Fei; Yu Chunshui; Qin Wen [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Dong Huiqing; Ye Jing [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Li Kuncheng, E-mail: likuncheng1955@yahoo.com.cn [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China)

    2011-11-15

    Purpose: Recent immunopathologic and MRI findings suggest that tissue damage in neuromyelitis optica (NMO) is not limited to spinal cord and optic nerve, but also in brain. Baseline brain activity can reveal the brain functional changes to the tissue damages and give clues to the pathophysiology of NMO, however, it has never been explored by resting-state functional MRI (fMRI). We used regional amplitude of low frequency fluctuation (ALFF) as an index in resting-state fMRI to investigate how baseline brain activity changes in patients with NMO. Methods: Resting-state fMRIs collected from seventeen NMO patients and seventeen age- and sex-matched normal controls were compared to investigate the ALFF difference between the two groups. The relationships between ALFF in regions with significant group differences and the EDSS (Expanded Disability Status Scale), disease duration were further explored. Results: Our results showed that NMO patients had significantly decreased ALFF in precuneus, posterior cingulate cortex (PCC) and lingual gyrus; and increased ALFF in middle frontal gyrus, caudate nucleus and thalamus, compared to normal controls. Moderate negative correlations were found between the EDSS and ALFF in the left middle frontal gyrus (r = -0.436, p = 0.040) and the left caudate (r = -0.542, p = 0.012). Conclusion: The abnormal baseline brain activity shown by resting-state fMRI in NMO is relevant to cognition, visual and motor systems. It implicates a complex baseline brain status of both functional impairments and adaptations caused by tissue damages in these systems, which gives clues to the pathophysiology of NMO.

  4. AUTOMATED CLASSIFICATION AND SEGREGATION OF BRAIN MRI IMAGES INTO IMAGES CAPTURED WITH RESPECT TO VENTRICULAR REGION AND EYE-BALL REGION

    Directory of Open Access Journals (Sweden)

    C. Arunkumar

    2014-05-01

    Full Text Available Magnetic Resonance Imaging (MRI images of the brain are used for detection of various brain diseases including tumor. In such cases, classification of MRI images captured with respect to ventricular and eye ball regions helps in automated location and classification of such diseases. The methods employed in the paper can segregate the given MRI images of brain into images of brain captured with respect to ventricular region and images of brain captured with respect to eye ball region. First, the given MRI image of brain is segmented using Particle Swarm Optimization (PSO algorithm, which is an optimized algorithm for MRI image segmentation. The algorithm proposed in the paper is then applied on the segmented image. The algorithm detects whether the image consist of a ventricular region or an eye ball region and classifies it accordingly.

  5. In vivo analysis of the human superficial cerebral venous anatomy by using 3D-MRI

    International Nuclear Information System (INIS)

    Fujinaga, Yasunari

    1997-01-01

    The purpose of this study is to show the reliability of three dimensional magnetic resonance imaging (3D-MRI), and to classify the drainage patterns of the superficial cerebral veins. At first, toothpicks were stuck into fixed brain surface of a dog. To examine the best methods for making 3D-MRI, the 3D-MRI, including the diameter of the holes, of the dog's brain were analyzed in four threshold values. The holes on the 3D-MRI appeared smaller than their actual size due to the partial volume effect. The low threshold showed more errors than the higher. This result showed it was necessary to display the good 3D-MRI to refer the original MR images. Next, the 3D-MRI of clinical patients who had brain tumors were correlated with operative findings especially in relation to the lesions and brain surface, vessels, ventricles. The relation between the lesions and brain surface, vessels were displayed well, but there were some problems with inadequate ventricular display. Finally, anatomical study using 3D-MRI was performed, because 3D-MRI could display the relation between the brain surface and the superficial cerebral veins in the basic studies. The third study demonstrated that the transverse frontal vein was found in 15%, vein of Trolard ran in front of the central sulcus in 91.5% and several anastomosing veins were frequently observed. These studies showed the progress of technology in bringing about a lot of new information by using 3D-MRI. (author)

  6. MRI-based quantification of brain damage in cerebrovascular disorders

    NARCIS (Netherlands)

    de Bresser, J.H.J.M.

    2011-01-01

    Brain diseases can lead to diverse structural abnormalities that can be assessed on magnetic resonance imaging (MRI) scans. These abnormalities can be quantified by (semi-)automated techniques. The studies described in this thesis aimed to optimize and apply cerebral quantification techniques in

  7. Functional MRI in the Investigation of Blast-Related Traumatic Brain Injury

    Science.gov (United States)

    Graner, John; Oakes, Terrence R.; French, Louis M.; Riedy, Gerard

    2012-01-01

    This review focuses on the application of functional magnetic resonance imaging (fMRI) to the investigation of blast-related traumatic brain injury (bTBI). Relatively little is known about the exact mechanisms of neurophysiological injury and pathological and functional sequelae of bTBI. Furthermore, in mild bTBI, standard anatomical imaging techniques (MRI and computed tomography) generally fail to show focal lesions and most of the symptoms present as subjective clinical functional deficits. Therefore, an objective test of brain functionality has great potential to aid in patient diagnosis and provide a sensitive measurement to monitor disease progression and treatment. The goal of this review is to highlight the relevant body of blast-related TBI literature and present suggestions and considerations in the development of fMRI studies for the investigation of bTBI. The review begins with a summary of recent bTBI publications followed by discussions of various elements of blast-related injury. Brief reviews of some fMRI techniques that focus on mental processes commonly disrupted by bTBI, including working memory, selective attention, and emotional processing, are presented in addition to a short review of resting state fMRI. Potential strengths and weaknesses of these approaches as regards bTBI are discussed. Finally, this review presents considerations that must be made when designing fMRI studies for bTBI populations, given the heterogeneous nature of bTBI and its high rate of comorbidity with other physical and psychological injuries. PMID:23460082

  8. Implanting Glioblastoma Spheroids into Rat Brains and Monitoring Tumor Growth by MRI Volumetry.

    Science.gov (United States)

    Löhr, Mario; Linsenmann, Thomas; Jawork, Anna; Kessler, Almuth F; Timmermann, Nils; Homola, György A; Ernestus, Ralf-Ingo; Hagemann, Carsten

    2017-01-01

    The outcome of patients suffering from glioblastoma multiforme (GBM) remains poor with a median survival of less than 15 months. To establish innovative therapeutical approaches or to analyze the effect of protein overexpression or protein knockdown by RNA interference in vivo, animal models are mandatory. Here, we describe the implantation of C6 glioma spheroids into the rats' brain and how to follow tumor growth by MRI scans. We show that C6 cells grown in Sprague-Dawley rats share several morphologic features of human glioblastoma like pleomorphic cells, areas of necrosis, vascular proliferation, and tumor cell invasion into the surrounding brain tissue. In addition, we describe a method for tumor volumetry utilizing the CISS 3D- or contrast-enhanced T1-weighted 3D sequence and freely available post-processing software.

  9. Multidimensional MRI-CT atlas of the naked mole-rat brain (Heterocephalus glaber).

    Science.gov (United States)

    Seki, Fumiko; Hikishima, Keigo; Nambu, Sanae; Okanoya, Kazuo; Okano, Hirotaka J; Sasaki, Erika; Miura, Kyoko; Okano, Hideyuki

    2013-01-01

    Naked mole-rats have a variety of distinctive features such as the organization of a hierarchical society (known as eusociality), extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI). Advanced MRI techniques such as diffusion tensor imaging (DTI), which generates high contrast images of fiber structures, can characterize unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D) images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualization of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  10. Probing region-specific microstructure of human cortical areas using high angular and spatial resolution diffusion MRI.

    Science.gov (United States)

    Aggarwal, Manisha; Nauen, David W; Troncoso, Juan C; Mori, Susumu

    2015-01-15

    Regional heterogeneity in cortical cyto- and myeloarchitecture forms the structural basis of mapping of cortical areas in the human brain. In this study, we investigate the potential of diffusion MRI to probe the microstructure of cortical gray matter and its region-specific heterogeneity across cortical areas in the fixed human brain. High angular resolution diffusion imaging (HARDI) data at an isotropic resolution of 92-μm and 30 diffusion-encoding directions were acquired using a 3D diffusion-weighted gradient-and-spin-echo sequence, from prefrontal (Brodmann area 9), primary motor (area 4), primary somatosensory (area 3b), and primary visual (area 17) cortical specimens (n=3 each) from three human subjects. Further, the diffusion MR findings in these cortical areas were compared with histological silver impregnation of the same specimens, in order to investigate the underlying architectonic features that constitute the microstructural basis of diffusion-driven contrasts in cortical gray matter. Our data reveal distinct and region-specific diffusion MR contrasts across the studied areas, allowing delineation of intracortical bands of tangential fibers in specific layers-layer I, layer VI, and the inner and outer bands of Baillarger. The findings of this work demonstrate unique sensitivity of diffusion MRI to differentiate region-specific cortical microstructure in the human brain, and will be useful for myeloarchitectonic mapping of cortical areas as well as to achieve an understanding of the basis of diffusion NMR contrasts in cortical gray matter. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Safety of a dedicated brain MRI protocol in patients with a vagus nerve stimulator.

    Science.gov (United States)

    de Jonge, Jeroen C; Melis, Gerrit I; Gebbink, Tineke A; de Kort, Gérard A P; Leijten, Frans S S

    2014-11-01

    Although implanted metallic devices constitute a relative contraindication to magnetic resonance imaging (MRI) scanning, the safety of brain imaging in a patient with a vagus nerve stimulator (VNS) is classified as "conditional," provided that specific manufacturer guidelines are followed when a transmit and receive head coil is used at 1.5 or 3.0 Tesla. The aim of this study was to evaluate the safety of performing brain MRI scans in patients with the VNS. From September 2009 until November 2011, 101 scans were requested in 73 patients with the VNS in The Netherlands. Patients were scanned according to the manufacturer's guidelines. No patient reported any side effect, discomfort, or pain during or after the MRI scan. In one patient, a lead break was detected based on device diagnostics after the MRI-scan. However, because no system diagnostics had been performed prior to MR scanning in this patient, it is unclear whether MR scanning was responsible for the lead break. The indication for most scans was epilepsy related. Twenty-six scans (26%) were part of a (new) presurgical evaluation and could probably better have been performed prior to VNS implantation. Performing brain MRI scans in patients with an implanted VNS is safe when a modified MRI protocol is followed. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

  12. Establishment of SHG-44 human glioma model in brain of wistar rat with stereotactic technique

    International Nuclear Information System (INIS)

    Hong Xinyu; Luo Yi'nan; Fu Shuanglin; Wang Zhanfeng; Bie Li; Cui Jiale

    2004-01-01

    Objective: To establish solid intracerebral human glioma model in Wistar rat with xenograft methods. Methods: The SHG-44 cells were injected into brain right caudate nucleus of previous immuno-inhibitory Wistar rats with stereotactic technique. The MRI scans were performed at 1 week and 2 weeks later after implantation. After 2 weeks the rats were killed and pathological examination and immunohistologic stain for human GFAP were used. Results: The MRI scan after 1 week of implantation showed the glioma was growing, pathological histochemical examination demonstrated the tumor was glioma. Human GFAP stain was positive. The growth rate of glioma model was about 60%. Conclusion: Solid intracerebral human glioma model in previous immuno-inhibitory Wistar rat is successfully established

  13. Assessment of MRI Parameters as Imaging Biomarkers for Radiation Necrosis in the Rat Brain

    Energy Technology Data Exchange (ETDEWEB)

    Wang Silun [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Zhou Tingting [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Armour, Michael [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Wen Zhibo [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong (China); Fu Dexue [Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Ford, Eric [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Zijl, Peter C.M. van [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland (United States); Zhou Jinyuan, E-mail: jzhou@mri.jhu.edu [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland (United States)

    2012-07-01

    Purpose: Radiation necrosis is a major complication of radiation therapy. We explore the features of radiation-induced brain necrosis in the rat, using multiple MRI approaches, including T{sub 1}, T{sub 2}, apparent diffusion constant (ADC), cerebral blood flow (CBF), magnetization transfer ratio (MTR), and amide proton transfer (APT) of endogenous mobile proteins and peptides. Methods and Materials: Adult rats (Fischer 344; n = 15) were irradiated with a single, well-collimated X-ray beam (40 Gy; 10 Multiplication-Sign 10 mm{sup 2}) in the left brain hemisphere. MRI was acquired on a 4.7-T animal scanner at {approx}25 weeks' postradiation. The MRI signals of necrotic cores and perinecrotic regions were assessed with a one-way analysis of variance. Histological evaluation was accomplished with hematoxylin and eosin staining. Results: ADC and CBF MRI could separate perinecrotic and contralateral normal brain tissue (p < 0.01 and < 0.05, respectively), whereas T{sub 1}, T{sub 2}, MTR, and APT could not. MRI signal intensities were significantly lower in the necrotic core than in normal brain for CBF (p < 0.001) and APT (p < 0.01) and insignificantly higher or lower for T{sub 1}, T{sub 2}, MTR, and ADC. Histological results demonstrated coagulative necrosis within the necrotic core and reactive astrogliosis and vascular damage within the perinecrotic region. Conclusion: ADC and CBF are promising imaging biomarkers for identifying perinecrotic regions, whereas CBF and APT are promising for identifying necrotic cores.

  14. Fast CSF MRI for brain segmentation; Cross-validation by comparison with 3D T1-based brain segmentation methods

    DEFF Research Database (Denmark)

    van der Kleij, Lisa A.; de Bresser, Jeroen; Hendrikse, Jeroen

    2018-01-01

    ObjectiveIn previous work we have developed a fast sequence that focusses on cerebrospinal fluid (CSF) based on the long T-2 of CSF. By processing the data obtained with this CSF MRI sequence, brain parenchymal volume (BPV) and intracranial volume (ICV) can be automatically obtained. The aim...... of this study was to assess the precision of the BPV and ICV measurements of the CSF MRI sequence and to validate the CSF MRI sequence by comparison with 3D T-1-based brain segmentation methods.Materials and methodsTen healthy volunteers (2 females; median age 28 years) were scanned (3T MRI) twice......cc) and CSF HR (5 +/- 5/4 +/- 2cc) were comparable to FSL HR (9 +/- 11/19 +/- 23cc), FSL LR (7 +/- 4,6 +/- 5cc),FreeSurfer HR (5 +/- 3/14 +/- 8cc), FreeSurfer LR (9 +/- 8,12 +/- 10cc), and SPM HR (5 +/- 3/4 +/- 7cc), and SPM LR (5 +/- 4,5 +/- 3cc). The correlation between the measured volumes...

  15. Structural Image Analysis of the Brain in Neuropsychology Using Magnetic Resonance Imaging (MRI) Techniques.

    Science.gov (United States)

    Bigler, Erin D

    2015-09-01

    Magnetic resonance imaging (MRI) of the brain provides exceptional image quality for visualization and neuroanatomical classification of brain structure. A variety of image analysis techniques provide both qualitative as well as quantitative methods to relate brain structure with neuropsychological outcome and are reviewed herein. Of particular importance are more automated methods that permit analysis of a broad spectrum of anatomical measures including volume, thickness and shape. The challenge for neuropsychology is which metric to use, for which disorder and the timing of when image analysis methods are applied to assess brain structure and pathology. A basic overview is provided as to the anatomical and pathoanatomical relations of different MRI sequences in assessing normal and abnormal findings. Some interpretive guidelines are offered including factors related to similarity and symmetry of typical brain development along with size-normalcy features of brain anatomy related to function. The review concludes with a detailed example of various quantitative techniques applied to analyzing brain structure for neuropsychological outcome studies in traumatic brain injury.

  16. Visual dictionaries as intermediate features in the human brain

    Directory of Open Access Journals (Sweden)

    Kandan eRamakrishnan

    2015-01-01

    Full Text Available The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HMAX model and Bag of Words (BoW model from computer vision. Both these computational models use visual dictionaries, candidate features of intermediate complexity, to represent visual scenes, and the models have been proven effective in automatic object and scene recognition. These models however differ in the computation of visual dictionaries and pooling techniques. We investigated where in the brain and to what extent human fMRI responses to short video can be accounted for by multiple hierarchical levels of the HMAX and BoW models. Brain activity of 20 subjects obtained while viewing a short video clip was analyzed voxel-wise using a distance-based variation partitioning method. Results revealed that both HMAX and BoW explain a significant amount of brain activity in early visual regions V1, V2 and V3. However BoW exhibits more consistency across subjects in accounting for brain activity compared to HMAX. Furthermore, visual dictionary representations by HMAX and BoW explain significantly some brain activity in higher areas which are believed to process intermediate features. Overall our results indicate that, although both HMAX and BoW account for activity in the human visual system, the BoW seems to more faithfully represent neural responses in low and intermediate level visual areas of the brain.

  17. Visual image reconstruction from human brain activity: A modular decoding approach

    International Nuclear Information System (INIS)

    Miyawaki, Yoichi; Uchida, Hajime; Yamashita, Okito; Sato, Masa-aki; Kamitani, Yukiyasu; Morito, Yusuke; Tanabe, Hiroki C; Sadato, Norihiro

    2009-01-01

    Brain activity represents our perceptual experience. But the potential for reading out perceptual contents from human brain activity has not been fully explored. In this study, we demonstrate constraint-free reconstruction of visual images perceived by a subject, from the brain activity pattern. We reconstructed visual images by combining local image bases with multiple scales, whose contrasts were independently decoded from fMRI activity by automatically selecting relevant voxels and exploiting their correlated patterns. Binary-contrast, 10 x 10-patch images (2 100 possible states), were accurately reconstructed without any image prior by measuring brain activity only for several hundred random images. The results suggest that our approach provides an effective means to read out complex perceptual states from brain activity while discovering information representation in multi-voxel patterns.

  18. Integration of ultra-high field MRI and histology for connectome based research of brain disorders

    Directory of Open Access Journals (Sweden)

    Shan eYang

    2013-09-01

    Full Text Available Ultra-high field magnetic resonance imaging (MRI became increasingly relevant for in vivo neuroscientific research because of improved spatial resolutions. However, this is still the unchallenged domain of histological studies, which long played an important role in the investigation of neuropsychiatric disorders. While the field of biological psychiatry strongly advanced on macroscopic levels, current developments are rediscovering the richness of immunohistological information when attempting a multi-level systematic approach to brain function and dysfunction. For most studies, histology sections lost information on three-dimensional reconstructions. Translating histological sections to 3D-volumes would thus not only allow for multi-stain and multi-subject alignment in post mortem data, but also provide a crucial step in big data initiatives involving the network analyses currently performed with in vivo MRI. We therefore investigated potential pitfalls during integration of MR and histological information where no additional blockface information is available. We demonstrated that strengths and requirements from both methods seem to be ideally merged at a spatial resolution of 200 μm. However, the success of this approach is heavily dependent on choices of hardware, sequence and reconstruction. We provide a fully automated pipeline that optimizes histological 3D reconstructions, providing a potentially powerful solution not only for primary human post mortem research institutions in neuropsychiatric research, but also to help alleviate the massive workloads in neuroanatomical atlas initiatives. We further demonstrate (for the first time the feasibility and quality of ultra-high spatial resolution (150 µm isotopic imaging of the entire human brain MRI at 7T, offering new opportunities for analyses on MR-derived information.

  19. Brain mechanisms underlying human communication

    Directory of Open Access Journals (Sweden)

    Matthijs L Noordzij

    2009-07-01

    Full Text Available Human communication has been described as involving the coding-decoding of a conventional symbol system, which could be supported by parts of the human motor system (i.e. the “mirror neurons system”. However, this view does not explain how these conventions could develop in the first place. Here we target the neglected but crucial issue of how people organize their non-verbal behavior to communicate a given intention without pre-established conventions. We have measured behavioral and brain responses in pairs of subjects during communicative exchanges occurring in a real, interactive, on-line social context. In two fMRI studies, we found robust evidence that planning new communicative actions (by a sender and recognizing the communicative intention of the same actions (by a receiver relied on spatially overlapping portions of their brains (the right posterior superior temporal sulcus. The response of this region was lateralized to the right hemisphere, modulated by the ambiguity in meaning of the communicative acts, but not by their sensorimotor complexity. These results indicate that the sender of a communicative signal uses his own intention recognition system to make a prediction of the intention recognition performed by the receiver. This finding supports the notion that our communicative abilities are distinct from both sensorimotor processes and language abilities.

  20. Brain mechanisms underlying human communication.

    Science.gov (United States)

    Noordzij, Matthijs L; Newman-Norlund, Sarah E; de Ruiter, Jan Peter; Hagoort, Peter; Levinson, Stephen C; Toni, Ivan

    2009-01-01

    Human communication has been described as involving the coding-decoding of a conventional symbol system, which could be supported by parts of the human motor system (i.e. the "mirror neurons system"). However, this view does not explain how these conventions could develop in the first place. Here we target the neglected but crucial issue of how people organize their non-verbal behavior to communicate a given intention without pre-established conventions. We have measured behavioral and brain responses in pairs of subjects during communicative exchanges occurring in a real, interactive, on-line social context. In two fMRI studies, we found robust evidence that planning new communicative actions (by a sender) and recognizing the communicative intention of the same actions (by a receiver) relied on spatially overlapping portions of their brains (the right posterior superior temporal sulcus). The response of this region was lateralized to the right hemisphere, modulated by the ambiguity in meaning of the communicative acts, but not by their sensorimotor complexity. These results indicate that the sender of a communicative signal uses his own intention recognition system to make a prediction of the intention recognition performed by the receiver. This finding supports the notion that our communicative abilities are distinct from both sensorimotor processes and language abilities.

  1. Findings at brain MRI in children with dengue fever and neurological symptoms

    International Nuclear Information System (INIS)

    Rastogi, Ruchi; Garg, Bhavya

    2016-01-01

    Dengue is a flavivirus of the genus arbovirus with four serotypes, from DEN 1 to DEN 4. There has been an increase in incidence of dengue infection in children in the tropics and subtropics. Dengue has a variable clinical presentation, with many patients being asymptomatic. Its clinical manifestations in children vary from fever and arthralgia to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We describe MRI findings in children with neurological involvement including dengue encephalopathy, acute hypoxic injury and dengue encephalitis. Dengue encephalopathy is usually secondary to multisystem derangement such as shock, hepatitis, coagulopathy and concurrent bacterial infection and is relatively common. Dengue encephalitis from direct neuronal invasion is rare. Nonspecific changes are seen on brain MRI in dengue infection. Clinical and laboratory findings as well as outcome do not necessarily correspond with brain MRI findings. (orig.)

  2. Findings at brain MRI in children with dengue fever and neurological symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Rastogi, Ruchi; Garg, Bhavya [Indraprastha Apollo Hospitals, Department of Radiodiagnosis, New Delhi (India)

    2016-01-15

    Dengue is a flavivirus of the genus arbovirus with four serotypes, from DEN 1 to DEN 4. There has been an increase in incidence of dengue infection in children in the tropics and subtropics. Dengue has a variable clinical presentation, with many patients being asymptomatic. Its clinical manifestations in children vary from fever and arthralgia to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We describe MRI findings in children with neurological involvement including dengue encephalopathy, acute hypoxic injury and dengue encephalitis. Dengue encephalopathy is usually secondary to multisystem derangement such as shock, hepatitis, coagulopathy and concurrent bacterial infection and is relatively common. Dengue encephalitis from direct neuronal invasion is rare. Nonspecific changes are seen on brain MRI in dengue infection. Clinical and laboratory findings as well as outcome do not necessarily correspond with brain MRI findings. (orig.)

  3. A three-dimensional MRI atlas of the zebra finch brain in stereotaxic coordinates

    DEFF Research Database (Denmark)

    Poirier, Colline; Vellema, Michiel; Verhoye, Marleen

    2008-01-01

    of different brain areas (nuclei) involved in the sensory and motor control of song. Until now, the only published atlases of songbird brains consisted in drawings based on histological slices of the canary and of the zebra finch brain. Taking advantage of high-magnetic field (7 Tesla) MRI technique, we...

  4. Evaluation of B1 inhomogeneity effect on DCE-MRI data analysis of brain tumor patients at 3T.

    Science.gov (United States)

    Sengupta, Anirban; Gupta, Rakesh Kumar; Singh, Anup

    2017-12-02

    Dynamic-contrast-enhanced (DCE) MRI data acquired using gradient echo based sequences is affected by errors in flip angle (FA) due to transmit B 1 inhomogeneity (B 1 inh). The purpose of the study was to evaluate the effect of B 1 inh on quantitative analysis of DCE-MRI data of human brain tumor patients and to evaluate the clinical significance of B 1 inh correction of perfusion parameters (PPs) on tumor grading. An MRI study was conducted on 35 glioma patients at 3T. The patients had histologically confirmed glioma with 23 high-grade (HG) and 12 low-grade (LG). Data for B 1 -mapping, T 1 -mapping and DCE-MRI were acquired. Relative B 1 maps (B 1rel ) were generated using the saturated-double-angle method. T 1 -maps were computed using the variable flip-angle method. Post-processing was performed for conversion of signal-intensity time (S(t)) curve to concentration-time (C(t)) curve followed by tracer kinetic analysis (K trans , Ve, Vp, Kep) and first pass analysis (CBV, CBF) using the general tracer-kinetic model. DCE-MRI data was analyzed without and with B 1 inh correction and errors in PPs were computed. Receiver-operating-characteristic (ROC) analysis was performed on HG and LG patients. Simulations were carried out to understand the effect of B 1 inhomogeneity on DCE-MRI data analysis in a systematic way. S(t) curves mimicking those in tumor tissue, were generated and FA errors were introduced followed by error analysis of PPs. Dependence of FA-based errors on the concentration of contrast agent and on the duration of DCE-MRI data was also studied. Simulations were also done to obtain K trans of glioma patients at different B 1rel values and see whether grading is affected or not. Current study shows that B 1rel value higher than nominal results in an overestimation of C(t) curves as well as derived PPs and vice versa. Moreover, at same B 1rel values, errors were large for larger values of C(t). Simulation results showed that grade of patients can change

  5. In Vivo H MR spectroscopic imaging of human brain

    International Nuclear Information System (INIS)

    Choe, Bo Young; Suh, Tae Suk; Choi, Kyo Ho; Bahk, Yong Whee; Shinn, Kyung Sub

    1994-01-01

    To evaluate the spatial distribution of various proton metabolites in the human brain with use of water-suppressed in vivo H MR spectroscopic imaging (MRSI) technique. All of water-suppressed in vivo H MRSI were performed on 1.5 T whole-body MRI/MRS system using Stimulated Echo Acquisition Method (STEAM) Chemical Shift Imaging (CSI) pulse sequence. T1-weighted MR images were used for CSI field of view (FOV; 24 cm). Voxel size of 1.5 cm 3 was designated from the periphery of the brain which was divided by 1024 X 16 X 16 data points. Metabolite images of N-acetylaspartate (NAA), creatine/ phosphocreatine (Cr) + choline/phosphocholine (Cho), and complex of γ-aminobutyric acid (GABA) + glutamate (Glu) were obtained on the human brain. Our preliminary study suggests that in vivo H MRSI could provide the metabolite imaging to compensate for hypermetabolism on Positron Emission Tomography (PET) scans on the basis of the metabolic informations on brain tissues. The unique ability of in vivo H MRSI to offer noninvasive information about tissue biochemistry in disease states will stimulate on clinical research and disease diagnosis

  6. Effects of overnight fasting on working memory-related brain network: an fMRI study.

    Science.gov (United States)

    Chechko, Natalia; Vocke, Sebastian; Habel, Ute; Toygar, Timur; Kuckartz, Lisa; Berthold-Losleben, Mark; Laoutidis, Zacharias G; Orfanos, Stelios; Wassenberg, Annette; Karges, Wölfram; Schneider, Frank; Kohn, Nils

    2015-03-01

    Glucose metabolism serves as the central source of energy for the human brain. Little is known about the effects of blood glucose level (BGL) on higher-order cognitive functions within a physiological range (e.g., after overnight fasting). In this randomized, placebo-controlled, double blind study, we assessed the impact of overnight fasting (14 h) on brain activation during a working memory task. We sought to mimic BGLs that occur naturally in healthy humans after overnight fasting. After standardized periods of food restriction, 40 (20 male) healthy participants were randomly assigned to receive either glucagon to balance the BGL or placebo (NaCl). A parametric fMRI paradigm, including 2-back and 0-back tasks, was used. Subclinically low BGL following overnight fasting was found to be linked to reduced involvement of the bilateral dorsal midline thalamus and the bilateral basal ganglia, suggesting high sensitivity of those regions to minimal changes in BGLs. Our results indicate that overnight fasting leads to physiologically low levels of glucose, impacting brain activation during working memory tasks even when there are no differences in cognitive performance. © 2014 Wiley Periodicals, Inc.

  7. Cerebrospinal fluid volumetric MRI mapping as a simple measurement for evaluating brain atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Vis, J.B. de; Zwanenburg, J.J.; Kleij, L.A. van der; Spijkerman, J.M.; Hendrikse, J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Biessels, G.J. [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Petersen, E.T. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Hvidovre Hospital, Danish Research Centre for Magnetic Resonance, Hvidovre (Denmark)

    2016-05-15

    To assess whether volumetric cerebrospinal fluid (CSF) MRI can be used as a surrogate for brain atrophy assessment and to evaluate how the T{sub 2} of the CSF relates to brain atrophy. Twenty-eight subjects [mean age 64 (sd 2) years] were included; T{sub 1}-weighted and CSF MRI were performed. The first echo data of the CSF MRI sequence was used to obtain intracranial volume, CSF partial volume was measured voxel-wise to obtain CSF volume (V{sub CSF}) and the T{sub 2} of CSF (T{sub 2,CSF}) was calculated. The correlation between V{sub CSF} / T{sub 2,CSF} and brain atrophy scores [global cortical atrophy (GCA) and medial temporal lobe atrophy (MTA)] was evaluated. Relative total, peripheral subarachnoidal, and ventricular V{sub CSF} increased significantly with increased scores on the GCA and MTA (R = 0.83, 0.78 and 0.78 and R = 0.72, 0.62 and 0.86). Total, peripheral subarachnoidal, and ventricular T{sub 2} of the CSF increased significantly with higher scores on the GCA and MTA (R = 0.72, 0.70 and 0.49 and R = 0.60, 0.57 and 0.41). A fast, fully automated CSF MRI volumetric sequence is an alternative for qualitative atrophy scales. The T{sub 2} of the CSF is related to brain atrophy and could thus be a marker of neurodegenerative disease. (orig.)

  8. Longitudinal MRI evaluation of intracranial development and vascular characteristics of breast cancer brain metastases in a mouse model.

    Directory of Open Access Journals (Sweden)

    Heling Zhou

    Full Text Available Longitudinal MRI was applied to monitor intracranial initiation and development of brain metastases and assess tumor vascular volume and permeability in a mouse model of breast cancer brain metastases. Using a 9.4T system, high resolution anatomic MRI and dynamic susceptibility contrast (DSC perfusion MRI were acquired at different time points after an intracardiac injection of brain-tropic breast cancer MDA-MB231BR-EGFP cells. Three weeks post injection, multifocal brain metastases were first observed with hyperintensity on T2-weighted images, but isointensity on T1-weighted post contrast images, indicating that blood-tumor-barrier (BTB at early stage of brain metastases was impermeable. Follow-up MRI revealed intracranial tumor growth and increased number of metastases that distributed throughout the whole brain. At the last scan on week 5, T1-weighted post contrast images detected BTB disruption in 160 (34% of a total of 464 brain metastases. Enhancement in some of the metastases was only seen in partial regions of the tumor, suggesting intratumoral heterogeneity of BTB disruption. DSC MRI measurements of relative cerebral blood volume (rCBV showed that rCBV of brain metastases was significantly lower (mean= 0.89±0.03 than that of contralateral normal brain (mean= 1.00±0.03; p<0.005. Intriguingly, longitudinal measurements revealed that rCBV of individual metastases at early stage was similar to, but became significantly lower than that of contralateral normal brain with tumor growth (p<0.05. The rCBV data were concordant with histological analysis of microvascular density (MVD. Moreover, comprehensive analysis suggested no significant correlation among tumor size, rCBV and BTB permeability. In conclusion, longitudinal MRI provides non-invasive in vivo assessments of spatial and temporal development of brain metastases and their vascular volume and permeability. The characteristic rCBV of brain metastases may have a diagnostic value.

  9. Real-Time fMRI in Neuroscience Research and Its Use in Studying the Aging Brain

    Science.gov (United States)

    Rana, Mohit; Varan, Andrew Q.; Davoudi, Anis; Cohen, Ronald A.; Sitaram, Ranganatha; Ebner, Natalie C.

    2016-01-01

    Cognitive decline is a major concern in the aging population. It is normative to experience some deterioration in cognitive abilities with advanced age such as related to memory performance, attention distraction to interference, task switching, and processing speed. However, intact cognitive functioning in old age is important for leading an independent day-to-day life. Thus, studying ways to counteract or delay the onset of cognitive decline in aging is crucial. The literature offers various explanations for the decline in cognitive performance in aging; among those are age-related gray and white matter atrophy, synaptic degeneration, blood flow reduction, neurochemical alterations, and change in connectivity patterns with advanced age. An emerging literature on neurofeedback and Brain Computer Interface (BCI) reports exciting results supporting the benefits of volitional modulation of brain activity on cognition and behavior. Neurofeedback studies based on real-time functional magnetic resonance imaging (rtfMRI) have shown behavioral changes in schizophrenia and behavioral benefits in nicotine addiction. This article integrates research on cognitive and brain aging with evidence of brain and behavioral modification due to rtfMRI neurofeedback. We offer a state-of-the-art description of the rtfMRI technique with an eye towards its application in aging. We present preliminary results of a feasibility study exploring the possibility of using rtfMRI to train older adults to volitionally control brain activity. Based on these first findings, we discuss possible implementations of rtfMRI neurofeedback as a novel technique to study and alleviate cognitive decline in healthy and pathological aging. PMID:27803662

  10. Functional MRI studies of human vision on a clinical imager

    International Nuclear Information System (INIS)

    George, J.S.; Lewine, J.D.; Aine, C.J.; van Hulsteyn, D.; Wood, C.C.; Sanders, J.; Maclin, E.; Belliveau, J.W.; Caprihan, A.

    1992-01-01

    During the past decade, Magnetic Resonance Imaging (MRI) has become the method of choice for imaging the anatomy of the human brain. Recently, Belliveau and colleagues have reported the use of echo planar magnetic resonance imaging (EPI) to image patterns of neural activity. Here, we report functional MR imaging in response to visual stimulation without the use of contrast agents, and without the extensive hardware modifications required for EPI. Regions of activity were observed near the expected locations of V1, V2 and possibly V3 and another active region was observed near the parietal-occipital sulcus on the superior surface of the cerebrum. These locations are consistent with sources observed in neuromagnetic studies of the human visual response

  11. Automated detection of multiple sclerosis lesions in serial brain MRI

    International Nuclear Information System (INIS)

    Llado, Xavier; Ganiler, Onur; Oliver, Arnau; Marti, Robert; Freixenet, Jordi; Valls, Laia; Vilanova, Joan C.; Ramio-Torrenta, Lluis; Rovira, Alex

    2012-01-01

    Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI. (orig.)

  12. Automated detection of multiple sclerosis lesions in serial brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Llado, Xavier; Ganiler, Onur; Oliver, Arnau; Marti, Robert; Freixenet, Jordi [University of Girona, Computer Vision and Robotics Group, Girona (Spain); Valls, Laia [Dr. Josep Trueta University Hospital, Department of Radiology, Girona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain); Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Department of Radiology, Barcelona (Spain)

    2012-08-15

    Multiple sclerosis (MS) is a serious disease typically occurring in the brain whose diagnosis and efficacy of treatment monitoring are vital. Magnetic resonance imaging (MRI) is frequently used in serial brain imaging due to the rich and detailed information provided. Time-series analysis of images is widely used for MS diagnosis and patient follow-up. However, conventional manual methods are time-consuming, subjective, and error-prone. Thus, the development of automated techniques for the detection and quantification of MS lesions is a major challenge. This paper presents an up-to-date review of the approaches which deal with the time-series analysis of brain MRI for detecting active MS lesions and quantifying lesion load change. We provide a comprehensive reference source for researchers in which several approaches to change detection and quantification of MS lesions are investigated and classified. We also analyze the results provided by the approaches, discuss open problems, and point out possible future trends. Lesion detection approaches are required for the detection of static lesions and for diagnostic purposes, while either quantification of detected lesions or change detection algorithms are needed to follow up MS patients. However, there is not yet a single approach that can emerge as a standard for the clinical practice, automatically providing an accurate MS lesion evolution quantification. Future trends will focus on combining the lesion detection in single studies with the analysis of the change detection in serial MRI. (orig.)

  13. A study of brain MRI findings in children with epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Sachiko; Sumida, Sawako; Muto, Ayako; Osawa, Makiko; Ono, Yuko [Tokyo Women' s Medical Coll. (Japan); Uchida, Moriyasu; Maruyama, Hiroshi

    2000-06-01

    Magnetic resonance imaging in the brain was performed in 293 patients with childhood-onset (<15 y.o.) epilepsy who had been classified into 4 groups, idiopathic localization-related epilepsy (ILRE), 78 patients; idiopathic generalized epilepsy (IGE), 116 patients; symptomatic localization-related epilepsy (SLRE), 68 patients and symptomatic generalized epilepsy (SGE), 31 patients, with the Classification of Epilepsies and Epileptic Syndrome (1989 International League Against Epilepsy). The examination was performed with a 1.5 T magnet. One hundred twenty-five patients (42.7%) showed abnormal findings, and the incidence in each group was as follows: Idiopathic epilepsy: The rate of abnormal findings in the ILRE and IGE groups was 21.8% and 20.7%, respectively. Most of the abnormal findings were secondary changes, such as diffuse or localized brain atrophy. Of the congenital abnormalities, the main finding was arachnoid cyst. Symptomatic epilepsy: The rate of abnormality in the SLRE patients was 88.2%, and 85% of the findings were secondary changes, i.e., brain atrophy, or degeneration of the white matter. In the SGE group, the rate was 77.4%, with an almost equal percentage of congenital and secondary changes. Of 255 patients who were examined by electroencephalography (EEG) on the same day as MRI, about 50% showed a correlation between the EEG records and the MRI abnormalities. However, only 8 patients showed a correlation in localization between the EEG and MRI abnormalities. (author)

  14. A study of brain MRI findings in children with epilepsy

    International Nuclear Information System (INIS)

    Kanematsu, Sachiko; Sumida, Sawako; Muto, Ayako; Osawa, Makiko; Ono, Yuko; Uchida, Moriyasu; Maruyama, Hiroshi

    2000-01-01

    Magnetic resonance imaging in the brain was performed in 293 patients with childhood-onset (<15 y.o.) epilepsy who had been classified into 4 groups, idiopathic localization-related epilepsy (ILRE), 78 patients; idiopathic generalized epilepsy (IGE), 116 patients; symptomatic localization-related epilepsy (SLRE), 68 patients and symptomatic generalized epilepsy (SGE), 31 patients, with the Classification of Epilepsies and Epileptic Syndrome (1989 International League Against Epilepsy). The examination was performed with a 1.5 T magnet. One hundred twenty-five patients (42.7%) showed abnormal findings, and the incidence in each group was as follows: Idiopathic epilepsy: The rate of abnormal findings in the ILRE and IGE groups was 21.8% and 20.7%, respectively. Most of the abnormal findings were secondary changes, such as diffuse or localized brain atrophy. Of the congenital abnormalities, the main finding was arachnoid cyst. Symptomatic epilepsy: The rate of abnormality in the SLRE patients was 88.2%, and 85% of the findings were secondary changes, i.e., brain atrophy, or degeneration of the white matter. In the SGE group, the rate was 77.4%, with an almost equal percentage of congenital and secondary changes. Of 255 patients who were examined by electroencephalography (EEG) on the same day as MRI, about 50% showed a correlation between the EEG records and the MRI abnormalities. However, only 8 patients showed a correlation in localization between the EEG and MRI abnormalities. (author)

  15. Decreased Complexity in Alzheimer's Disease: Resting-State fMRI Evidence of Brain Entropy Mapping

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2017-11-01

    Full Text Available Alzheimer's disease (AD is a frequently observed, irreversible brain function disorder among elderly individuals. Resting-state functional magnetic resonance imaging (rs-fMRI has been introduced as an alternative approach to assessing brain functional abnormalities in AD patients. However, alterations in the brain rs-fMRI signal complexities in mild cognitive impairment (MCI and AD patients remain unclear. Here, we described the novel application of permutation entropy (PE to investigate the abnormal complexity of rs-fMRI signals in MCI and AD patients. The rs-fMRI signals of 30 normal controls (NCs, 33 early MCI (EMCI, 32 late MCI (LMCI, and 29 AD patients were obtained from the Alzheimer's disease Neuroimaging Initiative (ADNI database. After preprocessing, whole-brain entropy maps of the four groups were extracted and subjected to Gaussian smoothing. We performed a one-way analysis of variance (ANOVA on the brain entropy maps of the four groups. The results after adjusting for age and sex differences together revealed that the patients with AD exhibited lower complexity than did the MCI and NC controls. We found five clusters that exhibited significant differences and were distributed primarily in the occipital, frontal, and temporal lobes. The average PE of the five clusters exhibited a decreasing trend from MCI to AD. The AD group exhibited the least complexity. Additionally, the average PE of the five clusters was significantly positively correlated with the Mini-Mental State Examination (MMSE scores and significantly negatively correlated with Functional Assessment Questionnaire (FAQ scores and global Clinical Dementia Rating (CDR scores in the patient groups. Significant correlations were also found between the PE and regional homogeneity (ReHo in the patient groups. These results indicated that declines in PE might be related to changes in regional functional homogeneity in AD. These findings suggested that complexity analyses using PE

  16. Brain MRI and SPECT in the diagnosis of early neurological involvement in Wilson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Piga, Mario; Satta, Loredana; Serra, Alessandra; Loi, Gianluigi [Policlinico Universitario, University of Cagliari, Nuclear Medicine, Department of Medical Science, Monserrato, Cagliari (Italy); Murru, Alessandra; Demelia, Luigi [Policlinico Universitario, University of Cagliari, Gastroenterology, Department of Medical Science, Monserrato, Cagliari (Italy); Sias, Alessandro [Policlinico Universitario, University of Cagliari, Radiology, Department of Medical Science, Monserrato, Cagliari (Italy); Marrosu, Francesco [Policlinico Universitario, University of Cagliari, Neurology, Department of Medical Science, Monserrato, Cagliari (Italy)

    2008-04-15

    To evaluate the impact of brain MRI and single-photon emission computed tomography (SPECT) in early detection of central nervous system abnormalities in patients affected by Wilson's disease (WD) with or without neurological involvement. Out of 25 consecutive WD patients, 13 showed hepatic involvement, ten hepatic and neurological manifestations, and twp hepatic, neurological, and psychiatric symptoms, including mainly movement disorders, major depression, and psychosis. Twenty-four healthy, age-gender matched subjects served as controls. All patients underwent brain MRI and {sup 99m}Tc-ethyl-cysteinate dimer (ECD) SPECT before starting specific therapy. Voxel-by-voxel analyses were performed using statistical parametric mapping to compare differences in {sup 99m}Tc-ECD brain uptake between the two groups. Brain MRI showed T2-weighted hyperintensities in seven patients (28%), six of whom were affected by hepatic and neurological forms. Brain perfusion SPECT showed pathological data in 19 patients (76%), revealing diffuse or focal hypoperfusion in superior frontal (Brodmann area (BA) 6), prefrontal (BA 9), parietal (BA 40), and occipital (BA 18, BA 39) cortices in temporal gyri (BA 37, BA 21) and in caudatus and putamen. Moreover, hepatic involvement was detected in nine subjects; eight presented both hepatic and neurological signs, while two exhibited WD-correlated hepatic, neurological, and psychiatric alterations. All but one patient with abnormal MRI matched with abnormal ECD SPECT. Pathologic MRI findings were obtained in six out of ten patients with hepatic and neurological involvement while abnormal ECD SPECT was revealed in eight patients. Both patients with hepatic, neurological, and psychiatric involvement displayed abnormal ECD SPECT and one displayed an altered MRI. These findings suggest that ECD SPECT might be useful in detecting early brain damage in WD, not only in the perspective of assessing and treating motor impairment but also in evaluating

  17. Volumetric MRI study of the intrauterine growth restriction fetal brain

    International Nuclear Information System (INIS)

    Polat, A.; Barlow, S.; Ber, R.; Achiron, R.; Katorza, E.

    2017-01-01

    Intrauterine growth restriction (IUGR) is a pathologic fetal condition known to affect the fetal brain regionally and associated with future neurodevelopmental abnormalities. This study employed MRI to assess in utero regional brain volume changes in IUGR fetuses compared to controls. Retrospectively, using MRI images of fetuses at 30-34 weeks gestational age, a total of 8 brain regions - supratentorial brain and cavity, cerebral hemispheres, temporal lobes and cerebellum - were measured for volume in 13 fetuses with IUGR due to placental insufficiency and in 21 controls. Volumes and their ratios were assessed for difference using regression models. Reliability was assessed by intraclass correlation coefficients (ICC) between two observers. In both groups, all structures increase in absolute volume during that gestation period, and the rate of cerebellar growth is higher compared to that of supratentorial structures. All structures' absolute volumes were significantly smaller for the IUGR group. Cerebellar to supratentorial ratios were found to be significantly smaller (P < 0.05) for IUGR compared to controls. No other significant ratio differences were found. ICC showed excellent agreement. The cerebellar to supratentorial volume ratio is affected in IUGR fetuses. Additional research is needed to assess this as a radiologic marker in relation to long-term outcome. (orig.)

  18. Volumetric MRI study of the intrauterine growth restriction fetal brain

    Energy Technology Data Exchange (ETDEWEB)

    Polat, A.; Barlow, S.; Ber, R.; Achiron, R.; Katorza, E. [Tel Aviv University, Sackler School of Medicine, Department of Obstetrics and Gynecology, Chaim Sheba Medical Center, Tel Hashomer (Israel)

    2017-05-15

    Intrauterine growth restriction (IUGR) is a pathologic fetal condition known to affect the fetal brain regionally and associated with future neurodevelopmental abnormalities. This study employed MRI to assess in utero regional brain volume changes in IUGR fetuses compared to controls. Retrospectively, using MRI images of fetuses at 30-34 weeks gestational age, a total of 8 brain regions - supratentorial brain and cavity, cerebral hemispheres, temporal lobes and cerebellum - were measured for volume in 13 fetuses with IUGR due to placental insufficiency and in 21 controls. Volumes and their ratios were assessed for difference using regression models. Reliability was assessed by intraclass correlation coefficients (ICC) between two observers. In both groups, all structures increase in absolute volume during that gestation period, and the rate of cerebellar growth is higher compared to that of supratentorial structures. All structures' absolute volumes were significantly smaller for the IUGR group. Cerebellar to supratentorial ratios were found to be significantly smaller (P < 0.05) for IUGR compared to controls. No other significant ratio differences were found. ICC showed excellent agreement. The cerebellar to supratentorial volume ratio is affected in IUGR fetuses. Additional research is needed to assess this as a radiologic marker in relation to long-term outcome. (orig.)

  19. Paediatrics brain imaging in epilepsy: common presenting symptoms and spectrum of abnormalities detected on MRI

    International Nuclear Information System (INIS)

    Ali, A.; Akram, F.; Khan, G.; Hussain, S.

    2017-01-01

    Epilepsy, a common neurological disorder can present at any age and has a number of aetiologies with underlying brain disease being the most common aetiology. Brain imaging becomes important and mandatory in the work up for epilepsy in localization and lateralization of the seizure focus. Methods: This cross-sectional study was conducted in the department of Radiology Ayub Medical Teaching Institution Abbottabad from 1st March 2015 to 31st March 2016. A total of 209 children aged 28 days to 14 years were included in the study who presented with seizures to clinicians. Information obtained from history, clinical examination and investigations especially MRI brains were recorded in a prescribed pro forma. The data was analysed in SPSS 20. Results: MRI examination was unremarkable in 44.01% (n=92) and mild generalized brain atrophy was noted in 12.91% (n=27). Arachnoid cysts, mild unilateral brain atrophy and hydrocephalous due to aqueduct stenosis were recorded in 3.82% (n=8) of each group. Neoplastic lesions were the second most common abnormal MRI finding and constituted 5.74% (n=12). Leukodystrophy was diagnosed in 4.78% (n=10). MRI examination showed ring enhancing lesions (tuberculomas) and AVM in 1.43% (n=3) of each group. Perinatal ischemia and intracranial infection, (focal or generalized) were recorded in 2.87% (n=6) of each group. A 0.95 % (n=2) of children in each group had agenesis of corpus callosum and cavernoma. The radiological MRI diagnosis of Raussmussen encephalitis was made in 3.34% (n=7). Single case, each of mesial temporal sclerosis, subdural haemorrhage, infarct and craniopharyngioma was recorded making 0.47 % of the total patients in each case. Conclusion: MRI examination was abnormal in significant number of patients (55.86%), so therefore if properly utilized, in a good clinical context, this can identify most of the structural brain abnormalities in paediatric patients presenting with seizures. (author)

  20. Brain Activities Associated with Graphic Emoticons: An fMRI Study

    Science.gov (United States)

    Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

    In this paper, we describe the brain activities that are associated with graphic emoticons by using functional MRI (fMRI). We use various types of faces from abstract to photorealistic in computer network applications. A graphics emoticon is an abstract face in communication over computer network. In this research, we created various graphic emoticons for the fMRI study and the graphic emoticons were classified according to friendliness and level of arousal. We investigated the brain activities of participants who were required to evaluate the emotional valence of the graphic emoticons (happy or sad). The experimental results showed that not only the right inferior frontal gyrus and the cingulate gyrus, but also the inferior and middle temporal gyrus and the fusiform gyrus, were found to be activated during the experiment. Forthermore, it is possible that the activation of the right inferior frontal gyrus and the cingulate gyrus is related to the type of abstract face. Since the inferior and middle temporal gyrus were activated, even though the graphic emoticons are static, we may perceive graphic emoticons as dynamic and living agents. Moreover, it is believed that text and graphics emoticons play an important role in enriching communication among users.

  1. Late radiation effects in the dog brain: correlation of MRI and histological changes

    International Nuclear Information System (INIS)

    Hopewell, J.; Tenhunen, M.; Joensuu, H.; Farkkila, M.; Joensuu, R.; Ramadan, U.A.; Kallio, M.; Snellman, M.; DeGritz, B.; Morris, G.M.

    2003-01-01

    The brains of groups of five beagle dogs were locally irradiated with single doses of 10 - 16 Gy of 6 MV photons in order to determine the correlation between sequential changes in the brain, as detected by magnetic resonance imaging (MRI), with the eventual appearance of histological lesions. Sequential MRIs were made to detect changes in the brain for up to 77-115 weeks after irradiation. Dose-effect relationships were established for changes in the brain as detected by MRI, gross morphology and histology. The doses that caused a specified response in 50 % of the animals (ED50 ± SE) were calculated using these dose-effect relationships for each endpoint. The ED50 values (± SE) for focal and diffuse changes on T2-weighted MRI were 11.0 ± 1.1 Gy and 10.8 ± 0.9 Gy, respectively. The ED50 values (± SE) for contrast enhancement on T1-weighted MRI was 13.4 ± 0.6 Gy. It was 11.4 ± 0.6 Gy for any type of histological lesion (haemorrhage, reactive change or glial scar) 77-115 weeks after irradiation. For a macroscopic lesion and for the histological appearance of a glial scar (indicative of an earlier area of necrosis) the ED50 (± SE) values were 13.0 ± 1.1 Gy and 13.4 ± 0.57 Gy, respectively. The presence of focal or diffuse changes on T2-weighted MRIs was the best indicator for the eventual appearance of any type of histological lesion in the dog brain after irradiation with single doses of photons. The ED50 for any histological lesion did not differ significantly from the ED50 for a focal (p > 0.35) or diffuse (p = 0.3) change on T2-weighted MRIs. The ED50 for a glial scar, indicative of an earlier region of necrosis, was not significantly different (p > 0.4) from that for the appearance of contrast enhancement on T1-weighted MRI

  2. The cooperation of the functional activation areas in human brain: an application of event-related fMRI study of the voluntary motor function

    International Nuclear Information System (INIS)

    Li Enzhong; Tian Jie; Dai Ruwei

    2002-01-01

    Objective: To detect the cooperation of the functional activation areas in human brain using event-related fMRI technique developed in recent years. Methods: Forty-four subjects were selected in this experiment and scanned by GE Signa Horizon 1.5 Tesla superconductive MR system. A CUE-GO paradigm was used in this experiment. The data were analyzed in SUN and SGI workstation. Results: The activation areas were found in contralateral primary motor area (Ml), bilateral supplementary motor areas (SMA), pre-motor areas (PMA), basal ganglia, and cerebellar cortices. The time-signal curve of Ml was a typical single-peak curve, but the curves in PMA, basal ganglia, and cerebellar cortices were double-peak curves. SMA had 2 parts, one was Pre-SMA, and another was SMA Proper. The curve was double-peak type in Pre-SMA and single-peak type in SMA Proper. There was difference between the time-signal intensity curves in above-mentioned areas. Conclusion: (1) Ml is mainly associated with motor execution, while others with both motor preparation and execution. There are differences in the function at the variant areas in the brain. (2) The fact that bilateral SMA, PMA, basal ganglia, and cerebellar cortices were activated, is different from what the classical theories told. (3) Event-related fMRI technique has higher temporary and spatial resolutions. (4) There is cooperation among different cortical areas, basal ganglia, and cerebellum

  3. A digital 3D atlas of the marmoset brain based on multi-modal MRI.

    Science.gov (United States)

    Liu, Cirong; Ye, Frank Q; Yen, Cecil Chern-Chyi; Newman, John D; Glen, Daniel; Leopold, David A; Silva, Afonso C

    2018-04-01

    The common marmoset (Callithrix jacchus) is a New-World monkey of growing interest in neuroscience. Magnetic resonance imaging (MRI) is an essential tool to unveil the anatomical and functional organization of the marmoset brain. To facilitate identification of regions of interest, it is desirable to register MR images to an atlas of the brain. However, currently available atlases of the marmoset brain are mainly based on 2D histological data, which are difficult to apply to 3D imaging techniques. Here, we constructed a 3D digital atlas based on high-resolution ex-vivo MRI images, including magnetization transfer ratio (a T1-like contrast), T2w images, and multi-shell diffusion MRI. Based on the multi-modal MRI images, we manually delineated 54 cortical areas and 16 subcortical regions on one hemisphere of the brain (the core version). The 54 cortical areas were merged into 13 larger cortical regions according to their locations to yield a coarse version of the atlas, and also parcellated into 106 sub-regions using a connectivity-based parcellation method to produce a refined atlas. Finally, we compared the new atlas set with existing histology atlases and demonstrated its applications in connectome studies, and in resting state and stimulus-based fMRI. The atlas set has been integrated into the widely-distributed neuroimaging data analysis software AFNI and SUMA, providing a readily usable multi-modal template space with multi-level anatomical labels (including labels from the Paxinos atlas) that can facilitate various neuroimaging studies of marmosets. Published by Elsevier Inc.

  4. A novel brain stimulation technology provides compatibility with MRI.

    Science.gov (United States)

    Serano, Peter; Angelone, Leonardo M; Katnani, Husam; Eskandar, Emad; Bonmassar, Giorgio

    2015-04-29

    Clinical electrical stimulation systems--such as pacemakers and deep brain stimulators (DBS)--are an increasingly common therapeutic option to treat a large range of medical conditions. Despite their remarkable success, one of the significant limitations of these medical devices is the limited compatibility with magnetic resonance imaging (MRI), a standard diagnostic tool in medicine. During an MRI exam, the leads used with these devices, implanted in the body of the patient, act as an electric antenna potentially causing a large amount of energy to be absorbed in the tissue, which can lead to serious heat-related injury. This study presents a novel lead design that reduces the antenna effect and allows for decreased tissue heating during MRI. The optimal parameters of the wire design were determined by a combination of computational modeling and experimental measurements. The results of these simulations were used to build a prototype, which was tested in a gel phantom during an MRI scan. Measurement results showed a three-fold decrease in heating when compared to a commercially available DBS lead. Accordingly, the proposed design may allow a significantly increased number of patients with medical implants to have safe access to the diagnostic benefits of MRI.

  5. MRI: A method to detect minor brain damage following coronary bypass surgery

    Energy Technology Data Exchange (ETDEWEB)

    Vik, A.; Brubakk, A.O. (Trondheim Univ. (Norway). Dept. of Biomedical Engineering); Rinck, P.A. (Trondheim Univ. (Norway). MR Center); Sande, E.; Levang, O.W. (Trondheim Univ. Hospital (Norway). Dept. of Surgery); Sellevold, O. (Trondheim Univ. Hospital (Norway). Dept. of Anaesthesiology)

    1991-10-01

    In order to assess the occurrence of minor focal brain lesions after coronary bypass surgery, magnetic resonance imaging (MRI) was used. Nine male patients (age 42-63) with angina pectoris were investigated at 0.5 Tesla. The investigation was performed one to seven weeks prior to the operation and one month after the operation. Before surgery, the images demonstrated more than five high intensity spots in the white matter of the brain in all but two patients. No additional spots were found after operation. This pilot study indicates that it might be difficult to use MRI to detect minor parenchymal lesions after cardiopulmonary bypass surgery. (orig.).

  6. Patterns of neonatal hypoxic-ischaemic brain injury

    International Nuclear Information System (INIS)

    Vries, Linda S. de; Groenendaal, Floris

    2010-01-01

    Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome. (orig.)

  7. Patterns of neonatal hypoxic-ischaemic brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Linda S. de [University Medical Centre, Department of Neonatology, Wilhelmina Children' s Hospital, Utrecht (Netherlands); Wilhelmina Children' s Hospital, University Medical Centre, Department of Neonatology, KE 04.123.1, P.O. Box 85090, Utrecht (Netherlands); Groenendaal, Floris [University Medical Centre, Department of Neonatology, Wilhelmina Children' s Hospital, Utrecht (Netherlands)

    2010-06-15

    Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome. (orig.)

  8. Value of repeat brain MRI in children with focal epilepsy and negative findings on initial MRI

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Tae Yeon; Kim, Ji Hye; Lee, Jee Hun; Yoo, So Young; Hwang, Sook Min; Lee, Mun Hyang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-08-01

    To evaluate the value of repeat brain magnetic resonance imaging (MRI) in identifying potential epileptogenic lesions in children with initial MRI-negative focal epilepsy. Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent. During a 15-year period, 257 children (148 boys and 109 girls) with initial MRI-negative focal epilepsy were included. After re-evaluating both initial and repeat MRIs, positive results at repeat MRI were classified into potential epileptogenic lesions (malformation of cortical development and hippocampal sclerosis) and other abnormalities. Contributing factors for improved lesion conspicuity of the initially overlooked potential epileptogenic lesions were analyzed and classified into lesion factors and imaging factors. Repeat MRI was positive in 21% (55/257) and negative in 79% cases (202/257). Of the positive results, potential epileptogenic lesions comprised 49% (27/55) and other abnormalities comprised 11% of the cases (28/257). Potential epileptogenic lesions included focal cortical dysplasia (n = 11), hippocampal sclerosis (n = 10), polymicrogyria (n = 2), heterotopic gray matter (n = 2), microlissencephaly (n = 1), and cortical tumor (n = 1). Of these, seven patients underwent surgical resection. Contributing factors for new diagnoses were classified as imaging factors alone (n = 6), lesion factors alone (n = 2), both (n = 18), and neither (n = 1). Repeat MRI revealed positive results in 21% of the children with initial MRI-negative focal epilepsy, with 50% of the positive results considered as potential epileptogenic lesions. Enhanced MRI techniques or considering the chronological changes of lesions on MRI may improve the diagnostic yield for identification of potential epileptogenic lesions on repeat MRI.

  9. Value of repeat brain MRI in children with focal epilepsy and negative findings on initial MRI

    International Nuclear Information System (INIS)

    Jeon, Tae Yeon; Kim, Ji Hye; Lee, Jee Hun; Yoo, So Young; Hwang, Sook Min; Lee, Mun Hyang

    2017-01-01

    To evaluate the value of repeat brain magnetic resonance imaging (MRI) in identifying potential epileptogenic lesions in children with initial MRI-negative focal epilepsy. Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent. During a 15-year period, 257 children (148 boys and 109 girls) with initial MRI-negative focal epilepsy were included. After re-evaluating both initial and repeat MRIs, positive results at repeat MRI were classified into potential epileptogenic lesions (malformation of cortical development and hippocampal sclerosis) and other abnormalities. Contributing factors for improved lesion conspicuity of the initially overlooked potential epileptogenic lesions were analyzed and classified into lesion factors and imaging factors. Repeat MRI was positive in 21% (55/257) and negative in 79% cases (202/257). Of the positive results, potential epileptogenic lesions comprised 49% (27/55) and other abnormalities comprised 11% of the cases (28/257). Potential epileptogenic lesions included focal cortical dysplasia (n = 11), hippocampal sclerosis (n = 10), polymicrogyria (n = 2), heterotopic gray matter (n = 2), microlissencephaly (n = 1), and cortical tumor (n = 1). Of these, seven patients underwent surgical resection. Contributing factors for new diagnoses were classified as imaging factors alone (n = 6), lesion factors alone (n = 2), both (n = 18), and neither (n = 1). Repeat MRI revealed positive results in 21% of the children with initial MRI-negative focal epilepsy, with 50% of the positive results considered as potential epileptogenic lesions. Enhanced MRI techniques or considering the chronological changes of lesions on MRI may improve the diagnostic yield for identification of potential epileptogenic lesions on repeat MRI

  10. An MRI-compatible hand sensory vibrotactile system

    International Nuclear Information System (INIS)

    Wang, Fa; Lakshminarayanan, Kishor; Slota, Gregory P; Seo, Na Jin; Webster, John G

    2015-01-01

    Recently, the application of vibrotactile noise to the wrist or back of the hand has been shown to enhance fingertip tactile sensory perception (Enders et al 2013), supporting the potential for an assistive device worn at the wrist, that generates minute vibrations to help the elderly or patients with sensory deficit. However, knowledge regarding the detailed physiological mechanism behind this sensory improvement in the central nervous system, especially in the human brain, is limited, hindering progress in development and use of such assistive devices. To enable investigation of the impact of vibrotactile noise on sensorimotor brain activity in humans, a magnetic resonance imaging (MRI)-compatible vibrotactile system was developed to provide vibrotactile noise during an MRI of the brain. The vibrotactile system utilizes a remote (outside the MR room) signal amplifier which provides a voltage from –40 to +40 V to drive a 12 mm diameter piezoelectric vibrator (inside the MR room). It is portable and is found to be MRI-compatible which enables its use for neurologic investigation with MRI. The system was also found to induce an improvement in fingertip tactile sensation, consistent with the previous study. (note)

  11. Relationship between brain function (aEEG) and brain structure (MRI) and their predictive value for neurodevelopmental outcome of preterm infants.

    Science.gov (United States)

    Hüning, Britta; Storbeck, Tobias; Bruns, Nora; Dransfeld, Frauke; Hobrecht, Julia; Karpienski, Julia; Sirin, Selma; Schweiger, Bernd; Weiss, Christel; Felderhoff-Müser, Ursula; Müller, Hanna

    2018-05-22

    To improve the prediction of neurodevelopmental outcome in very preterm infants, this study used the combination of amplitude-integrated electroencephalography (aEEG) within the first 72 h of life and cranial magnetic resonance imaging (MRI) at term equivalent age. A single-center cohort of 38 infants born before 32 weeks of gestation was subjected to both investigations. Structural measurements were performed on MRI. Multiple regression analysis was used to identify independent factors including functional and structural brain measurements associated with outcome at a corrected age of 24 months. aEEG parameters significantly correlated with MRI measurements. Reduced deep gray matter volume was associated with low Burdjalov Score on day 3 (p neurodevelopmental outcome: intraventricular hemorrhage (p = 0.0060) and interhemispheric distance (p = 0.0052) for mental developmental index; Burdjalov Score day 1 (p = 0.0201) and interhemispheric distance (p = 0.0142) for psychomotor developmental index. Functional aEEG parameters were associated with altered brain maturation on MRI. The combination of aEEG and MRI contributes to the prediction of outcome at 24 months. What is Known: • Prematurity remains a risk factor for impaired neurodevelopment. • aEEG is used to measure brain activity in preterm infants and cranial MRI is performed to identify structural gray and white matter abnormalities with impact on neurodevelopmental outcome. What is New: • aEEG parameters observed within the first 72 h of life were associated with altered deep gray matter volumes, biparietal width, and transcerebellar diameter at term equivalent age. • The combination of aEEG and MRI contributes to the prediction of neurodevelopmental outcome at 2 years of corrected age in very preterm infants.

  12. Dysglycemia, brain volume and vascular lesions on MRI in a memory clinic population

    NARCIS (Netherlands)

    Exalto, L.G.; van der Flier, W.M.; Scheltens, P.; Vrenken, H.; Biessels, G.J.

    2014-01-01

    Objective It is unclear, if the association between abnormalities in glucose metabolism (dysglycemia) and impaired cognitive functioning is primarily driven by degenerative or vascular brain damage. We therefore examined the relation between dysglycemia and brain volume and vascular lesions on MRI

  13. The Effects of Audiovisual Inputs on Solving the Cocktail Party Problem in the Human Brain: An fMRI Study.

    Science.gov (United States)

    Li, Yuanqing; Wang, Fangyi; Chen, Yongbin; Cichocki, Andrzej; Sejnowski, Terrence

    2017-09-25

    At cocktail parties, our brains often simultaneously receive visual and auditory information. Although the cocktail party problem has been widely investigated under auditory-only settings, the effects of audiovisual inputs have not. This study explored the effects of audiovisual inputs in a simulated cocktail party. In our fMRI experiment, each congruent audiovisual stimulus was a synthesis of 2 facial movie clips, each of which could be classified into 1 of 2 emotion categories (crying and laughing). Visual-only (faces) and auditory-only stimuli (voices) were created by extracting the visual and auditory contents from the synthesized audiovisual stimuli. Subjects were instructed to selectively attend to 1 of the 2 objects contained in each stimulus and to judge its emotion category in the visual-only, auditory-only, and audiovisual conditions. The neural representations of the emotion features were assessed by calculating decoding accuracy and brain pattern-related reproducibility index based on the fMRI data. We compared the audiovisual condition with the visual-only and auditory-only conditions and found that audiovisual inputs enhanced the neural representations of emotion features of the attended objects instead of the unattended objects. This enhancement might partially explain the benefits of audiovisual inputs for the brain to solve the cocktail party problem. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Metabolic connectivity mapping reveals effective connectivity in the resting human brain.

    Science.gov (United States)

    Riedl, Valentin; Utz, Lukas; Castrillón, Gabriel; Grimmer, Timo; Rauschecker, Josef P; Ploner, Markus; Friston, Karl J; Drzezga, Alexander; Sorg, Christian

    2016-01-12

    Directionality of signaling among brain regions provides essential information about human cognition and disease states. Assessing such effective connectivity (EC) across brain states using functional magnetic resonance imaging (fMRI) alone has proven difficult, however. We propose a novel measure of EC, termed metabolic connectivity mapping (MCM), that integrates undirected functional connectivity (FC) with local energy metabolism from fMRI and positron emission tomography (PET) data acquired simultaneously. This method is based on the concept that most energy required for neuronal communication is consumed postsynaptically, i.e., at the target neurons. We investigated MCM and possible changes in EC within the physiological range using "eyes open" versus "eyes closed" conditions in healthy subjects. Independent of condition, MCM reliably detected stable and bidirectional communication between early and higher visual regions. Moreover, we found stable top-down signaling from a frontoparietal network including frontal eye fields. In contrast, we found additional top-down signaling from all major clusters of the salience network to early visual cortex only in the eyes open condition. MCM revealed consistent bidirectional and unidirectional signaling across the entire cortex, along with prominent changes in network interactions across two simple brain states. We propose MCM as a novel approach for inferring EC from neuronal energy metabolism that is ideally suited to study signaling hierarchies in the brain and their defects in brain disorders.

  15. Brain infarcts due to scorpion stings in children: MRI

    International Nuclear Information System (INIS)

    Fernandez-Bouzas, A.; Ballesteros-Maresma, A.; Morales-Resendiz, M.L.; Llamas-Ibarra, F.; Martinez-Lopez, M.

    2000-01-01

    We report two children with severe neurological complications after having been stung by a scorpion. Clinical and MRI findings suggested brain infarcts. The lesions seen were in pons in one child and the right hemisphere in the other. The latter also showed possible hyperemia in the infarcted area. No vascular occlusions were observed and we therefore think the brain infarcts were a consequence of the scorpion sting. The cause of the infarct may be hypotension, shock or depressed left ventricular function, all of which are frequent in severe poisoning by scorpion sting. (orig.)

  16. The neural encoding of guesses in the human brain.

    Science.gov (United States)

    Bode, Stefan; Bogler, Carsten; Soon, Chun Siong; Haynes, John-Dylan

    2012-01-16

    Human perception depends heavily on the quality of sensory information. When objects are hard to see we often believe ourselves to be purely guessing. Here we investigated whether such guesses use brain networks involved in perceptual decision making or independent networks. We used a combination of fMRI and pattern classification to test how visibility affects the signals, which determine choices. We found that decisions regarding clearly visible objects are predicted by signals in sensory brain regions, whereas different regions in parietal cortex became predictive when subjects were shown invisible objects and believed themselves to be purely guessing. This parietal network was highly overlapping with regions, which have previously been shown to encode free decisions. Thus, the brain might use a dedicated network for determining choices when insufficient sensory information is available. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Energy landscape and dynamics of brain activity during human bistable perception.

    Science.gov (United States)

    Watanabe, Takamitsu; Masuda, Naoki; Megumi, Fukuda; Kanai, Ryota; Rees, Geraint

    2014-08-28

    Individual differences in the structure of parietal and prefrontal cortex predict the stability of bistable visual perception. However, the mechanisms linking such individual differences in brain structures to behaviour remain elusive. Here we demonstrate a systematic relationship between the dynamics of brain activity, cortical structure and behaviour underpinning bistable perception. Using fMRI in humans, we find that the activity dynamics during bistable perception are well described as fluctuating between three spatially distributed energy minimums: visual-area-dominant, frontal-area-dominant and intermediate states. Transitions between these energy minimums predicted behaviour, with participants whose brain activity tend to reflect the visual-area-dominant state exhibiting more stable perception and those whose activity transits to frontal-area-dominant states reporting more frequent perceptual switches. Critically, these brain activity dynamics are correlated with individual differences in grey matter volume of the corresponding brain areas. Thus, individual differences in the large-scale dynamics of brain activity link focal brain structure with bistable perception.

  18. Clinical application of functional MRI

    International Nuclear Information System (INIS)

    Taniwaki, Takayuki

    2010-01-01

    Described is the present state of clinical application of fMRI in the preoperative assessment of brain tumors, and plasticity in and pathophysiology of central diseases. For the tumor resection, fMRI is useful for risk assessment of postoperative nerve dysfunction, for selection of the patient rather suitable for brain mapping at the invasive surgery than at the pre-operation and for guidance of the operation itself. Preoperative fMRI alone can neither distinguish the regions of the primary and secondary functions nor exhibit the relation between the tumor and white matter fibers but there are compensatory means for these drawbacks. Benefit of preoperative fMRI has not yet been based on the evidence on double blind trials. Combination of fMRI imaging and electroencephalography (EEG) finding has shown that, in generalized epilepsy, extensive and stimulated activation occurs in both frontal/occipital regions and in thalamus area, respectively, and that the concomitant lowered activities are conceivably the reflection of burst discharge in normal brain functions. Plasticity in the human brain has been demonstrated by fMRI in cerebral vascular diseases, multiple sclerosis and amyotrophic lateral sclerosis. Pathogenesis of Parkinson disease and depression has been better understood by fMRI investigations revealing regions with elevated and reduced activities. Studies of attention deficit hyperactivity disorder have shown similar change of activities with functional reductions of the right dorsolateral frontal anterior area and of dorsal frontal cingulate gyrus, together with stimulated wider regions to given tasks. As above, fMRI has greatly contributed to our understanding of diseases of central nervous system and is to be expected to expand wider in this field. (T.T.)

  19. Registration and display of brain SPECT and MRI using external markers

    International Nuclear Information System (INIS)

    Pohjonen, H.; Nikkinen, P.; Sipilae, O.; Launes, J.; Salli, E.; Salonen, O.; Karp, P.; Ylae-Jaeaeski, J.; Katila, T.; Liewendahl, K.

    1996-01-01

    Accurate anatomical localisation of abnormalities observed in brain perfusion single-photon emission computed tomography (SPECT) is difficult, but can be improved by correlating data from SPECT and other tomographic imaging modalities. For this purpose we have developed software to register, analyse and display 99m Tc-hexamethylpropyleneamine oxime SPECT and 1.0 T MRI of the brain. For registration of SPECT and MRI data external skin markers containing 99m Tc (220 kBq) in 50 μl of coconut butter were used. The software is coded in the C programming language, and the X Window system and the OSF/Motif standards are used for graphics and definition of the user interface. The registration algorithm follows a noniterative least-squares method using singular value decomposition of a 3 x 3 covariance matrix. After registration, the image slices of both data sets are shown at identical tomographic levels. The registration error in phantom studies was on average 4 mm. In the two-dimensional display mode the orthogonal cross-sections of the data sets are displayed side by side. In the three-dimensional mode MRI data are displayed as a surface-shaded 3 D reconstruction and SPECT data as cut planes. The usefulness of this method is demonstrated in patients with cerebral infarcts, brain tumour, herpes simplex encephalitis and epilepsy. (orig.). With 9 figs

  20. Application of Quantitative MRI for Brain Tissue Segmentation at 1.5 T and 3.0 T Field Strengths

    Science.gov (United States)

    West, Janne; Blystad, Ida; Engström, Maria; Warntjes, Jan B. M.; Lundberg, Peter

    2013-01-01

    Background Brain tissue segmentation of white matter (WM), grey matter (GM), and cerebrospinal fluid (CSF) are important in neuroradiological applications. Quantitative Mri (qMRI) allows segmentation based on physical tissue properties, and the dependencies on MR scanner settings are removed. Brain tissue groups into clusters in the three dimensional space formed by the qMRI parameters R1, R2 and PD, and partial volume voxels are intermediate in this space. The qMRI parameters, however, depend on the main magnetic field strength. Therefore, longitudinal studies can be seriously limited by system upgrades. The aim of this work was to apply one recently described brain tissue segmentation method, based on qMRI, at both 1.5 T and 3.0 T field strengths, and to investigate similarities and differences. Methods In vivo qMRI measurements were performed on 10 healthy subjects using both 1.5 T and 3.0 T MR scanners. The brain tissue segmentation method was applied for both 1.5 T and 3.0 T and volumes of WM, GM, CSF and brain parenchymal fraction (BPF) were calculated on both field strengths. Repeatability was calculated for each scanner and a General Linear Model was used to examine the effect of field strength. Voxel-wise t-tests were also performed to evaluate regional differences. Results Statistically significant differences were found between 1.5 T and 3.0 T for WM, GM, CSF and BPF (p3.0 T. The mean differences between 1.5 T and 3.0 T were -66 mL WM, 40 mL GM, 29 mL CSF and -1.99% BPF. Voxel-wise t-tests revealed regional differences of WM and GM in deep brain structures, cerebellum and brain stem. Conclusions Most of the brain was identically classified at the two field strengths, although some regional differences were observed. PMID:24066153

  1. MRI patterns in prolonged low response states following traumatic brain injury in children and adolescents.

    Science.gov (United States)

    Patrick, Peter D; Mabry, Jennifer L; Gurka, Matthew J; Buck, Marcia L; Boatwright, Evelyn; Blackman, James A

    2007-01-01

    To explore the relationship between location and pattern of brain injury identified on MRI and prolonged low response state in children post-traumatic brain injury (TBI). This observational study compared 15 children who spontaneously recovered within 30 days post-TBI to 17 who remained in a prolonged low response state. 92.9% of children with brain stem injury were in the low response group. The predicted probability was 0.81 for brain stem injury alone, increasing to 0.95 with a regional pattern of injury to the brain stem, basal ganglia, and thalamus. Low response state in children post-TBI is strongly correlated with two distinctive regions of injury: the brain stem alone, and an injury pattern to the brain stem, basal ganglia, and thalamus. This study demonstrates the need for large-scale clinical studies using MRI as a tool for outcome assessment in children and adolescents following severe TBI.

  2. Low-Cost High-Performance MRI

    Science.gov (United States)

    Sarracanie, Mathieu; Lapierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-10-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (standards for affordable (<$50,000) and robust portable devices.

  3. MRI T2 relaxometry of brain regions and cognitive dysfunction following electroconvulsive therapy

    OpenAIRE

    Kunigiri, Girish; Jayakumar, P. N.; Janakiramaiah, N.; Gangadhar, B. N.

    2007-01-01

    Background: Although electroconvulsive therapy (ECT) causes no structural brain damage, recent studies reported altered brain perfusion acutely following ECT. This is in keeping with brain edema which was noted in animal experiments following electroconvulsive shock. Aim: This study examined alteration in magnetic resonance imaging (MRI) T2 relaxation time, a measure of brain edema, and its relation to therapeutic efficacy, orientation and memory impairment with ECT. Materials and Methods: Fi...

  4. Generation of Individual Whole-Brain Atlases With Resting-State fMRI Data Using Simultaneous Graph Computation and Parcellation.

    Science.gov (United States)

    Wang, J; Hao, Z; Wang, H

    2018-01-01

    The human brain can be characterized as functional networks. Therefore, it is important to subdivide the brain appropriately in order to construct reliable networks. Resting-state functional connectivity-based parcellation is a commonly used technique to fulfill this goal. Here we propose a novel individual subject-level parcellation approach based on whole-brain resting-state functional magnetic resonance imaging (fMRI) data. We first used a supervoxel method known as simple linear iterative clustering directly on resting-state fMRI time series to generate supervoxels, and then combined similar supervoxels to generate clusters using a clustering method known as graph-without-cut (GWC). The GWC approach incorporates spatial information and multiple features of the supervoxels by energy minimization, simultaneously yielding an optimal graph and brain parcellation. Meanwhile, it theoretically guarantees that the actual cluster number is exactly equal to the initialized cluster number. By comparing the results of the GWC approach and those of the random GWC approach, we demonstrated that GWC does not rely heavily on spatial structures, thus avoiding the challenges encountered in some previous whole-brain parcellation approaches. In addition, by comparing the GWC approach to two competing approaches, we showed that GWC achieved better parcellation performances in terms of different evaluation metrics. The proposed approach can be used to generate individualized brain atlases for applications related to cognition, development, aging, disease, personalized medicine, etc. The major source codes of this study have been made publicly available at https://github.com/yuzhounh/GWC.

  5. Volumetric quantification of brain development using MRI

    International Nuclear Information System (INIS)

    Iwasaki, N.; Hamano, K.; Okada, Y.; Horigome, Y.; Nakayama, J.; Takeya, T.; Takita, H.; Nose, T.

    1997-01-01

    We devised a three-dimensional method for estimation of cerebral development and myelination which measures cerebral volume using MRI. Accuracy of the system was estimated using cadaver brains. The mean percentage error in the calculated volumes compared with the real volumes was 2.33 %, range 0.00-5.33 %. We applied the method to the volume of both cerebral hemispheres (CH), basal ganglia, thalamus and internal capsule (BT), and myelinated white matter (WM) in 44 neurologically normal individuals (4 months to 28 years of age), 13 patients with spastic motor disturbances (2-25 years of age), and 9 patients with athetotic motor disturbances (2-23 years of age). In the neurologically normal cases, the volumes of CH, BT and WM increased with age; the volume of MW more slowly than that of CH. In cases with spastic motor disturbances, the volumes of CH, BT and WM were between -1.4 and 3.5 SD, -1.0 and -3.5 SD, and 0.0 and -5.2 SD respectively, of those of neurologically-normal cases. On the other hand, 7 of the 9 cases with athetotic motor disturbances were within 2 SD of the volume of CH in neurologically normal cases. Our method for direct measurement of cerebral volume based on serial MRI should be useful for the accurate assessment of brain development and quantitative analysis of delayed myelination. (orig.)

  6. Brain without anatomy: construction and comparison of fully network-driven structural MRI connectomes.

    Directory of Open Access Journals (Sweden)

    Olga Tymofiyeva

    Full Text Available MRI connectomics methods treat the brain as a network and provide new information about its organization, efficiency, and mechanisms of disruption. The most commonly used method of defining network nodes is to register the brain to a standardized anatomical atlas based on the Brodmann areas. This approach is limited by inter-subject variability and can be especially problematic in the context of brain maturation or neuroplasticity (cerebral reorganization after brain damage. In this study, we combined different image processing and network theory methods and created a novel approach that enables atlas-free construction and connection-wise comparison of diffusion MRI-based brain networks. We illustrated the proposed approach in three age groups: neonates, 6-month-old infants, and adults. First, we explored a data-driven method of determining the optimal number of equal-area nodes based on the assumption that all cortical areas of the brain are connected and, thus, no part of the brain is structurally isolated. Second, to enable a connection-wise comparison, alignment to a "reference brain" was performed in the network domain within each group using a matrix alignment algorithm with simulated annealing. The correlation coefficients after pair-wise network alignment ranged from 0.6102 to 0.6673. To test the method's reproducibility, one subject from the 6-month-old group and one from the adult group were scanned twice, resulting in correlation coefficients of 0.7443 and 0.7037, respectively. While being less than 1 due to parcellation and noise, statistically, these values were significantly higher than inter-subject values. Rotation of the parcellation largely explained the variability. Through the abstraction from anatomy, the developed framework allows for a fully network-driven analysis of structural MRI connectomes and can be applied to subjects at any stage of development and with substantial differences in cortical anatomy.

  7. PCA based clustering for brain tumor segmentation of T1w MRI images.

    Science.gov (United States)

    Kaya, Irem Ersöz; Pehlivanlı, Ayça Çakmak; Sekizkardeş, Emine Gezmez; Ibrikci, Turgay

    2017-03-01

    Medical images are huge collections of information that are difficult to store and process consuming extensive computing time. Therefore, the reduction techniques are commonly used as a data pre-processing step to make the image data less complex so that a high-dimensional data can be identified by an appropriate low-dimensional representation. PCA is one of the most popular multivariate methods for data reduction. This paper is focused on T1-weighted MRI images clustering for brain tumor segmentation with dimension reduction by different common Principle Component Analysis (PCA) algorithms. Our primary aim is to present a comparison between different variations of PCA algorithms on MRIs for two cluster methods. Five most common PCA algorithms; namely the conventional PCA, Probabilistic Principal Component Analysis (PPCA), Expectation Maximization Based Principal Component Analysis (EM-PCA), Generalize Hebbian Algorithm (GHA), and Adaptive Principal Component Extraction (APEX) were applied to reduce dimensionality in advance of two clustering algorithms, K-Means and Fuzzy C-Means. In the study, the T1-weighted MRI images of the human brain with brain tumor were used for clustering. In addition to the original size of 512 lines and 512 pixels per line, three more different sizes, 256 × 256, 128 × 128 and 64 × 64, were included in the study to examine their effect on the methods. The obtained results were compared in terms of both the reconstruction errors and the Euclidean distance errors among the clustered images containing the same number of principle components. According to the findings, the PPCA obtained the best results among all others. Furthermore, the EM-PCA and the PPCA assisted K-Means algorithm to accomplish the best clustering performance in the majority as well as achieving significant results with both clustering algorithms for all size of T1w MRI images. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Predicting decisions in human social interactions using real-time fMRI and pattern classification.

    Science.gov (United States)

    Hollmann, Maurice; Rieger, Jochem W; Baecke, Sebastian; Lützkendorf, Ralf; Müller, Charles; Adolf, Daniela; Bernarding, Johannes

    2011-01-01

    Negotiation and trade typically require a mutual interaction while simultaneously resting in uncertainty which decision the partner ultimately will make at the end of the process. Assessing already during the negotiation in which direction one's counterpart tends would provide a tremendous advantage. Recently, neuroimaging techniques combined with multivariate pattern classification of the acquired data have made it possible to discriminate subjective states of mind on the basis of their neuronal activation signature. However, to enable an online-assessment of the participant's mind state both approaches need to be extended to a real-time technique. By combining real-time functional magnetic resonance imaging (fMRI) and online pattern classification techniques, we show that it is possible to predict human behavior during social interaction before the interacting partner communicates a specific decision. Average accuracy reached approximately 70% when we predicted online the decisions of volunteers playing the ultimatum game, a well-known paradigm in economic game theory. Our results demonstrate the successful online analysis of complex emotional and cognitive states using real-time fMRI, which will enable a major breakthrough for social fMRI by providing information about mental states of partners already during the mutual interaction. Interestingly, an additional whole brain classification across subjects confirmed the online results: anterior insula, ventral striatum, and lateral orbitofrontal cortex, known to act in emotional self-regulation and reward processing for adjustment of behavior, appeared to be strong determinants of later overt behavior in the ultimatum game. Using whole brain classification we were also able to discriminate between brain processes related to subjective emotional and motivational states and brain processes related to the evaluation of objective financial incentives.

  9. Predicting decisions in human social interactions using real-time fMRI and pattern classification.

    Directory of Open Access Journals (Sweden)

    Maurice Hollmann

    Full Text Available Negotiation and trade typically require a mutual interaction while simultaneously resting in uncertainty which decision the partner ultimately will make at the end of the process. Assessing already during the negotiation in which direction one's counterpart tends would provide a tremendous advantage. Recently, neuroimaging techniques combined with multivariate pattern classification of the acquired data have made it possible to discriminate subjective states of mind on the basis of their neuronal activation signature. However, to enable an online-assessment of the participant's mind state both approaches need to be extended to a real-time technique. By combining real-time functional magnetic resonance imaging (fMRI and online pattern classification techniques, we show that it is possible to predict human behavior during social interaction before the interacting partner communicates a specific decision. Average accuracy reached approximately 70% when we predicted online the decisions of volunteers playing the ultimatum game, a well-known paradigm in economic game theory. Our results demonstrate the successful online analysis of complex emotional and cognitive states using real-time fMRI, which will enable a major breakthrough for social fMRI by providing information about mental states of partners already during the mutual interaction. Interestingly, an additional whole brain classification across subjects confirmed the online results: anterior insula, ventral striatum, and lateral orbitofrontal cortex, known to act in emotional self-regulation and reward processing for adjustment of behavior, appeared to be strong determinants of later overt behavior in the ultimatum game. Using whole brain classification we were also able to discriminate between brain processes related to subjective emotional and motivational states and brain processes related to the evaluation of objective financial incentives.

  10. Validation of DWI pre-processing procedures for reliable differentiation between human brain gliomas.

    Science.gov (United States)

    Vellmer, Sebastian; Tonoyan, Aram S; Suter, Dieter; Pronin, Igor N; Maximov, Ivan I

    2018-02-01

    Diffusion magnetic resonance imaging (dMRI) is a powerful tool in clinical applications, in particular, in oncology screening. dMRI demonstrated its benefit and efficiency in the localisation and detection of different types of human brain tumours. Clinical dMRI data suffer from multiple artefacts such as motion and eddy-current distortions, contamination by noise, outliers etc. In order to increase the image quality of the derived diffusion scalar metrics and the accuracy of the subsequent data analysis, various pre-processing approaches are actively developed and used. In the present work we assess the effect of different pre-processing procedures such as a noise correction, different smoothing algorithms and spatial interpolation of raw diffusion data, with respect to the accuracy of brain glioma differentiation. As a set of sensitive biomarkers of the glioma malignancy grades we chose the derived scalar metrics from diffusion and kurtosis tensor imaging as well as the neurite orientation dispersion and density imaging (NODDI) biophysical model. Our results show that the application of noise correction, anisotropic diffusion filtering, and cubic-order spline interpolation resulted in the highest sensitivity and specificity for glioma malignancy grading. Thus, these pre-processing steps are recommended for the statistical analysis in brain tumour studies. Copyright © 2017. Published by Elsevier GmbH.

  11. Patterns of differences in brain morphology in humans as compared to extant apes.

    Science.gov (United States)

    Aldridge, Kristina

    2011-01-01

    Although human evolution is characterized by a vast increase in brain size, it is not clear whether or not certain regions of the brain are enlarged disproportionately in humans, or how this enlargement relates to differences in overall neural morphology. The aim of this study is to determine whether or not there are specific suites of features that distinguish the morphology of the human brain from that of apes. The study sample consists of whole brain, in vivo magnetic resonance images (MRIs) of anatomically modern humans (Homo sapiens sapiens) and five ape species (gibbons, orangutans, gorillas, chimpanzees, bonobos). Twenty-nine 3D landmarks, including surface and internal features of the brain were located on 3D MRI reconstructions of each individual using MEASURE software. Landmark coordinate data were scaled for differences in size and analyzed using Euclidean Distance Matrix Analysis (EDMA) to statistically compare the brains of each non-human ape species to the human sample. Results of analyses show both a pattern of brain morphology that is consistently different between all apes and humans, as well as patterns that differ among species. Further, both the consistent and species-specific patterns include cortical and subcortical features. The pattern that remains consistent across species indicates a morphological reorganization of 1) relationships between cortical and subcortical frontal structures, 2) expansion of the temporal lobe and location of the amygdala, and 3) expansion of the anterior parietal region. Additionally, results demonstrate that, although there is a pattern of morphology that uniquely defines the human brain, there are also patterns that uniquely differentiate human morphology from the morphology of each non-human ape species, indicating that reorganization of neural morphology occurred at the evolutionary divergence of each of these groups. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Corpus callosum thickness on mid-sagittal MRI as a marker of brain volume: a pilot study in children with HIV-related brain disease and controls

    Energy Technology Data Exchange (ETDEWEB)

    Andronikou, Savvas [University of the Witwatersrand, Department of Radiology, Faculty of Health Sciences, Cape Town (South Africa); Ackermann, Christelle [University of Stellenbosch, Department of Radiology, Stellenbosch (South Africa); Laughton, Barbara; Cotton, Mark [Stellenbosch University and Tygerberg Children' s Hospital, Children' s Infectious Diseases Research Unit, Stellenbosch (South Africa); Tomazos, Nicollette [University of Cape Town, Faculty of Commerce, Department of Management Studies, Cape Town (South Africa); Spottiswoode, Bruce [University of Cape Town, MRC/UCT Medical Imaging Research Unit, Department of Human Biology, Cape Town (South Africa); Mauff, Katya [University of Cape Town, Department of Statistical Sciences, Cape Town (South Africa); Pettifor, John M. [University of the Witwatersrand, MRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, Witwatersrand (South Africa)

    2015-07-15

    Corpus callosum thickness measurement on mid-sagittal MRI may be a surrogate marker of brain volume. This is important for evaluation of diseases causing brain volume gain or loss, such as HIV-related brain disease and HIV encephalopathy. To determine if thickness of the corpus callosum on mid-sagittal MRI is a surrogate marker of brain volume in children with HIV-related brain disease and in controls without HIV. A retrospective MRI analysis in children (<5 years old) with HIV-related brain disease and controls used a custom-developed semi-automated tool, which divided the midline corpus callosum and measured its thickness in multiple locations. Brain volume was determined using volumetric analysis. Overall corpus callosum thickness and thickness of segments of the corpus callosum were correlated with overall and segmented (grey and white matter) brain volume. Forty-four children (33 HIV-infected patients and 11 controls) were included. Significant correlations included overall corpus callosum (mean) and total brain volume (P = 0.05); prefrontal corpus callosum maximum with white matter volume (P = 0.02); premotor corpus callosum mean with total brain volume (P = 0.04) and white matter volume (P = 0.02), premotor corpus callosum maximum with white matter volume (P = 0.02) and sensory corpus callosum mean with total brain volume (P = 0.02). Corpus callosum thickness correlates with brain volume both in HIV-infected patients and controls. (orig.)

  13. Corpus callosum thickness on mid-sagittal MRI as a marker of brain volume: a pilot study in children with HIV-related brain disease and controls

    International Nuclear Information System (INIS)

    Andronikou, Savvas; Ackermann, Christelle; Laughton, Barbara; Cotton, Mark; Tomazos, Nicollette; Spottiswoode, Bruce; Mauff, Katya; Pettifor, John M.

    2015-01-01

    Corpus callosum thickness measurement on mid-sagittal MRI may be a surrogate marker of brain volume. This is important for evaluation of diseases causing brain volume gain or loss, such as HIV-related brain disease and HIV encephalopathy. To determine if thickness of the corpus callosum on mid-sagittal MRI is a surrogate marker of brain volume in children with HIV-related brain disease and in controls without HIV. A retrospective MRI analysis in children (<5 years old) with HIV-related brain disease and controls used a custom-developed semi-automated tool, which divided the midline corpus callosum and measured its thickness in multiple locations. Brain volume was determined using volumetric analysis. Overall corpus callosum thickness and thickness of segments of the corpus callosum were correlated with overall and segmented (grey and white matter) brain volume. Forty-four children (33 HIV-infected patients and 11 controls) were included. Significant correlations included overall corpus callosum (mean) and total brain volume (P = 0.05); prefrontal corpus callosum maximum with white matter volume (P = 0.02); premotor corpus callosum mean with total brain volume (P = 0.04) and white matter volume (P = 0.02), premotor corpus callosum maximum with white matter volume (P = 0.02) and sensory corpus callosum mean with total brain volume (P = 0.02). Corpus callosum thickness correlates with brain volume both in HIV-infected patients and controls. (orig.)

  14. Computation of an MRI brain atlas from a population of Parkinson’s disease patients

    Science.gov (United States)

    Angelidakis, L.; Papageorgiou, I. E.; Damianou, C.; Psychogios, M. N.; Lingor, P.; von Eckardstein, K.; Hadjidemetriou, S.

    2017-11-01

    Parkinson’s Disease (PD) is a degenerative disorder of the brain. This study presents an MRI-based brain atlas of PD to characterize associated alterations for diagnostic and interventional purposes. The atlas standardizes primarily the implicated subcortical regions such as the globus pallidus (GP), substantia nigra (SN), subthalamic nucleus (STN), caudate nucleus (CN), thalamus (TH), putamen (PUT), and red nucleus (RN). The data were 3.0 T MRI brain images from 16 PD patients and 10 matched controls. The images used were T1-weighted (T 1 w), T2-weighted (T 2 w) images, and Susceptibility Weighted Images (SWI). The T1w images were the reference for the inter-subject non-rigid registration available from 3DSlicer. Anatomic labeling was achieved with BrainSuite and regions were refined with the level sets segmentation of ITK-Snap. The subcortical centers were analyzed for their volume and signal intensity. Comparison with an age-matched control group unravels a significant PD-related T1w signal loss in the striatum (CN and PUT) centers, but approximately a constant volume. The results in this study improve MRI based PD localization and can lead to the development of novel biomarkers.

  15. The dynamic programming high-order Dynamic Bayesian Networks learning for identifying effective connectivity in human brain from fMRI.

    Science.gov (United States)

    Dang, Shilpa; Chaudhury, Santanu; Lall, Brejesh; Roy, Prasun Kumar

    2017-06-15

    Determination of effective connectivity (EC) among brain regions using fMRI is helpful in understanding the underlying neural mechanisms. Dynamic Bayesian Networks (DBNs) are an appropriate class of probabilistic graphical temporal-models that have been used in past to model EC from fMRI, specifically order-one. High-order DBNs (HO-DBNs) have still not been explored for fMRI data. A fundamental problem faced in the structure-learning of HO-DBN is high computational-burden and low accuracy by the existing heuristic search techniques used for EC detection from fMRI. In this paper, we propose using dynamic programming (DP) principle along with integration of properties of scoring-function in a way to reduce search space for structure-learning of HO-DBNs and finally, for identifying EC from fMRI which has not been done yet to the best of our knowledge. The proposed exact search-&-score learning approach HO-DBN-DP is an extension of the technique which was originally devised for learning a BN's structure from static data (Singh and Moore, 2005). The effectiveness in structure-learning is shown on synthetic fMRI dataset. The algorithm reaches globally-optimal solution in appreciably reduced time-complexity than the static counterpart due to integration of properties. The proof of optimality is provided. The results demonstrate that HO-DBN-DP is comparably more accurate and faster than currently used structure-learning algorithms used for identifying EC from fMRI. The real data EC from HO-DBN-DP shows consistency with previous literature than the classical Granger Causality method. Hence, the DP algorithm can be employed for reliable EC estimates from experimental fMRI data. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Automatic procedure for realistic 3D finite element modelling of human brain for bioelectromagnetic computations

    International Nuclear Information System (INIS)

    Aristovich, K Y; Khan, S H

    2010-01-01

    Realistic computer modelling of biological objects requires building of very accurate and realistic computer models based on geometric and material data, type, and accuracy of numerical analyses. This paper presents some of the automatic tools and algorithms that were used to build accurate and realistic 3D finite element (FE) model of whole-brain. These models were used to solve the forward problem in magnetic field tomography (MFT) based on Magnetoencephalography (MEG). The forward problem involves modelling and computation of magnetic fields produced by human brain during cognitive processing. The geometric parameters of the model were obtained from accurate Magnetic Resonance Imaging (MRI) data and the material properties - from those obtained from Diffusion Tensor MRI (DTMRI). The 3D FE models of the brain built using this approach has been shown to be very accurate in terms of both geometric and material properties. The model is stored on the computer in Computer-Aided Parametrical Design (CAD) format. This allows the model to be used in a wide a range of methods of analysis, such as finite element method (FEM), Boundary Element Method (BEM), Monte-Carlo Simulations, etc. The generic model building approach presented here could be used for accurate and realistic modelling of human brain and many other biological objects.

  17. Altered brain functions in HIV positive patients free of HIV- associated neurocognitive disorders: A MRI study during unilateral hand movements

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2015-03-01

    Full Text Available This paper aimed to investigate the brain activity of human immunodeficiency virus (HIV positive patients with normal cognition during unilateral hand movement and whether highly active antiretroviral therapy (HAART could affect the brain function. Functional magnetic resonance imaging (fMRI was performed for 60 HIV positive (HIV+ subjects and −42 healthy age-matched right-handed control subjects. Each subject was evaluated by the neuropsychological test and examined with fMRI during left and right hand movement tasks. HIV+ subjects showed greater activation in anterior cingulum, precuneus, occipital lobes, ipsilateral postcentral gyrus and contralateral cerebellum compared with control group during right hand movement task. However, during left hand movement no statistically significant difference was detected between these two groups. HAART medication for HIV+ subjects lowered the increased activity to normal level. Meanwhile patients receiving the regimen of zidovudine, lamivudine and efavirenz showed lower activity at bilateral caudate and ipsilateral inferior frontal gyrus in comparison with subjects receiving other HAART regimens. Therefore, HIV+ subjects demonstrated brain asymmetry in motor cortex, with increased activity present during right hand movement but absent during left hand movement. HAART proves effective in HIV+ subjects even with normal cognition and the specific regimen of HAART could prevent cerebral abnormal functions. Meanwhile, this study validates that during motor tasks, fMRI can detect the brain signal changes prior to the occurrences of other HIV- associated dysfunctions.

  18. Prevalence of incidental findings on magnetic resonance imaging: Cuban project to map the human brain

    International Nuclear Information System (INIS)

    Hernandez Gonzalez, Gertrudis de los Angeles; Alvarez Sanchez, Marilet; Jordan Gonzalez, Jose

    2010-01-01

    To determine the prevalence of incidental findings in healthy subjects of the Cuban Human Brain Mapping Project sample, it was performed a retrospective descriptive study of the magnetic resonance imaging (MRI) obtained from 394 healthy subjects that make up the sample of the project, between 2006-2007, with an age range of 18 to 68 years (mean 33,12), of which 269 (68,27 %) are male and 125 (31,73 %) are women. It was shown that 40,36 % had one or more anomaly in the magnetic resonance imaging (MRI). In total, the number of incidental findings was 188, 23,6 % of which were brain findings and 24,11 % were non-brain findings, among the latter, were the sinusopathy with 20,81 % and maxillary polyps with 3,30 %. The most prevalent brain findings were: intrasellar arachnoidocele, 11,93 %, followed by the prominence of the pituitary gland, 5,84 %, ventricular asymmetry, 1,77 % and bone defects, 1,02 %. Other brain abnormalities found with very low prevalence had no pathological significance, except for two cases with brain tumor, which were immediately sent to a specialist. Incidental findings in MRI are common in the general population (40,36 %), being the sinusopathy, and intrasellar arachnoidocele the most common findings. Asymptomatic individuals who have any type of structural abnormality provide invaluable information on the prevalence of these abnormalities in a presumably healthy population, which may be used as references for epidemiological studies

  19. Dissecting the pathobiology of altered MRI signal in amyotrophic lateral sclerosis: A post mortem whole brain sampling strategy for the integration of ultra-high-field MRI and quantitative neuropathology.

    Science.gov (United States)

    Pallebage-Gamarallage, Menuka; Foxley, Sean; Menke, Ricarda A L; Huszar, Istvan N; Jenkinson, Mark; Tendler, Benjamin C; Wang, Chaoyue; Jbabdi, Saad; Turner, Martin R; Miller, Karla L; Ansorge, Olaf

    2018-03-13

    Amyotrophic lateral sclerosis (ALS) is a clinically and histopathologically heterogeneous neurodegenerative disorder, in which therapy is hindered by the rapid progression of disease and lack of biomarkers. Magnetic resonance imaging (MRI) has demonstrated its potential for detecting the pathological signature and tracking disease progression in ALS. However, the microstructural and molecular pathological substrate is poorly understood and generally defined histologically. One route to understanding and validating the pathophysiological correlates of MRI signal changes in ALS is to directly compare MRI to histology in post mortem human brains. The article delineates a universal whole brain sampling strategy of pathologically relevant grey matter (cortical and subcortical) and white matter tracts of interest suitable for histological evaluation and direct correlation with MRI. A standardised systematic sampling strategy that was compatible with co-registration of images across modalities was established for regions representing phosphorylated 43-kDa TAR DNA-binding protein (pTDP-43) patterns that were topographically recognisable with defined neuroanatomical landmarks. Moreover, tractography-guided sampling facilitated accurate delineation of white matter tracts of interest. A digital photography pipeline at various stages of sampling and histological processing was established to account for structural deformations that might impact alignment and registration of histological images to MRI volumes. Combined with quantitative digital histology image analysis, the proposed sampling strategy is suitable for routine implementation in a high-throughput manner for acquisition of large-scale histology datasets. Proof of concept was determined in the spinal cord of an ALS patient where multiple MRI modalities (T1, T2, FA and MD) demonstrated sensitivity to axonal degeneration and associated heightened inflammatory changes in the lateral corticospinal tract. Furthermore

  20. Conventional 3T brain MRI and diffusion tensor imaging in the diagnostic workup of early stage parkinsonism

    International Nuclear Information System (INIS)

    Meijer, Frederick J.A.; Rumund, Anouke van; Tuladhar, Anil M.; Aerts, Marjolein B.; Titulaer, Imke; Esselink, Rianne A.J.; Bloem, Bastiaan R.; Verbeek, Marcel M.; Goraj, Bozena

    2015-01-01

    The aim of this study is to evaluate whether the diagnostic accuracy of 3 T brain MRI is improved by region of interest (ROI) measures of diffusion tensor imaging (DTI), to differentiate between neurodegenerative atypical parkinsonism (AP) and Parkinson's disease (PD) in early stage parkinsonism. We performed a prospective observational cohort study of 60 patients presenting with early stage parkinsonism and initial uncertain diagnosis. At baseline, patients underwent a 3 T brain MRI including DTI. After clinical follow-up (mean 28.3 months), diagnoses could be made in 49 patients (30 PD and 19 AP). Conventional brain MRI was evaluated for regions of atrophy and signal intensity changes. Tract-based spatial statistics and ROI analyses of DTI were performed to analyze group differences in mean diffusivity (MD) and fractional anisotropy (FA), and diagnostic thresholds were determined. Diagnostic accuracy of conventional brain MRI and DTI was assessed with the receiver operating characteristic (ROC). Significantly higher MD of the centrum semiovale, body corpus callosum, putamen, external capsule, midbrain, superior cerebellum, and superior cerebellar peduncles was found in AP. Significantly increased MD of the putamen was found in multiple system atrophy-parkinsonian form (MSA-P) and increased MD in the midbrain and superior cerebellar peduncles in progressive supranuclear palsy (PSP). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by ROI measures of MD, though the diagnostic accuracy to identify MSA-P was slightly increased (AUC 0.82 to 0.85). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by the current analysis approach to DTI, though DTI measures could be of added value to identify AP subgroups. (orig.)

  1. Conventional 3T brain MRI and diffusion tensor imaging in the diagnostic workup of early stage parkinsonism

    Energy Technology Data Exchange (ETDEWEB)

    Meijer, Frederick J.A. [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Rumund, Anouke van; Tuladhar, Anil M.; Aerts, Marjolein B.; Titulaer, Imke; Esselink, Rianne A.J.; Bloem, Bastiaan R. [Radboud University Nijmegen Medical Center, Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen (Netherlands); Verbeek, Marcel M. [Radboud University Nijmegen Medical Center, Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Nijmegen (Netherlands); Radboud University Nijmegen Medical Center, Department of Laboratory Medicine, Nijmegen (Netherlands); Goraj, Bozena [Radboud University Nijmegen Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Medical Center of Postgraduate Education, Department of Diagnostic Imaging, Warsaw (Poland)

    2015-07-15

    The aim of this study is to evaluate whether the diagnostic accuracy of 3 T brain MRI is improved by region of interest (ROI) measures of diffusion tensor imaging (DTI), to differentiate between neurodegenerative atypical parkinsonism (AP) and Parkinson's disease (PD) in early stage parkinsonism. We performed a prospective observational cohort study of 60 patients presenting with early stage parkinsonism and initial uncertain diagnosis. At baseline, patients underwent a 3 T brain MRI including DTI. After clinical follow-up (mean 28.3 months), diagnoses could be made in 49 patients (30 PD and 19 AP). Conventional brain MRI was evaluated for regions of atrophy and signal intensity changes. Tract-based spatial statistics and ROI analyses of DTI were performed to analyze group differences in mean diffusivity (MD) and fractional anisotropy (FA), and diagnostic thresholds were determined. Diagnostic accuracy of conventional brain MRI and DTI was assessed with the receiver operating characteristic (ROC). Significantly higher MD of the centrum semiovale, body corpus callosum, putamen, external capsule, midbrain, superior cerebellum, and superior cerebellar peduncles was found in AP. Significantly increased MD of the putamen was found in multiple system atrophy-parkinsonian form (MSA-P) and increased MD in the midbrain and superior cerebellar peduncles in progressive supranuclear palsy (PSP). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by ROI measures of MD, though the diagnostic accuracy to identify MSA-P was slightly increased (AUC 0.82 to 0.85). The diagnostic accuracy of brain MRI to identify AP as a group was not improved by the current analysis approach to DTI, though DTI measures could be of added value to identify AP subgroups. (orig.)

  2. Reconstruction of human brain spontaneous activity based on frequency-pattern analysis of magnetoencephalography data

    Directory of Open Access Journals (Sweden)

    Rodolfo R Llinas

    2015-10-01

    Full Text Available A new method for the analysis and localization of brain activity has been developed, based on multichannel magnetic field recordings, over minutes, superimposed on the MRI of the individual. Here, a high resolution Fourier Transform is obtained over the entire recording period, leading to a detailed multi-frequency spectrum. Further analysis implements a total decomposition of the frequency components into functionally invariant entities, each having an invariant field pattern localizable in recording space. The method, addressed as functional tomography, makes it possible to find the distribution of magnetic field sources in space. Here, the method is applied to the analysis of simulated data, to oscillating signals activating a physical current dipoles phantom, and to recordings of spontaneous brain activity in ten healthy adults. In the analysis of simulated data, 61 dipoles are localized with 0.7 mm precision. Concerning the physical phantom the method is able to localize three simultaneously activated current dipoles with 1 mm precision. Spatial resolution 3 mm was attained when localizing spontaneous alpha rhythm activity in ten healthy adults, where the alpha peak was specified for each subject individually. Co-registration of the functional tomograms with each subject’s head MRI localized alpha range activity to the occipital and/or posterior parietal brain region. This is the first application of this new functional tomography to human brain activity. The method successfully provides an overall view of brain electrical activity, a detailed spectral description and, combined with MRI, the localization of sources in anatomical brain space.

  3. Reconstruction of human brain spontaneous activity based on frequency-pattern analysis of magnetoencephalography data

    Science.gov (United States)

    Llinás, Rodolfo R.; Ustinin, Mikhail N.; Rykunov, Stanislav D.; Boyko, Anna I.; Sychev, Vyacheslav V.; Walton, Kerry D.; Rabello, Guilherme M.; Garcia, John

    2015-01-01

    A new method for the analysis and localization of brain activity has been developed, based on multichannel magnetic field recordings, over minutes, superimposed on the MRI of the individual. Here, a high resolution Fourier Transform is obtained over the entire recording period, leading to a detailed multi-frequency spectrum. Further analysis implements a total decomposition of the frequency components into functionally invariant entities, each having an invariant field pattern localizable in recording space. The method, addressed as functional tomography, makes it possible to find the distribution of magnetic field sources in space. Here, the method is applied to the analysis of simulated data, to oscillating signals activating a physical current dipoles phantom, and to recordings of spontaneous brain activity in 10 healthy adults. In the analysis of simulated data, 61 dipoles are localized with 0.7 mm precision. Concerning the physical phantom the method is able to localize three simultaneously activated current dipoles with 1 mm precision. Spatial resolution 3 mm was attained when localizing spontaneous alpha rhythm activity in 10 healthy adults, where the alpha peak was specified for each subject individually. Co-registration of the functional tomograms with each subject's head MRI localized alpha range activity to the occipital and/or posterior parietal brain region. This is the first application of this new functional tomography to human brain activity. The method successfully provides an overall view of brain electrical activity, a detailed spectral description and, combined with MRI, the localization of sources in anatomical brain space. PMID:26528119

  4. Assessment of brain perfusion with MRI: methodology and application to acute stroke

    International Nuclear Information System (INIS)

    Grandin, C.B.

    2003-01-01

    We review the methodology of brain perfusion measurements with MRI and their application to acute stroke, with particular emphasis on the work awarded by the 6th Lucien Appel Prize for Neuroradiology. The application of the indicator dilution theory to the dynamic susceptibility-weighted bolus-tracking method is explained, as is the approach to obtaining quantitative measurements of cerebral blood flow (CBF) and volume (CBV). Our contribution to methodological developments, such as CBV measurement with the frequency-shifted burst sequence, development of the PRESTO sequence, comparison of different deconvolution methods and of spin- and gradient-echo sequences, and the validation of MRI measurements against positron emission tomography is summarised. The pathophysiology of brain ischaemia and the role of neuroimaging in the setting of acute stroke are reviewed, with an introduction to the concepts of ischaemic penumbra and diffusion/perfusion mismatch. Our work on the determination of absolute CBF and CBV thresholds for predicting the area of infarct growth, identification of the best perfusion parameters (relative or absolute) for predicting the area of infarct growth and the role of MR angiography is also summarised. We conclude that MRI is a very powerful way to assess brain perfusion and that its use might help in selecting patients who will benefit most from treatment such as thrombolysis. (orig.)

  5. Fetal functional imaging portrays heterogeneous development of emerging human brain networks

    OpenAIRE

    Schwartz, Ernst; Kasprian, Gregor; Gruber, Gerlinde M.; Prayer, Daniela; Langs, Georg; Jakab, András; Schöpf, Veronika

    2014-01-01

    The functional connectivity architecture of the adult human brain enables complex cognitive processes, and exhibits a remarkably complex structure shared across individuals. We are only beginning to understand its heterogeneous structure, ranging from a strongly hierarchical organization in sensorimotor areas to widely distributed networks in areas such as the parieto-frontal cortex. Our study relied on the functional magnetic resonance imaging (fMRI) data of 32 fetuses with no detectable mor...

  6. Acoustic pressure waves induced in human heads by RF pulses from high-field MRI scanners.

    Science.gov (United States)

    Lin, James C; Wang, Zhangwei

    2010-04-01

    The current evolution toward greater image resolution from magnetic resonance image (MRI) scanners has prompted the exploration of higher strength magnetic fields and use of higher levels of radio frequencies (RFs). Auditory perception of RF pulses by humans has been reported during MRI with head coils. It has shown that the mechanism of interaction for the auditory effect is caused by an RF pulse-induced thermoelastic pressure wave inside the head. We report a computational study of the intensity and frequency of thermoelastic pressure waves generated by RF pulses in the human head inside high-field MRI and clinical scanners. The U.S. Food and Drug Administration (U.S. FDA) guides limit the local specific absorption rate (SAR) in the body-including the head-to 8 W kg(-1). We present results as functions of SAR and show that for a given SAR the peak acoustic pressures generated in the anatomic head model were essentially the same at 64, 300, and 400 MHz (1.5, 7.0, and 9.4 T). Pressures generated in the anatomic head are comparable to the threshold pressure of 20 mPa for sound perception by humans at the cochlea for 4 W kg(-1). Moreover, results indicate that the peak acoustic pressure in the brain is only 2 to 3 times the auditory threshold at the U.S. FDA guideline of 8 W kg(-1). Even at a high SAR of 20 W kg(-1), where the acoustic pressure in the brain could be more than 7 times the auditory threshold, the sound pressure levels would not be more than 17 db above threshold of perception at the cochlea.

  7. Brain herniations into the dural venous sinus or calvarium: MRI findings, possible causes and clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Battal, Bilal; Hamcan, Salih; Akgun, Veysel; Sari, Sebahattin; Tasar, Mustafa [Gulhane Military Medical School, Department of Radiology, Ankara (Turkey); Oz, Oguzhan [Gulhane Military Medical School, Department of Neurology, Ankara (Turkey); Castillo, Mauricio [University of North Carolina School of Medicine, Division of Neuroradiology, Department of Radiology, Chapel Hill, NC (United States)

    2016-06-15

    To determine frequency, imaging features and clinical significance of herniations of brain parenchyma into dural venous sinuses (DVS) and/or calvarium found on MRI. A total of 6160 brain MRI examinations containing at least one high-resolution T1- or T2-weighted sequence were retrospectively evaluated to determine the presence of incidental brain herniations into the DVS or calvarium. MRI sequences available for review were evaluated according to their capability to demonstrate these herniations. Patients' symptoms and clinical findings were recorded. Twenty-one (0.32 %) brain parenchyma herniations into the DVS (n = 18) or calvarium (n = 3) in 20 patients were detected. The most common locations of the herniations were the transverse sinuses (n = 13) and those involving inferior gyrus of the temporal lobe (n = 9). High-resolution T1- and T2-weighted sequences were equally useful in the detection of these brain herniations. According to clinical symptoms, brain herniations were considered to be incidental but headaches were present in nine patients. Brain herniations with surrounding cerebrospinal fluid (CSF) into the DVS and/or calvarium are incidental findings and not proven to be associated with any symptoms. Although rare, these herniations are more common than previously recognized and should not be confused with arachnoid granulations, clots or tumours. (orig.)

  8. A comparative study of postmortem MR imaging and pathological examination of human brain specimens

    International Nuclear Information System (INIS)

    Shiga, Tohru

    1998-01-01

    This study was designed to assess the value of MRI of the postmortem brain specimens by comparing MRI findings with neuropathological findings. Postmortem MRI was performed in 17 consecutive formalin-fixed whole brains comprising 3 with primary CNS neoplasm, 1 with metastatic brain tumor, 6 with cerebral vascular disease (CVD), 1 with degenerative disease, 1 with spongy state in thalamus, and 5 with no abnormality. Postmortem T2WI detected all neuropathological abnormalities but sparsely distributed tumor cells without edema. In one case of CNS neoplasm, the tumor lesions with little necrosis or edema showed isointensity to brain tissue, while others with large amounts of necrosis and edema showed high signal intensity on T2WI. In the cases of CVD, the major signal changes on T2WI were due to edema, necrosis, and damage of the organization as observed on neuropathological studies. There was one case in which both MRI and neuropathological examination showed an abnormality, which was pathologically unexplainable. In two cases, findings of postmortem MRI were more apparent than those of macroscopic examination. Postmortem MRI appeared different from premortem MRI in one of the rest three cases whereas the postmortem MRI correlated well with neuropathological findings. Progression of the disease immediately before death may have caused this difference. In conclusion, the correlations between MRI and neuropathological findings facilitate understanding the mechanisms responsible for MRI abnormalities. An increase in free water in edema, necrosis, and damage in brain tissue can explain an increased signal intensity on T2WI. Postmortem MRI may contribute to the effective pathological examination by pointing out subtle abnormalities before brain cutting. (author)

  9. Creation of computerized 3D MRI-integrated atlases of the human basal ganglia and thalamus

    Directory of Open Access Journals (Sweden)

    Abbas F. Sadikot

    2011-09-01

    Full Text Available Functional brain imaging and neurosurgery in subcortical areas often requires visualization of brain nuclei beyond the resolution of current Magnetic Resonance Imaging (MRI methods. We present techniques used to create: 1 a lower resolution 3D atlas, based on the Schaltenbrand and Wahren print atlas, which was integrated into a stereotactic neurosurgery planning and visualization platform (VIPER; and 2 a higher resolution 3D atlas derived from a single set of manually segmented histological slices containing nuclei of the basal ganglia, thalamus, basal forebrain and medial temporal lobe. Both atlases were integrated to a canonical MRI (Colin27 from a young male participant by manually identifying homologous landmarks. The lower resolution atlas was then warped to fit the MRI based on the identified landmarks. A pseudo-MRI representation of the high-resolution atlas was created, and a nonlinear transformation was calculated in order to match the atlas to the template MRI. The atlas can then be warped to match the anatomy of Parkinson’s disease surgical candidates by using 3D automated nonlinear deformation methods. By way of functional validation of the atlas, the location of the sensory thalamus was correlated with stereotactic intraoperative physiological data. The position of subthalamic electrode positions in patients with Parkinson’s disease was also evaluated in the atlas-integrated MRI space. Finally, probabilistic maps of subthalamic stimulation electrodes were developed, in order to allow group analysis of the location of contacts associated with the best motor outcomes. We have therefore developed, and are continuing to validate, a high-resolution computerized MRI-integrated 3D histological atlas, which is useful in functional neurosurgery, and for functional and anatomical studies of the human basal ganglia, thalamus and basal forebrain.

  10. MRI visualization of endogenous neural progenitor cell migration along the RMS in the adult mouse brain

    DEFF Research Database (Denmark)

    Vreys, Ruth; Vande Velde, Greetje; Krylychkina, Olga

    2010-01-01

    The adult rodent brain contains neural progenitor cells (NPCs), generated in the subventricular zone (SVZ), which migrate along the rostral migratory stream (RMS) towards the olfactory bulb (OB) where they differentiate into neurons. The aim of this study was to visualize endogenous NPC migration...... by a longitudinal MRI study and validated with histology. Here, we visualized endogenous NPC migration in the mouse brain by in vivo MRI and demonstrated accumulation of MPIO-labeled NPCs in the OB over time with ex vivo MRI. Furthermore, we investigated the influence of in situ injection of MPIOs on adult...

  11. Genome-wide association studies of mri-defined brain infarcts: Meta-analysis from the charge consortium

    NARCIS (Netherlands)

    S. Debette (Stéphanie); J.C. Bis (Joshua); M. Fornage (Myriam); H.A. Schmid (Herbert); M.A. Ikram (Arfan); S. Sigurdsson (Stefan); G. Heiss (Gerardo); M.V. Struchalin (Maksim); A.V. Smith (Albert Vernon); A. van der Lugt (Aad); C. DeCarli (Charles); T. Lumley (Thomas); D.S. Knopman (David); C. Enzinger (Christian); G. Eiriksdottir (Gudny); P.J. Koudstaal (Peter Jan); A.L. DeStefano (Anita); B.M. Psaty (Bruce); C. Dufouil (Carole); D.J. Catellier (Diane); F. Fazekas (Franz); T. Aspelund (Thor); Y.S. Aulchenko (Yurii); A. Beiser (Alexa); J.I. Rotter (Jerome); C. Tzourio (Christophe); D.K. Shibata (Dean); M. Tscherner (Maria); T.B. Harris (Tamara); F. Rivadeneira Ramirez (Fernando); L.D. Atwood (Larry); K. Rice (Kenneth); R.F. Gottesman (Rebecca); M.A. van Buchem (Mark); A.G. Uitterlinden (André); M. Kelly-Hayes (Margaret); M. Cushman (Mary Ann); Y. Zhu (Yicheng); E.A. Boerwinkle (Eric); V. Gudnason (Vilmundur); A. Hofman (Albert); J.R. Romero (Jose Rafael); M.M.B. Breteler (Monique); R. Schmidt (Reinhold); L.J. Launer (Lenore); W.T. Longstreth Jr

    2010-01-01

    textabstractBackground and Purpose-Previous studies examining genetic associations with MRI-defined brain infarct have yielded inconsistent findings. We investigated genetic variation underlying covert MRI infarct in persons without histories of transient ischemic attack or stroke. We performed

  12. Novel applications of quantitative MRI for the fetal brain

    Energy Technology Data Exchange (ETDEWEB)

    Clouchoux, Cedric [Children' s National Medical Center, Division of Diagnostic Imaging and Radiology, Washington, DC (United States); Limperopoulos, Catherine [Children' s National Medical Center, Division of Diagnostic Imaging and Radiology, Washington, DC (United States); McGill University, McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal (Canada); McGill University, Department of Neurology and Neurosurgery, Montreal (Canada); Children' s National Medical Center, Division of Fetal and Transitional Medicine, Washington, DC (United States)

    2012-01-15

    The advent of ultrafast MRI acquisitions is offering vital insights into the critical maturational events that occur throughout pregnancy. Concurrent with the ongoing enhancement of ultrafast imaging has been the development of innovative image-processing techniques that are enabling us to capture and quantify the exuberant growth, and organizational and remodeling processes that occur during fetal brain development. This paper provides an overview of the role of advanced neuroimaging techniques to study in vivo brain maturation and explores the application of a range of new quantitative imaging biomarkers that can be used clinically to monitor high-risk pregnancies. (orig.)

  13. Mapping the order and pattern of brain structural MRI changes using change-point analysis in premanifest Huntington's disease.

    Science.gov (United States)

    Wu, Dan; Faria, Andreia V; Younes, Laurent; Mori, Susumu; Brown, Timothy; Johnson, Hans; Paulsen, Jane S; Ross, Christopher A; Miller, Michael I

    2017-10-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that progressively affects motor, cognitive, and emotional functions. Structural MRI studies have demonstrated brain atrophy beginning many years prior to clinical onset ("premanifest" period), but the order and pattern of brain structural changes have not been fully characterized. In this study, we investigated brain regional volumes and diffusion tensor imaging (DTI) measurements in premanifest HD, and we aim to determine (1) the extent of MRI changes in a large number of structures across the brain by atlas-based analysis, and (2) the initiation points of structural MRI changes in these brain regions. We adopted a novel multivariate linear regression model to detect the inflection points at which the MRI changes begin (namely, "change-points"), with respect to the CAG-age product (CAP, an indicator of extent of exposure to the effects of CAG repeat expansion). We used approximately 300 T1-weighted and DTI data from premanifest HD and control subjects in the PREDICT-HD study, with atlas-based whole brain segmentation and change-point analysis. The results indicated a distinct topology of structural MRI changes: the change-points of the volumetric measurements suggested a central-to-peripheral pattern of atrophy from the striatum to the deep white matter; and the change points of DTI measurements indicated the earliest changes in mean diffusivity in the deep white matter and posterior white matter. While interpretation needs to be cautious given the cross-sectional nature of the data, these findings suggest a spatial and temporal pattern of spread of structural changes within the HD brain. Hum Brain Mapp 38:5035-5050, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Graph-based network analysis of resting-state functional MRI.

    Science.gov (United States)

    Wang, Jinhui; Zuo, Xinian; He, Yong

    2010-01-01

    In the past decade, resting-state functional MRI (R-fMRI) measures of brain activity have attracted considerable attention. Based on changes in the blood oxygen level-dependent signal, R-fMRI offers a novel way to assess the brain's spontaneous or intrinsic (i.e., task-free) activity with both high spatial and temporal resolutions. The properties of both the intra- and inter-regional connectivity of resting-state brain activity have been well documented, promoting our understanding of the brain as a complex network. Specifically, the topological organization of brain networks has been recently studied with graph theory. In this review, we will summarize the recent advances in graph-based brain network analyses of R-fMRI signals, both in typical and atypical populations. Application of these approaches to R-fMRI data has demonstrated non-trivial topological properties of functional networks in the human brain. Among these is the knowledge that the brain's intrinsic activity is organized as a small-world, highly efficient network, with significant modularity and highly connected hub regions. These network properties have also been found to change throughout normal development, aging, and in various pathological conditions. The literature reviewed here suggests that graph-based network analyses are capable of uncovering system-level changes associated with different processes in the resting brain, which could provide novel insights into the understanding of the underlying physiological mechanisms of brain function. We also highlight several potential research topics in the future.

  15. Non-invasive imaging of transplanted human neural stem cells and ECM scaffold remodeling in the stroke-damaged rat brain by 19F- and diffusion-MRI

    Science.gov (United States)

    Bible, Ellen; Dell’Acqua, Flavio; Solanky, Bhavana; Balducci, Anthony; Crapo, Peter; Badylak, Stephen F.; Ahrens, Eric T.; Modo, Michel

    2012-01-01

    Transplantation of human neural stem cells (hNSCs) is emerging as a viable treatment for stroke related brain injury. However, intraparenchymal grafts do not regenerate lost tissue, but rather integrate into the host parenchyma without significantly affecting the lesion cavity. Providing a structural support for the delivered cells appears important for cell based therapeutic approaches. The non-invasive monitoring of therapeutic methods would provide valuable information regarding therapeutic strategies but remains a challenge. Labeling transplanted cells with metal-based 1H-magnetic resonance imaging (MRI) contrast agents affects the visualization of the lesion cavity. Herein, we demonstrate that a 19F-MRI contrast agent can adequately monitor the distribution of transplanted cells, whilst allowing an evaluation of the lesion cavity and the formation of new tissue on 1H-MRI scans. Twenty percent of cells labeled with the 19F-agent were of host origin, potentially reflecting the re-uptake of label from dead transplanted cells. Both T2- and diffusion-weighted MRI scans indicated that transplantation of hNSCs suspended in a gel form of a xenogeneic extracellular matrix (ECM) bioscaffold resulted in uniformly distributed cells throughout the lesion cavity. However, diffusion MRI indicated that the injected materials did not yet establish diffusion barriers (i.e. cellular network, fiber tracts) normally found within striatal tissue. The ECM bioscaffold therefore provides an important support to hNSCs for the creation of de novo tissue and multi-nuclei MRI represents an adept method for the visualization of some aspects of this process. However, significant developments of both the transplantation paradigm, as well as regenerative imaging, are required to successfully create new tissue in the lesion cavity and to monitor this process non-invasively. PMID:22244696

  16. Non-invasive imaging of transplanted human neural stem cells and ECM scaffold remodeling in the stroke-damaged rat brain by (19)F- and diffusion-MRI.

    Science.gov (United States)

    Bible, Ellen; Dell'Acqua, Flavio; Solanky, Bhavana; Balducci, Anthony; Crapo, Peter M; Badylak, Stephen F; Ahrens, Eric T; Modo, Michel

    2012-04-01

    Transplantation of human neural stem cells (hNSCs) is emerging as a viable treatment for stroke related brain injury. However, intraparenchymal grafts do not regenerate lost tissue, but rather integrate into the host parenchyma without significantly affecting the lesion cavity. Providing a structural support for the delivered cells appears important for cell based therapeutic approaches. The non-invasive monitoring of therapeutic methods would provide valuable information regarding therapeutic strategies but remains a challenge. Labeling transplanted cells with metal-based (1)H-magnetic resonance imaging (MRI) contrast agents affects the visualization of the lesion cavity. Herein, we demonstrate that a (19)F-MRI contrast agent can adequately monitor the distribution of transplanted cells, whilst allowing an evaluation of the lesion cavity and the formation of new tissue on (1)H-MRI scans. Twenty percent of cells labeled with the (19)F agent were of host origin, potentially reflecting the re-uptake of label from dead transplanted cells. Both T(2)- and diffusion-weighted MRI scans indicated that transplantation of hNSCs suspended in a gel form of a xenogeneic extracellular matrix (ECM) bioscaffold resulted in uniformly distributed cells throughout the lesion cavity. However, diffusion MRI indicated that the injected materials did not yet establish diffusion barriers (i.e. cellular network, fiber tracts) normally found within striatal tissue. The ECM bioscaffold therefore provides an important support to hNSCs for the creation of de novo tissue and multi-nuclei MRI represents an adept method for the visualization of some aspects of this process. However, significant developments of both the transplantation paradigm, as well as regenerative imaging, are required to successfully create new tissue in the lesion cavity and to monitor this process non-invasively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. BrainK for Structural Image Processing: Creating Electrical Models of the Human Head

    Directory of Open Access Journals (Sweden)

    Kai Li

    2016-01-01

    Full Text Available BrainK is a set of automated procedures for characterizing the tissues of the human head from MRI, CT, and photogrammetry images. The tissue segmentation and cortical surface extraction support the primary goal of modeling the propagation of electrical currents through head tissues with a finite difference model (FDM or finite element model (FEM created from the BrainK geometries. The electrical head model is necessary for accurate source localization of dense array electroencephalographic (dEEG measures from head surface electrodes. It is also necessary for accurate targeting of cerebral structures with transcranial current injection from those surface electrodes. BrainK must achieve five major tasks: image segmentation, registration of the MRI, CT, and sensor photogrammetry images, cortical surface reconstruction, dipole tessellation of the cortical surface, and Talairach transformation. We describe the approach to each task, and we compare the accuracies for the key tasks of tissue segmentation and cortical surface extraction in relation to existing research tools (FreeSurfer, FSL, SPM, and BrainVisa. BrainK achieves good accuracy with minimal or no user intervention, it deals well with poor quality MR images and tissue abnormalities, and it provides improved computational efficiency over existing research packages.

  18. Using real-time fMRI brain-computer interfacing to treat eating disorders.

    Science.gov (United States)

    Sokunbi, Moses O

    2018-05-15

    Real-time functional magnetic resonance imaging based brain-computer interfacing (fMRI neurofeedback) has shown encouraging outcomes in the treatment of psychiatric and behavioural disorders. However, its use in the treatment of eating disorders is very limited. Here, we give a brief overview of how to design and implement fMRI neurofeedback intervention for the treatment of eating disorders, considering the basic and essential components. We also attempt to develop potential adaptations of fMRI neurofeedback intervention for the treatment of anorexia nervosa, bulimia nervosa and binge eating disorder. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Brain tissue- and region-specific abnormalities on volumetric MRI scans in 21 patients with Bardet-Biedl syndrome (BBS

    Directory of Open Access Journals (Sweden)

    Johnston Jennifer

    2011-07-01

    Full Text Available Abstract Background Bardet-Biedl syndrome (BBS is a heterogeneous human disorder inherited in an autosomal recessive pattern, and characterized by the primary findings of obesity, polydactyly, hypogonadism, and learning and behavioural problems. BBS mouse models have a neuroanatomical phenotype consisting of third and lateral ventriculomegaly, thinning of the cerebral cortex, and reduction in the size of the corpus striatum and hippocampus. These abnormalities raise the question of whether humans with BBS have a characteristic morphologic brain phenotype. Further, although behavioral, developmental, neurological and motor defects have been noted in patients with BBS, to date, there are limited reports of brain findings in BBS. The present study represents the largest systematic evaluation for the presence of structural brain malformations and/or progressive changes, which may contribute to these functional problems. Methods A case-control study of 21 patients, most aged 13-35 years, except for 2 patients aged 4 and 8 years, who were diagnosed with BBS by clinical criteria and genetic analysis of known BBS genes, and were evaluated by qualitative and volumetric brain MRI scans. Healthy controls were matched 3:1 by age, sex and race. Statistical analysis was performed using SAS language with SAS STAT procedures. Results All 21 patients with BBS were found to have statistically significant region- and tissue-specific patterns of brain abnormalities. There was 1 normal intracranial volume; 2 reduced white matter in all regions of the brain, but most in the occipital region; 3 preserved gray matter volume, with increased cerebral cortex volume in only the occipital lobe; 4 reduced gray matter in the subcortical regions of the brain, including the caudate, putamen and thalamus, but not in the cerebellum; and 5 increased cerebrospinal fluid volume. Conclusions There are distinct and characteristic abnormalities in tissue- and region- specific volumes

  20. The registration accuracy analysis of different CT-MRI imaging fusion method in brain tumor

    International Nuclear Information System (INIS)

    Lu Jie; Yin Yong; Shao Qian; Zhang Zicheng; Chen Jinhu; Chen Zhaoqiu

    2010-01-01

    Objective: To find an effective CT-MRI image fusion protocol in brain tumor by analyzing the registration accuracy of different methods. Methods: The simulation CT scan and MRI T 1 WI imaging of 10 brain tumor patients obtained with same position were registered by Tris-Axes landmark ,Tris-Axes landmark + manual adjustment, mutual information and mutual information + manual adjustment method. The clinical tumor volume (CTV) were contoured on both CT and MRI images respectively. The accuracy of image fusion was assessed by the mean distance of five bone markers (d 1-5 ), central position of CTV (d CTV ) the percentage of CTV overlap (P CT-MRI ) between CT and MRI images. The difference between different methods was analyzed by Freedman M non-parameter test. Results: The difference of the means d1-5 between the Tris-Axes landmark,Tris-Axes landmark plus manual adjustment,mutual information and mutual information plus manual adjustment methods were 0.28 cm ±0.12 cm, 0.15 cm ±0.02 cm, 0.25 cm± 0.19 cm, 0.10 cm ± 0.06 cm, (M = 14.41, P = 0.002). the means d CTV were 0.59 cm ± 0.28 cm, 0.60 cm± 0.32 cm, 0.58 cm ± 0.39 cm, 0.42 cm± 0.30 cm (M = 9.72, P = 0.021), the means P CT-MRI were 0.69% ±0.18%, 0.68% ±0.16%, 0.66% ±0.17%, 0.74% ±0.14% (M =14.82, P=0.002), respectively. Conclusions: Mutual information plus manual adjustment registration method was the preferable fusion method for brain tumor patients. (authors)

  1. Postoperative meningeal enhancement on MRI in children with brain neoplasms

    International Nuclear Information System (INIS)

    Lee, Min Hee; Han, Bokyung Kim; Yoon, Hye Kyung; Shin, Hyung Jin

    2000-01-01

    The meninges composed of the dura, the arachnoid and the pia are significant sites of blood-brain barrier. Physical disruption of the integrity of the meninges from a variety of causes including surgery results in various patterns of meningeal enhancement on contrast enhanced MR images. It is important to distinguish normal reactive or benign postoperative enhancement from more serious leptomeningeal metastasis or infection, particularly in children with intracranial neoplasms. We present various patterns of meningeal enhancement on MRI in children following surgery for brain neoplasms. (author)

  2. Feasibility of using fMRI to study mothers responding to infant cries.

    Science.gov (United States)

    Lorberbaum, J P; Newman, J D; Dubno, J R; Horwitz, A R; Nahas, Z; Teneback, C C; Bloomer, C W; Bohning, D E; Vincent, D; Johnson, M R; Emmanuel, N; Brawman-Mintzer, O; Book, S W; Lydiard, R B; Ballenger, J C; George, M S

    1999-01-01

    While parenting is a universal human behavior, its neuroanatomic basis is currently unknown. Animal data suggest that the cingulate may play an important function in mammalian parenting behavior. For example, in rodents cingulate lesions impair maternal behavior. Here, in an attempt to understand the brain basis of human maternal behavior, we had mothers listen to recorded infant cries and white noise control sounds while they underwent functional MRI (fMRI) of the brain. We hypothesized that mothers would show significantly greater cingulate activity during the cries compared to the control sounds. Of 7 subjects scanned, 4 had fMRI data suitable for analysis. When fMRI data were averaged for these 4 subjects, the anterior cingulate and right medial prefrontal cortex were the only brain regions showing statistically increased activity with the cries compared to white noise control sounds (cluster analysis with one-tailed z-map threshold of P parent-infant bond and (2) examine whether markers of this bond, such as maternal brain response to infant crying, can predict maternal style (i.e., child neglect), offspring temperament, or offspring depression or anxiety.

  3. Generation of Individual Whole-Brain Atlases With Resting-State fMRI Data Using Simultaneous Graph Computation and Parcellation

    Directory of Open Access Journals (Sweden)

    J. Wang

    2018-05-01

    Full Text Available The human brain can be characterized as functional networks. Therefore, it is important to subdivide the brain appropriately in order to construct reliable networks. Resting-state functional connectivity-based parcellation is a commonly used technique to fulfill this goal. Here we propose a novel individual subject-level parcellation approach based on whole-brain resting-state functional magnetic resonance imaging (fMRI data. We first used a supervoxel method known as simple linear iterative clustering directly on resting-state fMRI time series to generate supervoxels, and then combined similar supervoxels to generate clusters using a clustering method known as graph-without-cut (GWC. The GWC approach incorporates spatial information and multiple features of the supervoxels by energy minimization, simultaneously yielding an optimal graph and brain parcellation. Meanwhile, it theoretically guarantees that the actual cluster number is exactly equal to the initialized cluster number. By comparing the results of the GWC approach and those of the random GWC approach, we demonstrated that GWC does not rely heavily on spatial structures, thus avoiding the challenges encountered in some previous whole-brain parcellation approaches. In addition, by comparing the GWC approach to two competing approaches, we showed that GWC achieved better parcellation performances in terms of different evaluation metrics. The proposed approach can be used to generate individualized brain atlases for applications related to cognition, development, aging, disease, personalized medicine, etc. The major source codes of this study have been made publicly available at https://github.com/yuzhounh/GWC.

  4. fMRI and brain activation after sport concussion: a tale of two cases

    Directory of Open Access Journals (Sweden)

    Michael G Hutchison

    2014-04-01

    Full Text Available Sport-related concussions are now recognized as a major public health concern: The number of participants in sport and recreation is growing, possibly playing their games faster, and there is heightened public awareness of injuries to some high-profile athletes. However, many clinicians still rely on subjective symptom reports for the clinical determination of recovery. Relying on subjective symptom reports can be dangerous, as it has been shown that some concussed athletes may downplay their symptoms. The use of neuropsychological (NP testing tools has enabled clinicians to measure the effects and extent of impairment following concussion more precisely, providing more objective metrics for determining recovery after concussion. Nevertheless, there is a remaining concern that brain abnormalities may exist beyond the point at which individuals achieve recovery in self-reported symptoms and cognition measured by NP testing. Our understanding of brain recovery after concussion is important not only from a neuroscience perspective, but also from the perspective of clinical decision making for safe return-to-play (RTP. A number of advanced neuroimaging tools, including blood oxygen level dependent (BOLD functional magnetic resonance imaging (fMRI, have independently yielded early information on these abnormal brain functions. In the two cases presented in this article, we report contrasting brain activation patterns and recovery profiles using fMRI. Importantly, fMRI was conducted using adapted versions of the most sensitive computerized NP tests administered in current clinical practice to determine impairments and recovery after sport-related concussion. One of the cases is consistent with the concept of lagging brain recovery.

  5. Quantitative diffusion characteristics of the human brain depend on MRI sequence parameters

    International Nuclear Information System (INIS)

    Wilson, M.; Blumhardt, L.D.; Morgan, P.S.

    2002-01-01

    Quantitative diffusion-weighted MRI has been applied to the study of neurological diseases, including multiple sclerosis, where the molecular self-diffusion coefficient D has been measured in both lesions and normal-appearing white matter. Histograms of D have been used as a novel measure of the ''lesion load'', with potential applications that include the monitoring of efficacy in new treatment trials. However different ways of measuring D may affect its value, making comparison between different centres and research groups impossible. We aimed to assess the effect, if any, of using two different MRI sequences on the value of D. We studied 13 healthy volunteers, using two different quantitative diffusion sequences (including different b max values and gradient applications). Maps of D were analysed using both regions of interest (ROI) in white matter and ''whole brain'' histograms, and compared between the two sequences. In addition, we studied three standardised test liquids (with known values of D) using both sequences. Histograms from the two sequences had different distributions, with a greater spread and higher peak position from the sequence with lower b max . This greater spread of D was also evident in the white matter and test liquid ROI. ''Limits of agreement'' analysis demonstrated that the differences could be clinically relevant, despite significant correlations between the sequences obtained using simple rank methods. We conclude that different quantitative diffusion sequences are unlikely to produce directly comparable values of D, particularly if different b max values are used. In addition, the use of inappropriate statistical tests may give false impressions of close agreement. Standardisation of methods for the measurement of D are required if these techniques are to become useful tools, for example in monitoring changes in the disease burden of multiple sclerosis. (orig.)

  6. Quantitative diffusion characteristics of the human brain depend on MRI sequence parameters

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.; Blumhardt, L.D. [University of Nottingham, Department of Neurology, Royal Preston Hospital, Preston (United Kingdom); Morgan, P.S. [Division of Academic Radiology, Queens Medical Centre, Nottingham (United Kingdom)

    2002-07-01

    Quantitative diffusion-weighted MRI has been applied to the study of neurological diseases, including multiple sclerosis, where the molecular self-diffusion coefficient D has been measured in both lesions and normal-appearing white matter. Histograms of D have been used as a novel measure of the ''lesion load'', with potential applications that include the monitoring of efficacy in new treatment trials. However different ways of measuring D may affect its value, making comparison between different centres and research groups impossible. We aimed to assess the effect, if any, of using two different MRI sequences on the value of D. We studied 13 healthy volunteers, using two different quantitative diffusion sequences (including different b{sub max} values and gradient applications). Maps of D were analysed using both regions of interest (ROI) in white matter and ''whole brain'' histograms, and compared between the two sequences. In addition, we studied three standardised test liquids (with known values of D) using both sequences. Histograms from the two sequences had different distributions, with a greater spread and higher peak position from the sequence with lower b{sub max}. This greater spread of D was also evident in the white matter and test liquid ROI. ''Limits of agreement'' analysis demonstrated that the differences could be clinically relevant, despite significant correlations between the sequences obtained using simple rank methods. We conclude that different quantitative diffusion sequences are unlikely to produce directly comparable values of D, particularly if different b{sub max} values are used. In addition, the use of inappropriate statistical tests may give false impressions of close agreement. Standardisation of methods for the measurement of D are required if these techniques are to become useful tools, for example in monitoring changes in the disease burden of multiple sclerosis. (orig.)

  7. Measurements of RF Heating during 3.0T MRI of a Pig Implanted with Deep Brain Stimulator

    Science.gov (United States)

    Gorny, Krzysztof R; Presti, Michael F; Goerss, Stephan J; Hwang, Sun C; Jang, Dong-Pyo; Kim, Inyong; Shu, Yunhong; Favazza, Christopher P; Lee, Kendall H; Bernstein, Matt A

    2012-01-01

    Purpose To present preliminary, in vivo temperature measurements during MRI of a pig implanted with a deep brain stimulation (DBS) system. Materials and Methods DBS system (Medtronic Inc., Minneapolis, MN) was implanted in the brain of an anesthetized pig. 3.0T MRI was performed with a T/R head coil using the low-SAR GRE EPI and IR-prepped GRE sequences (SAR: 0.42 W/kg and 0.39 W/kg, respectively), and the high-SAR 4-echo RF spin echo (SAR: 2.9 W/kg). Fluoroptic thermometry was used to directly measure RF-related heating at the DBS electrodes, and at the implantable pulse generator (IPG). For reference the measurements were repeated in the same pig at 1.5T and, at both field strengths, in a phantom. Results At 3.0T, the maximal temperature elevations at DBS electrodes were 0.46 °C and 2.3 °C, for the low- and high-SAR sequences, respectively. No heating was observed on the implanted IPG during any of the measurements. Measurements of in-vivo heating differed from those obtained in the phantom. Conclusion The 3.0T MRI using GRE EPI and IR-prepped GRE sequences resulted in local temperature elevations at DBS electrodes of no more than 0.46°C. Although no extrapolation should be made to human exams and much further study will be needed, these preliminary data are encouraging for the future use 3.0T MRI in patients with DBS. PMID:23228310

  8. Measurements of RF heating during 3.0-T MRI of a pig implanted with deep brain stimulator.

    Science.gov (United States)

    Gorny, Krzysztof R; Presti, Michael F; Goerss, Stephan J; Hwang, Sun C; Jang, Dong-Pyo; Kim, Inyong; Min, Hoon-Ki; Shu, Yunhong; Favazza, Christopher P; Lee, Kendall H; Bernstein, Matt A

    2013-06-01

    To present preliminary, in vivo temperature measurements during MRI of a pig implanted with a deep brain stimulation (DBS) system. DBS system (Medtronic Inc., Minneapolis, MN) was implanted in the brain of an anesthetized pig. 3.0-T MRI was performed with a T/R head coil using the low-SAR GRE EPI and IR-prepped GRE sequences (SAR: 0.42 and 0.39 W/kg, respectively), and the high-SAR 4-echo RF spin echo (SAR: 2.9 W/kg). Fluoroptic thermometry was used to directly measure RF-related heating at the DBS electrodes, and at the implantable pulse generator (IPG). For reference the measurements were repeated in the same pig at 1.5 T and, at both field strengths, in a phantom. At 3.0T, the maximal temperature elevations at DBS electrodes were 0.46 °C and 2.3 °C, for the low- and high-SAR sequences, respectively. No heating was observed on the implanted IPG during any of the measurements. Measurements of in vivo heating differed from those obtained in the phantom. The 3.0-T MRI using GRE EPI and IR-prepped GRE sequences resulted in local temperature elevations at DBS electrodes of no more than 0.46 °C. Although no extrapolation should be made to human exams and much further study will be needed, these preliminary data are encouraging for the future use 3.0-T MRI in patients with DBS. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. The Increase of the Functional Entropy of the Human Brain with Age

    Science.gov (United States)

    Yao, Y.; Lu, W. L.; Xu, B.; Li, C. B.; Lin, C. P.; Waxman, D.; Feng, J. F.

    2013-01-01

    We use entropy to characterize intrinsic ageing properties of the human brain. Analysis of fMRI data from a large dataset of individuals, using resting state BOLD signals, demonstrated that a functional entropy associated with brain activity increases with age. During an average lifespan, the entropy, which was calculated from a population of individuals, increased by approximately 0.1 bits, due to correlations in BOLD activity becoming more widely distributed. We attribute this to the number of excitatory neurons and the excitatory conductance decreasing with age. Incorporating these properties into a computational model leads to quantitatively similar results to the fMRI data. Our dataset involved males and females and we found significant differences between them. The entropy of males at birth was lower than that of females. However, the entropies of the two sexes increase at different rates, and intersect at approximately 50 years; after this age, males have a larger entropy. PMID:24103922

  10. Aggression-related brain function assessed with the Point Subtraction Aggression Paradigm in fMRI

    DEFF Research Database (Denmark)

    Skibsted, Anine P; Cunha-Bang, Sofi da; Carré, Justin M

    2017-01-01

    The Point Subtraction Aggression Paradigm (PSAP) measures aggressive behavior in response to provocations. The aim of the study was to implement the PSAP in a functional neuroimaging environment (fMRI) and evaluate aggression-related brain reactivity including response to provocations and associa......The Point Subtraction Aggression Paradigm (PSAP) measures aggressive behavior in response to provocations. The aim of the study was to implement the PSAP in a functional neuroimaging environment (fMRI) and evaluate aggression-related brain reactivity including response to provocations...... and associations with aggression within the paradigm. Twenty healthy participants completed two 12-min PSAP sessions within the scanner. We evaluated brain responses to aggressive behavior (removing points from an opponent), provocations (point subtractions by the opponent), and winning points. Our results showed...... with the involvement of these brain regions in emotional and impulsive behavior. Striatal reactivity may suggest an involvement of reward during winning and stealing points....

  11. Putting age-related task activation into large-scale brain networks: A meta-analysis of 114 fMRI studies on healthy aging.

    Science.gov (United States)

    Li, Hui-Jie; Hou, Xiao-Hui; Liu, Han-Hui; Yue, Chun-Lin; Lu, Guang-Ming; Zuo, Xi-Nian

    2015-10-01

    Normal aging is associated with cognitive decline and underlying brain dysfunction. Previous studies concentrated less on brain network changes at a systems level. Our goal was to examine these age-related changes of fMRI-derived activation with a common network parcellation of the human brain function, offering a systems-neuroscience perspective of healthy aging. We conducted a series of meta-analyses on a total of 114 studies that included 2035 older adults and 1845 young adults. Voxels showing significant age-related changes in activation were then overlaid onto seven commonly referenced neuronal networks. Older adults present moderate cognitive decline in behavioral performance during fMRI scanning, and hypo-activate the visual network and hyper-activate both the frontoparietal control and default mode networks. The degree of increased activation in frontoparietal network was associated with behavioral performance in older adults. Age-related changes in activation present different network patterns across cognitive domains. The systems neuroscience approach used here may be useful for elucidating the underlying network mechanisms of various brain plasticity processes during healthy aging. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Mask_explorer: A tool for exploring brain masks in fMRI group analysis.

    Science.gov (United States)

    Gajdoš, Martin; Mikl, Michal; Mareček, Radek

    2016-10-01

    Functional magnetic resonance imaging (fMRI) studies of the human brain are appearing in increasing numbers, providing interesting information about this complex system. Unique information about healthy and diseased brains is inferred using many types of experiments and analyses. In order to obtain reliable information, it is necessary to conduct consistent experiments with large samples of subjects and to involve statistical methods to confirm or reject any tested hypotheses. Group analysis is performed for all voxels within a group mask, i.e. a common space where all of the involved subjects contribute information. To our knowledge, a user-friendly interface with the ability to visualize subject-specific details in a common analysis space did not yet exist. The purpose of our work is to develop and present such interface. Several pitfalls have to be avoided while preparing fMRI data for group analysis. One such pitfall is spurious non-detection, caused by inferring conclusions in the volume of a group mask that has been corrupted due to a preprocessing failure. We describe a MATLAB toolbox, called the mask_explorer, designed for prevention of this pitfall. The mask_explorer uses a graphical user interface, enables a user-friendly exploration of subject masks and is freely available. It is able to compute subject masks from raw data and create lists of subjects with potentially problematic data. It runs under MATLAB with the widely used SPM toolbox. Moreover, we present several practical examples where the mask_explorer is usefully applied. The mask_explorer is designed to quickly control the quality of the group fMRI analysis volume and to identify specific failures related to preprocessing steps and acquisition. It helps researchers detect subjects with potentially problematic data and consequently enables inspection of the data. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Fingolimod's Impact on MRI Brain Volume Measures in Multiple Sclerosis: Results from MS-MRIUS.

    Science.gov (United States)

    Zivadinov, Robert; Medin, Jennie; Khan, Nasreen; Korn, Jonathan R; Bergsland, Niels; Dwyer, Michael G; Chitnis, Tanuja; Naismith, Robert T; Alvarez, Enrique; Kinkel, Peter; Cohan, Stanley; Hunter, Samuel F; Silva, Diego; Weinstock-Guttman, Bianca

    2018-05-11

    Evidence is needed to understand the effect of fingolimod on slowing down brain atrophy progression in multiple sclerosis (MS) patients in clinical practice. We investigated the effect of fingolimod on brain atrophy in MS patients with active disease (clinically and/or magnetic resonance imaging [MRI]) versus no evidence of active disease (NEAD). MS and clinical outcome and MRI in the United States (MS-MRIUS) is a multicenter, retrospective study that included 590 relapsing-remitting MS patients, who initiated fingolimod, and were followed for a median of 16 months. Patients with active disease at baseline (245, 41.5%) were defined as those who had one or more relapses in the year previous starting fingolimod, and/or displayed gadolinium enhancing lesions(s) at baseline MRI scan, whereas patients with NEAD at baseline (345, 58.5%) did not fulfill these criteria. Annualized percentage brain volume change (PBVC) and percentage lateral ventricle volume change (PLVVC) over the follow-up were analyzed in both groups. Over the follow-up, the rate of PBVC was -.38% in active disease and -.25% in NEAD patients (P = .076), whereas PLLVC was 1.76% in active disease and .28% in NEAD patients (P = .046). No changes in timed 25-foot walk (P = .619) and Expanded Disability Status Scale (P = .275) scores or MRI lesion accumulation (P > 0.08) were detected, although the active disease group had a higher proportion of relapses during the follow-up period (P = .02). The study provides real-world evidence that rate of brain atrophy in MS patients with underlying active disease and NEAD in fingolimod treated patients is below the established pathological cutoff for loss of whole brain volume (>-.4%) or expansion of lateral ventricles (> 3.5%). Copyright © 2018 by the American Society of Neuroimaging.

  14. Acoustic fMRI noise : Linear time-invariant system model

    NARCIS (Netherlands)

    Sierra, Carlos V. Rizzo; Versluis, Maarten J.; Hoogduin, Johannes M.; Duifhuis, Hendrikus (Diek)

    Functional magnetic resonance imaging (fMRI) enables sites of brain activation to be localized in human subjects. For auditory system studies, however, the acoustic noise generated by the scanner tends to interfere with the assessments of this activation. Understanding and modeling fMRI acoustic

  15. Comparing three-dimensional serial optical coherence tomography histology to MRI imaging in the entire mouse brain

    Science.gov (United States)

    Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Lesage, Frédéric

    2018-01-01

    An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size of (4.9×4.9×6.5) μm3 stitched back together to give a three-dimensional map of the brain from which a template OCT brain was obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, OCT datasets were compared to both in vivo and ex vivo magnetic resonance imaging (MRI) imaging. The OCT brain template yielded a highly detailed map of the brain structure, with a high contrast in white matter fiber bundles and was highly resemblant to the in vivo MRI template. Brain labeling using the Allen brain framework showed little variation in regional brain volume among imaging modalities with no statistical differences. The high correspondence between the OCT template brain and its in vivo counterpart demonstrates the potential of whole brain histology to validate in vivo imaging.

  16. Whole-brain functional connectivity predicted by indirect structural connections

    DEFF Research Database (Denmark)

    Røge, Rasmus; Ambrosen, Karen Marie Sandø; Albers, Kristoffer Jon

    2017-01-01

    Modern functional and diffusion magnetic resonance imaging (fMRI and dMRI) provide data from which macro-scale networks of functional and structural whole brain connectivity can be estimated. Although networks derived from these two modalities describe different properties of the human brain, the...

  17. Cortical hypoxic-ischemic brain damage in shaken-baby (shaken impact) syndrome: value of diffusion-weighted MRI

    International Nuclear Information System (INIS)

    Parizel, Paul M.; Oezsarlak, Oezkan; Goethem, Johan W. van; Ceulemans, Berten; Laridon, Annick; Jorens, Philippe G.

    2003-01-01

    Shaken-baby syndrome (SBS) is a type of child abuse caused by violent shaking of an infant, with or without impact, and characterized by subdural hematomas, retinal hemorrhages, and occult bone fractures. Parenchymal brain lesions in SBS may be missed or underestimated on CT scans, but can be detected at an earlier stage with diffusion-weighted MRI (DW-MRI) as areas of restricted diffusion. We demonstrate the value of DW-MRI in a 2-month-old baby boy with suspected SBS. The pattern of diffusion abnormalities indicates that the neuropathology of parenchymal lesions in SBS is due to hypoxic-ischemic brain injuries, and not to diffuse axonal injury. (orig.)

  18. Cortical hypoxic-ischemic brain damage in shaken-baby (shaken impact) syndrome: value of diffusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Parizel, Paul M.; Oezsarlak, Oezkan; Goethem, Johan W. van [Department of Radiology, University of Antwerp, Wilrijkstraat 10, 2650, Edegem (Belgium); Ceulemans, Berten; Laridon, Annick [Department of Pediatric Neurology, University of Antwerp, Wilrijkstraat 10, 2650, Edegem (Belgium); Jorens, Philippe G. [Department of Pediatric Intensive Care Medicine, University of Antwerp, Wilrijkstraat 10, 2650, Edegem (Belgium)

    2003-12-01

    Shaken-baby syndrome (SBS) is a type of child abuse caused by violent shaking of an infant, with or without impact, and characterized by subdural hematomas, retinal hemorrhages, and occult bone fractures. Parenchymal brain lesions in SBS may be missed or underestimated on CT scans, but can be detected at an earlier stage with diffusion-weighted MRI (DW-MRI) as areas of restricted diffusion. We demonstrate the value of DW-MRI in a 2-month-old baby boy with suspected SBS. The pattern of diffusion abnormalities indicates that the neuropathology of parenchymal lesions in SBS is due to hypoxic-ischemic brain injuries, and not to diffuse axonal injury. (orig.)

  19. Magnetic resonance imaging provides evidence of glymphatic drainage from human brain to cervical lymph nodes.

    Science.gov (United States)

    Eide, Per Kristian; Vatnehol, Svein Are Sirirud; Emblem, Kyrre Eeg; Ringstad, Geir

    2018-05-08

    Pre-clinical research in rodents provides evidence that the central nervous system (CNS) has functional lymphatic vessels. In-vivo observations in humans, however, are not demonstrated. We here show data on CNS lymphatic drainage to cervical lymph nodes in-vivo by magnetic resonance imaging (MRI) enhanced with an intrathecal contrast agent as a cerebrospinal fluid (CSF) tracer. Standardized MRI of the intracranial compartment and the neck were acquired before and up to 24-48 hours following intrathecal contrast agent administration in 19 individuals. Contrast enhancement was radiologically confirmed by signal changes in CSF nearby inferior frontal gyrus, brain parenchyma of inferior frontal gyrus, parahippocampal gyrus, thalamus and pons, and parenchyma of cervical lymph node, and with sagittal sinus and neck muscle serving as reference tissue for cranial and neck MRI acquisitions, respectively. Time series of changes in signal intensity shows that contrast enhancement within CSF precedes glymphatic enhancement and peaks at 4-6 hours following intrathecal injection. Cervical lymph node enhancement coincides in time with peak glymphatic enhancement, with peak after 24 hours. Our findings provide in-vivo evidence of CSF tracer drainage to cervical lymph nodes in humans. The time course of lymph node enhancement coincided with brain glymphatic enhancement rather than with CSF enhancement.

  20. Childhood acute disseminated encephalomyelitis: the role of brain and spinal cord MRI

    International Nuclear Information System (INIS)

    Khong, Pek-Lan; Cheng, Pui-Wai; Chan, Fu-Luk; Ho, Hok-Kung; Wong, Virginia C.N.; Goh, Winnie

    2002-01-01

    Background. It is recognised that the clinical and radiological spectrum of childhood acute disseminated encephalomyelitis (ADEM) is wide. Objective. To determine whether initial MRI features are predictive of clinical outcome and to determine the role of MRI in the management of ADEM. Materials and methods. The MRI scans of ten consecutive children (eight boys, two girls), clinically and radiologically diagnosed to have ADEM, were retrospectively reviewed. Follow-up MRI was available for eight patients. Results. Lesions ranged from small and punctate (<1 cm) to moderate sized and confluent (4-5 cm) to diffuse and extensive. Spinal cord lesions, seen in five of seven children, were contiguous or segmental. Seven children (70%) made good clinical recovery while three children (30%) remained severely handicapped. There was no correlation between the site, extent and pattern of involvement and clinical outcome. However, the evolution of MRI findings on follow-up correlated well with the subsequent clinical course and outcome. Conclusions. Although the extent and site of lesions on initial MRI scans are not predictive of clinical outcome, early MRI of the brain and spine is useful in aiding clinical diagnosis, and subsequent follow-up MRI is helpful in monitoring disease progression. (orig.)

  1. Eigenvector centrality mapping for analyzing connectivity patterns in fMRI data of the human brain.

    Directory of Open Access Journals (Sweden)

    Gabriele Lohmann

    Full Text Available Functional magnetic resonance data acquired in a task-absent condition ("resting state" require new data analysis techniques that do not depend on an activation model. In this work, we introduce an alternative assumption- and parameter-free method based on a particular form of node centrality called eigenvector centrality. Eigenvector centrality attributes a value to each voxel in the brain such that a voxel receives a large value if it is strongly correlated with many other nodes that are themselves central within the network. Google's PageRank algorithm is a variant of eigenvector centrality. Thus far, other centrality measures - in particular "betweenness centrality" - have been applied to fMRI data using a pre-selected set of nodes consisting of several hundred elements. Eigenvector centrality is computationally much more efficient than betweenness centrality and does not require thresholding of similarity values so that it can be applied to thousands of voxels in a region of interest covering the entire cerebrum which would have been infeasible using betweenness centrality. Eigenvector centrality can be used on a variety of different similarity metrics. Here, we present applications based on linear correlations and on spectral coherences between fMRI times series. This latter approach allows us to draw conclusions of connectivity patterns in different spectral bands. We apply this method to fMRI data in task-absent conditions where subjects were in states of hunger or satiety. We show that eigenvector centrality is modulated by the state that the subjects were in. Our analyses demonstrate that eigenvector centrality is a computationally efficient tool for capturing intrinsic neural architecture on a voxel-wise level.

  2. Mapping fetal brain development in utero using magnetic resonance imaging: the Big Bang of brain mapping.

    Science.gov (United States)

    Studholme, Colin

    2011-08-15

    The development of tools to construct and investigate probabilistic maps of the adult human brain from magnetic resonance imaging (MRI) has led to advances in both basic neuroscience and clinical diagnosis. These tools are increasingly being applied to brain development in adolescence and childhood, and even to neonatal and premature neonatal imaging. Even earlier in development, parallel advances in clinical fetal MRI have led to its growing use as a tool in challenging medical conditions. This has motivated new engineering developments encompassing optimal fast MRI scans and techniques derived from computer vision, the combination of which allows full 3D imaging of the moving fetal brain in utero without sedation. These promise to provide a new and unprecedented window into early human brain growth. This article reviews the developments that have led us to this point, examines the current state of the art in the fields of fast fetal imaging and motion correction, and describes the tools to analyze dynamically changing fetal brain structure. New methods to deal with developmental tissue segmentation and the construction of spatiotemporal atlases are examined, together with techniques to map fetal brain growth patterns.

  3. Image quality transfer and applications in diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C.; Zikic, Darko; Ghosh, Aurobrata

    2017-01-01

    and the uniquely rich diffusion MRI data set from the human connectome project (HCP). Results highlight potential benefits of IQT in both brain connectivity mapping and microstructure imaging. In brain connectivity mapping, IQT reveals, from standard data sets, thin connection pathways that tractography normally...

  4. Serial cranial ultrasonography or early MRI for detecting preterm brain injury?

    NARCIS (Netherlands)

    Plaisier, Annemarie; Raets, Marlou M A; Ecury-Goossen, Ginette M; Govaert, Paul; Feijen-Roon, Monique; Reiss, Irwin K M; Smit, Liesbeth S; Lequin, Maarten H; Dudink, Jeroen

    OBJECTIVE: To investigate detection ability and feasibility of serial cranial ultrasonography (CUS) and early MRI in preterm brain injury. DESIGN: Prospective cohort study. SETTING: Level III neonatal intensive care unit. PATIENTS: 307 infants, born below 29 weeks of gestation. METHODS: Serial CUS

  5. Serum BDNF correlates with connectivity in the (pre)motor hub in the aging human brain--a resting-state fMRI pilot study.

    Science.gov (United States)

    Mueller, Karsten; Arelin, Katrin; Möller, Harald E; Sacher, Julia; Kratzsch, Jürgen; Luck, Tobias; Riedel-Heller, Steffi; Villringer, Arno; Schroeter, Matthias L

    2016-02-01

    Brain-derived neurotrophic factor (BDNF) has been discussed to be involved in plasticity processes in the human brain, in particular during aging. Recently, aging and its (neurodegenerative) diseases have increasingly been conceptualized as disconnection syndromes. Here, connectivity changes in neural networks (the connectome) are suggested to be the most relevant and characteristic features for such processes or diseases. To further elucidate the impact of aging on neural networks, we investigated the interaction between plasticity processes, brain connectivity, and healthy aging by measuring levels of serum BDNF and resting-state fMRI data in 25 young (mean age 24.8 ± 2.7 (SD) years) and 23 old healthy participants (mean age, 68.6 ± 4.1 years). To identify neural hubs most essentially related to serum BDNF, we applied graph theory approaches, namely the new data-driven and parameter-free approach eigenvector centrality (EC) mapping. The analysis revealed a positive correlation between serum BDNF and EC in the premotor and motor cortex in older participants in contrast to young volunteers, where we did not detect any association. This positive relationship between serum BDNF and EC appears to be specific for older adults. Our results might indicate that the amount of physical activity and learning capacities, leading to higher BDNF levels, increases brain connectivity in (pre)motor areas in healthy aging in agreement with rodent animal studies. Pilot results have to be replicated in a larger sample including behavioral data to disentangle the cause for the relationship between BDNF levels and connectivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Graph-based network analysis of resting-state functional MRI

    Directory of Open Access Journals (Sweden)

    Jinhui Wang

    2010-06-01

    Full Text Available In the past decade, resting-state functional MRI (R-fMRI measures of brain activity have attracted considerable attention. Based on changes in the blood oxygen level-dependent signal, R-fMRI offers a novel way to assess the brain’s spontaneous or intrinsic (i.e., task-free activity with both high spatial and temporal resolutions. The properties of both the intra- and inter-regional connectivity of resting-state brain activity have been well documented, promoting our understanding of the brain as a complex network. Specifically, the topological organization of brain networks has been recently studied with graph theory. In this review, we will summarize the recent advances in graph-based brain network analyses of R-fMRI signals, both in typical and atypical populations. Application of these approaches to R-fMRI data has demonstrated non-trivial topological properties of functional networks in the human brain. Among these is the knowledge that the brain’s intrinsic activity is organized as a small-world, highly efficient network, with significant modularity and highly connected hub regions. These network properties have also been found to change throughout normal development, aging and in various pathological conditions. The literature reviewed here suggests that graph-based network analyses are capable of uncovering system-level changes associated with different processes in the resting brain, which could provide novel insights into the understanding of the underlying physiological mechanisms of brain function. We also highlight several potential research topics in the future.

  7. Degree of contribution (DoC) feature selection algorithm for structural brain MRI volumetric features in depression detection.

    Science.gov (United States)

    Kipli, Kuryati; Kouzani, Abbas Z

    2015-07-01

    Accurate detection of depression at an individual level using structural magnetic resonance imaging (sMRI) remains a challenge. Brain volumetric changes at a structural level appear to have importance in depression biomarkers studies. An automated algorithm is developed to select brain sMRI volumetric features for the detection of depression. A feature selection (FS) algorithm called degree of contribution (DoC) is developed for selection of sMRI volumetric features. This algorithm uses an ensemble approach to determine the degree of contribution in detection of major depressive disorder. The DoC is the score of feature importance used for feature ranking. The algorithm involves four stages: feature ranking, subset generation, subset evaluation, and DoC analysis. The performance of DoC is evaluated on the Duke University Multi-site Imaging Research in the Analysis of Depression sMRI dataset. The dataset consists of 115 brain sMRI scans of 88 healthy controls and 27 depressed subjects. Forty-four sMRI volumetric features are used in the evaluation. The DoC score of forty-four features was determined as the accuracy threshold (Acc_Thresh) was varied. The DoC performance was compared with that of four existing FS algorithms. At all defined Acc_Threshs, DoC outperformed the four examined FS algorithms for the average classification score and the maximum classification score. DoC has a good ability to generate reduced-size subsets of important features that could yield high classification accuracy. Based on the DoC score, the most discriminant volumetric features are those from the left-brain region.

  8. Glucose administration enhances fMRI brain activation and connectivity related to episodic memory encoding for neutral and emotional stimuli.

    Science.gov (United States)

    Parent, Marise B; Krebs-Kraft, Desiree L; Ryan, John P; Wilson, Jennifer S; Harenski, Carla; Hamann, Stephan

    2011-04-01

    Glucose enhances memory in a variety of species. In humans, glucose administration enhances episodic memory encoding, although little is known regarding the neural mechanisms underlying these effects. Here we examined whether elevating blood glucose would enhance functional MRI (fMRI) activation and connectivity in brain regions associated with episodic memory encoding and whether these effects would differ depending on the emotional valence of the material. We used a double-blind, within-participants, crossover design in which either glucose (50g) or a saccharin placebo were administered before scanning, on days approximately 1 week apart. We scanned healthy young male participants with fMRI as they viewed emotionally arousing negative pictures and emotionally neutral pictures, intermixed with baseline fixation. Free recall was tested at 5 min after scanning and again after 1 day. Glucose administration increased activation in brain regions associated with successful episodic memory encoding. Glucose also enhanced activation in regions whose activity was correlated with subsequent successful recall, including the hippocampus, prefrontal cortex, and other regions, and these effects differed for negative vs. neutral stimuli. Finally, glucose substantially increased functional connectivity between the hippocampus and amygdala and a network of regions previously implicated in successful episodic memory encoding. These findings fit with evidence from nonhuman animals indicating glucose modulates memory by selectively enhancing neural activity in brain regions engaged during memory tasks. Our results highlight the modulatory effects of glucose and the importance of examining both regional changes in activity and functional connectivity to fully characterize the effects of glucose on brain function and memory. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Transient ischemic attacks and presence of an acute brain lesion in diffusion-weighted MRI: study of 50 patients

    Directory of Open Access Journals (Sweden)

    Sabeti M

    2012-10-01

    Full Text Available Background: Finding an acute brain lesion by diffusion-weighted (DW MRI upon an episode of transient ischemic attack (TIA is a predictor of imminent stroke in the near future. Therefore, exploring risk factors associated with lesions in DW-MRI of the brain is important in adopting an approach to TIA management. In the current study, we tried to determine the risk factors associated with lesions in DW-MRI of the brain in patients experiencing TIA episodes.Methods: Fifty patients with TIA were recruited consecutively in Sina Hospital, Tehran, Iran, over a 6-month period between July 2008 and January 2009. All of the patients underwent a complete neurological examination and laboratory tests. Brain DW-MRIs were performed for all the patients within 72 hours of a TIA episode.Results: DW-MRI revealed an acute lesion in 16% of the participants. There was a significant correlation between presence of an acute lesion in DW-MRI and TIA duration, history of diabetes mellitus and presence of unilateral facial palsy (P=0.0003, P=0.02 and P=0.008, respectively. Other variables such as age, hypertension, hyperlipidemia, past history of TIA, headache, vertigo, and sensory or visual disturbances had no significant relation with the presence of an acute lesion in DW-MRI.Conclusion: Duration of TIA, presence of diabetes mellitus and unilateral facial palsy are risk factors for an acute lesion in DW-MRI, meaning that patients with such risk factors are at risk for stroke in the near future.

  10. Multiple "buy buttons" in the brain: Forecasting chocolate sales at point-of-sale based on functional brain activation using fMRI.

    Science.gov (United States)

    Kühn, Simone; Strelow, Enrique; Gallinat, Jürgen

    2016-08-01

    We set out to forecast consumer behaviour in a supermarket based on functional magnetic resonance imaging (fMRI). Data was collected while participants viewed six chocolate bar communications and product pictures before and after each communication. Then self-reports liking judgement were collected. fMRI data was extracted from a priori selected brain regions: nucleus accumbens, medial orbitofrontal cortex, amygdala, hippocampus, inferior frontal gyrus, dorsomedial prefrontal cortex assumed to contribute positively and dorsolateral prefrontal cortex and insula were hypothesized to contribute negatively to sales. The resulting values were rank ordered. After our fMRI-based forecast an instore test was conducted in a supermarket on n=63.617 shoppers. Changes in sales were best forecasted by fMRI signal during communication viewing, second best by a comparison of brain signal during product viewing before and after communication and least by explicit liking judgements. The results demonstrate the feasibility of applying neuroimaging methods in a relatively small sample to correctly forecast sales changes at point-of-sale. Copyright © 2016. Published by Elsevier Inc.

  11. A High-Resolution In Vivo Atlas of the Human Brain's Serotonin System.

    Science.gov (United States)

    Beliveau, Vincent; Ganz, Melanie; Feng, Ling; Ozenne, Brice; Højgaard, Liselotte; Fisher, Patrick M; Svarer, Claus; Greve, Douglas N; Knudsen, Gitte M

    2017-01-04

    The serotonin (5-hydroxytryptamine, 5-HT) system modulates many important brain functions and is critically involved in many neuropsychiatric disorders. Here, we present a high-resolution, multidimensional, in vivo atlas of four of the human brain's 5-HT receptors (5-HT 1A , 5-HT 1B , 5-HT 2A , and 5-HT 4 ) and the 5-HT transporter (5-HTT). The atlas is created from molecular and structural high-resolution neuroimaging data consisting of positron emission tomography (PET) and magnetic resonance imaging (MRI) scans acquired in a total of 210 healthy individuals. Comparison of the regional PET binding measures with postmortem human brain autoradiography outcomes showed a high correlation for the five 5-HT targets and this enabled us to transform the atlas to represent protein densities (in picomoles per milliliter). We also assessed the regional association between protein concentration and mRNA expression in the human brain by comparing the 5-HT density across the atlas with data from the Allen Human Brain atlas and identified receptor- and transporter-specific associations that show the regional relation between the two measures. Together, these data provide unparalleled insight into the serotonin system of the human brain. We present a high-resolution positron emission tomography (PET)- and magnetic resonance imaging-based human brain atlas of important serotonin receptors and the transporter. The regional PET-derived binding measures correlate strongly with the corresponding autoradiography protein levels. The strong correlation enables the transformation of the PET-derived human brain atlas into a protein density map of the serotonin (5-hydroxytryptamine, 5-HT) system. Next, we compared the regional receptor/transporter protein densities with mRNA levels and uncovered unique associations between protein expression and density at high detail. This new in vivo neuroimaging atlas of the 5-HT system not only provides insight in the human brain's regional protein

  12. Sources of variation influencing concordance between functional MRI and direct cortical stimulation in brain tumor surgery

    Directory of Open Access Journals (Sweden)

    Melanie A Morrison

    2016-10-01

    Full Text Available Object: Preoperative functional magnetic resonance imaging (fMRI remains a promising method to aid in the surgical management of patients diagnosed with brain tumors. For patients that are candidates for awake craniotomies, surgical decisions can potentially be improved by fMRI but this depends on the level of concordance between preoperative brain maps and the maps provided by the gold standard intraoperative method, direct cortical stimulation (DCS. There have been numerous studies of the concordance between fMRI and DCS using sensitivity and specificity measures, however the results are variable across studies and the key factors influencing variability are not well understood. Thus, the present work addresses the influence of technical factors on fMRI and DCS concordance. Methods: Motor and language mapping data were collected for a group of glioma patients (n = 14 who underwent both preoperative fMRI and intraoperative DCS in an awake craniotomy procedure for tumor removal. Normative fMRI data were also acquired in a healthy control group (n = 12. The fMRI and DCS mapping data were co-registered; true positive (TP, true negative (TN, false positive (FP and false negative (FN occurrences were tabulated over the exposed brain surface. Sensitivity and specificity were measured for the total group, and the motor and language sub-groups. The influence of grid placement, fMRI statistical thresholding, and task standardization were assessed. Correlations between proportions of agreement and error were carefully scrutinized to evaluate concordance more in-depth. Results: Concordance was significantly better for motor versus language mapping. There was an inverse relationship between TP and TN with increasing statistical threshold, and FP dominated the total error. Sensitivity and specificity were reduced when tasks were not standardized across fMRI and DCS. Conclusions: Although the agreement between fMRI and DCS is good, variability is introduced

  13. Automatic delineation of brain regions on MRI and PET images from the pig.

    Science.gov (United States)

    Villadsen, Jonas; Hansen, Hanne D; Jørgensen, Louise M; Keller, Sune H; Andersen, Flemming L; Petersen, Ida N; Knudsen, Gitte M; Svarer, Claus

    2018-01-15

    The increasing use of the pig as a research model in neuroimaging requires standardized processing tools. For example, extraction of regional dynamic time series from brain PET images requires parcellation procedures that benefit from being automated. Manual inter-modality spatial normalization to a MRI atlas is operator-dependent, time-consuming, and can be inaccurate with lack of cortical radiotracer binding or skull uptake. A parcellated PET template that allows for automatic spatial normalization to PET images of any radiotracer. MRI and [ 11 C]Cimbi-36 PET scans obtained in sixteen pigs made the basis for the atlas. The high resolution MRI scans allowed for creation of an accurately averaged MRI template. By aligning the within-subject PET scans to their MRI counterparts, an averaged PET template was created in the same space. We developed an automatic procedure for spatial normalization of the averaged PET template to new PET images and hereby facilitated transfer of the atlas regional parcellation. Evaluation of the automatic spatial normalization procedure found the median voxel displacement to be 0.22±0.08mm using the MRI template with individual MRI images and 0.92±0.26mm using the PET template with individual [ 11 C]Cimbi-36 PET images. We tested the automatic procedure by assessing eleven PET radiotracers with different kinetics and spatial distributions by using perfusion-weighted images of early PET time frames. We here present an automatic procedure for accurate and reproducible spatial normalization and parcellation of pig PET images of any radiotracer with reasonable blood-brain barrier penetration. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Intraoperative functional MRI as a new approach to monitor deep brain stimulation in Parkinson's disease

    International Nuclear Information System (INIS)

    Hesselmann, Volker; Sorger, Bettina; Girnus, Ralf; Lasek, Kathrin; Schulte, Oliver; Krug, Barbara; Lackner, Klaus; Maarouf, Mohammad; Sturm, Volker; Wedekind, Christoph; Bunke, Juergen

    2004-01-01

    This article deals with technical aspects of intraoperative functional magnetic resonance imaging (fMRI) for monitoring the effect of deep brain stimulation (DBS) in a patient with Parkinson's disease. Under motor activation, therapeutic high-frequency stimulation of the subthalamic nucleus was accompanied by an activation decrease in the contralateral primary sensorimotor cortex and the ipsilateral cerebellum. Furthermore, an activation increase in the contralateral basal ganglia and insula region were detected. These findings demonstrate that fMRI constitutes a promising clinical application for investigating brain activity changes induced by DBS. (orig.)

  15. MRI and brain spect findings in patients with unilateral temporal lobe epilepsy and normal CT scan

    Directory of Open Access Journals (Sweden)

    P.G. Carrilho

    1994-06-01

    Full Text Available 26 patients with temporal lobe epilepsy clinically documented by several abnormal interictal surface EEGs with typical unitemporal epileptiform activity and a normal CT scan were studied. Interictal99mTC HMPAO brain SPECT and MRI were performed in all subjects. Abnormalities were shown in 61.5% of MRI (n=16 and 65.4% of SPECT (n=17. Hippocampal atrophy associated to a high signal on T2-weighted MRI slices suggesting mesial temporal sclerosis was the main finding (n=12; 75% of abnormal MRI. MRI correlated well to surface EEG in 50% (n=13. There was also a good correlation between MRI and SPECT in 30.7% (n=8. SPECT and EEG were in agreement in 57.7% (n=l5. MRI, SPECT and EEG were congruent in 26.9% (n=7. These results support the usefulness of interictal brain SPECT and MRI in detecting lateralized abnormalities in temporal lobe epilepsy. On the other hand, in two cases, interictal SPECT correlated poorly with surface EEG. This functional method should not be used isolately in the detection of temporal lobe foci. MRI is more useful than CT as a neuroimaging technique in temporal lobe epilepsy. It may detect small structural lesions and mesial temporal lobe sclerosis which are not easily seen with traditional CT scanning.

  16. MRI quantitative assessment of brain maturation and prognosis in premature infants using total maturation score

    International Nuclear Information System (INIS)

    Qi Ying; Wang Xiaoming

    2009-01-01

    Objective: To quantitatively assess brain maturation and prognosis in premature infants on conventional MRI using total maturation score (TMS). Methods: Nineteen cases of sequelae of white matter damage (WMD group )and 21 cases of matched controls (control group) in premature infants confirmed by MRI examinations were included in the study. All cases underwent conventional MR imaging approximately during the perinatal period after birth. Brain development was quantitatively assessed using Childs AM's validated scoring system of TMS by two sophisticated radiology physicians. Interobserver agreement and reliability was evaluated by using intraclass correlation (ICC). Linear regression analysis between TMS and postmenstrual age (PMA) was made(Y: TMS, X: PMA). Independent-sample t test of the two groups' TMS was made. Results: Sixteen of 19 cases revealed MRI abnormalities. Lesions showing T 1 and T 2 shortening tended to occur in clusters or a linear pattern in the deep white matter of the centrum semiovale, periventricular white matter. Diffusion-weighted MR image (DWI) showed 3 cases with greater lesions and 4 cases with new lesions in corpus callosum. There was no abnormality in control group on MRI and DWI. The average numbers of TMS between the two observers were 7.13±2.27, 7.13±2.21. Interobservcer agreement was found to be high (ICC=0.990, P 2 =0.6401,0.5156 respectively, P 0.05). Conclusion: Conventional MRI is able to quantify the brain maturation and prognosis of premature infants using TMS. (authors)

  17. Providing and optimizing functional MR (Magnetic Resonance) of motor cortex of human brain by MRI ( Magnetic Resonance Imaging) facilities of Imam Khomeinie Hospital

    International Nuclear Information System (INIS)

    Khosravie, H.R.

    2000-01-01

    Display of human brain cortical activity is accomplished using various techniques, by them different spatial and temporal resolution may be obtained. F MRI technique with proper spatial and temporal resolution due to its noninvasivity is one of the promising techniques for detection of brain activities. This can be used as an important tool by neurologists, since a great development has been achieved for display different brain function. This thesis report the results of simulation effects of thumb motor cortex of normal volunteer by using conventional standard 1.5 T imager and optimized gradient echo techniques. Activating sensory and motor stimulations can be led to, respective cortical area of that stimulation by which oxygenated blood flow is increased in that area (Bold contrast). By designing of a T 2* sensitized gradient echo protocol, thumb's sensory and motor cortex activation is evaluated. A protocol known as F AST i n picker system with the following specifications was used for F MRI: Band Width:24 Hz/Pixel, Tr=101 m Sec , T E=49 m Sec , Flip Angle= 10 deg., N E X=1 ,Slice thickness=5-7 mm F O V=250 mm ,Matrix=128*128 and total scan time= 14 Sec. Stimulation of the motor cortex was performed by periodic movement of dominant thumb in up-down and right-left direction within a Ls hape trajectory of plastic sheet with a frequency about 2 Hz. Then, acquired images in rest and stimulation period were evaluated by S P M 97, S P M 99 b software. During the stimulation, an observable increased signal (%2-%5)in respective sensory-motor cortex was obtained after correcting for partial volume effects, optimizing S/N,and incorporating small vowels. The 2 D F A S T functional image obtained by this method, showed an anatomical association of the increased signal with gray matter of sensory-motor cortex(in T 1 weighted image). The resultant data showed the feasibility of functional magnetic resonance imaging using optimized gradient echo sequences on a standard 1.5 T

  18. A New Generation of Brain-Computer Interfaces Driven by Discovery of Latent EEG-fMRI Linkages Using Tensor Decomposition.

    Science.gov (United States)

    Deshpande, Gopikrishna; Rangaprakash, D; Oeding, Luke; Cichocki, Andrzej; Hu, Xiaoping P

    2017-01-01

    A Brain-Computer Interface (BCI) is a setup permitting the control of external devices by decoding brain activity. Electroencephalography (EEG) has been extensively used for decoding brain activity since it is non-invasive, cheap, portable, and has high temporal resolution to allow real-time operation. Due to its poor spatial specificity, BCIs based on EEG can require extensive training and multiple trials to decode brain activity (consequently slowing down the operation of the BCI). On the other hand, BCIs based on functional magnetic resonance imaging (fMRI) are more accurate owing to its superior spatial resolution and sensitivity to underlying neuronal processes which are functionally localized. However, due to its relatively low temporal resolution, high cost, and lack of portability, fMRI is unlikely to be used for routine BCI. We propose a new approach for transferring the capabilities of fMRI to EEG, which includes simultaneous EEG/fMRI sessions for finding a mapping from EEG to fMRI, followed by a BCI run from only EEG data, but driven by fMRI-like features obtained from the mapping identified previously. Our novel data-driven method is likely to discover latent linkages between electrical and hemodynamic signatures of neural activity hitherto unexplored using model-driven methods, and is likely to serve as a template for a novel multi-modal strategy wherein cross-modal EEG-fMRI interactions are exploited for the operation of a unimodal EEG system, leading to a new generation of EEG-based BCIs.

  19. Can musical training influence brain connectivity? Evidence from diffusion tensor MRI.

    Science.gov (United States)

    Moore, Emma; Schaefer, Rebecca S; Bastin, Mark E; Roberts, Neil; Overy, Katie

    2014-06-10

    In recent years, musicians have been increasingly recruited to investigate grey and white matter neuroplasticity induced by skill acquisition. The development of Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) has allowed more detailed investigation of white matter connections within the brain, addressing questions about the effect of musical training on connectivity between specific brain regions. Here, current DT-MRI analysis techniques are discussed and the available evidence from DT-MRI studies into differences in white matter architecture between musicians and non-musicians is reviewed. Collectively, the existing literature tends to support the hypothesis that musical training can induce changes in cross-hemispheric connections, with significant differences frequently reported in various regions of the corpus callosum of musicians compared with non-musicians. However, differences found in intra-hemispheric fibres have not always been replicated, while findings regarding the internal capsule and corticospinal tracts appear to be contradictory. There is also recent evidence to suggest that variances in white matter structure in non-musicians may correlate with their ability to learn musical skills, offering an alternative explanation for the structural differences observed between musicians and non-musicians. Considering the inconsistencies in the current literature, possible reasons for conflicting results are offered, along with suggestions for future research in this area.

  20. Prenatal brain MRI of fetuses with Zika virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Guillemette-Artur, Prisca [Centre Hospitalier de Polynesie Francaise, Service de Radiologie, Pirae, Tahiti (Country Unknown); Besnard, Marianne [Centre Hospitalier de Polynesie Francaise, Service de Reanimation Neo-natale, Pirae, Tahiti (Country Unknown); Eyrolle-Guignot, Dominique [Centre Hospitalier de Polynesie Francaise, Service d' Obstetrique, Pirae, Tahiti (Country Unknown); Jouannic, Jean-Marie [Universite Pierre et Marie Curie, Service de Medecine Foetale, Hopital d' Enfants Armand-Trousseau, Paris (France); Garel, Catherine [Hopital d' Enfants Armand-Trousseau, Department of Radiology, Paris (France)

    2016-06-15

    An outbreak of Zika virus was observed in French Polynesia in 2013-2014. Maternal Zika virus infection has been associated with fetal microcephaly and severe cerebral damage. To analyze the MRI cerebral findings in fetuses with intrauterine Zika virus infection. We retrospectively analyzed prospectively collected data. Inclusion criteria comprised cases with (1) estimated conception date between June 2013 and May 2014, (2) available US and MRI scans revealing severe fetal brain lesions and (3) positive polymerase chain reaction for Zika virus in the amniotic fluid. We recorded pregnancy history of Zika virus infection and analyzed US and MRI scans. Three out of 12 cases of severe cerebral lesions fulfilled all inclusion criteria. History of maternal Zika virus infection had been documented in two cases. Calcifications and ventriculomegaly were present at US in all cases. MRI showed micrencephaly (n = 3), low cerebellar biometry (n = 2), occipital subependymal pseudocysts (n = 2), polymicrogyria with laminar necrosis and opercular dysplasia (n = 3), absent (n = 1) or hypoplastic (n = 1) corpus callosum and hypoplastic brainstem (n = 1). Severe cerebral damage was observed in our series, with indirect findings suggesting that the germinal matrix is the principal target for Zika virus. The lesions are very similar to severe forms of congenital cytomegalovirus and lymphocytic choriomeningitis virus infections. (orig.)

  1. Prenatal brain MRI of fetuses with Zika virus infection

    International Nuclear Information System (INIS)

    Guillemette-Artur, Prisca; Besnard, Marianne; Eyrolle-Guignot, Dominique; Jouannic, Jean-Marie; Garel, Catherine

    2016-01-01

    An outbreak of Zika virus was observed in French Polynesia in 2013-2014. Maternal Zika virus infection has been associated with fetal microcephaly and severe cerebral damage. To analyze the MRI cerebral findings in fetuses with intrauterine Zika virus infection. We retrospectively analyzed prospectively collected data. Inclusion criteria comprised cases with (1) estimated conception date between June 2013 and May 2014, (2) available US and MRI scans revealing severe fetal brain lesions and (3) positive polymerase chain reaction for Zika virus in the amniotic fluid. We recorded pregnancy history of Zika virus infection and analyzed US and MRI scans. Three out of 12 cases of severe cerebral lesions fulfilled all inclusion criteria. History of maternal Zika virus infection had been documented in two cases. Calcifications and ventriculomegaly were present at US in all cases. MRI showed micrencephaly (n = 3), low cerebellar biometry (n = 2), occipital subependymal pseudocysts (n = 2), polymicrogyria with laminar necrosis and opercular dysplasia (n = 3), absent (n = 1) or hypoplastic (n = 1) corpus callosum and hypoplastic brainstem (n = 1). Severe cerebral damage was observed in our series, with indirect findings suggesting that the germinal matrix is the principal target for Zika virus. The lesions are very similar to severe forms of congenital cytomegalovirus and lymphocytic choriomeningitis virus infections. (orig.)

  2. Data-driven analysis of functional brain interactions during free listening to music and speech.

    Science.gov (United States)

    Fang, Jun; Hu, Xintao; Han, Junwei; Jiang, Xi; Zhu, Dajiang; Guo, Lei; Liu, Tianming

    2015-06-01

    Natural stimulus functional magnetic resonance imaging (N-fMRI) such as fMRI acquired when participants were watching video streams or listening to audio streams has been increasingly used to investigate functional mechanisms of the human brain in recent years. One of the fundamental challenges in functional brain mapping based on N-fMRI is to model the brain's functional responses to continuous, naturalistic and dynamic natural stimuli. To address this challenge, in this paper we present a data-driven approach to exploring functional interactions in the human brain during free listening to music and speech streams. Specifically, we model the brain responses using N-fMRI by measuring the functional interactions on large-scale brain networks with intrinsically established structural correspondence, and perform music and speech classification tasks to guide the systematic identification of consistent and discriminative functional interactions when multiple subjects were listening music and speech in multiple categories. The underlying premise is that the functional interactions derived from N-fMRI data of multiple subjects should exhibit both consistency and discriminability. Our experimental results show that a variety of brain systems including attention, memory, auditory/language, emotion, and action networks are among the most relevant brain systems involved in classic music, pop music and speech differentiation. Our study provides an alternative approach to investigating the human brain's mechanism in comprehension of complex natural music and speech.

  3. Improving Brain Magnetic Resonance Image (MRI Segmentation via a Novel Algorithm based on Genetic and Regional Growth

    Directory of Open Access Journals (Sweden)

    Javadpour A.

    2016-06-01

    Full Text Available Background: Regarding the importance of right diagnosis in medical applications, various methods have been exploited for processing medical images solar. The method of segmentation is used to analyze anal to miscall structures in medical imaging. Objective: This study describes a new method for brain Magnetic Resonance Image (MRI segmentation via a novel algorithm based on genetic and regional growth. Methods: Among medical imaging methods, brains MRI segmentation is important due to high contrast of non-intrusive soft tissue and high spatial resolution. Size variations of brain tissues are often accompanied by various diseases such as Alzheimer’s disease. As our knowledge about the relation between various brain diseases and deviation of brain anatomy increases, MRI segmentation is exploited as the first step in early diagnosis. In this paper, regional growth method and auto-mate selection of initial points by genetic algorithm is used to introduce a new method for MRI segmentation. Primary pixels and similarity criterion are automatically by genetic algorithms to maximize the accuracy and validity in image segmentation. Results: By using genetic algorithms and defining the fixed function of image segmentation, the initial points for the algorithm were found. The proposed algorithms are applied to the images and results are manually selected by regional growth in which the initial points were compared. The results showed that the proposed algorithm could reduce segmentation error effectively. Conclusion: The study concluded that the proposed algorithm could reduce segmentation error effectively and help us to diagnose brain diseases.

  4. Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms.

    Science.gov (United States)

    Carhart-Harris, Robin L; Roseman, Leor; Bolstridge, Mark; Demetriou, Lysia; Pannekoek, J Nienke; Wall, Matthew B; Tanner, Mark; Kaelen, Mendel; McGonigle, John; Murphy, Kevin; Leech, Robert; Curran, H Valerie; Nutt, David J

    2017-10-13

    Psilocybin with psychological support is showing promise as a treatment model in psychiatry but its therapeutic mechanisms are poorly understood. Here, cerebral blood flow (CBF) and blood oxygen-level dependent (BOLD) resting-state functional connectivity (RSFC) were measured with functional magnetic resonance imaging (fMRI) before and after treatment with psilocybin (serotonin agonist) for treatment-resistant depression (TRD). Quality pre and post treatment fMRI data were collected from 16 of 19 patients. Decreased depressive symptoms were observed in all 19 patients at 1-week post-treatment and 47% met criteria for response at 5 weeks. Whole-brain analyses revealed post-treatment decreases in CBF in the temporal cortex, including the amygdala. Decreased amygdala CBF correlated with reduced depressive symptoms. Focusing on a priori selected circuitry for RSFC analyses, increased RSFC was observed within the default-mode network (DMN) post-treatment. Increased ventromedial prefrontal cortex-bilateral inferior lateral parietal cortex RSFC was predictive of treatment response at 5-weeks, as was decreased parahippocampal-prefrontal cortex RSFC. These data fill an important knowledge gap regarding the post-treatment brain effects of psilocybin, and are the first in depressed patients. The post-treatment brain changes are different to previously observed acute effects of psilocybin and other 'psychedelics' yet were related to clinical outcomes. A 'reset' therapeutic mechanism is proposed.

  5. High spatial resolution brain functional MRI using submillimeter balanced steady-state free precession acquisition

    International Nuclear Information System (INIS)

    Wu, Pei-Hsin; Chung, Hsiao-Wen; Tsai, Ping-Huei; Wu, Ming-Long; Chuang, Tzu-Chao; Shih, Yi-Yu; Huang, Teng-Yi

    2013-01-01

    Purpose: One of the technical advantages of functional magnetic resonance imaging (fMRI) is its precise localization of changes from neuronal activities. While current practice of fMRI acquisition at voxel size around 3 × 3 × 3 mm 3 achieves satisfactory results in studies of basic brain functions, higher spatial resolution is required in order to resolve finer cortical structures. This study investigated spatial resolution effects on brain fMRI experiments using balanced steady-state free precession (bSSFP) imaging with 0.37 mm 3 voxel volume at 3.0 T. Methods: In fMRI experiments, full and unilateral visual field 5 Hz flashing checkerboard stimulations were given to healthy subjects. The bSSFP imaging experiments were performed at three different frequency offsets to widen the coverage, with functional activations in the primary visual cortex analyzed using the general linear model. Variations of the spatial resolution were achieved by removing outerk-space data components. Results: Results show that a reduction in voxel volume from 3.44 × 3.44 × 2 mm 3 to 0.43 × 0.43 × 2 mm 3 has resulted in an increase of the functional activation signals from (7.7 ± 1.7)% to (20.9 ± 2.0)% at 3.0 T, despite of the threefold SNR decreases in the original images, leading to nearly invariant functional contrast-to-noise ratios (fCNR) even at high spatial resolution. Activation signals aligning nicely with gray matter sulci at high spatial resolution would, on the other hand, have possibly been mistaken as noise at low spatial resolution. Conclusions: It is concluded that the bSSFP sequence is a plausible technique for fMRI investigations at submillimeter voxel widths without compromising fCNR. The reduction of partial volume averaging with nonactivated brain tissues to retain fCNR is uniquely suitable for high spatial resolution applications such as the resolving of columnar organization in the brain

  6. High spatial resolution brain functional MRI using submillimeter balanced steady-state free precession acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Pei-Hsin; Chung, Hsiao-Wen [Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Tsai, Ping-Huei [Imaging Research Center, Taipei Medical University, Taipei 11031, Taiwan and Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei 11031, Taiwan (China); Wu, Ming-Long, E-mail: minglong.wu@csie.ncku.edu.tw [Institute of Medical Informatics, National Cheng-Kung University, Tainan 70101, Taiwan and Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China); Chuang, Tzu-Chao [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Shih, Yi-Yu [Siemens Limited Healthcare Sector, Taipei 11503, Taiwan (China); Huang, Teng-Yi [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2013-12-15

    Purpose: One of the technical advantages of functional magnetic resonance imaging (fMRI) is its precise localization of changes from neuronal activities. While current practice of fMRI acquisition at voxel size around 3 × 3 × 3 mm{sup 3} achieves satisfactory results in studies of basic brain functions, higher spatial resolution is required in order to resolve finer cortical structures. This study investigated spatial resolution effects on brain fMRI experiments using balanced steady-state free precession (bSSFP) imaging with 0.37 mm{sup 3} voxel volume at 3.0 T. Methods: In fMRI experiments, full and unilateral visual field 5 Hz flashing checkerboard stimulations were given to healthy subjects. The bSSFP imaging experiments were performed at three different frequency offsets to widen the coverage, with functional activations in the primary visual cortex analyzed using the general linear model. Variations of the spatial resolution were achieved by removing outerk-space data components. Results: Results show that a reduction in voxel volume from 3.44 × 3.44 × 2 mm{sup 3} to 0.43 × 0.43 × 2 mm{sup 3} has resulted in an increase of the functional activation signals from (7.7 ± 1.7)% to (20.9 ± 2.0)% at 3.0 T, despite of the threefold SNR decreases in the original images, leading to nearly invariant functional contrast-to-noise ratios (fCNR) even at high spatial resolution. Activation signals aligning nicely with gray matter sulci at high spatial resolution would, on the other hand, have possibly been mistaken as noise at low spatial resolution. Conclusions: It is concluded that the bSSFP sequence is a plausible technique for fMRI investigations at submillimeter voxel widths without compromising fCNR. The reduction of partial volume averaging with nonactivated brain tissues to retain fCNR is uniquely suitable for high spatial resolution applications such as the resolving of columnar organization in the brain.

  7. Preterm brain injury on term-equivalent age MRI in relation to perinatal factors and neurodevelopmental outcome at two years.

    Directory of Open Access Journals (Sweden)

    Margaretha J Brouwer

    Full Text Available First, to apply a recently extended scoring system for preterm brain injury at term-equivalent age (TEA-MRI in a regional extremely preterm cohort; second, to identify independent perinatal factors associated with this score; and third, to assess the prognostic value of this TEA-MRI score with respect to early neurodevelopmental outcome.239 extremely preterm infants (median gestational age [range] in weeks: 26.6 [24.3-27.9], admitted to the Wilhelmina Children's Hospital between 2006 and 2012 were included. Brain abnormalities in white matter, cortical and deep grey matter and cerebellum and brain growth were scored on T1- and T2-weighted TEA-MRI using the Kidokoro scoring system. Neurodevelopmental outcome was assessed at two years corrected age using the Bayley Scales of Infant and Toddler Development, third edition. The association between TEA-MRI and perinatal factors as well as neurodevelopmental outcome was evaluated using multivariable regression analysis.The distribution of brain abnormalities and brain metrics in the Utrecht cohort differed from the original St. Louis cohort (p 7 days (β [95% confidence interval, CI]: 1.3 [.5; 2.0] and parenteral nutrition >21 days (2.2 [1.2; 3.2] were independently associated with higher global brain abnormality scores (p < .001. Global brain abnormality scores were inversely associated with cognitive (β in composite scores [95% CI]: -.7 [-1.2; -.2], p = .004, fine motor (β in scaled scores [95% CI]: -.1 [-.3; -.0], p = .007 and gross motor outcome (β in scaled scores [95% CI]: -.2 [-.3; -.1], p < .001 at two years corrected age, although the explained variances were low (R2 ≤.219.Patterns of brain injury differed between cohorts. Prolonged mechanical ventilation and parenteral nutrition were identified as independent perinatal risk factors. The prognostic value of the TEA-MRI score was rather limited in this well-performing cohort.

  8. Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

    International Nuclear Information System (INIS)

    Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I.; Rota Kops, Elena; Shah, N. Jon; Ribeiro, Andre; Yakushev, Igor

    2016-01-01

    The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [ 18 F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are inferior

  9. Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Rota Kops, Elena; Shah, N. Jon [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Ribeiro, Andre [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Institute of Biophysics and Biomedical Engineering, Lisbon (Portugal); Yakushev, Igor [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Institute TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-11-15

    The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [{sup 18}F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are

  10. MGH-USC Human Connectome Project datasets with ultra-high b-value diffusion MRI.

    Science.gov (United States)

    Fan, Qiuyun; Witzel, Thomas; Nummenmaa, Aapo; Van Dijk, Koene R A; Van Horn, John D; Drews, Michelle K; Somerville, Leah H; Sheridan, Margaret A; Santillana, Rosario M; Snyder, Jenna; Hedden, Trey; Shaw, Emily E; Hollinshead, Marisa O; Renvall, Ville; Zanzonico, Roberta; Keil, Boris; Cauley, Stephen; Polimeni, Jonathan R; Tisdall, Dylan; Buckner, Randy L; Wedeen, Van J; Wald, Lawrence L; Toga, Arthur W; Rosen, Bruce R

    2016-01-01

    The MGH-USC CONNECTOM MRI scanner housed at the Massachusetts General Hospital (MGH) is a major hardware innovation of the Human Connectome Project (HCP). The 3T CONNECTOM scanner is capable of producing a magnetic field gradient of up to 300 mT/m strength for in vivo human brain imaging, which greatly shortens the time spent on diffusion encoding, and decreases the signal loss due to T2 decay. To demonstrate the capability of the novel gradient system, data of healthy adult participants were acquired for this MGH-USC Adult Diffusion Dataset (N=35), minimally preprocessed, and shared through the Laboratory of Neuro Imaging Image Data Archive (LONI IDA) and the WU-Minn Connectome Database (ConnectomeDB). Another purpose of sharing the data is to facilitate methodological studies of diffusion MRI (dMRI) analyses utilizing high diffusion contrast, which perhaps is not easily feasible with standard MR gradient system. In addition, acquisition of the MGH-Harvard-USC Lifespan Dataset is currently underway to include 120 healthy participants ranging from 8 to 90 years old, which will also be shared through LONI IDA and ConnectomeDB. Here we describe the efforts of the MGH-USC HCP consortium in acquiring and sharing the ultra-high b-value diffusion MRI data and provide a report on data preprocessing and access. We conclude with a demonstration of the example data, along with results of standard diffusion analyses, including q-ball Orientation Distribution Function (ODF) reconstruction and tractography. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. In vivo functional connectome of human brainstem nuclei of the ascending arousal, autonomic, and motor systems by high spatial resolution 7-Tesla fMRI.

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Eichner, Cornelius; Polimeni, Jonathan R; Setsompop, Kawin; Brown, Emery N; Hämäläinen, Matti S; Rosen, Bruce R; Wald, Lawrence L

    2016-06-01

    Our aim was to map the in vivo human functional connectivity of several brainstem nuclei with the rest of the brain by using seed-based correlation of ultra-high magnetic field functional magnetic resonance imaging (fMRI) data. We used the recently developed template of 11 brainstem nuclei derived from multi-contrast structural MRI at 7 Tesla as seed regions to determine their connectivity to the rest of the brain. To achieve this, we used the increased contrast-to-noise ratio of 7-Tesla fMRI compared with 3 Tesla and time-efficient simultaneous multi-slice imaging to cover the brain with high spatial resolution (1.1-mm isotropic nominal resolution) while maintaining a short repetition time (2.5 s). The delineated Pearson's correlation-based functional connectivity diagrams (connectomes) of 11 brainstem nuclei of the ascending arousal, motor, and autonomic systems from 12 controls are presented and discussed in the context of existing histology and animal work. Considering that the investigated brainstem nuclei play a crucial role in several vital functions, the delineated preliminary connectomes might prove useful for future in vivo research and clinical studies of human brainstem function and pathology, including disorders of consciousness, sleep disorders, autonomic disorders, Parkinson's disease, and other motor disorders.

  12. Brain MRI findings of welders : high signal intensity in T1WI secondary to manganese exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. W.; Lim, M. A.; Shon, M. Y.; Lee, S. H.; Ha, D. G.; Kwon, K. R.; Kim, S. S.; Hong, Y. S.; Lee, Y. H. [Sunlin Presbyterian Hospital, Pohang (Korea, Republic of); Cheong, H. K. [Dongguk University, Seoul (Korea, Republic of)

    1998-03-01

    To evaluate the clinical and brain MRI findings of welders and to determine the utility of MRI in the assessment of occupational manganese exposure. All welders complained of fatigue, headache, anorexia, and decreased libido. The palmomental reflex was positive in five (28%), Myerson`s sign in four (22%), and intention tremor in three (17%). Mean blood Mn was 5.18 (range, 1.77-9.34) {mu}g/dl, mean urine Mn was 5.84 (range, 1.07 -22) {mu}g/l, serum Fe was elevated in one welder, and serum Cd in two. T1WI of brain MRI revealed high signal intensities in the globus pallidus, the putamen, the substantia nigra, the tectum, the caudate nucleus, the subthalamic nucleus, the hypothalamus and the pituitary gland. These intensities correlated closely with blood Mn levels, suggesting their potential role in estimating the accumulation of Mn in the brain. (author). 25 refs., 2 tabs., 5 figs.

  13. Statistical approach of measurement of signal to noise ratio in according to change pulse sequence on brain MRI meningioma and cyst images

    International Nuclear Information System (INIS)

    Lee, Eul Kyu; Choi, Kwan Woo; Jeong, Hoi Woun; Jang, Seo Goo; Kim, Ki Won; Son, Soon Yong; Min, Jung Whan; Son, Jin Hyun

    2016-01-01

    The purpose of this study was to needed basis of measure MRI CAD development for signal to noise ratio (SNR) by pulse sequence analysis from region of interest (ROI) in brain magnetic resonance imaging (MRI) contrast. We examined images of brain MRI contrast enhancement of 117 patients, from January 2005 to December 2015 in a University-affiliated hospital, Seoul, Korea. Diagnosed as one of two brain diseases such as meningioma and cysts SNR for each patient's image of brain MRI were calculated by using Image J. Differences of SNR among two brain diseases were tested by SPSS Statistics21 ANOVA test for there was statistical significance (p < 0.05). We have analysis socio-demographical variables, SNR according to sequence disease, 95% confidence according to SNR of sequence and difference in a mean of SNR. Meningioma results, with the quality of distributions in the order of T1CE, T2 and T1, FLAIR. Cysts results, with the quality of distributions in the order of T2 and T1, T1CE and FLAIR. SNR of MRI sequences of the brain would be useful to classify disease. Therefore, this study will contribute to evaluate brain diseases, and be a fundamental to enhancing the accuracy of CAD development

  14. Statistical approach of measurement of signal to noise ratio in according to change pulse sequence on brain MRI meningioma and cyst images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eul Kyu [Inje Paik University Hospital Jeo-dong, Seoul (Korea, Republic of); Choi, Kwan Woo [Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [The Baekseok Culture University, Cheonan (Korea, Republic of); Jang, Seo Goo [The Soonchunhyang University, Asan (Korea, Republic of); Kim, Ki Won [Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Son, Soon Yong [The Wonkwang Health Science University, Iksan (Korea, Republic of); Min, Jung Whan; Son, Jin Hyun [The Shingu University, Sungnam (Korea, Republic of)

    2016-09-15

    The purpose of this study was to needed basis of measure MRI CAD development for signal to noise ratio (SNR) by pulse sequence analysis from region of interest (ROI) in brain magnetic resonance imaging (MRI) contrast. We examined images of brain MRI contrast enhancement of 117 patients, from January 2005 to December 2015 in a University-affiliated hospital, Seoul, Korea. Diagnosed as one of two brain diseases such as meningioma and cysts SNR for each patient's image of brain MRI were calculated by using Image J. Differences of SNR among two brain diseases were tested by SPSS Statistics21 ANOVA test for there was statistical significance (p < 0.05). We have analysis socio-demographical variables, SNR according to sequence disease, 95% confidence according to SNR of sequence and difference in a mean of SNR. Meningioma results, with the quality of distributions in the order of T1CE, T2 and T1, FLAIR. Cysts results, with the quality of distributions in the order of T2 and T1, T1CE and FLAIR. SNR of MRI sequences of the brain would be useful to classify disease. Therefore, this study will contribute to evaluate brain diseases, and be a fundamental to enhancing the accuracy of CAD development.

  15. Use of 3.0-T MRI for Stereotactic Radiosurgery Planning for Treatment of Brain Metastases: A Single-Institution Retrospective Review

    International Nuclear Information System (INIS)

    Saconn, Paul A.; Shaw, Edward G.; Chan, Michael D.; Squire, Sarah E.; Johnson, Annette J.; McMullen, Kevin P.; Tatter, Stephen B.; Ellis, Thomas L.; Lovato, James; Bourland, J. Daniel; Ekstrand, Kenneth E.; DeGuzman, Allan F.; Munley, Michael T.

    2010-01-01

    Purpose: To investigate the efficacy of 3.0-T magnetic resonance imaging (MRI) for detecting brain metastases for stereotactic radiosurgery (SRS) planning. Methods and Materials: All adult patients scheduled for SRS treatment for brain metastases at our institution between October 2005 and January 2008 were eligible for analysis. All patients underwent radiosurgery treatment planning 3.0-T MRI on the day of scheduled radiosurgery and a diagnostic 1.5-T MRI in the days or weeks prior to radiosurgery for comparison. Both scans were interpreted by neuroradiologists who reported their findings in the radiology reports. We performed a retrospective review of the radiology reports to determine the number of brain metastases identified using each MRI system. Results: Of 254 patients scheduled for treatment from October 2005 to January 2008, 138 patients had radiology reports that explicitly described the number of metastases identified on both scans. With a median interval of 17 days (range, 1-82) between scans, the number of metastases detected using 1.5-T MRI system ranged from 1 to 5 and from 1 to 8 using the 3.0 T-MRI system. Twenty-two percent of patients were found to have a greater number of metastases with the 3.0 T-MRI system. The difference in number of metastases detected between the two scans for the entire cohort ranged from 0 to 6. Neither histology (p = 0.52 by chi-sq test) nor time between scans (p = 0.62 by linear regression) were significantly associated with the difference in number of metastases between scans. Conclusions: The 3.0-T MRI system appears to be superior to a 1.5-T MRI system for detecting brain metastases, which may have significant implications in determining the appropriate treatment modality. Our findings suggest the need for a prospectively designed study to further evaluate the use of a 3.0 T-MRI system for stereotactic radiosurgery planning in the treatment of brain metastases.

  16. Value of MRI of the brain in patients with systemic lupus erythematosus and neurologic disturbance

    International Nuclear Information System (INIS)

    Jennings, J.E.; Sundgren, P.C.; Maly, P.; Attwood, J.; McCune, J.

    2004-01-01

    Our objective was to review the frequency and pattern of signal abnormalities seen on conventional MRI in patients with suspected neuropsychiatric systemic lupus erythematosus (NP-SLE). We reviewed 116 MRI examinations of the brain performed on 85 patients with SLE, (81 women, four men, aged 21-78 years, mean 40.6 years) presenting with neurological disturbances. MRI was normal or nearly normal in 34%. In 60% high-signal lesions were observed on T2-weighted images, frequently in the frontal and parietal subcortical white matter. Infarct-like lesions involving gray and white matter were demonstrated in 21 of cases. Areas of restricted diffusion were seen in 12 of the 67 patients who underwent diffusion-weighted imaging. Other abnormalities included loss of brain volume, hemorrhage, meningeal enhancement, and bilateral high signal in occipital white-matter. The MRI findings alone did not allow us to distinguish between thromboembolic and inflammatory events in many patients. Some patients with normal MRI improved clinically while on immunosuppressive therapy. More sensitive and/or specific imaging methods, such as spectroscopy and perfusion-weighted imaging, should be investigated in these subgroups of patients with suspected NP-SLE. (orig.)

  17. Diagnostic usefulness of 3 tesla MRI of the brain for cushing disease in a child.

    Science.gov (United States)

    Ono, Erina; Ozawa, Ayako; Matoba, Kaori; Motoki, Takanori; Tajima, Asako; Miyata, Ichiro; Ito, Junko; Inoshita, Naoko; Yamada, Syozo; Ida, Hiroyuki

    2011-10-01

    It is sometimes difficult to confirm the location of a microadenoma in Cushing disease. Recently, we experienced an 11-yr-old female case of Cushing disease with hyperprolactinemia. She was referred to our hospital because of decrease of height velocity with body weight gain. On admission, she had typical symptoms of Cushing syndrome. Although no pituitary microadenomas were detected on 1.5 Tesla MRI of the brain, endocrinological examinations including IPS and CS sampling were consistent with Cushing disease with hyperprolactinemia. Oral administration of methyrapone instead of neurosurgery was started after discharge, but subsequent 3 Tesla MRI of the brain clearly demonstrated a 3-mm less-enhanced lesion in the left side of the pituitary gland. Finally, transsphenoidal surgery was performed, and a 3.5-mm left-sided microadenoma was resected. Compared with 1.5 Tesla MRI, 3 Tesla MRI offers the advantage of a higher signal to noise ratio (SNR), which provides higher resolution and proper image quality. Therefore, 3 Tesla MRI is a very useful tool to localize microadenomas in Cushing disease in children as well as in adults. It will be the first choice of radiological examinations in suspected cases of Cushing disease.

  18. On the characterization of single-event related brain activity from functional Magnetic Resonance Imaging (fMRI) measurements

    KAUST Repository

    Khoram, Nafiseh

    2014-08-01

    We propose an efficient numerical technique for calibrating the mathematical model that describes the singleevent related brain response when fMRI measurements are given. This method employs a regularized Newton technique in conjunction with a Kalman filtering procedure. We have applied this method to estimate the biophysiological parameters of the Balloon model that describes the hemodynamic brain responses. Illustrative results obtained with both synthetic and real fMRI measurements are presented. © 2014 IEEE.

  19. Hierarchical functional modularity in the resting-state human brain.

    Science.gov (United States)

    Ferrarini, Luca; Veer, Ilya M; Baerends, Evelinda; van Tol, Marie-José; Renken, Remco J; van der Wee, Nic J A; Veltman, Dirk J; Aleman, André; Zitman, Frans G; Penninx, Brenda W J H; van Buchem, Mark A; Reiber, Johan H C; Rombouts, Serge A R B; Milles, Julien

    2009-07-01

    Functional magnetic resonance imaging (fMRI) studies have shown that anatomically distinct brain regions are functionally connected during the resting state. Basic topological properties in the brain functional connectivity (BFC) map have highlighted the BFC's small-world topology. Modularity, a more advanced topological property, has been hypothesized to be evolutionary advantageous, contributing to adaptive aspects of anatomical and functional brain connectivity. However, current definitions of modularity for complex networks focus on nonoverlapping clusters, and are seriously limited by disregarding inclusive relationships. Therefore, BFC's modularity has been mainly qualitatively investigated. Here, we introduce a new definition of modularity, based on a recently improved clustering measurement, which overcomes limitations of previous definitions, and apply it to the study of BFC in resting state fMRI of 53 healthy subjects. Results show hierarchical functional modularity in the brain. Copyright 2009 Wiley-Liss, Inc

  20. A reliability study on brain activation during active and passive arm movements supported by an MRI-compatible robot.

    Science.gov (United States)

    Estévez, Natalia; Yu, Ningbo; Brügger, Mike; Villiger, Michael; Hepp-Reymond, Marie-Claude; Riener, Robert; Kollias, Spyros

    2014-11-01

    In neurorehabilitation, longitudinal assessment of arm movement related brain function in patients with motor disability is challenging due to variability in task performance. MRI-compatible robots monitor and control task performance, yielding more reliable evaluation of brain function over time. The main goals of the present study were first to define the brain network activated while performing active and passive elbow movements with an MRI-compatible arm robot (MaRIA) in healthy subjects, and second to test the reproducibility of this activation over time. For the fMRI analysis two models were compared. In model 1 movement onset and duration were included, whereas in model 2 force and range of motion were added to the analysis. Reliability of brain activation was tested with several statistical approaches applied on individual and group activation maps and on summary statistics. The activated network included mainly the primary motor cortex, primary and secondary somatosensory cortex, superior and inferior parietal cortex, medial and lateral premotor regions, and subcortical structures. Reliability analyses revealed robust activation for active movements with both fMRI models and all the statistical methods used. Imposed passive movements also elicited mainly robust brain activation for individual and group activation maps, and reliability was improved by including additional force and range of motion using model 2. These findings demonstrate that the use of robotic devices, such as MaRIA, can be useful to reliably assess arm movement related brain activation in longitudinal studies and may contribute in studies evaluating therapies and brain plasticity following injury in the nervous system.

  1. Isointense infant brain MRI segmentation with a dilated convolutional neural network

    NARCIS (Netherlands)

    Moeskops, P.; Pluim, J.P.W.

    2017-01-01

    Quantitative analysis of brain MRI at the age of 6 months is difficult because of the limited contrast between white matter and gray matter. In this study, we use a dilated triplanar convolutional neural network in combination with a non-dilated 3D convolutional neural network for the segmentation

  2. Skull and cerebrospinal fluid effects on microwave radiation propagation in human brain

    Science.gov (United States)

    Ansari, M. A.; Zarei, M.; Akhlaghipour, N.; Niknam, A. R.

    2017-12-01

    The determination of microwave absorption distribution in the human brain is necessary for the detection of brain tumors using thermo-acoustic imaging and for removing them using hyperthermia treatment. In contrast to ionizing radiation, hyperthermia treatment can be applied to remove tumors inside the brain without the concern of including secondary malignancies, which typically form from the neuronal cells of the septum pellucidum. The aim of this study is to determine the microwave absorption distribution in an adult human brain and to study the effects of skull and cerebrospinal fluid on the propagation of microwave radiation inside the brain. To this end, we simulate the microwave absorption distribution in a realistic adult brain model (Colin 27) using the mesh-based Monte Carlo (MMC) method. This is because in spite of there being other numerical methods, the MMC does not require a large memory, even for complicated geometries, and its algorithm is simple and easy to implement with low computational cost. The brain model is constructed using high-resolution (1 mm isotropic voxel) and low noise magnetic resonance imaging (MRI) scans and its volume contains 181×217×181 voxels, covering the brain completely. Using the MMC method, the radiative transport equation is solved and the absorbed microwave energy distribution in different brain regions is obtained without any fracture or anomaly. The simulation results show that the skull and cerebrospinal fluid guide the microwave radiation and suppress its penetration through deep brain compartments as a shielding factor. These results reveal that the MMC can be used to predict the amount of required energy to increase the temperature inside the tumour during hyperthermia treatment. Our results also show why a deep tumour inside an adult human brain cannot be efficiently treated using hyperthermia treatment. Finally, the accuracy of the presented numerical method is verified using the signal flow graph technique.

  3. Structural brain alterations in primary open angle glaucoma: a 3T MRI study

    OpenAIRE

    Jieqiong Wang; Ting Li; Bernhard A. Sabel; Zhiqiang Chen; Hongwei Wen; Jianhong Li; Xiaobin Xie; Diya Yang; Weiwei Chen; Ningli Wang; Junfang Xian; Huiguang He

    2016-01-01

    Glaucoma is not only an eye disease but is also associated with degeneration of brain structures. We now investigated the pattern of visual and non-visual brain structural changes in 25 primary open angle glaucoma (POAG) patients and 25 age-gender-matched normal controls using T1-weighted imaging. MRI images were subjected to volume-based analysis (VBA) and surface-based analysis (SBA) in the whole brain as well as ROI-based analysis of the lateral geniculate nucleus (LGN), visual cortex (V1/...

  4. Usefulness of MRI detection of cervical spine and brain injuries in the evaluation of abusive head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Kadom, Nadja [Children' s National Medical Center, Department of Diagnostic Imaging and Radiology, Washington, DC (United States); Boston University Medical Center, Boston, MA (United States); Khademian, Zarir; Vezina, Gilbert; Shalaby-Rana, Eglal [Children' s National Medical Center, Department of Diagnostic Imaging and Radiology, Washington, DC (United States); Rice, Amy [Independent Consultant (Biostatistics), Chevy Chase, MD (United States); Hinds, Tanya [Children' s National Medical Center, Child and Adolescent Protection Center, Washington, DC (United States)

    2014-07-15

    In the evaluation of children younger than 3 years with intracranial hemorrhage it can be difficult to determine whether the cause of hemorrhage was traumatic, and if so, whether abusive head trauma (AHT) is a possibility. Cervical spine MRI is not a routine part of the nationally recommended imaging workup for children with suspected abusive head trauma. There is increasing evidence that spinal injuries are found at autopsy or MRI in abused children. However the prevalence of cervical spine injuries in children evaluated for abusive head trauma is unknown. We sought to determine both the incidence and the spectrum of cervical spine and brain injuries in children being evaluated for possible abusive head trauma. We also examined the relationship between cervical and brain MRI findings and selected study outcome categories. This study is a 3-year retrospective review of children evaluated for abusive head trauma. Inclusion criteria were: children with head trauma seen at our institution between 2008 and 2010, age younger than 36 months, availability of diagnostic-quality brain and cervical spine MRI, and child abuse team involvement because abusive head trauma was a possibility. A child abuse pediatrician and pediatric radiologists, all with board certification, were involved in data collection, image interpretation and data analysis. Statistical analysis was performed using Stata v12.1. The study included 74 children (43 boys, 31 girls) with a mean age of 164 days (range, 20-679 days). Study outcomes were categorized as: n = 26 children with accidental head trauma, n = 38 with abusive head trauma (n = 18 presumptive AHT, n = 20 suspicious for AHT), and n = 10 with undefined head trauma. We found cervical spine injuries in 27/74 (36%) children. Most cervical spine injuries were ligamentous injuries. One child had intrathecal spinal blood and two had spinal cord edema; all three of these children had ligamentous injury. MRI signs of cervical injury did not show a

  5. Usefulness of MRI detection of cervical spine and brain injuries in the evaluation of abusive head trauma

    International Nuclear Information System (INIS)

    Kadom, Nadja; Khademian, Zarir; Vezina, Gilbert; Shalaby-Rana, Eglal; Rice, Amy; Hinds, Tanya

    2014-01-01

    In the evaluation of children younger than 3 years with intracranial hemorrhage it can be difficult to determine whether the cause of hemorrhage was traumatic, and if so, whether abusive head trauma (AHT) is a possibility. Cervical spine MRI is not a routine part of the nationally recommended imaging workup for children with suspected abusive head trauma. There is increasing evidence that spinal injuries are found at autopsy or MRI in abused children. However the prevalence of cervical spine injuries in children evaluated for abusive head trauma is unknown. We sought to determine both the incidence and the spectrum of cervical spine and brain injuries in children being evaluated for possible abusive head trauma. We also examined the relationship between cervical and brain MRI findings and selected study outcome categories. This study is a 3-year retrospective review of children evaluated for abusive head trauma. Inclusion criteria were: children with head trauma seen at our institution between 2008 and 2010, age younger than 36 months, availability of diagnostic-quality brain and cervical spine MRI, and child abuse team involvement because abusive head trauma was a possibility. A child abuse pediatrician and pediatric radiologists, all with board certification, were involved in data collection, image interpretation and data analysis. Statistical analysis was performed using Stata v12.1. The study included 74 children (43 boys, 31 girls) with a mean age of 164 days (range, 20-679 days). Study outcomes were categorized as: n = 26 children with accidental head trauma, n = 38 with abusive head trauma (n = 18 presumptive AHT, n = 20 suspicious for AHT), and n = 10 with undefined head trauma. We found cervical spine injuries in 27/74 (36%) children. Most cervical spine injuries were ligamentous injuries. One child had intrathecal spinal blood and two had spinal cord edema; all three of these children had ligamentous injury. MRI signs of cervical injury did not show a

  6. A New Generation of Brain-Computer Interfaces Driven by Discovery of Latent EEG-fMRI Linkages Using Tensor Decomposition

    Directory of Open Access Journals (Sweden)

    Gopikrishna Deshpande

    2017-06-01

    Full Text Available A Brain-Computer Interface (BCI is a setup permitting the control of external devices by decoding brain activity. Electroencephalography (EEG has been extensively used for decoding brain activity since it is non-invasive, cheap, portable, and has high temporal resolution to allow real-time operation. Due to its poor spatial specificity, BCIs based on EEG can require extensive training and multiple trials to decode brain activity (consequently slowing down the operation of the BCI. On the other hand, BCIs based on functional magnetic resonance imaging (fMRI are more accurate owing to its superior spatial resolution and sensitivity to underlying neuronal processes which are functionally localized. However, due to its relatively low temporal resolution, high cost, and lack of portability, fMRI is unlikely to be used for routine BCI. We propose a new approach for transferring the capabilities of fMRI to EEG, which includes simultaneous EEG/fMRI sessions for finding a mapping from EEG to fMRI, followed by a BCI run from only EEG data, but driven by fMRI-like features obtained from the mapping identified previously. Our novel data-driven method is likely to discover latent linkages between electrical and hemodynamic signatures of neural activity hitherto unexplored using model-driven methods, and is likely to serve as a template for a novel multi-modal strategy wherein cross-modal EEG-fMRI interactions are exploited for the operation of a unimodal EEG system, leading to a new generation of EEG-based BCIs.

  7. MRI findings in acute Hendra virus meningoencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Nakka, P.; Amos, G.J. [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia); Saad, N., E-mail: nivena100@hotmail.com [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia); Jeavons, S. [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia)

    2012-05-15

    Aim: To describe serial changes in brain magnetic resonance imaging (MRI) in acute human infection from two outbreaks of Hendra virus (HeV), relate these changes to disease prognosis, and compare HeV encephalitis to reported cases of Nipah virus encephalitis. Materials and methods: The MRI images of three human cases (two of which were fatal) of acute HeV meningoencephalitis were reviewed. Results: Cortical selectivity early in the disease is evident in all three patients, while deep white matter involvement appears to be a late and possibly premorbid finding. This apparent early grey matter selectivity may be related to viral biology or ribavirin pharmacokinetics. Neuronal loss is evident at MRI, and the rate of progression of MRI abnormalities can predict the outcome of the infection. In both fatal cases, the serial changes in the MRI picture mirrored the clinical course. Conclusion: This is the first comprehensive report of serial MRI findings in acute human cerebral HeV infection from two outbreaks. The cortical selectivity appears to be an early finding while deep white matter involvement a late, and possibly premorbid, finding. In both fatal cases, the serial changes in MRI mirrored the clinical course.

  8. MRI findings in acute Hendra virus meningoencephalitis

    International Nuclear Information System (INIS)

    Nakka, P.; Amos, G.J.; Saad, N.; Jeavons, S.

    2012-01-01

    Aim: To describe serial changes in brain magnetic resonance imaging (MRI) in acute human infection from two outbreaks of Hendra virus (HeV), relate these changes to disease prognosis, and compare HeV encephalitis to reported cases of Nipah virus encephalitis. Materials and methods: The MRI images of three human cases (two of which were fatal) of acute HeV meningoencephalitis were reviewed. Results: Cortical selectivity early in the disease is evident in all three patients, while deep white matter involvement appears to be a late and possibly premorbid finding. This apparent early grey matter selectivity may be related to viral biology or ribavirin pharmacokinetics. Neuronal loss is evident at MRI, and the rate of progression of MRI abnormalities can predict the outcome of the infection. In both fatal cases, the serial changes in the MRI picture mirrored the clinical course. Conclusion: This is the first comprehensive report of serial MRI findings in acute human cerebral HeV infection from two outbreaks. The cortical selectivity appears to be an early finding while deep white matter involvement a late, and possibly premorbid, finding. In both fatal cases, the serial changes in MRI mirrored the clinical course.

  9. The Prognostic Value of MRI in Moderate and Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Haghbayan, Hourmazd; Boutin, Amélie; Laflamme, Mathieu; Lauzier, François; Shemilt, Michèle; Moore, Lynne; Zarychanski, Ryan; Douville, Vincent; Fergusson, Dean; Turgeon, Alexis F

    2017-12-01

    Traumatic brain injury is a major cause of death and disability, yet many predictors of outcome are not precise enough to guide initial clinical decision-making. Although increasingly used in the early phase following traumatic brain injury, the prognostic utility of MRI remains uncertain. We thus undertook a systematic review and meta-analysis of studies evaluating the predictive value of acute MRI lesion patterns for discriminating clinical outcome in traumatic brain injury. MEDLINE, EMBASE, BIOSIS, and CENTRAL from inception to November 2015. Studies of adults who had MRI in the acute phase following moderate or severe traumatic brain injury. Our primary outcomes were all-cause mortality and the Glasgow Outcome Scale. Two authors independently performed study selection and data extraction. We calculated pooled effect estimates with a random effects model, evaluated the risk of bias using a modified version of Quality in Prognostic Studies and determined the strength of evidence with the Grading of Recommendations, Assessment, Development, and Evaluation. We included 58 eligible studies, of which 27 (n = 1,652) contributed data to meta-analysis. Brainstem lesions were associated with all-cause mortality (risk ratio, 1.78; 95% CI, 1.01-3.15; I = 43%) and unfavorable Glasgow Outcome Scale (risk ratio, 2.49; 95% CI, 1.72-3.58; I = 81%) at greater than or equal to 6 months. Diffuse axonal injury patterns were associated with an increased risk of unfavorable Glasgow Outcome Scale (risk ratio, 2.46; 95% CI, 1.06-5.69; I = 74%). MRI scores based on lesion depth demonstrated increasing risk of unfavorable neurologic outcome as more caudal structures were affected. Most studies were at high risk of methodological bias. MRI following traumatic brain injury yields important prognostic information, with several lesion patterns significantly associated with long-term survival and neurologic outcome. Given the high risk of bias in the current body of literature, large well

  10. Brain MRI signal abnormalities and right-to-left shunting in asymptomatic military divers.

    Science.gov (United States)

    Gempp, Emmanuel; Sbardella, Fabrice; Stephant, Eric; Constantin, Pascal; De Maistre, Sebastien; Louge, Pierre; Blatteau, Jean-Eric

    2010-11-01

    We conducted a controlled study to assess the prevalence of brain MRI hyperintense signals and their correlation with right-to-left shunting (RLS) in military divers. We prospectively enrolled 32 asymptomatic military divers under 41 yr of age and 32 non-diving healthy subjects matched with respect to age and vascular disease risk factors. We examined both groups with a 3-Tesla brain MRI; RLS was detected using transcranial pulsed Doppler in divers only. Hyperintense spots were observed in 43.7% of the divers and 21.8% of the control subjects. In particular, divers with significant shunting exhibited a higher prevalence of hyperintensities compared to those with slight or no RLS (75% vs. 25%, respectively). Linear trend analysis also revealed a positive correlation between focal white matter changes, determined using a validated visual rating scale and the RLS grade. Healthy military divers with a hemodynamically relevant RLS have an increased likelihood of cerebral hyperintense spots compared to age-matched normal subjects. The clinical relevance of these MRI signal abnormalities and their causal relationship with diving remain unclear.

  11. Functional MRI studies of the neural mechanisms of human brain attentional networks

    International Nuclear Information System (INIS)

    Hao Jing; Li Kuncheng; Chen Qi; Wang Yan; Peng Xiaozhe; Zhou Xiaolin

    2005-01-01

    Objective: To identify the neural mechanisms of the anterior attention network (AAN) and posterior attention network (PAN) , investigate the possible interaction between them with event-related functional MRI(ER-fMRI). Methods: Eight right-handed healthy volunteers participated in the experiment designed with inhibition of return in visual orienting and Stroop color-word interference effect. The fMRI data were collected on Siemens 1.5 T Sonata MRI systems and analyzed by AFNI to generate the activation map. Results: The data sets from 6 of 8 subjects were used in the study. The functional localizations of the Stroop and IOR, which manifest the function of the AAN and PAN respectively, were consistent with previous imaging researches. On cued locations, left inferior parietal lobule (IPL), area MT/V5, right dorsolateral prefrontal cortex (DLPFC) and left anterior cingulated cortex (ACC) were significantly activated. On uncued locations, right superior parietal lobule (SPL) and bilateral area MT/V5 were significantly activated. Conclusion: The AAN exerts control over the PAN, while its function can be in turn modulated by the PAN. There are interaction between the AAN and PAN. In addition, it is also proved that ER-fMRI is a feasible method to revise preexisting cognitive model and theory. (authors)

  12. Hierarchical Functional Modularity in the Resting-State Human Brain

    NARCIS (Netherlands)

    Ferrarini, Luca; Veer, Ilya M.; Baerends, Evelinda; van Tol, Marie-Jose; Renken, Remco J.; van der Wee, Nic J. A.; Veltman, Dirk. J.; Aleman, Andre; Zitman, Frans G.; Penninx, Brenda W. J. H.; van Buchem, Mark A.; Reiber, Johan H. C.; Rombouts, Serge A. R. B.; Milles, Julien

    Functional magnetic resonance imaging (fMRI) studies have shown that anatomically distinct brain regions are functionally connected during the resting state. Basic topological properties in the brain functional connectivity (BFC) map have highlighted the BFC's small-world topology. Modularity, a

  13. Hierarchical Functional Modularity in the Resting-State Human Brain

    NARCIS (Netherlands)

    Ferrarini, L.; Veer, I.M.; Baerends, E.; van Tol, M.J.; Renken, R.J.; van der Wee, N.J.A.; Veltman, D.J.; Aleman, A.; Zitman, F.G.; Penninx, B.W.J.H.; van Buchem, M.A.; Reiber, J.H.C.; Rombouts, S.A.R.B.; Milles, J.

    2009-01-01

    Functional magnetic resonance imaging (fMRI) studies have shown that anatomically distinct brain regions are functionally connected during the resting state. Basic topological properties in the brain functional connectivity (BFC) map have highlighted the BFC's small-world topology. Modularity, a

  14. Structural linear measurements in the newborn brain: accuracy of cranial ultrasound compared to MRI

    International Nuclear Information System (INIS)

    Leijser, Lara M.; Srinivasan, Latha; Cowan, Frances M.; Rutherford, Mary A.; Counsell, Serena J.; Allsop, Joanna M.

    2007-01-01

    Structural size in the neonatal brain is of clinical importance. Cranial ultrasonography (cUS) is the primary method used for evaluating the neonatal brain and it is important to know whether linear measurements made using this technique are accurate. To compare linear measurements of different cerebral structures made from neonatal cUS and contemporaneous MRI. Preterm and term infants studies with cUS and MRI on the same day were studied. Linear measurements made using both techniques from many cerebral structures were compared using a paired t-test. A total of 44 sets of scans from 26 preterm and 8 term infants were assessed. Small but significant differences between the cUS and MRI measurements (P<0.05) were found for the ventricular index, the posterior horn depth of the lateral ventricle, the extracerebral space and interhemispheric fissure, and the cortex of the cingulate gyrus. No significant differences were found for any other measurements. Linear measurements from cUS are accurate for most neonatal cerebral structures. Significant differences compared to MRI were found for a few structures, but only for the cortex were the absolute differences marked and possibly of clinical importance. (orig.)

  15. A tale of two methods: combining near-infrared spectroscopy with MRI for studies of brain oxygenation and metabolism.

    Science.gov (United States)

    Dunn, Jeff F; Nathoo, Nabeela; Yang, Runze

    2014-01-01

    Combining magnetic resonance imaging (MRI) with near-infrared spectroscopy (NIRS) leads to excellent synergies which can improve the interpretation of either method and can provide novel data with respect to measuring brain oxygenation and metabolism. MRI has good spatial resolution, can detect a range of physiological parameters and is sensitive to changes in deoxyhemoglobin content. NIRS has lower spatial resolution, but can detect, and with specific technologies, quantify, deoxyhemoglobin, oxyhemoglobin, total hemoglobin and cytochrome oxidase. This paper reviews the application of both methods, as a multimodal technology, for assessing changes in brain oxygenation that may occur with changes in functional activation state or metabolic rate. Examples of hypoxia and ischemia are shown. Data support the concept of reduced metabolic rate resulting from hypoxia/ischemia and that metabolic rate in brain is not close to oxygen limitation during normoxia. We show that multimodal MRI and NIRS can provide novel information for studies of brain metabolism.

  16. Cerebral perfusion abnormalities in therapy-resistant epilepsy in childhood: comparison between EEG, MRI and 99Tcm-ECD brain SPET.

    Science.gov (United States)

    Vattimo, A; Burroni, L; Bertelli, P; Volterrani, D; Vella, A

    1996-01-01

    We performed 99Tcm-ethyl cysteinate dimer (ECD) interictal single photon emission tomography (SPET) in 26 children with severe therapy-resistant epilepsy. All the children underwent a detailed clinical examination, an electroencephalogram (EEG) investigation and brain magnetic resonance imaging (MRI). In 21 of the 26 children, SPET demonstrated brain blood flow abnormalities, in 13 cases in the same territories that showed EEG alterations. MRI showed structural lesions in 6 of the 26 children, while SPET imaging confirmed these abnormalities in only 5 children. The lesion not detected on SPET was shown to be 3 mm thick on MRI. Five symptomatic patients had normal SPET. In one of these patients, the EEG findings were normal and MRI revealed a small calcific nodule (4 mm thick); in the others, the EEG showed non-focal but diffuse abnormalities. These data confirm that brain SPET is sensitive in detecting and localizing hypoperfused areas that could be associated with epileptic foci in this group of patients, even when the MRI image is normal.

  17. Mapping brain activity in gradient-echo functional MRI using principal component analysis

    Science.gov (United States)

    Khosla, Deepak; Singh, Manbir; Don, Manuel

    1997-05-01

    The detection of sites of brain activation in functional MRI has been a topic of immense research interest and many technique shave been proposed to this end. Recently, principal component analysis (PCA) has been applied to extract the activated regions and their time course of activation. This method is based on the assumption that the activation is orthogonal to other signal variations such as brain motion, physiological oscillations and other uncorrelated noises. A distinct advantage of this method is that it does not require any knowledge of the time course of the true stimulus paradigm. This technique is well suited to EPI image sequences where the sampling rate is high enough to capture the effects of physiological oscillations. In this work, we propose and apply tow methods that are based on PCA to conventional gradient-echo images and investigate their usefulness as tools to extract reliable information on brain activation. The first method is a conventional technique where a single image sequence with alternating on and off stages is subject to a principal component analysis. The second method is a PCA-based approach called the common spatial factor analysis technique (CSF). As the name suggests, this method relies on common spatial factors between the above fMRI image sequence and a background fMRI. We have applied these methods to identify active brain ares during visual stimulation and motor tasks. The results from these methods are compared to those obtained by using the standard cross-correlation technique. We found good agreement in the areas identified as active across all three techniques. The results suggest that PCA and CSF methods have good potential in detecting the true stimulus correlated changes in the presence of other interfering signals.

  18. Studying variability in human brain aging in a population-based German cohort – Rationale and design of 1000BRAINS

    Directory of Open Access Journals (Sweden)

    Svenja eCaspers

    2014-07-01

    Full Text Available The ongoing 1000 brains study (1000BRAINS is an epidemiological and neuroscientific investigation of structural and functional variability in the human brain during aging. The two recruitment sources are the 10-year follow-up cohort of the German Heinz Nixdorf Recall (HNR Study, and the HNR MultiGeneration Study cohort, which comprises spouses and offspring of HNR subjects. The HNR is a longitudinal epidemiological investigation of cardiovascular risk factors, with a comprehensive collection of clinical, laboratory, socioeconomic, and environmental data from population-based subjects aged 45-75 years on inclusion. HNR subjects underwent detailed assessments in 2000, 2006, and 2011, and completed annual postal questionnaires on health status. 1000BRAINS accesses these HNR data and applies a separate protocol comprising: neuropsychological tests of attention, memory, executive functions & language; examination of motor skills; ratings of personality, life quality, mood & daily activities; analysis of laboratory and genetic data; and state-of-the-art magnetic resonance imaging (MRI, 3 Tesla of the brain. The latter includes (i 3D-T1- and 3D-T2-weighted scans for structural analyses and myelin mapping; (ii three diffusion imaging sequences optimized for diffusion tensor imaging, high-angular resolution diffusion imaging for detailed fibre tracking and for diffusion kurtosis imaging; (iii resting-state and task-based functional MRI; and (iv fluid-attenuated inversion recovery and MR angiography for the detection of vascular lesions and the mapping of white matter lesions. The unique design of 1000BRAINS allows: (i comprehensive investigation of various influences including genetics, environment and health status on variability in brain structure and function during aging; and (ii identification of the impact of selected influencing factors on specific cognitive subsystems and their anatomical correlates.

  19. A hybrid CPU-GPU accelerated framework for fast mapping of high-resolution human brain connectome.

    Directory of Open Access Journals (Sweden)

    Yu Wang

    Full Text Available Recently, a combination of non-invasive neuroimaging techniques and graph theoretical approaches has provided a unique opportunity for understanding the patterns of the structural and functional connectivity of the human brain (referred to as the human brain connectome. Currently, there is a very large amount of brain imaging data that have been collected, and there are very high requirements for the computational capabilities that are used in high-resolution connectome research. In this paper, we propose a hybrid CPU-GPU framework to accelerate the computation of the human brain connectome. We applied this framework to a publicly available resting-state functional MRI dataset from 197 participants. For each subject, we first computed Pearson's Correlation coefficient between any pairs of the time series of gray-matter voxels, and then we constructed unweighted undirected brain networks with 58 k nodes and a sparsity range from 0.02% to 0.17%. Next, graphic properties of the functional brain networks were quantified, analyzed and compared with those of 15 corresponding random networks. With our proposed accelerating framework, the above process for each network cost 80∼150 minutes, depending on the network sparsity. Further analyses revealed that high-resolution functional brain networks have efficient small-world properties, significant modular structure, a power law degree distribution and highly connected nodes in the medial frontal and parietal cortical regions. These results are largely compatible with previous human brain network studies. Taken together, our proposed framework can substantially enhance the applicability and efficacy of high-resolution (voxel-based brain network analysis, and have the potential to accelerate the mapping of the human brain connectome in normal and disease states.

  20. Processing of targets in smooth or apparent motion along the vertical in the human brain: an fMRI study.

    Science.gov (United States)

    Maffei, Vincenzo; Macaluso, Emiliano; Indovina, Iole; Orban, Guy; Lacquaniti, Francesco

    2010-01-01

    Neural substrates for processing constant speed visual motion have been extensively studied. Less is known about the brain activity patterns when the target speed changes continuously, for instance under the influence of gravity. Using functional MRI (fMRI), here we compared brain responses to accelerating/decelerating targets with the responses to constant speed targets. The target could move along the vertical under gravity (1g), under reversed gravity (-1g), or at constant speed (0g). In the first experiment, subjects observed targets moving in smooth motion and responded to a GO signal delivered at a random time after target arrival. As expected, we found that the timing of the motor responses did not depend significantly on the specific motion law. Therefore brain activity in the contrast between different motion laws was not related to motor timing responses. Average BOLD signals were significantly greater for 1g targets than either 0g or -1g targets in a distributed network including bilateral insulae, left lingual gyrus, and brain stem. Moreover, in these regions, the mean activity decreased monotonically from 1g to 0g and to -1g. In the second experiment, subjects intercepted 1g, 0g, and -1g targets either in smooth motion (RM) or in long-range apparent motion (LAM). We found that the sites in the right insula and left lingual gyrus, which were selectively engaged by 1g targets in the first experiment, were also significantly more active during 1g trials than during -1g trials both in RM and LAM. The activity in 0g trials was again intermediate between that in 1g trials and that in -1g trials. Therefore in these regions the global activity modulation with the law of vertical motion appears to hold for both RM and LAM. Instead, a region in the inferior parietal lobule showed a preference for visual gravitational motion only in LAM but not RM.

  1. Sensitivity analysis of brain morphometry based on MRI-derived surface models

    Science.gov (United States)

    Klein, Gregory J.; Teng, Xia; Schoenemann, P. T.; Budinger, Thomas F.

    1998-07-01

    Quantification of brain structure is important for evaluating changes in brain size with growth and aging and for characterizing neurodegeneration disorders. Previous quantification efforts using ex vivo techniques suffered considerable error due to shrinkage of the cerebrum after extraction from the skull, deformation of slices during sectioning, and numerous other factors. In vivo imaging studies of brain anatomy avoid these problems and allow repetitive studies following progression of brain structure changes due to disease or natural processes. We have developed a methodology for obtaining triangular mesh models of the cortical surface from MRI brain datasets. The cortex is segmented from nonbrain tissue using a 2D region-growing technique combined with occasional manual edits. Once segmented, thresholding and image morphological operations (erosions and openings) are used to expose the regions between adjacent surfaces in deep cortical folds. A 2D region- following procedure is then used to find a set of contours outlining the cortical boundary on each slice. The contours on all slices are tiled together to form a closed triangular mesh model approximating the cortical surface. This model can be used for calculation of cortical surface area and volume, as well as other parameters of interest. Except for the initial segmentation of the cortex from the skull, the technique is automatic and requires only modest computation time on modern workstations. Though the use of image data avoids many of the pitfalls of ex vivo and sectioning techniques, our MRI-based technique is still vulnerable to errors that may impact the accuracy of estimated brain structure parameters. Potential inaccuracies include segmentation errors due to incorrect thresholding, missed deep sulcal surfaces, falsely segmented holes due to image noise and surface tiling artifacts. The focus of this paper is the characterization of these errors and how they affect measurements of cortical surface

  2. Improving fMRI reliability in presurgical mapping for brain tumours.

    Science.gov (United States)

    Stevens, M Tynan R; Clarke, David B; Stroink, Gerhard; Beyea, Steven D; D'Arcy, Ryan Cn

    2016-03-01

    Functional MRI (fMRI) is becoming increasingly integrated into clinical practice for presurgical mapping. Current efforts are focused on validating data quality, with reliability being a major factor. In this paper, we demonstrate the utility of a recently developed approach that uses receiver operating characteristic-reliability (ROC-r) to: (1) identify reliable versus unreliable data sets; (2) automatically select processing options to enhance data quality; and (3) automatically select individualised thresholds for activation maps. Presurgical fMRI was conducted in 16 patients undergoing surgical treatment for brain tumours. Within-session test-retest fMRI was conducted, and ROC-reliability of the patient group was compared to a previous healthy control cohort. Individually optimised preprocessing pipelines were determined to improve reliability. Spatial correspondence was assessed by comparing the fMRI results to intraoperative cortical stimulation mapping, in terms of the distance to the nearest active fMRI voxel. The average ROC-r reliability for the patients was 0.58±0.03, as compared to 0.72±0.02 in healthy controls. For the patient group, this increased significantly to 0.65±0.02 by adopting optimised preprocessing pipelines. Co-localisation of the fMRI maps with cortical stimulation was significantly better for more reliable versus less reliable data sets (8.3±0.9 vs 29±3 mm, respectively). We demonstrated ROC-r analysis for identifying reliable fMRI data sets, choosing optimal postprocessing pipelines, and selecting patient-specific thresholds. Data sets with higher reliability also showed closer spatial correspondence to cortical stimulation. ROC-r can thus identify poor fMRI data at time of scanning, allowing for repeat scans when necessary. ROC-r analysis provides optimised and automated fMRI processing for improved presurgical mapping. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence

  3. Biophysical modeling of high field diffusion MRI demonstrates micro-structural aberration in chronic mild stress rat brain

    DEFF Research Database (Denmark)

    Khan, Ahmad Raza; Chuhutin, Andrey; Wiborg, Ove

    2016-01-01

    anhedonia is considered to be a realistic model of depression in studies of animal subjects. Stereological and neuronal tracing techniques have demonstrated persistent remodeling of microstructure in hippocampus, prefrontal cortex and amygdala of CMS brains. Recent developments in diffusion MRI (d...... microstructure in the hippocampus, prefrontal cortex, caudate putamen and amygdala regions of CMS rat brains by comparison to brains from normal controls. To validate findings of CMS induced microstructural alteration, histology was performed to determine neurite, nuclear and astrocyte density. d-MRI based...... neurite density and tensor-based mean kurtosis (MKT) were significantly higher, while mean diffusivity (MD), extracellular diffusivity (Deff) and intra-neurite diffusivity(DL) were significantly lower in the amygdala of CMS rat brains. Deff was also significantly lower in the hippocampus and caudate...

  4. Neuropsychology and cognitive neuroscience in the fMRI era: A recapitulation of localizationist and connectionist views.

    Science.gov (United States)

    Sutterer, Matthew J; Tranel, Daniel

    2017-11-01

    We highlight the past 25 years of cognitive neuroscience and neuropsychology, focusing on the impact to the field of the introduction in 1992 of functional MRI (fMRI). We reviewed the past 25 years of literature in cognitive neuroscience and neuropsychology, focusing on the relation and interplay of fMRI studies and studies utilizing the "lesion method" in human participants with focal brain damage. Our review highlights the state of localist/connectionist research debates in cognitive neuroscience and neuropsychology circa 1992, and details how the introduction of fMRI into the field at that time catalyzed a new wave of efforts to map complex human behavior to specific brain regions. This, in turn, eventually evolved into many studies that focused on networks and connections between brain areas, culminating in recent years with large-scale investigations such as the Human Connectome Project. We argue that throughout the past 25 years, neuropsychology-and more precisely, the "lesion method" in humans-has continued to play a critical role in arbitrating conclusions and theories derived from inferred patterns of local brain activity or wide-spread connectivity from functional imaging approaches. We conclude by highlighting the future for neuropsychology in the context of an increasingly complex methodological armamentarium. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  5. Abstract representations of associated emotions in the human brain.

    Science.gov (United States)

    Kim, Junsuk; Schultz, Johannes; Rohe, Tim; Wallraven, Christian; Lee, Seong-Whan; Bülthoff, Heinrich H

    2015-04-08

    Emotions can be aroused by various kinds of stimulus modalities. Recent neuroimaging studies indicate that several brain regions represent emotions at an abstract level, i.e., independently from the sensory cues from which they are perceived (e.g., face, body, or voice stimuli). If emotions are indeed represented at such an abstract level, then these abstract representations should also be activated by the memory of an emotional event. We tested this hypothesis by asking human participants to learn associations between emotional stimuli (videos of faces or bodies) and non-emotional stimuli (fractals). After successful learning, fMRI signals were recorded during the presentations of emotional stimuli and emotion-associated fractals. We tested whether emotions could be decoded from fMRI signals evoked by the fractal stimuli using a classifier trained on the responses to the emotional stimuli (and vice versa). This was implemented as a whole-brain searchlight, multivoxel activation pattern analysis, which revealed successful emotion decoding in four brain regions: posterior cingulate cortex (PCC), precuneus, MPFC, and angular gyrus. The same analysis run only on responses to emotional stimuli revealed clusters in PCC, precuneus, and MPFC. Multidimensional scaling analysis of the activation patterns revealed clear clustering of responses by emotion across stimulus types. Our results suggest that PCC, precuneus, and MPFC contain representations of emotions that can be evoked by stimuli that carry emotional information themselves or by stimuli that evoke memories of emotional stimuli, while angular gyrus is more likely to take part in emotional memory retrieval. Copyright © 2015 the authors 0270-6474/15/355655-09$15.00/0.

  6. Correlation of auditory brain stem response and the MRI measurements in neuro-degenerative disorders

    International Nuclear Information System (INIS)

    Kamei, Hidekazu

    1989-01-01

    The purpose of this study is to elucidate correlations of several MRI measurements of the cranium and brain, functioning as a volume conductor, to the auditory brain stem response (ABR) in neuro-degenerative disorders. The subjects included forty-seven patients with spinocerebellar degeneration (SCD) and sixteen of amyotrophic lateral sclerosis (ALS). Statistically significant positive correlations were found between I-V and III-V interpeak latencies (IPLs) and the area of cranium and brain in the longitudinal section of SCD patients, and between I-III and III-V IPLs and the area in the longitudinal section of those with ALS. And, also there were statistically significant correlations between the amplitude of the V wave and the area of brain stem as well as that of the cranium in the longitudinal section of SCD patients, and between the amplitude of the V wave and the area of the cerebrum in the longitudinal section of ALS. In conclusion, in the ABR, the IPLs were prolonged and the amplitude of the V wave was decreased while the MRI size of the cranium and brain increased. When the ABR is applied to neuro-degenerative disorders, it might be important to consider not only the conduction of the auditory tracts in the brain stem, but also the correlations of the size of the cranium and brain which act as a volume conductor. (author)

  7. Correlation of auditory brain stem response and the MRI measurements in neuro-degenerative disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kamei, Hidekazu (Tokyo Women' s Medical Coll. (Japan))

    1989-06-01

    The purpose of this study is to elucidate correlations of several MRI measurements of the cranium and brain, functioning as a volume conductor, to the auditory brain stem response (ABR) in neuro-degenerative disorders. The subjects included forty-seven patients with spinocerebellar degeneration (SCD) and sixteen of amyotrophic lateral sclerosis (ALS). Statistically significant positive correlations were found between I-V and III-V interpeak latencies (IPLs) and the area of cranium and brain in the longitudinal section of SCD patients, and between I-III and III-V IPLs and the area in the longitudinal section of those with ALS. And, also there were statistically significant correlations between the amplitude of the V wave and the area of brain stem as well as that of the cranium in the longitudinal section of SCD patients, and between the amplitude of the V wave and the area of the cerebrum in the longitudinal section of ALS. In conclusion, in the ABR, the IPLs were prolonged and the amplitude of the V wave was decreased while the MRI size of the cranium and brain increased. When the ABR is applied to neuro-degenerative disorders, it might be important to consider not only the conduction of the auditory tracts in the brain stem, but also the correlations of the size of the cranium and brain which act as a volume conductor. (author).

  8. Functional MRI in pre-surgical planning: case study and cautionary ...

    African Journals Online (AJOL)

    Background. Since its inception almost 20 years ago, functional magnetic resonance imaging (fMRI) has greatly advanced our knowledge of human brain function. Although the clinical applications of fMRI are still limited, there have recently been encouraging advances for its use in pre-operative functional cortical mapping ...

  9. PET/MRI for neurologic applications.

    Science.gov (United States)

    Catana, Ciprian; Drzezga, Alexander; Heiss, Wolf-Dieter; Rosen, Bruce R

    2012-12-01

    PET and MRI provide complementary information in the study of the human brain. Simultaneous PET/MRI data acquisition allows the spatial and temporal correlation of the measured signals, creating opportunities impossible to realize using stand-alone instruments. This paper reviews the methodologic improvements and potential neurologic and psychiatric applications of this novel technology. We first present methods for improving the performance and information content of each modality by using the information provided by the other technique. On the PET side, we discuss methods that use the simultaneously acquired MRI data to improve the PET data quantification. On the MRI side, we present how improved PET quantification can be used to validate several MRI techniques. Finally, we describe promising research, translational, and clinical applications that can benefit from these advanced tools.

  10. A multimodal MRI dataset of professional chess players.

    Science.gov (United States)

    Li, Kaiming; Jiang, Jing; Qiu, Lihua; Yang, Xun; Huang, Xiaoqi; Lui, Su; Gong, Qiyong

    2015-01-01

    Chess is a good model to study high-level human brain functions such as spatial cognition, memory, planning, learning and problem solving. Recent studies have demonstrated that non-invasive MRI techniques are valuable for researchers to investigate the underlying neural mechanism of playing chess. For professional chess players (e.g., chess grand masters and masters or GM/Ms), what are the structural and functional alterations due to long-term professional practice, and how these alterations relate to behavior, are largely veiled. Here, we report a multimodal MRI dataset from 29 professional Chinese chess players (most of whom are GM/Ms), and 29 age matched novices. We hope that this dataset will provide researchers with new materials to further explore high-level human brain functions.

  11. Educating the Human Brain. Human Brain Development Series

    Science.gov (United States)

    Posner, Michael I.; Rothbart, Mary K.

    2006-01-01

    "Educating the Human Brain" is the product of a quarter century of research. This book provides an empirical account of the early development of attention and self regulation in infants and young children. It examines the brain areas involved in regulatory networks, their connectivity, and how their development is influenced by genes and…

  12. The mean-variance relationship reveals two possible strategies for dynamic brain connectivity analysis in fMRI.

    Science.gov (United States)

    Thompson, William H; Fransson, Peter

    2015-01-01

    When studying brain connectivity using fMRI, signal intensity time-series are typically correlated with each other in time to compute estimates of the degree of interaction between different brain regions and/or networks. In the static connectivity case, the problem of defining which connections that should be considered significant in the analysis can be addressed in a rather straightforward manner by a statistical thresholding that is based on the magnitude of the correlation coefficients. More recently, interest has come to focus on the dynamical aspects of brain connectivity and the problem of deciding which brain connections that are to be considered relevant in the context of dynamical changes in connectivity provides further options. Since we, in the dynamical case, are interested in changes in connectivity over time, the variance of the correlation time-series becomes a relevant parameter. In this study, we discuss the relationship between the mean and variance of brain connectivity time-series and show that by studying the relation between them, two conceptually different strategies to analyze dynamic functional brain connectivity become available. Using resting-state fMRI data from a cohort of 46 subjects, we show that the mean of fMRI connectivity time-series scales negatively with its variance. This finding leads to the suggestion that magnitude- versus variance-based thresholding strategies will induce different results in studies of dynamic functional brain connectivity. Our assertion is exemplified by showing that the magnitude-based strategy is more sensitive to within-resting-state network (RSN) connectivity compared to between-RSN connectivity whereas the opposite holds true for a variance-based analysis strategy. The implications of our findings for dynamical functional brain connectivity studies are discussed.

  13. Learning-dependent plasticity with and without training in the human brain.

    Science.gov (United States)

    Zhang, Jiaxiang; Kourtzi, Zoe

    2010-07-27

    Long-term experience through development and evolution and shorter-term training in adulthood have both been suggested to contribute to the optimization of visual functions that mediate our ability to interpret complex scenes. However, the brain plasticity mechanisms that mediate the detection of objects in cluttered scenes remain largely unknown. Here, we combine behavioral and functional MRI (fMRI) measurements to investigate the human-brain mechanisms that mediate our ability to learn statistical regularities and detect targets in clutter. We show two different routes to visual learning in clutter with discrete brain plasticity signatures. Specifically, opportunistic learning of regularities typical in natural contours (i.e., collinearity) can occur simply through frequent exposure, generalize across untrained stimulus features, and shape processing in occipitotemporal regions implicated in the representation of global forms. In contrast, learning to integrate discontinuities (i.e., elements orthogonal to contour paths) requires task-specific training (bootstrap-based learning), is stimulus-dependent, and enhances processing in intraparietal regions implicated in attention-gated learning. We propose that long-term experience with statistical regularities may facilitate opportunistic learning of collinear contours, whereas learning to integrate discontinuities entails bootstrap-based training for the detection of contours in clutter. These findings provide insights in understanding how long-term experience and short-term training interact to shape the optimization of visual recognition processes.

  14. Interaction vs. observation: distinctive modes of social cognition in human brain and behavior? A combined fMRI and eye-tracking study.

    Science.gov (United States)

    Tylén, Kristian; Allen, Micah; Hunter, Bjørk K; Roepstorff, Andreas

    2012-01-01

    Human cognition has usually been approached on the level of individual minds and brains, but social interaction is a challenging case. Is it best thought of as a self-contained individual cognitive process aiming at an "understanding of the other," or should it rather be approached as an collective, inter-personal process where individual cognitive components interact on a moment-to-moment basis to form coupled dynamics? In a combined fMRI and eye-tracking study we directly contrasted these models of social cognition. We found that the perception of situations affording social contingent responsiveness (e.g., someone offering or showing you an object) elicited activations in regions of the right posterior temporal sulcus and yielded greater pupil dilation corresponding to a model of coupled dynamics (joint action). In contrast, the social-cognitive perception of someone "privately" manipulating an object elicited activation in medial prefrontal cortex, the right inferior frontal gyrus and right inferior parietal lobus, regions normally associated with Theory of Mind and with the mirror neuron system. Our findings support a distinction in social cognition between social observation and social interaction, and demonstrate that simple ostensive cues may shift participants' experience, behavior, and brain activity between these modes. The identification of a distinct, interactive mode has implications for research on social cognition, both in everyday life and in clinical conditions.

  15. Interaction versus Observation: distinctive modes of social cognition in human brain and behavior? A combined fMRI and eye-tracking study.

    Directory of Open Access Journals (Sweden)

    Kristian eTylen

    2012-12-01

    Full Text Available Human cognition has usually been approached on the level of individual minds and brains, but social interaction is a challenging case. Is it best thought of as a self-contained individual cognitive process aiming at an ‘understanding of the other’, or should it rather be approached as an collective, inter-personal process where individual cognitive components interact on a moment-to-moment basis to form coupled dynamics? In a combined fMRI and eye tracking study we directly contrasted these models of social cognition. We found that the perception of situations affording social contingent responsiveness (e.g. someone offering or showing you an object elicited activations in regions of the right posterior temporal sulcus and yielded greater pupil dilation corresponding to a model of coupled dynamics (joint action. In contrast, the social-cognitive perception of someone ‘privately’ manipulating an object elicited activation in medial prefrontal cortex, the right inferior frontal gyrus and right inferior parietal lobus, regions normally associated with Theory of Mind and with the mirror neuron system. Our findings support a distinction in social cognition between social observation and social interaction, and demonstrate that simple ostensive cues may shift participants’ experience, behavior and brain activity between these modes. The identification of a distinct, interactive mode has implications for research on social cognition, both in everyday life and in clinical conditions.

  16. Prenatal brain MRI of fetuses with Zika virus infection.

    Science.gov (United States)

    Guillemette-Artur, Prisca; Besnard, Marianne; Eyrolle-Guignot, Dominique; Jouannic, Jean-Marie; Garel, Catherine

    2016-06-01

    An outbreak of Zika virus was observed in French Polynesia in 2013-2014. Maternal Zika virus infection has been associated with fetal microcephaly and severe cerebral damage. To analyze the MRI cerebral findings in fetuses with intrauterine Zika virus infection. We retrospectively analyzed prospectively collected data. Inclusion criteria comprised cases with (1) estimated conception date between June 2013 and May 2014, (2) available US and MRI scans revealing severe fetal brain lesions and (3) positive polymerase chain reaction for Zika virus in the amniotic fluid. We recorded pregnancy history of Zika virus infection and analyzed US and MRI scans. Three out of 12 cases of severe cerebral lesions fulfilled all inclusion criteria. History of maternal Zika virus infection had been documented in two cases. Calcifications and ventriculomegaly were present at US in all cases. MRI showed micrencephaly (n = 3), low cerebellar biometry (n = 2), occipital subependymal pseudocysts (n = 2), polymicrogyria with laminar necrosis and opercular dysplasia (n = 3), absent (n = 1) or hypoplastic (n = 1) corpus callosum and hypoplastic brainstem (n = 1). Severe cerebral damage was observed in our series, with indirect findings suggesting that the germinal matrix is the principal target for Zika virus. The lesions are very similar to severe forms of congenital cytomegalovirus and lymphocytic choriomeningitis virus infections.

  17. Developments in boron magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Schweizer, M.

    1995-01-01

    This report summarizes progress during the past year on maturing Boron-11 magnetic resonance imaging (MRI) methodology for noninvasive determination of BNCT agents (BSH) spatially in time. Three major areas are excerpted: (1) Boron-11 MRI of BSH distributions in a canine intracranial tumor model and the first human glioblastoma patient, (2) whole body Boron-11 MRI of BSH pharmacokinetics in a rat flank tumor model, and (3) penetration of gadolinium salts through the BBB as a function of tumor growth in the canine brain

  18. Learning-based meta-algorithm for MRI brain extraction.

    Science.gov (United States)

    Shi, Feng; Wang, Li; Gilmore, John H; Lin, Weili; Shen, Dinggang

    2011-01-01

    Multiple-segmentation-and-fusion method has been widely used for brain extraction, tissue segmentation, and region of interest (ROI) localization. However, such studies are hindered in practice by their computational complexity, mainly coming from the steps of template selection and template-to-subject nonlinear registration. In this study, we address these two issues and propose a novel learning-based meta-algorithm for MRI brain extraction. Specifically, we first use exemplars to represent the entire template library, and assign the most similar exemplar to the test subject. Second, a meta-algorithm combining two existing brain extraction algorithms (BET and BSE) is proposed to conduct multiple extractions directly on test subject. Effective parameter settings for the meta-algorithm are learned from the training data and propagated to subject through exemplars. We further develop a level-set based fusion method to combine multiple candidate extractions together with a closed smooth surface, for obtaining the final result. Experimental results show that, with only a small portion of subjects for training, the proposed method is able to produce more accurate and robust brain extraction results, at Jaccard Index of 0.956 +/- 0.010 on total 340 subjects under 6-fold cross validation, compared to those by the BET and BSE even using their best parameter combinations.

  19. Brain volume measurement using three-dimensional magnetic resonance images

    International Nuclear Information System (INIS)

    Ishimaru, Yoshihiro

    1996-01-01

    This study was designed to validate accurate measurement method of human brain volume using three dimensional (3D) MRI data on a workstation, and to establish optimal correcting method of human brain volume on diagnosis of brain atrophy. 3D MRI data were acquired by fast SPGR sequence using 1.5 T MR imager. 3D MRI data were segmented by region growing method and 3D image was displayed by surface rendering method on the workstation. Brain volume was measured by the volume measurement function of the workstation. In order to validate the accurate measurement method, phantoms and a specimen of human brain were examined. Phantom volume was measured by changing the lower level of threshold value. At the appropriate threshold value, percentage of error of phantoms and the specimen were within 0.6% and 0.08%, respectively. To establish the optimal correcting method, 130 normal volunteers were examined. Brain volumes corrected with height weight, body surface area, and alternative skull volume were evaluated. Brain volume index, which is defined as dividing brain volume by alternative skull volume, had the best correlation with age (r=0.624, p<0.05). No gender differences was observed in brain volume index in contrast to in brain volume. The clinical usefulness of this correcting method for brain atrophy diagnosis was evaluated in 85 patients. Diagnosis by 2D spin echo MR images was compared with brain volume index. Diagnosis of brain atrophy by 2D MR image was concordant with the evaluation by brain volume index. These results indicated that this measurement method had high accuracy, and it was important to set the appropriate threshold value. Brain volume index was the appropriate indication for evaluation of human brain volume, and was considered to be useful for the diagnosis of brain atrophy. (author)

  20. Fusion of PET and MRI for Hybrid Imaging

    Science.gov (United States)

    Cho, Zang-Hee; Son, Young-Don; Kim, Young-Bo; Yoo, Seung-Schik

    Recently, the development of the fusion PET-MRI system has been actively studied to meet the increasing demand for integrated molecular and anatomical imaging. MRI can provide detailed anatomical information on the brain, such as the locations of gray and white matter, blood vessels, axonal tracts with high resolution, while PET can measure molecular and genetic information, such as glucose metabolism, neurotransmitter-neuroreceptor binding and affinity, protein-protein interactions, and gene trafficking among biological tissues. State-of-the-art MRI systems, such as the 7.0 T whole-body MRI, now can visualize super-fine structures including neuronal bundles in the pons, fine blood vessels (such as lenticulostriate arteries) without invasive contrast agents, in vivo hippocampal substructures, and substantia nigra with excellent image contrast. High-resolution PET, known as High-Resolution Research Tomograph (HRRT), is a brain-dedicated system capable of imaging minute changes of chemicals, such as neurotransmitters and -receptors, with high spatial resolution and sensitivity. The synergistic power of the two, i.e., ultra high-resolution anatomical information offered by a 7.0 T MRI system combined with the high-sensitivity molecular information offered by HRRT-PET, will significantly elevate the level of our current understanding of the human brain, one of the most delicate, complex, and mysterious biological organs. This chapter introduces MRI, PET, and PET-MRI fusion system, and its algorithms are discussed in detail.