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Sample records for eeg-correlated functional mri

  1. EEG correlates of time-varying BOLD functional connectivity

    Science.gov (United States)

    Chang, Catie; Liu, Zhongming; Chen, Michael C.; Liu, Xiao; Duyn, Jeff H.

    2013-01-01

    Recent resting-state fMRI studies have shown that the apparent functional connectivity (FC) between brain regions may undergo changes on time-scales of seconds to minutes, the basis and importance of which are largely unknown. Here, we examine the electrophysiological correlates of within-scan FC variations during a condition of eyes-closed rest. A sliding window analysis of simultaneous EEG-fMRI data was performed to examine whether temporal variations in coupling between three major networks (default mode; DMN, dorsal attention; DAN, and salience network; SN) are associated with temporal variations in mental state, as assessed from the amplitude of alpha and theta oscillations in the EEG. In our dataset, alpha power showed a significant inverse relationship with the strength of connectivity between DMN and DAN. In addition, alpha power covaried with the spatial extent of anticorrelation between DMN and DAN, with higher alpha power associated with larger anticorrelation extent. Results suggest an electrical signature of the time-varying FC between the DAN and DMN, potentially reflecting neural and state-dependent variations. PMID:23376790

  2. EEG Correlates of Ten Positive Emotions

    OpenAIRE

    Hu, Xin; Yu, Jianwen; Song, Mengdi; Yu, Chun; Wang, Fei; Sun, Pei; Wang, Daifa; Zhang, Dan

    2017-01-01

    Compared with the well documented neurophysiological findings on negative emotions, much less is known about positive emotions. In the present study, we explored the EEG correlates of ten different positive emotions (joy, gratitude, serenity, interest, hope, pride, amusement, inspiration, awe, and love). A group of 20 participants were invited to watch 30 short film clips with their EEGs simultaneously recorded. Distinct topographical patterns for different positive emotions were found for th...

  3. EEG Correlates of Ten Positive Emotions.

    Science.gov (United States)

    Hu, Xin; Yu, Jianwen; Song, Mengdi; Yu, Chun; Wang, Fei; Sun, Pei; Wang, Daifa; Zhang, Dan

    2017-01-01

    Compared with the well documented neurophysiological findings on negative emotions, much less is known about positive emotions. In the present study, we explored the EEG correlates of ten different positive emotions (joy, gratitude, serenity, interest, hope, pride, amusement, inspiration, awe, and love). A group of 20 participants were invited to watch 30 short film clips with their EEGs simultaneously recorded. Distinct topographical patterns for different positive emotions were found for the correlation coefficients between the subjective ratings on the ten positive emotions per film clip and the corresponding EEG spectral powers in different frequency bands. Based on the similarities of the participants' ratings on the ten positive emotions, these emotions were further clustered into three representative clusters, as 'encouragement' for awe, gratitude, hope, inspiration, pride, 'playfulness' for amusement, joy, interest, and 'harmony' for love, serenity. Using the EEG spectral powers as features, both the binary classification on the higher and lower ratings on these positive emotions and the binary classification between the three positive emotion clusters, achieved accuracies of approximately 80% and above. To our knowledge, our study provides the first piece of evidence on the EEG correlates of different positive emotions.

  4. EEG-fMRI correlation patterns in the presurgical evaluation of focal epilepsy: A comparison with electrocorticographic data and surgical outcome measures

    NARCIS (Netherlands)

    van Houdt, P.J.; de Munck, J.C.; Leijten, F.S.S.; Huiskamp, G.J.M.; Colon, A.J.; Boon, P.A.J.M.; Ossenblok, P.P.W.

    2013-01-01

    EEG-correlated functional MRI (EEG-fMRI) visualizes brain regions associated with interictal epileptiform discharges (IEDs). This technique images the epileptiform network, including multifocal, superficial and deeply situated cortical areas. To understand the role of EEG-fMRI in presurgical

  5. Clinical functional MRI. Presurgical functional neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Stippich, C. (ed.) [Heidelberg Univ. (Germany). Div. of Neuroradiology

    2007-07-01

    Functional magnetic resonance imaging (fMRI) permits noninvasive imaging of the ''human brain at work'' under physiological conditions. This is the first textbook on clinical fMRI. It is devoted to preoperative fMRI in patients with brain tumors and epilepsies, which are the most well-established clinical applications. By localizing and lateralizing specific brain functions, as well as epileptogenic zones, fMRI facilitates the selection of a safe treatment and the planning and performance of function-preserving neurosurgery. State of the art fMRI procedures are presented, with detailed consideration of the physiological and methodological background, imaging and data processing, normal and pathological findings, diagnostic possibilities and limitations, and other related techniques. All chapters are written by recognized experts in their fields, and the book is designed to be of value to beginners, trained clinicians and experts alike. (orig.)

  6. 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.)

  7. Mandarin functional MRI Language paradigms

    OpenAIRE

    Ci, He; van Graan, Andre; Gonz?lvez, Gloria; Thompson, Pamela; Hill, Andrea; Duncan, John S.

    2016-01-01

    Abstract Objective The objective of this study was to implement convenient, fast, and accurate Mandarin task paradigms for functional MRI, and to locate the Chinese language functional areas in frontal and temporal lobes. Materials and Methods Nineteen healthy Chinese volunteers participated in this study, which utilized a block design with four language tasks: auditory naming (AN), picture naming (PN), verbal fluency?character (VFC), and verbal fluency?letter (VFL). All functional images wer...

  8. Electrocortical (EEG correlates of music and states of consciousness

    Directory of Open Access Journals (Sweden)

    Lazar Skaric

    2007-11-01

    Full Text Available The study of the perception of music is a paramount example of multidisciplinary research. In spite of a lot of theoretical and experimental efforts to understand musical processing, attempts to localize musical abilities in particular brain regions were largely unsuccessful, save for the difference between musicians and non musicians, especially in hemispheric specialization and in EEG correlational dimensions. Having in mind that human emotional response to music and to art in general is limbic dependent, this motivated us to address our question to a similar possible neurobiological origin of musicogenic altered states of consciousness and its possible EEG correlates, “resonantly” induced by deep spiritual music. For example, as in sound-induced altered states of consciousness cultivated in some Eastern yogic practices. The musicogenic states of consciousness are evaluated within a group of 6 adults, upon the influence of 4 types of spiritual music. The most prominent changes in theta or alpha frequency bands were induced in two subjects, upon the influence of Indian spiritual music, Bhajan.

  9. Behavioral and EEG Correlates of Reduced Executive Functioning in Adolescents

    OpenAIRE

    Espano, Joshua

    2013-01-01

    Exposure to orphanage care or other deprived conditions represent a contributing risk factor in the development of ADHD behaviors. Upon leaving these contexts, the resting EEG patterns found in post-institutionalized (PI) children resemble the EEG profile of children with behavior problems, such as inattention, hyperactivity, and impulsivity. Specifically, this atypical pattern consists of increased theta power relative to other power spectra and decreased alpha power. This study examined if ...

  10. Research progress of functional MRI in depression

    International Nuclear Information System (INIS)

    Xie Shenghui; Niu Guangming; Han Xiaodong; Qiao Pengfei

    2013-01-01

    The mood disorders of depression are associated with abnormalities of brain structure and function, and exploring their pathological mechanism has important significance for the choice of treatment and the curative effect evaluation. In recent years, the research of MRI on brain structure and function of depression has made great progress, especially in functional magnetic resonance imaging (fMRI). fMRI can detect the functional change in real time, and also can display the activity of brain and changes in the nerve pathways in patients with depression. This article summarizes the present research situation and progress of MRI in the diagnosis of depression. (authors)

  11. Functional MRI of the patellofemoral joint: comparison of ultrafast MRI, motion-triggered cine MRI and static MRI

    International Nuclear Information System (INIS)

    Muhle, C.; Brossmann, J.; Melchert, U.H.; Schroeder, C.; Boer, R. de; Spielmann, R.P.; Heller, M.

    1995-01-01

    To evaluate the feasibility and usefulness of ultrafast MRI (u), patellar tracking from 30 of flexion to knee extension (0 ) was analysed and compared with motion-triggered cine MRI (m) and a static MRI technique (s). The different imaging methods were compared in respect of the patellofemoral relationship, the examination time and image quality. Eight healthy subjects and four patients (in total 18 joints) with patellar subluxation or luxation were examined. Significant differences between the static MRI series without quadriceps contraction and the functional MRI studies (motion-triggered cine MRI and ultrafast MRI) were found for the patellar tilt angle. In the dynamic joint studies there was no statistical difference of the regression coefficients between the motion-triggered cine MRI studies and the ultrafast MRI studies. The findings of the functional MRI studies compared with the static MRI images were significantly different for the lateralisation of the patella, expressed by the lateral patellar displacement and bisect offset. No significant differences in patellar lateralisation were found between motion-triggered cine MRI and ultrafast MRI. Ultrafast MRI was superior to motion-triggered cine MRI in terms of the reduction in imaging time and improvement of the image quality. (orig.)

  12. Functional MRI of the patellofemoral joint: comparison of ultrafast MRI, motion-triggered cine MRI and static MRI

    Energy Technology Data Exchange (ETDEWEB)

    Muhle, C. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Brossmann, J. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Melchert, U.H. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Schroeder, C. [Radiologische Abt., Universitaets-Kinderklinik, Christian-Albrechts-Universitaet, Kiel (Germany); Boer, R. de [Philips Medical Systems, Best (Netherlands); Spielmann, R.P. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany); Heller, M. [Klinik fuer Radiologische Diagnostik, Univ. Kiel (Germany)

    1995-12-31

    To evaluate the feasibility and usefulness of ultrafast MRI (u), patellar tracking from 30 of flexion to knee extension (0 ) was analysed and compared with motion-triggered cine MRI (m) and a static MRI technique (s). The different imaging methods were compared in respect of the patellofemoral relationship, the examination time and image quality. Eight healthy subjects and four patients (in total 18 joints) with patellar subluxation or luxation were examined. Significant differences between the static MRI series without quadriceps contraction and the functional MRI studies (motion-triggered cine MRI and ultrafast MRI) were found for the patellar tilt angle. In the dynamic joint studies there was no statistical difference of the regression coefficients between the motion-triggered cine MRI studies and the ultrafast MRI studies. The findings of the functional MRI studies compared with the static MRI images were significantly different for the lateralisation of the patella, expressed by the lateral patellar displacement and bisect offset. No significant differences in patellar lateralisation were found between motion-triggered cine MRI and ultrafast MRI. Ultrafast MRI was superior to motion-triggered cine MRI in terms of the reduction in imaging time and improvement of the image quality. (orig.)

  13. Functional MRI of Multilingual Subjects

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jae Min; Ryoo, Jae Wook; Choi, Dae Seob; Shin, Tae Beom; Chung, Sung Hoon; Kim, Ji Eun [Gyeongsang National University School of Medicine, Jinju (Korea, Republic of); Han, Heon; Kim, Sam Soo; Jeon, Yong Hwan [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

    2009-12-15

    To evaluate brain activation areas during the processing of languages in multilingual volunteers by functional MRI and to examine the differences between the mother and foreign languages. Nine multilingual (Korean, French, and English speaking) Korean individuals were enrolled in this study. Functional images were acquired during a lexical decision task (LDT) and picture naming task (PNT) in each of the Korean, French and English languages. The areas activated were analyzed topographically in each language and task, and compared between languages. Activation was noted in Broca's area, supramarginal gyrus, fusiform gyrus during the LDT. During the PNT, activation was noted in Broca's area, left prefrontal area, cerebellum, right extrastriated cortex. While Broca's area activation was observed for all languages during LDT, there was more activation in Broca's area and additional activation in the right prefrontal area with foreign languages. During the PNT, there was more activation in the left prefrontal area with foreign languages. Broca's area, which is known as a major language region, was activated by all languages and tasks. The brain activation areas were largely overlapping with the mother and foreign languages. However, there were wider areas of activation and additional different activation areas with foreign languages. These results suggest more cerebral effort during foreign language processing

  14. Functional MRI of Multilingual Subjects

    International Nuclear Information System (INIS)

    Cho, Jae Min; Ryoo, Jae Wook; Choi, Dae Seob; Shin, Tae Beom; Chung, Sung Hoon; Kim, Ji Eun; Han, Heon; Kim, Sam Soo; Jeon, Yong Hwan

    2009-01-01

    To evaluate brain activation areas during the processing of languages in multilingual volunteers by functional MRI and to examine the differences between the mother and foreign languages. Nine multilingual (Korean, French, and English speaking) Korean individuals were enrolled in this study. Functional images were acquired during a lexical decision task (LDT) and picture naming task (PNT) in each of the Korean, French and English languages. The areas activated were analyzed topographically in each language and task, and compared between languages. Activation was noted in Broca's area, supramarginal gyrus, fusiform gyrus during the LDT. During the PNT, activation was noted in Broca's area, left prefrontal area, cerebellum, right extrastriated cortex. While Broca's area activation was observed for all languages during LDT, there was more activation in Broca's area and additional activation in the right prefrontal area with foreign languages. During the PNT, there was more activation in the left prefrontal area with foreign languages. Broca's area, which is known as a major language region, was activated by all languages and tasks. The brain activation areas were largely overlapping with the mother and foreign languages. However, there were wider areas of activation and additional different activation areas with foreign languages. These results suggest more cerebral effort during foreign language processing

  15. EEG correlates of visual short-term memory in older age vary with adult lifespan cognitive development

    DEFF Research Database (Denmark)

    Wiegand, Iris; Lauritzen, Martin J.; Osler, Merete

    2018-01-01

    Visual short-term memory (vSTM) is a cognitive resource that declines with age. This study investigated whether electroencephalography (EEG) correlates of vSTM vary with cognitive development over individuals' lifespan. We measured vSTM performance and EEG in a lateralized whole-report task...... in a healthy birth cohort, whose cognitive function (intelligence quotient) was assessed in youth and late-middle age. Higher vSTM capacity (K; measured by Bundesen's theory of visual attention) was associated with higher amplitudes of the contralateral delay activity (CDA) and the central positivity (CP...

  16. Functional MRI using regularized parallel imaging acquisition.

    Science.gov (United States)

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M; Belliveau, John W; Wald, Lawrence L; Kwong, Kenneth K

    2005-08-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions. 2005 Wiley-Liss, Inc

  17. Adaptive Analysis of Functional MRI Data

    International Nuclear Information System (INIS)

    Friman, Ola

    2003-01-01

    Functional Magnetic Resonance Imaging (fMRI) is a recently developed neuro-imaging technique with capacity to map neural activity with high spatial precision. To locate active brain areas, the method utilizes local blood oxygenation changes which are reflected as small intensity changes in a special type of MR images. The ability to non-invasively map brain functions provides new opportunities to unravel the mysteries and advance the understanding of the human brain, as well as to perform pre-surgical examinations in order to optimize surgical interventions. This dissertation introduces new approaches for the analysis of fMRI data. The detection of active brain areas is a challenging problem due to high noise levels and artifacts present in the data. A fundamental tool in the developed methods is Canonical Correlation Analysis (CCA). CCA is used in two novel ways. First as a method with the ability to fully exploit the spatio-temporal nature of fMRI data for detecting active brain areas. Established analysis approaches mainly focus on the temporal dimension of the data and they are for this reason commonly referred to as being mass-univariate. The new CCA detection method encompasses and generalizes the traditional mass-univariate methods and can in this terminology be viewed as a mass-multivariate approach. The concept of spatial basis functions is introduced as a spatial counterpart of the temporal basis functions already in use in fMRI analysis. The spatial basis functions implicitly perform an adaptive spatial filtering of the fMRI images, which significantly improves detection performance. It is also shown how prior information can be incorporated into the analysis by imposing constraints on the temporal and spatial models and a constrained version of CCA is devised to this end. A general Principal Component Analysis technique for generating and constraining temporal and spatial subspace models is proposed to be used in combination with the constrained CCA

  18. Verbal and visuospatial working memory during pregnancy: EEG correlation between the prefrontal and parietal cortices.

    Science.gov (United States)

    Almanza-Sepúlveda, Mayra Linné; Hernández-González, Marisela; Hevia-Orozco, Jorge Carlos; Amezcua-Gutiérrez, Claudia; Guevara, Miguel Angel

    2018-02-01

    Pregnancy is a dynamic process during which significant cognitive changes take place. It has been suggested that working memory (WM) is affected during gestation as a result of functional changes among cortical areas, such as the prefrontal and parietal cortices. This study examined cortical electroencephalographic correlations (rEEG) during performance of WM tasks in each trimester of pregnancy. Forty women were divided into 4 groups: first (T1), second (T2), and third (T3) trimester of pregnancy, and a control group of non-pregnant women. Electroencephalographic activity (EEG) was recorded from the frontopolar, dorsolateral and parietal cortices during performance of one verbal and one visuospatial working memory task. Only groups T2 and T3 showed increased onset latency in the visuospatial WM. During the verbal WM task, the T1 group showed a higher correlation between dorsolateral areas in the theta and alpha bands, as well as a lower left prefrontal-parietal correlation in the gamma band. During the visuospatial WM task, the T1 and T3 groups showed a higher left EEG correlation in the delta and alpha1 bands, whereas T2 presented a higher right prefrontal-parietal correlation in the gamma band. Although pregnancy had only a subtle effect on the visuospatial WM task, these different patterns of cortical synchronization in each trimester of pregnancy could represent adaptive mechanisms that enabled the pregnant women to focus their attention and use more cognitive resources and so adequately solve the WM tasks. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Tinnitus: A Large VBM-EEG Correlational Study

    Science.gov (United States)

    Vanneste, Sven; Van De Heyning, Paul; De Ridder, Dirk

    2015-01-01

    A surprising fact in voxel-based morphometry (VBM) studies performed in tinnitus is that not one single region is replicated in studies of different centers. The question then rises whether this is related to the low sample size of these studies, the selection of non-representative patient subgroups, or the absence of stratification according to clinical characteristics. Another possibility is that VBM is not a good tool to study functional pathologies such as tinnitus, in contrast to pathologies like Alzheimer’s disease where it is known the pathology is related to cell loss. In a large sample of 154 tinnitus patients VBM and QEEG (Quantitative Electroencephalography) was performed and evaluated by a regression analysis. Correlation analyses are performed between VBM and QEEG data. Uncorrected data demonstrated structural differences in grey matter in hippocampal and cerebellar areas related to tinnitus related distress and tinnitus duration. After control for multiple comparisons, only cerebellar VBM changes remain significantly altered. Electrophysiological differences are related to distress, tinnitus intensity, and tinnitus duration in the subgenual anterior cingulate cortex, dorsal anterior cingulate cortex, hippocampus, and parahippocampus, which confirms previous results. The absence of QEEG-VBM correlations suggest functional changes are not reflected by co-occurring structural changes in tinnitus, and the absence of VBM changes (except for the cerebellum) that survive correct statistical analysis in a large study population suggests that VBM might not be very sensitive for studying tinnitus. PMID:25781934

  20. Musical Sequence Learning and EEG Correlates of Audiomotor Processing

    Directory of Open Access Journals (Sweden)

    Matt D. Schalles

    2015-01-01

    Full Text Available Our motor and auditory systems are functionally connected during musical performance, and functional imaging suggests that the association is strong enough that passive music listening can engage the motor system. As predictive coding constrains movement sequence selections, could the motor system contribute to sequential processing of musical passages? If this is the case, then we hypothesized that the motor system should respond preferentially to passages of music that contain similar sequential information, even if other aspects of music, such as the absolute pitch, have been altered. We trained piano naive subjects with a learn-to play-by-ear paradigm, to play a simple melodic sequence over five days. After training, we recorded EEG of subjects listening to the song they learned to play, a transposed version of that song, and a control song with different notes and sequence from the learned song. Beta band power over sensorimotor scalp showed increased suppression for the learned song, a moderate level of suppression for the transposed song, and no suppression for the control song. As beta power is associated with attention and motor processing, we interpret this as support of the motor system’s activity during covert perception of music one can play and similar musical sequences.

  1. Neuro-pharmacological functional MRI of epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Kiriyama, Hideki; Makabe, Tetsuo; Tomita, Susumu; Omoto, Takashi; Asari, Shoji [Okayama Univ. (Japan). School of Medicine; Aihara, Hiroshi; Kinugasa, Kazushi; Nishimoto, Akira; Ito, Takahiko

    2000-03-01

    We studied patients with epilepsy by neuro-pharmacological functional MRI technique using diazepam. Five normal volunteers and 7 patients with epilepsy were investigated. MRI was performed by a 1.5 T unit (SIGNA Horizon, GE) using the following parameters: TR/TE 5000 msec/80 msec, FA 90 deg, FOV 200 mm, matrix 128 x 128, slice thickness 7 mm. We performed MRI scanning over 5 minutes (2 minutes before and 3 minutes after injection of diazepam) for each 1 session; we scanned 3 sessions for each patient at intervals of 5 minutes. The diazepam was injected rapidly from the antecubital vein. The dose of diazepam was 0.05 mg/kg/injection (total dose was 0.15 mg/kg). The data were analyzed statistically using t-test. Signal change after administration of diazepam was less than 1 to 2% in healthy volunteers. By contrast, in patient with epilepsy, the signal change was almost 3%, which was significantly greater than that of the normal area (p=0.01). The neuro-pharmacological functional MRI technique using diazepam might be a useful method to identify epileptic foci. (author)

  2. Neuro-pharmacological functional MRI of epilepsy

    International Nuclear Information System (INIS)

    Kiriyama, Hideki; Makabe, Tetsuo; Tomita, Susumu; Omoto, Takashi; Asari, Shoji; Aihara, Hiroshi; Kinugasa, Kazushi; Nishimoto, Akira; Ito, Takahiko

    2000-01-01

    We studied patients with epilepsy by neuro-pharmacological functional MRI technique using diazepam. Five normal volunteers and 7 patients with epilepsy were investigated. MRI was performed by a 1.5 T unit (SIGNA Horizon, GE) using the following parameters: TR/TE 5000 msec/80 msec, FA 90 deg, FOV 200 mm, matrix 128 x 128, slice thickness 7 mm. We performed MRI scanning over 5 minutes (2 minutes before and 3 minutes after injection of diazepam) for each 1 session; we scanned 3 sessions for each patient at intervals of 5 minutes. The diazepam was injected rapidly from the antecubital vein. The dose of diazepam was 0.05 mg/kg/injection (total dose was 0.15 mg/kg). The data were analyzed statistically using t-test. Signal change after administration of diazepam was less than 1 to 2% in healthy volunteers. By contrast, in patient with epilepsy, the signal change was almost 3%, which was significantly greater than that of the normal area (p=0.01). The neuro-pharmacological functional MRI technique using diazepam might be a useful method to identify epileptic foci. (author)

  3. Clinical functional MRI. Persurgical functional neuroimaging. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Stippich, Christoph (ed.) [Univ. Hospitals Basel (Switzerland). Division of Diagnostic and Inventional Neuroradiology

    2015-06-01

    The second, revised edition of this successful textbook provides an up-to-date description of the use of preoperative fMRI in patients with brain tumors and epilepsies. State of the art fMRI procedures are presented, with detailed consideration of practical aspects, imaging and data processing, normal and pathological findings, and diagnostic possibilities and limitations. Relevant information on brain physiology, functional neuroanatomy, imaging technique, and methodology is provided by recognized experts in these fields. Compared with the first edition, chapters have been updated to reflect the latest developments and in particular the current use of diffusion tensor imaging (DTI) and resting-state fMRI. Entirely new chapters are included on resting-state presurgical fMRI and the role of DTI and tractography in brain tumor surgery. Further chapters address multimodality functional neuroimaging, brain plasticity, and pitfalls, tips, and tricks.

  4. Imaging tools to study pharmacology: functional MRI on small rodents

    Directory of Open Access Journals (Sweden)

    Elisabeth eJonckers

    2015-10-01

    Full Text Available 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 sensory stimulation and/or a pharmacological challenge. The first part of this review describes the physiological basis of BOLD fMRI and the hemodynamic response on which the MRI contrast is based. Specific emphasis goes to possible effects of anaesthesia and the animal’s physiological conditions on neural activity and the hemodynamic response. The second part of this review describes applications of the aforementioned techniques in pharmacologically-induced, as well as in traumatic and transgenic disease models and illustrates how multiple fMRI methods can be applied successfully to evaluate different aspects of a specific disorder. For example, fMRI techniques can be used to pinpoint the neural substrate of a disease beyond previously defined hypothesis-driven regions-of-interest (ROIs. In addition, fMRI techniques allow one to dissect how specific modifications (e.g. treatment, lesion etc. modulate the functioning of specific brain areas (st-fMRI, phMRI and how functional connectivity (rsfMRI between several brain regions is affected, both in acute and extended time frames. Furthermore, fMRI techniques can be used to assess/explore the efficacy of novel treatments in depth, both in fundamental research as well as in preclinical settings. In conclusion, by describing several exemplary studies, we aim to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with

  5. Functional MRI for planning in neurosurgery

    International Nuclear Information System (INIS)

    Erb, M.; Saur, R.

    2007-01-01

    Beside structural images from CT and MR, functional data about localization of brain activations with different tasks becomes more and more important for presurgical planning. With this method, it's possible to depict mainly primary sensory and motoric areas, but also higher functions like speech and memory. To judge this information adequately, one has to be aware of the variability of activation pattern dependent on chosen threshold. Especially, the absence of such activation at a given location does not necessary mean that this area has no function. The reliability of a measurement strongly depends on efficiency of experimental design and cooperation of the patient. Therefore, short and easy tasks which can be performed in a block design should be preferred. Information about localization of functions determined by fMRI can mainly be used for presurgical planning. Intraoperative usage in the navigation system is problematic due to the brain shift. Therefore, intraoperative imaging together with dynamic adaptation using nonlinear deformation algorithms may improve the value of fMRI in the future. (orig.)

  6. ORIGINAL ARTICLE CASE REPORT Functional MRI in pre-surgical ...

    African Journals Online (AJOL)

    cognitive task. The number of publications using fMRI has increased exponentially1 since the technique was first introduced over 20 years ago.2 A PubMed search using the keywords 'fMRI OR ('functional. MRI')' at ..... Picht T, Kombos T, Gramm HJ, Brock M, Suess O. Multimodal protocol for awake craniotomy in language.

  7. IClinfMRI Software for Integrating Functional MRI Techniques in Presurgical Mapping and Clinical Studies.

    Science.gov (United States)

    Hsu, Ai-Ling; Hou, Ping; Johnson, Jason M; Wu, Changwei W; Noll, Kyle R; Prabhu, Sujit S; Ferguson, Sherise D; Kumar, Vinodh A; Schomer, Donald F; Hazle, John D; Chen, Jyh-Horng; Liu, Ho-Ling

    2018-01-01

    Task-evoked and resting-state (rs) functional magnetic resonance imaging (fMRI) techniques have been applied to the clinical management of neurological diseases, exemplified by presurgical localization of eloquent cortex, to assist neurosurgeons in maximizing resection while preserving brain functions. In addition, recent studies have recommended incorporating cerebrovascular reactivity (CVR) imaging into clinical fMRI to evaluate the risk of lesion-induced neurovascular uncoupling (NVU). Although each of these imaging techniques possesses its own advantage for presurgical mapping, a specialized clinical software that integrates the three complementary techniques and promptly outputs the analyzed results to radiology and surgical navigation systems in a clinical format is still lacking. We developed the Integrated fMRI for Clinical Research (IClinfMRI) software to facilitate these needs. Beyond the independent processing of task-fMRI, rs-fMRI, and CVR mapping, IClinfMRI encompasses three unique functions: (1) supporting the interactive rs-fMRI mapping while visualizing task-fMRI results (or results from published meta-analysis) as a guidance map, (2) indicating/visualizing the NVU potential on analyzed fMRI maps, and (3) exporting these advanced mapping results in a Digital Imaging and Communications in Medicine (DICOM) format that are ready to export to a picture archiving and communication system (PACS) and a surgical navigation system. In summary, IClinfMRI has the merits of efficiently translating and integrating state-of-the-art imaging techniques for presurgical functional mapping and clinical fMRI studies.

  8. IClinfMRI Software for Integrating Functional MRI Techniques in Presurgical Mapping and Clinical Studies

    Directory of Open Access Journals (Sweden)

    Ai-Ling Hsu

    2018-03-01

    Full Text Available Task-evoked and resting-state (rs functional magnetic resonance imaging (fMRI techniques have been applied to the clinical management of neurological diseases, exemplified by presurgical localization of eloquent cortex, to assist neurosurgeons in maximizing resection while preserving brain functions. In addition, recent studies have recommended incorporating cerebrovascular reactivity (CVR imaging into clinical fMRI to evaluate the risk of lesion-induced neurovascular uncoupling (NVU. Although each of these imaging techniques possesses its own advantage for presurgical mapping, a specialized clinical software that integrates the three complementary techniques and promptly outputs the analyzed results to radiology and surgical navigation systems in a clinical format is still lacking. We developed the Integrated fMRI for Clinical Research (IClinfMRI software to facilitate these needs. Beyond the independent processing of task-fMRI, rs-fMRI, and CVR mapping, IClinfMRI encompasses three unique functions: (1 supporting the interactive rs-fMRI mapping while visualizing task-fMRI results (or results from published meta-analysis as a guidance map, (2 indicating/visualizing the NVU potential on analyzed fMRI maps, and (3 exporting these advanced mapping results in a Digital Imaging and Communications in Medicine (DICOM format that are ready to export to a picture archiving and communication system (PACS and a surgical navigation system. In summary, IClinfMRI has the merits of efficiently translating and integrating state-of-the-art imaging techniques for presurgical functional mapping and clinical fMRI studies.

  9. EEG correlates of visual short-term memory in older age vary with adult lifespan cognitive development.

    Science.gov (United States)

    Wiegand, Iris; Lauritzen, Martin J; Osler, Merete; Mortensen, Erik Lykke; Rostrup, Egill; Rask, Lene; Richard, Nelly; Horwitz, Anna; Benedek, Krisztina; Vangkilde, Signe; Petersen, Anders

    2018-02-01

    Visual short-term memory (vSTM) is a cognitive resource that declines with age. This study investigated whether electroencephalography (EEG) correlates of vSTM vary with cognitive development over individuals' lifespan. We measured vSTM performance and EEG in a lateralized whole-report task in a healthy birth cohort, whose cognitive function (intelligence quotient) was assessed in youth and late-middle age. Higher vSTM capacity (K; measured by Bundesen's theory of visual attention) was associated with higher amplitudes of the contralateral delay activity (CDA) and the central positivity (CP). In addition, rightward hemifield asymmetry of vSTM (K λ ) was associated with lower CDA amplitudes. Furthermore, more severe cognitive decline from young adulthood to late-middle age predicted higher CDA amplitudes, and the relationship between K and the CDA was less reliable in individuals who show higher levels of cognitive decline compared to individuals with preserved abilities. By contrast, there was no significant effect of lifespan cognitive changes on the CP or the relationship between behavioral measures of vSTM and the CP. Neither the CDA, nor the CP, nor the relationships between K or K λ and the event-related potentials were predicted by individuals' current cognitive status. Together, our findings indicate complex age-related changes in processes underlying behavioral and EEG measures of vSTM and suggest that the K-CDA relationship might be a marker of cognitive lifespan trajectories. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Ultradian and circadian modulation of dream recall: EEG correlates and age effects.

    Science.gov (United States)

    Chellappa, Sarah Laxhmi; Cajochen, Christian

    2013-08-01

    Dreaming occurs during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, which both are regulated by homeostatic, ultradian, and circadian processes. However, the magnitude of how ultradian REM and NREM sleep and its EEG correlates impact onto dream recall remains fairly unknown. In this review, we address three questions: 1. Is there an ultradian NREM-REM sleep modulation in successful dream recall, which is gated by the circadian clock? 2. What are the key electrophysiological correlates that account for dream recall during NREM and REM sleep and 3. Are there age-related changes in the ultradian and circadian regulation in dream recall and its electrophysiological correlates? Knowledge on the specific frequency and topography NREM and REM sleep differences prior to dream recall may pinpoint to the cerebral correlates that account for this cognitive process, and hint to their possible physiological meaning. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Functional MRI of Language Processing and Recovery

    NARCIS (Netherlands)

    C. Méndez Orellana (Carolina)

    2015-01-01

    markdownabstract__Abstract__ My thesis describe the utility of implementing fMRI to investigate how the language system is reorganized in brain damaged patients. Specifically for aphasia research fMRI allows to show how specific language treatment methods have the potential to enhance language

  12. Quantitation of global and regional left ventricular function by MRI

    NARCIS (Netherlands)

    van der Geest, RJ; Reiber, JHC; Reiber, JHC; VanDerWall, EE

    1998-01-01

    Magnetic resonance imaging (MRI) provides several imaging strategies for assessing left ventricular function. As a three-dimensional imaging technique, all measurements can be performed without relying on geometrical assumptions. Global and regional function parameters can be derived from

  13. Diagnostic functional MRI: illustrated clinical applications and decision-making.

    Science.gov (United States)

    Bartsch, Andreas Joachim; Homola, György; Biller, Armin; Solymosi, László; Bendszus, Martin

    2006-06-01

    Functional magnetic resonance imaging (fMRI) has become a popular research tool, yet its use for diagnostic purposes and actual treatment planning has remained less widespread. The literature yields rather sparse evidence-based data on clinical fMRI applications and accordant decision-making. Notwithstanding, blood oxygenation level dependent (BOLD)- and arterial spin labeling (ASL)-fMRI can be judiciously combined with perfusion measurements, electroencephalographic (EEG) recordings, diffusion-weighted imaging (DWI), and fiber tractographies to assist clinical decisions. In this article we provide an overview of clinical fMRI applications based on illustrative examples. Assessment of cochlear implant candidates by fMRI is covered in some detail, and distinct reference is made to particular challenges imposed by brain tumors, other space-occupying lesions, cortical dysplasias, seizure disorders, and vascular malformations. Specific strategies, merits, and pitfalls of analyzing and interpreting diagnostic fMRI studies in individual patients are highlighted. Copyright 2006 Wiley-Liss, Inc.

  14. Hippocampal EEG and behaviour in dog. III. Hippocampal EEG correlates of stimulus-response tasks and of sexual behaviour

    NARCIS (Netherlands)

    Arnolds, D.E.A.T.; Lopes da Silva, F.H.; Aitink, J.W.; Kamp, A.

    A dog was trained to perform a spatial sound discrimination. The hippocampal EEG correlates and the movement correlates of correct trials were compared with those of incorrect trials and of ‘pressings in between’. Correct and wrong responses on a place learning task were compared both with

  15. Functional MRI language mapping in pre-surgical epilepsy patients ...

    African Journals Online (AJOL)

    Background. Functional magnetic resonance imaging (fMRI) is commonly applied to study the neural substrates of language in clinical research and for neurosurgical planning. fMRI language mapping is used to assess language lateralisation, or determine hemispheric dominance, and to localise regions of the brain ...

  16. Event-related functional MRI: implications for cognitive psychology.

    Science.gov (United States)

    D'Esposito, M; Zarahn, E; Aguirre, G K

    1999-01-01

    Functional magnetic resonance imaging (fMRI) has rapidly emerged as a powerful technique in cognitive neuroscience. We describe and critique a new class of imaging experimental designs called event-related fMRI that exploit the temporal resolution of fMRI by modeling fMRI signal changes associated with behavioral trials as opposed to blocks of behavioral trials. Advantages of this method over block designs include the ability to (a) randomize trial presentations, (b) test for functional correlates of behavioral measures with greater power, (c) directly examine the neural correlates of temporally dissociable components of behavioral trials (e.g., the delay period of a working memory task), and (d) test for differences in the onset time of neural activity evoked by different trial types. Consequently, event-related fMRI has the potential to address a number of cognitive psychology questions with a degree of inferential and statistical power not previously available.

  17. MRI of neuronal network structure, function, and plasticity.

    Science.gov (United States)

    Voss, Henning U; Schiff, Nicholas D

    2009-01-01

    We review two complementary MRI imaging modalities to characterize structure and function of neuronal networks in the human brain, and their application to subjects with severe brain injury. The structural imaging modality, diffusion tensor imaging, is based on imaging the diffusion of water protons in the brain parenchyma. From the diffusion tensor, several quantities characterizing fiber structure in the brain can be derived. The principal direction of the diffusion tensor has been found to depend on the fiber direction of myelinated axons. It can be used for white matter fiber tracking. The anisotropy (or directional dependence) of diffusion has been shown to be sensitive to developmental as well as white matter changes during training and recovery from brain injury. The functional MRI imaging modality, resting state fMRI, concerns the functional connectivity of neuronal networks rather than their anatomical structure. Subjects undergo a conventional fMRI imaging protocol without performing specific tasks. Various resting state network patterns can be computed by algorithms that reveal correlations in the fMRI signal. Often, thalamic structures are involved, suggesting that resting state fMRI could reflect global brain network functionality. Clinical applications of resting state fMRI have been reported, in particular relating signal abnormalities to neurodegenerative processes. To better understand to which degree resting state patterns reflect neuronal network function, we are comparing network patterns of normal subjects with those having severe brain lesions in a small pilot study.

  18. EEG correlates of social interaction at distance [version 5; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    William Giroldini

    2016-02-01

    Full Text Available This study investigated EEG correlates of social interaction at distance between twenty-five pairs of participants who were not connected by any traditional channels of communication. Each session involved the application of 128 stimulations separated by intervals of random duration ranging from 4 to 6 seconds. One of the pair received a one-second stimulation from a light signal produced by an arrangement of red LEDs, and a simultaneous 500 Hz sinusoidal audio signal of the same length. The other member of the pair sat in an isolated sound-proof room, such that any sensory interaction between the pair was impossible. An analysis of the Event-Related Potentials associated with sensory stimulation using traditional averaging methods showed a distinct peak at approximately 300 ms, but only in the EEG activity of subjects who were directly stimulated. However, when a new algorithm was applied to the EEG activity based on the correlation between signals from all active electrodes, a weak but robust response was also detected in the EEG activity of the passive member of the pair, particularly within 9 – 10 Hz in the Alpha range. Using the Bootstrap method and the Monte Carlo emulation, this signal was found to be statistically significant.

  19. Absence of EEG correlates of self-referential processing depth in ALS.

    Directory of Open Access Journals (Sweden)

    Tatiana Fomina

    Full Text Available Self-referential processing is a key cognitive process, associated with the serotonergic system and the default mode network (DMN. Decreased levels of serotonin and reduced activations of the DMN observed in amyotrophic lateral sclerosis (ALS suggest that self-referential processing might be altered in patients with ALS. Here, we investigate the effects of ALS on the electroencephalography correlates of self-referential thinking. We find that electroencephalography (EEG correlates of self-referential thinking are present in healthy individuals, but not in those with ALS. In particular, thinking about themselves or others significantly modulates the bandpower in the medial prefrontal cortex in healthy individuals, but not in ALS patients. This finding supports the view of ALS as a complex multisystem disorder which, as shown here, includes dysfunctional processing of the medial prefrontal cortex. It points towards possible alterations of self-consciousness in ALS patients, which might have important consequences for patients' self-conceptions, personal relations, and decision-making.

  20. 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

  1. Functional imaging of the kidneys with fast MRI techniques

    International Nuclear Information System (INIS)

    Prasad, P.V.; Priatna, A.

    1999-01-01

    Availability of faster and stronger gradient systems have given rise to a multitude of fast MRI data acquisition strategies which have tremendously increased the scope of MRI applications. These have led to the realization of long desired comprehensive approaches to evaluate anatomy and function using a single modality. In this work, we describe some of our own experiences with functional evaluation of the kidneys using MRI. Examples that suggest the feasibility of comprehensive approaches for evaluation of renal disease are also provided. We also introduce BOLD renal MRI, a method that may allow basic understanding of human renal physiology and pathophysiology in a way that has not been previously possible. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. 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.)

  3. Methodological Improvements in Combining TMS and Functional MRI

    OpenAIRE

    Moisa, Marius

    2011-01-01

    Since 1997, when Bohning and colleagues demonstrated for the first time the feasibility of interleaving transcranial magnetic stimulation (TMS) with blood oxygenation level dependency functional magnetic resonance imaging (BOLD fMRI), this combination became a very promising techniques to study brain connectivity. However, the implementation of a reliable setup for interleaved TMS/fMRI is still technically challenging. In this thesis, I intended to further explore and develop methodological i...

  4. Clinical application of functional MRI for chronic epilepsy

    International Nuclear Information System (INIS)

    Woermann, F.G.; Labudda, K.

    2010-01-01

    Functional magnetic resonance imaging (fMRI) is frequently used in the presurgical diagnostic procedure of epilepsy patients, in particular for lateralization of speech and memory and for localization of the primary motor cortex to delineate the epileptogenic lesion from eloquent brain areas. fMRI is one of the non-invasive procedures in the presurgical diagnostic process, together with medical history, seizure semiology, neurological examination, interictal and ictal EEG, structural MRI, video EEG monitoring and neuropsychology. This diagnostic sequence leads either to the decision for or against elective epilepsy surgery or to the decision to proceed with invasive diagnostic techniques (Wada test, intra-operative or extra-operative cortical stimulation). It is difficult to evaluate the contribution of the fMRI test in isolation to the validity of the entire diagnostic sequence. Complications such as memory loss and aphasia in temporal lobe resections or paresis after frontal lobe resections are rare and rarely of disastrous extent. This further complicates the evaluation of the clinical relevance of fMRI as a predictive tool. In this article studies which investigated the concordance between fMRI and other diagnostic gold standards will be presented as well as the association between presurgical fMRI and postsurgical morbidity. (orig.) [de

  5. 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

  6. Functional MRI-based lie detection: scientific and societal challenges.

    Science.gov (United States)

    Farah, Martha J; Hutchinson, J Benjamin; Phelps, Elizabeth A; Wagner, Anthony D

    2014-02-01

    Functional MRI (fMRI)-based lie detection has been marketed as a tool for enhancing personnel selection, strengthening national security and protecting personal reputations, and at least three US courts have been asked to admit the results of lie detection scans as evidence during trials. How well does fMRI-based lie detection perform, and how should the courts, and society more generally, respond? Here, we address various questions — some of which are based on a meta-analysis of published studies — concerning the scientific state of the art in fMRI-based lie detection and its legal status, and discuss broader ethical and societal implications. We close with three general policy recommendations.

  7. Fuzzy cluster analysis of high-field functional MRI data.

    Science.gov (United States)

    Windischberger, Christian; Barth, Markus; Lamm, Claus; Schroeder, Lee; Bauer, Herbert; Gur, Ruben C; Moser, Ewald

    2003-11-01

    Functional magnetic resonance imaging (fMRI) based on blood-oxygen level dependent (BOLD) contrast today is an established brain research method and quickly gains acceptance for complementary clinical diagnosis. However, neither the basic mechanisms like coupling between neuronal activation and haemodynamic response are known exactly, nor can the various artifacts be predicted or controlled. Thus, modeling functional signal changes is non-trivial and exploratory data analysis (EDA) may be rather useful. In particular, identification and separation of artifacts as well as quantification of expected, i.e. stimulus correlated, and novel information on brain activity is important for both, new insights in neuroscience and future developments in functional MRI of the human brain. After an introduction on fuzzy clustering and very high-field fMRI we present several examples where fuzzy cluster analysis (FCA) of fMRI time series helps to identify and locally separate various artifacts. We also present and discuss applications and limitations of fuzzy cluster analysis in very high-field functional MRI: differentiate temporal patterns in MRI using (a) a test object with static and dynamic parts, (b) artifacts due to gross head motion artifacts. Using a synthetic fMRI data set we quantitatively examine the influences of relevant FCA parameters on clustering results in terms of receiver-operator characteristics (ROC) and compare them with a commonly used model-based correlation analysis (CA) approach. The application of FCA in analyzing in vivo fMRI data is shown for (a) a motor paradigm, (b) data from multi-echo imaging, and (c) a fMRI study using mental rotation of three-dimensional cubes. We found that differentiation of true "neural" from false "vascular" activation is possible based on echo time dependence and specific activation levels, as well as based on their signal time-course. Exploratory data analysis methods in general and fuzzy cluster analysis in particular may

  8. 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.

  9. [EEG-correlates of pilots' functional condition in simulated flight dynamics].

    Science.gov (United States)

    Kiroy, V N; Aslanyan, E V; Bakhtin, O M; Minyaeva, N R; Lazurenko, D M

    2015-01-01

    The spectral characteristics of the EEG recorded on two professional pilots in the simulator TU-154 aircraft in flight dynamics, including takeoff, landing and horizontal flight (in particular during difficult conditions) were analyzed. EEG recording was made with frequency band 0.1-70 Hz continuously from 15 electrodes. The EEG recordings were evaluated using analysis of variance and discriminant analysis. Statistical significant of the identified differences and the influence of the main factors and their interactions were evaluated using Greenhouse - Gaiser corrections. It was shown that the spectral characteristics of the EEG are highly informative features of the state of the pilots, reflecting the different flight phases. High validity ofthe differences including individual characteristic, indicates their non-random nature and the possibility of constructing a system of pilots' state control during all phases of flight, based on EEG features.

  10. Functional MRI in awake unrestrained dogs.

    Directory of Open Access Journals (Sweden)

    Gregory S Berns

    Full Text Available Because of dogs' prolonged evolution with humans, many of the canine cognitive skills are thought to represent a selection of traits that make dogs particularly sensitive to human cues. But how does the dog mind actually work? To develop a methodology to answer this question, we trained two dogs to remain motionless for the duration required to collect quality fMRI images by using positive reinforcement without sedation or physical restraints. The task was designed to determine which brain circuits differentially respond to human hand signals denoting the presence or absence of a food reward. Head motion within trials was less than 1 mm. Consistent with prior reinforcement learning literature, we observed caudate activation in both dogs in response to the hand signal denoting reward versus no-reward.

  11. MRI in Optic Neuritis: Structure, Function, Interactions

    DEFF Research Database (Denmark)

    Fuglø, Dan

    2011-01-01

    Optic neuritis (ON) is an acute inflammatory demyelinating condition of the optic nerve characterised by transient visual loss and eye pain. ON is the presenting symptom in 20% of patients with multiple sclerosis (MS) and the 15 year risk of developing MS after ON is about 50%. Decline in vision...... usually occurs over several days and is accompanied by eye pain. Patients start to recover 2 to 4 weeks after onset and most of the recovery typically occurs within 6 months. However, despite clinical recovery, patients develop atrophy of the optic nerve, which has been demonstrated using magnetic...... of the damage to the afferent visual pathway is needed. Optical coherence tomography (OCT) is a tissue imaging technique capable of measuring the RNFL thickness around the optic disc. We investigated the correlation between optic nerve lesion length, the RNFL thickness and the fMRI response in a group of 41...

  12. Functional MRI: Genesis, State of the art and the Sequel

    International Nuclear Information System (INIS)

    Bharath, Rose Dawn

    2014-01-01

    The last 25 years have seen functional magnetic resonance imaging (fMRI) grow from an interesting experimental imaging technique in the hands of some to a primary investigation of choice in the localization and lateralization of brain function prior to surgery. Developments in the field of computational neurosciences have transformed fMRI analysis from classical subtractive type analysis to dynamic casual modeling, and now to graph theory analysis. This has widened the scope of fMRI, and is therefore finding applications in understanding neural correlates of diseases like autism and Alzheimer's disease, prognostication of diseases like traumatic brain injury, and has the potential to direct therapy. It is unfortunately true that this widened ambit has not received the clinical attention it deserves, probably because fMRI is susceptible to artifacts from skull base and blood products and has reduced sensitivity in patients with vascular malformations, or because a change in medical practice usually lags behind the technological and scientific developments that make it possible. This review focuses on the developmental chronology of fMRI image analysis in the last 25 years with highlights on major milestones like developments in the field of paradigms, analysis methods, resting state fMRI, and functional connectivity. To make the statistical images of brain at work more colorful, the article starts with genesis of fMRI and ends with the hope of a promising bright future. Many inputs for this article are obtained from a series of 103 review articles edited by Bandettini et al., compiling personal experiences of pioneers in this field. Interested readers are encouraged to refer to these for a more complete overview.

  13. Research progress of BOLD-functional MRI of hepatic encephalopathy

    International Nuclear Information System (INIS)

    Ni Ling; Zhang Longjiang; Lu Guangming

    2013-01-01

    Hepatic encephalopathy (HE), characterized by a wide spectrum of clinical manifestations, ranging from behavior abnormality, conscious disorder and even coma, is a consequence of liver dysfunction in both acute and chronic hepatic diseases. Minimal hepatic encephalopathy (MHE) refers to a subgroup of cirrhotic patients without clinical overt hepatic encephalopathy symptoms hut with abnormalities in neuro -cognitive functions. HE/MHE can have a far-reaching impact on quality of life and prognosis. The exact neuropathology mechanism was still unclear. Recently, functional MRI (fMRI) has been increasingly applied for investigating the neuro-pathophysiological mechanism of HE. This paper will review the fMRI research applied on uncovering the neuropathology mechanism of HE. (authors)

  14. Functional MRI of the placenta – From rodents to humans

    Science.gov (United States)

    Avni, R.; Neeman, M.; Garbow, J.R.

    2015-01-01

    The placenta performs a wide range of physiological functions; insufficiencies in these functions may result in a variety of severe prenatal and postnatal syndromes with long-term negative impacts on human adult health. Recent advances in magnetic resonance imaging (MRI) studies of placental function, in both animal models and humans, have contributed significantly to our understanding of placental structure, blood flow, oxygenation status, and metabolic profile, and have provided important insights into pregnancy complications. PMID:25916594

  15. An Introduction to Normalization and Calibration Methods in Functional MRI

    Science.gov (United States)

    Liu, Thomas T.; Glover, Gary H.; Mueller, Bryon A.; Greve, Douglas N.; Brown, Gregory G.

    2013-01-01

    In functional magnetic resonance imaging (fMRI), the blood oxygenation level dependent (BOLD) signal is often interpreted as a measure of neural activity. However, because the BOLD signal reflects the complex interplay of neural, vascular, and metabolic processes, such an interpretation is not always valid. There is growing evidence that changes…

  16. Functional MRI of human hypothalamic responses following glucose ingestion

    NARCIS (Netherlands)

    Smeets, P.A.M.; Graaf, C. de; Stafleu, A.; Osch, M.J.P. van; Grond, J. van der

    2005-01-01

    The hypothalamus is intimately involved in the regulation of food intake, integrating multiple neural and hormonal signals. Several hypothalamic nuclei contain glucose-sensitive neurons, which play a crucial role in energy homeostasis. Although a few functional magnetic resonance imaging (fMRI)

  17. Cortical language activation in aphasia: a functional MRI study

    International Nuclear Information System (INIS)

    Xu Xiaojun; Zhang Minming; Shang Desheng; Wang Qidong; Luo Benyan

    2004-01-01

    Objective: To investigate the differences of the underlying neural basis of language processing between normal subjects and aphasics, and to study the feasibility for functional magnetic resonance imaging (fMRI) in examining the cortical language activation in clinical aphasics. Methods: fMRI was used to map language network in 6 normal subjects and 3 patients with aphasia who were in the stage of recovery from acute stroke. The participants performed word generation task during fMRI scanning, which measured the signal changes associated with regional neural activity induced by the task. These signal changes were processed to statistically generate the activation map that represented the language area. Results: In normal subjects, a distributed language network was activated. Activations were present in the frontal, temporal, parietal and occipital regions in normal group. In the patient group, however, no activation was showed in the left inferior frontal gyrus whether or not the patient had lesion in the left frontal lobe. Two patients showed activations in some right hemisphere regions where no activation appeared in normal subjects. Conclusion: The remote effect of focal lesion and functional redistribution or reorganization was found in aphasic patients. fMRI was useful in evaluating the language function in aphasic patients. (authors)

  18. Attention, in and Out: Scalp-Level and Intracranial EEG Correlates of Interoception and Exteroception

    Science.gov (United States)

    García-Cordero, Indira; Esteves, Sol; Mikulan, Ezequiel P.; Hesse, Eugenia; Baglivo, Fabricio H.; Silva, Walter; García, María del Carmen; Vaucheret, Esteban; Ciraolo, Carlos; García, Hernando S.; Adolfi, Federico; Pietto, Marcos; Herrera, Eduar; Legaz, Agustina; Manes, Facundo; García, Adolfo M.; Sigman, Mariano; Bekinschtein, Tristán A.; Ibáñez, Agustín; Sedeño, Lucas

    2017-01-01

    Interoception, the monitoring of visceral signals, is often presumed to engage attentional mechanisms specifically devoted to inner bodily sensing. In fact, most standardized interoceptive tasks require directing attention to internal signals. However, most studies in the field have failed to compare attentional modulations between internally- and externally-driven processes, thus probing blind to the specificity of the former. Here we address this issue through a multidimensional approach combining behavioral measures, analyses of event-related potentials and functional connectivity via high-density electroencephalography, and intracranial recordings. In Study 1, 50 healthy volunteers performed a heartbeat detection task as we recorded modulations of the heartbeat-evoked potential (HEP) in three conditions: exteroception, basal interoception (also termed interoceptive accuracy), and post-feedback interoception (sometimes called interoceptive learning). In Study 2, to evaluate whether key interoceptive areas (posterior insula, inferior frontal gyrus, amygdala, and somatosensory cortex) were differentially modulated by externally- and internally-driven processes, we analyzed human intracranial recordings with depth electrodes in these regions. This unique technique provides a very fine grained spatio-temporal resolution compared to other techniques, such as EEG or fMRI. We found that both interoceptive conditions in Study 1 yielded greater HEP amplitudes than the exteroceptive one. In addition, connectivity analysis showed that post-feedback interoception, relative to basal interoception, involved enhanced long-distance connections linking frontal and posterior regions. Moreover, results from Study 2 showed a differentiation between oscillations during basal interoception (broadband: 35–110 Hz) and exteroception (1–35 Hz) in the insula, the amygdala, the somatosensory cortex, and the inferior frontal gyrus. In sum, this work provides convergent evidence for the

  19. Combination of functional MRI with SAS and MRA

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, Masayuki; Takeshita, Shinichirou; Kutsuna, Munenori; Akimitsu, Tomohide; Arita, Kazunori; Kurisu, Kaoru [Hiroshima Univ. (Japan). School of Medicine

    1999-02-01

    For presurgical diagnosis of brain surface, combination of functional MRI (fMRI) with the MR angiography was examined. This method could visualize brain bay, convolution and vein as index of surface. Five normal adults (male, mean age: 28-year-old) and 7 patients with brain tumor on the main locus to surface (male: 4, female: 3, mean age: 52.3-year-old) were studied. fMRI was performed by SPGR method (TR 70, TE 40, flip angle 60, one slice, thickness 10 mm, FOV 20 cm, matrix 128 x 128). The brain surface was visualized by SAS (surface anatomy scanning). SAS was performed by FSE method (TR 6000, TE 200, echo train 16, thickness 20 mm, slice 3, NEX 2). Cortical veins near superior sagittal sinus were visualized by MRA with 2D-TOF method (TR 50, TE 20, flip angle 60, thickness 2 mm, slice 28, NEX 1). These images were superimposed and functional image of peripheral sensorimotor region was evaluated anatomically. In normal adults, high signal was visualized at another side of near sensorimotor region at 8 of 10 sides. All high signal area of fMRI agreed with cortical vein near sensorimotor region that was visualized by MRA. In patients with brain tumor, signal was visualized at another side of sensorimotor region of tumor without 2 cases with palsy. In another side of tumor, signal of fMRI was visualized in 5 of 7 cases. The tumor was visualized as opposite low signal field in SAS. Locational relation between tumor and brain surface and brain function was visualized distinctly by combination of MRA, SAS and MRA. This method could become useful for presurgical diagnosis. (K.H.)

  20. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery

    International Nuclear Information System (INIS)

    Bourgeois, G.; Magnin, M.; Morel, A.; Jeanmonod, D.; Sartoretti, S.; Huisman, T.; Tuncdogan, E.; Meier, D.

    1999-01-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy. (orig.)

  1. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, G.; Magnin, M.; Morel, A.; Jeanmonod, D. [Laboratory for Functional Neurosurgery, Neurosurgical Clinic, University Hospital, Zurich (Switzerland); Sartoretti, S.; Huisman, T.; Tuncdogan, E. [Department of Neuroradiology, University Hospital, Zurich (Switzerland); Meier, D. [Institute of Biomedical Engineering and Medical Informatics, University and ETH, Zurich (Switzerland)

    1999-09-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy. (orig.)

  2. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery.

    Science.gov (United States)

    Bourgeois, G; Magnin, M; Morel, A; Sartoretti, S; Huisman, T; Tuncdogan, E; Meier, D; Jeanmonod, D

    1999-09-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy.

  3. High spatial resolution compressed sensing (HSPARSE) functional MRI.

    Science.gov (United States)

    Fang, Zhongnan; Van Le, Nguyen; Choy, ManKin; Lee, Jin Hyung

    2016-08-01

    To propose a novel compressed sensing (CS) high spatial resolution functional MRI (fMRI) method and demonstrate the advantages and limitations of using CS for high spatial resolution fMRI. A randomly undersampled variable density spiral trajectory enabling an acceleration factor of 5.3 was designed with a balanced steady state free precession sequence to achieve high spatial resolution data acquisition. A modified k-t SPARSE method was then implemented and applied with a strategy to optimize regularization parameters for consistent, high quality CS reconstruction. The proposed method improves spatial resolution by six-fold with 12 to 47% contrast-to-noise ratio (CNR), 33 to 117% F-value improvement and maintains the same temporal resolution. It also achieves high sensitivity of 69 to 99% compared the original ground-truth, small false positive rate of less than 0.05 and low hemodynamic response function distortion across a wide range of CNRs. The proposed method is robust to physiological noise and enables detection of layer-specific activities in vivo, which cannot be resolved using the highest spatial resolution Nyquist acquisition. The proposed method enables high spatial resolution fMRI that can resolve layer-specific brain activity and demonstrates the significant improvement that CS can bring to high spatial resolution fMRI. Magn Reson Med 76:440-455, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  4. Functional MRI and neurophysiological aspects of obesity

    International Nuclear Information System (INIS)

    Sztrokay, A.; Reiser, M.; Meindl, T.; Gutyrchik, E.

    2011-01-01

    Functional magnetic resonance imaging studies have revealed that metabolic signals and food stimuli activate the mesocorticolimbic neural network involved in processing the reward system. Activation is influenced by obesity and hunger and many recent brain imaging studies have detected that food and drug stimuli activate many of the same reward circuits. These findings have implications for obesity prevention and therapy. Educational efforts need to be directed towards those at increased risk of becoming obese and the food industry has to be involved in providing and promoting healthier food options. Given that visual food stimuli are potent triggers of desire, seductive advertising of high calorie foods directed towards children should be curtailed. The application of non-invasive brain imaging methodologies to the study of hedonic and homeostatic eating behavior represents a novel and important experimental approach. Further advances in imaging technology and improved experimental designs will provide new and important insights into human ingestive behavior that may lead to new developments in behavioral and pharmacological therapies. (orig.) [de

  5. Inaudible functional MRI using a truly mute gradient echo sequence

    Energy Technology Data Exchange (ETDEWEB)

    Marcar, V.L. [University of Zurich, Department of Psychology, Neuropsychology, Treichlerstrasse 10, 8032 Zurich (Switzerland); Girard, F. [GE Medical Systems SA, 283, rue de la Miniere B.P. 34, 78533 Buc Cedex (France); Rinkel, Y.; Schneider, J.F.; Martin, E. [University Children' s Hospital, Neuroradiology and Magnetic Resonance, Department of Diagnostic Imaging, Steinwiesstrasse 75, 8032 Zurich (Switzerland)

    2002-11-01

    We performed functional MRI experiments using a mute version of a gradient echo sequence on adult volunteers using either a simple visual stimulus (flicker goggles: 4 subjects) or an auditory stimulus (music: 4 subjects). Because the mute sequence delivers fewer images per unit time than a fast echo planar imaging (EPI) sequence, we explored our data using a parametric ANOVA test and a non-parametric Wilcoxon-Mann-Whitney test in addition to performing a cross-correlation analysis. All three methods were in close agreement regarding the location of the BOLD contrast signal change. We demonstrated that, using appropriate statistical analysis, functional MRI using an MR sequence that is acoustically inaudible to the subject is feasible. Furthermore compared with the ''silent'' event-related procedures involving an EPI protocol, our mGE protocol compares favourably with respect to experiment time and the BOLD signal. (orig.)

  6. Congenital heart disease. Evaluation of anatomy and function by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Rebergen, S.A.; Roos, A. de [Dept. of Radiology, Leiden Univ. Medical Center, Leiden (Netherlands)

    2000-06-01

    With the increasing number of patients surviving after therapeutic intervention for congenital heart disease (CHD), accurate and frequent follow-up of their morphologic and functional cardiovascular status is required, preferably with a noninvasive imaging technique. Echocardiography, either transthoracic or transesophageal, has been the first choice for this purpose, and will probably keep that status, at least in a large segment of the CHD spectrum. Magnetic resonance imaging (MRI) is an established method for high-resolution visualization of cardiovascular morphology. In the past decade, newer MRI techniques have been developed that allow functional evaluation of CHD patients. Particularly the introduction of breath-hold imaging, contrast-enhanced MRA and user-friendly computer software for image analysis may move functional MRI of CHD from the science laboratory to clinical use. It is already evident that MRI is superior to echocardiography in certain areas of limited echocardiographic acces, such as the pulmonary artery branches and the aortic arch in adult patients. But MRI has also a unique potential for accurate volumetric analysis of ventricular function and cardiovascular blood flow, without any geometric assumptions. If supported by increased cooperation between cardiologists and radiologists, MRI will grow into a useful noninvasive imaging tool that, together with echocardiography, will obviate the need for invasive catheter studies for diagnostic purposes. (orig.) [German] Weltweit werden jaehrlich etwa 1,5 Millionen Kinder mit kongenitalen Herzerkrankungen (CHD, congenital heart disease) geboren. Durch Verbesserung der verschiedenen chirurgischen und interventionellen Techniken ist die Ueberlebensrate von CHD-Patienten drastisch gestiegen. Immer mehr Patienten mit postoperativen Residuen, Folgezustaenden und Komplikationen benoetigen eine umfassende Nachsorge. Die Darstellung und Quantifizierung morphologischer und funktioneller kardiovaskulaerer

  7. Functional MRI of the placenta--From rodents to humans.

    Science.gov (United States)

    Avni, R; Neeman, M; Garbow, J R

    2015-06-01

    The placenta performs a wide range of physiological functions; insufficiencies in these functions may result in a variety of severe prenatal and postnatal syndromes with long-term negative impacts on human adult health. Recent advances in magnetic resonance imaging (MRI) studies of placental function, in both animal models and humans, have contributed significantly to our understanding of placental structure, blood flow, oxygenation status, and metabolic profile, and have provided important insights into pregnancy complications. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Functional MRI in Patients with Intracranial Lesions near Language Areas.

    Science.gov (United States)

    Hakyemez, B; Erdogan, C; Yildirim, N; Bora, I; Bekar, A; Parlak, M

    2006-06-30

    We aimed to depict Broca's area and Wernicke's area by word generation and sentence formation paradigms in patients with various intracranial lesions adjacent to language areas using functional MRI technique and to evaluate the ability of functional MRI to lateralize the hemispheric dominance for language. Twenty-three right-handed patients were included in this study. Lesions were classified as low-grade glioma (n=8), high-grade glioma (n=9), metastasis (n=1), meningioma (n=1), arteriovenous malformation (n=2) and mesial temporal sclerosis (n=2). We performed blood-oxygenated-level-dependant functional MRI using a 1.5-T unit. Word generation and sentence formation tasks were used to activate language areas. Language areas were defined as Brodmann 44, 45 (Broca's area) and Brodmann 22 area (Wernicke's area). Laterality index was used to show the dominant hemisphere. Two poorly cooperative patients showed no activation and were excluded from the study. Broca's area was localized in 21 patients (100 %). Wernicke's area, on the other hand, could only be localized in eight of the 21 patients (38 %).The left hemisphere was dominant in 86% of patients while atypical language lateralization (right or bilateral) was demonstrated in 14% of the patients. Bilateral activation areas were shown in 10% of those patients while right cerebral hemisphere was dominant in 4% of the patients. Word generation and sentence formation tasks are especially helpful in localizing Broca's area. Wernicke's area could also be demonstrated in some of the cases. Functional MRI can be used as an important and useful means of demonstrating language areas in patients with lesions adjacent to those areas and depicting the hemispheric dominance.

  9. Comparative studies of brain activation with MEG and functional MRI

    International Nuclear Information System (INIS)

    George, J.S.; Aine, C.J.; Sanders, J.A.; Lewine, J.D.; Caprihan, A.

    1993-01-01

    The past two years have witnessed the emergence of MRI as a functional imaging methodology. Initial demonstrations involved the injection of a paramagnetic contrast agent and required ultrafast echo planar imaging capability to adequately resolve the passage of the injected bolus. By measuring the local reduction in image intensity due to magnetic susceptibility, it was possible to calculate blood volume, which changes as a function of neural activation. Later developments have exploited endogenous contrast mechanisms to monitor changes in blood volume or in venous blood oxygen content. Recently, we and others have demonstrated that it is possible to make such measurements in a clinical imager, suggesting that the large installed base of such machines might be utilized for functional imaging. Although it is likely that functional MRI (fMRI) will subsume some of the clinical and basic neuroscience applications now touted for MEG, it is also clear that these techniques offer different largely complementary, capabilities. At the very least, it is useful to compare and cross-validate the activation maps produced by these techniques. Such studies will be valuable as a check on results of neuromagnetic distributed current reconstructions and will allow better characterization of the relationship between neurophysiological activation and associated hemodynamic changes. A more exciting prospect is the development of analyses that combine information from the two modalities to produce a better description of underlying neural activity than is possible with either technique in isolation. In this paper we describe some results from initial comparative studies and outline several techniques that can be used to treat MEG and fMRI data within a unified computational framework

  10. High temporal resolution functional MRI using parallel echo volumar imaging

    International Nuclear Information System (INIS)

    Rabrait, C.; Ciuciu, P.; Ribes, A.; Poupon, C.; Dehaine-Lambertz, G.; LeBihan, D.; Lethimonnier, F.; Le Roux, P.; Dehaine-Lambertz, G.

    2008-01-01

    Purpose: To combine parallel imaging with 3D single-shot acquisition (echo volumar imaging, EVI) in order to acquire high temporal resolution volumar functional MRI (fMRI) data. Materials and Methods: An improved EVI sequence was associated with parallel acquisition and field of view reduction in order to acquire a large brain volume in 200 msec. Temporal stability and functional sensitivity were increased through optimization of all imaging parameters and Tikhonov regularization of parallel reconstruction. Two human volunteers were scanned with parallel EVI in a 1.5 T whole-body MR system, while submitted to a slow event-related auditory paradigm. Results: Thanks to parallel acquisition, the EVI volumes display a low level of geometric distortions and signal losses. After removal of low-frequency drifts and physiological artifacts,activations were detected in the temporal lobes of both volunteers and voxel-wise hemodynamic response functions (HRF) could be computed. On these HRF different habituation behaviors in response to sentence repetition could be identified. Conclusion: This work demonstrates the feasibility of high temporal resolution 3D fMRI with parallel EVI. Combined with advanced estimation tools,this acquisition method should prove useful to measure neural activity timing differences or study the nonlinearities and non-stationarities of the BOLD response. (authors)

  11. Joint compression-segmentation of functional MRI data sets

    Science.gov (United States)

    Zhang, Ning; Wu, Mo; Forchhammer, Soren; Wu, Xiaolin

    2005-04-01

    Functional Magnetic Resonance Imaging (fMRI) data sets are four dimensional (4D) and very large in size. Compression can enhance system performance in terms of storage and transmission capacities. Two approaches are investigated: adaptive DPCM and integer wavelets. In the DPCM approach, each voxel is coded as a 1D signal in time. Due to the spatial coherence of human anatomy and the similarities in responses of a given substance to stimuli, we classify the voxels by quantizing autoregressive coefficients of the associated time sequences. The resulting 2D classification map is sent as side information. Each voxel time sequence is DPCM coded using a quantized autoregressive model. The prediction residuals are coded by simple Rice coding for high decoder throughput. In the wavelet approach, the 4D fMRI data set is mapped to a 3D data set, with the 3D volume at each time instance being laid out into a 2D plane as a slice mosaic. 3D integer wavelet packets are used for lossless compression of fMRI data. The wavelet coefficients are compressed by 3D context-based adaptive arithmetic coding. An object-oriented compression mode is also introduced in the wavelet codec. An elliptic mask combined with the classification of the background is used to segment the regions of interest from the background. Significantly higher lossless compression of 4D fMRI than JPEG 2000 and JPEG-LS is achieved by both methods. The 2D classification map for compression can also be used for image segmentation in 3D space for analysis and recognition purposes. This segmentation supports object-based random access to very large 4D data volumes. The time sequence of DPCM prediction residuals can be analyzed to yield information on the responses of the imaged anatomy to the stimuli. The proposed wavelet method provides an object-oriented progressive (lossy to lossless) compression of 4D fMRI data set.

  12. Functional MRI studies in children with attention deficit hyperactivity disorder

    International Nuclear Information System (INIS)

    Zhang Lei; Jin Zhen; Zeng Yawei; Wang Yan; Zang Yufeng

    2004-01-01

    Objective: To investigate the brain activation map during Go-NoGo tasks in children with attention deficit hyperactivity disorder (ADHD) and matched controls using functional MRI. Methods: Block designed BOLD functional MRI scan covering the whole brain was performed on 10 boys having ADHD and 11 healthy boys. The 2 groups were matched by age, sex, and handedness. Executing advanced inhibitory Go-NoGo tasks served as stimuli for all subjects. The fMRI data was analyzed by SPM99 (Statistical Parametric Mapping) software with statistic t-test to generate the activation map. Results: (1) The normal children showed significant activations in left thalamus and right cingulate gyrus and fewer activations in right middle frontal gyrus during stimulate controlled Go task, but the children with ADHD showed less activations in left thalamus. (2) In response controlled Go task, the normal children showed activations in right insula, cingulate gyrus and left frontal gyrus, while the ADHD children showed lower power of response in the right middle frontal gyrus.(3) In NoGo task, right middle frontal gyrus was the dominant activated regions, and left anterior cingulate, left middle frontal gyrus and right thalamus also had some activations in normal children, while the activations of right prefrontal decreased and the thalamus increased in ADHD boys. Conclusion: In children with ADHD, some dysfunctional brain areas, mainly the prefrontal lobe and anterior cingulate gyrus were found. Thalamus was also involved according to the brain activation map

  13. Joint Compression-Segmentation of functional MRI Data

    DEFF Research Database (Denmark)

    Zhang, N.; Wu, Mo; Forchhammer, Søren

    2005-01-01

    and recognition purposes. This segmentation supports object-based random access to very large 4D data volumes. The time sequence of DPCM prediction residuals can be analyzed to yield information on the responses of the imaged anatomy to the stimuli. The proposed wavelet method provides an object......Functional Magnetic Resonance Imaging (fMRI) data sets are four dimensional (4D) and very large in size. Compression can enhance system performance in terms of storage and transmission capacities. Two approaches are investigated: adaptive DPCM and integer wavelets. In the DPCM approach, each voxel...... into a 2D plane as a slice mosaic. 3D integer wavelet packets are used for lossless compression of fMRI data. The wavelet coefficients are compressed by 3D context-based adaptive arithmetic coding. An object-oriented compression mode is also introduced in the wavelet codec. An elliptic mask combined...

  14. Incidental MRI Findings in Patients with Impaired Cognitive Function

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yoon Joon [Dept. of Radiology, College of Medicine, Inje University, Ilsan Paik Hospital, Goyang (Korea, Republic of)

    2013-01-15

    This study aims to evaluate the incidental findings on brain MRI of patients with cognitive function impairments. We analyzed magnetic resonance (MR) findings of 236 patients with decreased cognitive function. MR protocols include conventional T2 weighted axial images, fluid attenuated inversion recovery axial images, T1 weighted coronal 3-dimensional magnetization-prepared rapid acquisition of gradient echo and diffusion tensor images. We retrospectively evaluated the signal changes that suggest acute/subacute infarction and space occupying lesions which show mass effect. Incidental MR findings were seen in 16 patients. Nine patients (3.8%) showed increased signal intensity on trace map of diffusion tensor images suggesting acute/subacute infarctions. Space occupying lesions were detected in 7 patients, and 3 lesions (1.27%) had mass effect and edema and were considered clinically significant lesions that diminish cognitive functions. Several incidental MR findings were detected in patients with decreased cognitive function, and the incidence of aucte/subacute infarctions were higher. Proper evaluations of MRI in patients with impaired cognitive functions will be helpful in early detection and management of ischemic lesions and space occupying lesions.

  15. Quantitative evaluation of the reticuloendothelial system function with dynamic MRI.

    Directory of Open Access Journals (Sweden)

    Ting Liu

    Full Text Available To evaluate the reticuloendothelial system (RES function by real-time imaging blood clearance as well as hepatic uptake of superparamagnetic iron oxide nanoparticle (SPIO using dynamic magnetic resonance imaging (MRI with two-compartment pharmacokinetic modeling.Kinetics of blood clearance and hepatic accumulation were recorded in young adult male 01b74 athymic nude mice by dynamic T2* weighted MRI after the injection of different doses of SPIO nanoparticles (0.5, 3 or 10 mg Fe/kg. Association parameter, Kin, dissociation parameter, Kout, and elimination constant, Ke, derived from dynamic data with two-compartment model, were used to describe active binding to Kupffer cells and extrahepatic clearance. The clodrosome and liposome were utilized to deplete macrophages and block the RES function to evaluate the capability of the kinetic parameters for investigation of macrophage function and density.The two-compartment model provided a good description for all data and showed a low sum squared residual for all mice (0.27±0.03. A lower Kin, a lower Kout and a lower Ke were found after clodrosome treatment, whereas a lower Kin, a higher Kout and a lower Ke were observed after liposome treatment in comparison to saline treatment (P<0.005.Dynamic SPIO-enhanced MR imaging with two-compartment modeling can provide information on RES function on both a cell number and receptor function level.

  16. Functional MRI in schizophrenia. Diagnostics and therapy monitoring of cognitive deficits of schizophrenic patients by functional MRI

    International Nuclear Information System (INIS)

    Furtner, J.; Prayer, D.; Sachs, G.

    2010-01-01

    Cognitive impairments are core psychopathological components of the symptomatic of schizophrenic patients. These dysfunctions are generally related to attention, executive functions and memory. This report provides information on the importance of using functional magnetic resonance imaging (fMRI) for the diagnostics and therapy monitoring of the different subtypes of cognitive dysfunctions. Furthermore, it describes the typical differences in the activation of individual brain regions between schizophrenic patients and healthy control persons. This information should be helpful in identifying the deficit profile of each patient and create an individual therapy plan. (orig.) [de

  17. Considerations for Resting State Functional MRI and Functional Connectivity Studies in Rodents

    Directory of Open Access Journals (Sweden)

    Wen-Ju ePan

    2015-08-01

    Full Text Available Resting state functional MRI (rs-fMRI and functional connectivity mapping have become widely used tools in the human neuroimaging community and their use is rapidly spreading into the realm of rodent research as well. One of the many attractive features of rs-fMRI is that it is readily translatable from humans to animals and back again. Changes in functional connectivity observed in human studies can be followed by more invasive animal experiments to determine the neurophysiological basis for the alterations, while exploratory work in animal models can identify possible biomarkers for further investigation in human studies. These types of interwoven human and animal experiments have a potentially large impact on neuroscience and clinical practice. However, impediments exist to the optimal application of rs-fMRI in small animals, some similar to those encountered in humans and some quite different. In this review we identify the most prominent of these barriers, discuss differences between rs-fMRI in rodents and in humans, highlight best practices for animal studies, and review selected applications of rs-fMRI in rodents. Our goal is to facilitate the integration of human and animal work to the benefit of both fields.

  18. MRI

    DEFF Research Database (Denmark)

    Schroeter, Aileen; Rudin, Markus; Gianolio, Eliana

    2017-01-01

    This chapter discusses principles of nuclear magnetic resonance (NMR) and MRI followed by a survey on the major classes of MRI contrast agents (CA), their modes of action, and some of the most significative applications. The two more established classes of MRI-CA are represented by paramagnetic...... markedly broadened the range of applications in respect to the clinically used systems. CEST agents represent innovative frequency-encoding probes that yield negative contrast in the MR images upon transfer of saturated magnetization from the agent to the “bulk” water signal. Interesting developments have...

  19. Simultaneous resting-state functional MRI and electroencephalography recordings of functional connectivity in patients with schizophrenia.

    Science.gov (United States)

    Kirino, Eiji; Tanaka, Shoji; Fukuta, Mayuko; Inami, Rie; Arai, Heii; Inoue, Reiichi; Aoki, Shigeki

    2017-04-01

    It remains unclear how functional connectivity (FC) may be related to specific cognitive domains in neuropsychiatric disorders. Here we used simultaneous resting-state functional magnetic resonance imaging (rsfMRI) and electroencephalography (EEG) recording in patients with schizophrenia, to evaluate FC within and outside the default mode network (DMN). Our study population included 14 patients with schizophrenia and 15 healthy control participants. From all participants, we acquired rsfMRI data, and simultaneously recorded EEG data using an MR-compatible amplifier. We analyzed the rsfMRI-EEG data, and used the CONN toolbox to calculate the FC between regions of interest. We also performed between-group comparisons of standardized low-resolution electromagnetic tomography-based intracortical lagged coherence for each EEG frequency band. FC within the DMN, as measured by rsfMRI and EEG, did not significantly differ between groups. Analysis of rsfMRI data showed that FC between the right posterior inferior temporal gyrus and medial prefrontal cortex was stronger among patients with schizophrenia compared to control participants. Analysis of FC within the DMN using rsfMRI and EEG data revealed no significant differences between patients with schizophrenia and control participants. However, rsfMRI data revealed over-modulated FC between the medial prefrontal cortex and right posterior inferior temporal gyrus in patients with schizophrenia compared to control participants, suggesting that the patients had altered FC, with higher correlations across nodes within and outside of the DMN. Further studies using simultaneous rsfMRI and EEG are required to determine whether altered FC within the DMN is associated with schizophrenia. © 2016 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.

  20. Functional MRI for Assessment of the Default Mode Network in Acute Brain Injury

    DEFF Research Database (Denmark)

    Kondziella, Daniel; Fisher, Patrick M.; Larsen, Vibeke Andrée

    2017-01-01

    Background: Assessment of the default mode network (DMN) using resting-state functional magnetic resonance imaging (fMRI) may improve assessment of the level of consciousness in chronic brain injury, and therefore, fMRI may also have prognostic value in acute brain injury. However, fMRI is much...

  1. A novel passive paradigm for functional magnetic resonance imaging (fMRI) to localize brain functions

    International Nuclear Information System (INIS)

    Gasser, T.; Sandalcioglu, I.E.; Skwarek, V.; Gizewski, E.; Stolke, D.; Hans, V.

    2003-01-01

    The design of a shielded stimulation-device for electrical stimulation of peripheral nerves in the MRI-environment as passive fMRI-paradigm is content of this study. Especially the technical aspects and selection criteria of the stimulation-parameters are discussed. The clinical value for neurosurgical patients is outlined by supplying data from clinical studies, evaluating this novel paradigm. Thus neurosurgeons are supplied with superior information about functional anatomy, therefore being able to preserve functionally relevant brain-structures. (orig.) [de

  2. Quantification of Movement-Related EEG Correlates Associated with Motor Training: A Study on Movement-Related Cortical Potentials and Sensorimotor Rhythms.

    Science.gov (United States)

    Jochumsen, Mads; Rovsing, Cecilie; Rovsing, Helene; Cremoux, Sylvain; Signal, Nada; Allen, Kathryn; Taylor, Denise; Niazi, Imran K

    2017-01-01

    The ability to learn motor tasks is important in both healthy and pathological conditions. Measurement tools commonly used to quantify the neurophysiological changes associated with motor training such as transcranial magnetic stimulation and functional magnetic resonance imaging pose some challenges, including safety concerns, utility, and cost. EEG offers an attractive alternative as a quantification tool. Different EEG phenomena, movement-related cortical potentials (MRCPs) and sensorimotor rhythms (event-related desynchronization-ERD, and event-related synchronization-ERS), have been shown to change with motor training, but conflicting results have been reported. The aim of this study was to investigate how the EEG correlates (MRCP and ERD/ERS) from the motor cortex are modulated by short (single session in 14 subjects) and long (six sessions in 18 subjects) motor training. Ninety palmar grasps were performed before and after 1 × 45 (or 6 × 45) min of motor training with the non-dominant hand (laparoscopic surgery simulation). Four channels of EEG were recorded continuously during the experiments. The MRCP and ERD/ERS from the alpha/mu and beta bands were calculated and compared before and after the training. An increase in the MRCP amplitude was observed after a single session of training, and a decrease was observed after six sessions. For the ERD/ERS analysis, a significant change was observed only after the single training session in the beta ERD. In conclusion, the MRCP and ERD change as a result of motor training, but they are subject to a marked intra- and inter-subject variability.

  3. Quantification of Movement-Related EEG Correlates Associated with Motor Training: A Study on Movement-Related Cortical Potentials and Sensorimotor Rhythms

    Directory of Open Access Journals (Sweden)

    Mads Jochumsen

    2017-12-01

    Full Text Available The ability to learn motor tasks is important in both healthy and pathological conditions. Measurement tools commonly used to quantify the neurophysiological changes associated with motor training such as transcranial magnetic stimulation and functional magnetic resonance imaging pose some challenges, including safety concerns, utility, and cost. EEG offers an attractive alternative as a quantification tool. Different EEG phenomena, movement-related cortical potentials (MRCPs and sensorimotor rhythms (event-related desynchronization—ERD, and event-related synchronization—ERS, have been shown to change with motor training, but conflicting results have been reported. The aim of this study was to investigate how the EEG correlates (MRCP and ERD/ERS from the motor cortex are modulated by short (single session in 14 subjects and long (six sessions in 18 subjects motor training. Ninety palmar grasps were performed before and after 1 × 45 (or 6 × 45 min of motor training with the non-dominant hand (laparoscopic surgery simulation. Four channels of EEG were recorded continuously during the experiments. The MRCP and ERD/ERS from the alpha/mu and beta bands were calculated and compared before and after the training. An increase in the MRCP amplitude was observed after a single session of training, and a decrease was observed after six sessions. For the ERD/ERS analysis, a significant change was observed only after the single training session in the beta ERD. In conclusion, the MRCP and ERD change as a result of motor training, but they are subject to a marked intra- and inter-subject variability.

  4. 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

  5. Functional mapping of the sensorimotor cortex: combined use of magnetoencephalography, functional MRI, and motor evoked potentials

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, T. [Dept. of Neurosurgery, Neurological Inst., Kyshu Univ., Fukuoka (Japan); Fujii, K. [Dept. of Neurosurgery, Neurological Inst., Kyshu Univ., Fukuoka (Japan); Fukui, M. [Dept. of Neurosurgery, Neurological Inst., Kyshu Univ., Fukuoka (Japan); Mizushima, A. [Dept. of Radiology, Kyushu Univ. Fukuoka (Japan); Matsumoto, S. [Dept. of Radiology, Kyushu Univ. Fukuoka (Japan); Hasuo, K. [Dept. of Radiology, Kyushu Univ. Fukuoka (Japan); Yamamoto, T. [Dept. of Otolaryngology, Kyushu Univ. Fukuoka (Japan); Tobimatsu, S. [Dept. of Clinical Neurophysiology, Neurological Inst., Kyushu Univ., Fukuoka (Japan)

    1995-10-01

    Combined use of magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) was carried out on one patient in an attempt to localise precisely a structural lesion to the central sulcus. A small cyst in the right frontoparietal region was thought to be the cause of generalised seizures in an otherwise asymptomatic woman. First the primary sensory cortex was identified with magnetic source imaging (MSI) of somatosensory evoked magnetic fields using MEG and MRI. Second, the motor area of the hand was identified using f-MRI during handsqueezing. Then transcranial magnetic stimulation localised the hand motor area on the scalp, which was mapped onto the MRI. There was a good agreement between MSI, f-MRI and MEP as to the location of the sensorimotor cortex and its relationship to the lesion. Multimodality mapping techniques may thus prove useful in the precise localisation of cortical lesions, and in the preoperative determination of the best treatment for peri-rolandic lesions. (orig.)

  6. Functional mapping of the sensorimotor cortex: combined use of magnetoencephalography, functional MRI, and motor evoked potentials

    International Nuclear Information System (INIS)

    Morioka, T.; Fujii, K.; Fukui, M.; Mizushima, A.; Matsumoto, S.; Hasuo, K.; Yamamoto, T.; Tobimatsu, S.

    1995-01-01

    Combined use of magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) was carried out on one patient in an attempt to localise precisely a structural lesion to the central sulcus. A small cyst in the right frontoparietal region was thought to be the cause of generalised seizures in an otherwise asymptomatic woman. First the primary sensory cortex was identified with magnetic source imaging (MSI) of somatosensory evoked magnetic fields using MEG and MRI. Second, the motor area of the hand was identified using f-MRI during handsqueezing. Then transcranial magnetic stimulation localised the hand motor area on the scalp, which was mapped onto the MRI. There was a good agreement between MSI, f-MRI and MEP as to the location of the sensorimotor cortex and its relationship to the lesion. Multimodality mapping techniques may thus prove useful in the precise localisation of cortical lesions, and in the preoperative determination of the best treatment for peri-rolandic lesions. (orig.)

  7. Cardiac functional analysis with MRI; Kardiale Funktionsanalyse mittels MRT

    Energy Technology Data Exchange (ETDEWEB)

    Sandner, T.A.; Theisen, D.; Bauner, K.U.; Picciolo, M.; Reiser, M.F.; Wintersperger, B.J. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2010-06-15

    Cardiovascular diseases (CVD) are among the leading causes of death worldwide. Even in the 21{sup st} century CVD will still be the most frequent cause of morbidity and mortality. Precise evaluation of cardiac function is therefore mandatory for therapy planning and monitoring. In this article the contribution of MRI-based analysis of cardiac function will be addressed. Nowadays cine-MRI is considered as the standard of reference (SOR) in cardiac functional analysis. ECG-triggered steady-state free precession (SSFP) sequences are mainly used as they stand out due to short acquisition times and excellent contrast between the myocardium and the ventricular cavity. An indispensible requirement for cardiac functional analysis is an exact planning of the examination and based on that the coverage of the whole ventricle in short axial slices. By means of dedicated post-processing software, manual or semi-automatic segmentation of the endocardial and epicardial contours is necessary for functional analysis. In this way end-diastolic volume (EDV), end-systolic volume (ESV) and the ejection fraction (EF) are defined and regional wall motion abnormalities (RWMA) can be detected. (orig.) [German] Weltweit gehoeren Herz-Kreislauf-Erkrankungen zu den haeufigsten Todesursachen. Auch im 21. Jahrhundert werden diese Erkrankungen das Erkrankungsspektrum und die Todesursachenstatistik anfuehren. Eine genaue Beurteilung der kardialen Funktion ist fuer die Therapieplanung und -ueberwachung unerlaesslich. In diesem Beitrag wird der Stellenwert der MRT bei der Beurteilung der kardialen Funktion eroertert. Als Standard der kardialen Funktionsanalyse kann heute die Cine-MRT angesehen werden, wofuer man ueberwiegend EGK-getriggerte Steady-state-free-precession- (SSFP-)Sequenzen einsetzt, die sich durch kurze Messzeiten und einen hervorragenden Kontrast zwischen Myokard und Ventrikelkavum auszeichnen. Voraussetzung fuer kardiale Funktionsuntersuchungen ist eine exakte Einstellung der

  8. Functional lung MRI for regional monitoring of patients with cystic fibrosis.

    Directory of Open Access Journals (Sweden)

    Till F Kaireit

    Full Text Available To test quantitative functional lung MRI techniques in young adults with cystic fibrosis (CF compared to healthy volunteers and to monitor immediate treatment effects of a single inhalation of hypertonic saline in comparison to clinical routine pulmonary function tests.Sixteen clinically stable CF patients and 12 healthy volunteers prospectively underwent two functional lung MRI scans and pulmonary function tests before and 2h after a single treatment of inhaled hypertonic saline or without any treatment. MRI-derived oxygen enhanced T1 relaxation measurements, fractional ventilation, first-pass perfusion parameters and a morpho-functional CF-MRI score were acquired.Compared to healthy controls functional lung MRI detected and quantified significantly increased ventilation heterogeneity in CF patients. Regional functional lung MRI measures of ventilation and perfusion as well as the CF-MRI score and pulmonary function tests could not detect a significant treatment effect two hours after a single treatment with hypertonic saline in young adults with CF (p>0.05.This study shows the feasibility of functional lung MRI as a non-invasive, radiation-free tool for monitoring patients with CF.

  9. EEG Correlates of Preparatory Orienting, Contextual Updating, and Inhibition of Sensory Processing in Left Spatial Neglect.

    Science.gov (United States)

    Lasaponara, Stefano; D'Onofrio, Marianna; Pinto, Mario; Dragone, Alessio; Menicagli, Dario; Bueti, Domenica; De Lucia, Marzia; Tomaiuolo, Francesco; Doricchi, Fabrizio

    2018-04-11

    Studies with event-related potentials have highlighted deficits in the early phases of orienting to left visual targets in right-brain-damaged patients with left spatial neglect (N+). However, brain responses associated with preparatory orienting of attention, with target novelty and with the detection of a match/mismatch between expected and actual targets (contextual updating), have not been explored in N+. Here in a study in healthy humans and brain-damaged patients of both sexes we demonstrate that frontal activity that reflects supramodal mechanisms of attentional orienting (Anterior Directing Attention Negativity, ADAN) is entirely spared in N+. In contrast, posterior responses that mark the early phases of cued orienting (Early Directing Attention Negativity, EDAN) and the setting up of sensory facilitation over the visual cortex (Late Directing Attention Positivity, LDAP) are suppressed in N+. This uncoupling is associated with damage of parietal-frontal white matter. N+ also exhibit exaggerated novelty reaction to targets in the right side of space and reduced novelty reaction for those in the left side (P3a) together with impaired contextual updating (P3b) in the left space. Finally, we highlight a drop in the amplitude and latency of the P1 that over the left hemisphere signals the early blocking of sensory processing in the right space when targets occur in the left one: this identifies a new electrophysiological marker of the rightward attentional bias in N+. The heterogeneous effects and spatial biases produced by localized brain damage on the different phases of attentional processing indicate relevant functional independence among their underlying neural mechanisms and improve the understanding of the spatial neglect syndrome. SIGNIFICANCE STATEMENT Our investigation answers important questions: are the different components of preparatory orienting (EDAN, ADAN, LDAP) functionally independent in the healthy brain? Is preparatory orienting of

  10. EEG correlates of cognitive time scales in the Necker-Zeno model for bistable perception.

    Science.gov (United States)

    Kornmeier, J; Friedel, E; Wittmann, M; Atmanspacher, H

    2017-08-01

    The Necker-Zeno model of bistable perception provides a formal relation between the average duration of meta-stable percepts (dwell times T) of ambiguous figures and two other basic time scales (t 0 , ΔT) underlying cognitive processing. The model predicts that dwell times T covary with t 0 , ΔT or both. We tested this prediction by exploiting that observers, in particular experienced meditators, can volitionally control dwell times T. Meditators and non-meditators observed bistable Necker cubes either passively or tried to hold their current percept. The latencies of a centro-parietal event-related potential (CPP) were recorded as a physiological correlate of t 0 . Dwell times T and the CPP latencies, correlated with t 0 , differed between conditions and observer groups, while ΔT remained constant in the range predicted by the model. The covariation of CPP latencies and dwell times, as well as their quadratic functional dependence extends previous psychophysical confirmation of the Necker-Zeno model to psychophysiological measures. Copyright © 2017. Published by Elsevier Inc.

  11. Functional Correlates of Cognitive Dysfunction in Multiple Sclerosis: A Multicenter fMRI Study

    NARCIS (Netherlands)

    Rocca, M.A.; Valsasina, P.; Hulst, H.E.; Abdel-Aziz, K.; Enzinger, C.; Gallo, A.; Pareto, D.; Riccitelli, G.; Muhlert, N.; Ciccarelli, O.; Barkhof, F.; Fazekas, F.; Tedeschi, G.; Arevalo, M.J.; Filippi, M.

    2014-01-01

    In this multicenter study, we applied functional magnetic resonance imaging (fMRI) to define the functional correlates of cognitive dysfunction in patients with multiple sclerosis (MS). fMRI scans during the performance of the N-back task were acquired from 42 right-handed relapsing remitting (RR)

  12. “Awake” intraoperative functional MRI (ai-fMRI) for mapping the eloquent cortex: Is it possible in awake craniotomy?☆

    Science.gov (United States)

    Lu, Jun-Feng; Zhang, Han; Wu, Jin-Song; Yao, Cheng-Jun; Zhuang, Dong-Xiao; Qiu, Tian-Ming; Jia, Wen-Bin; Mao, Ying; Zhou, Liang-Fu

    2012-01-01

    As a promising noninvasive imaging technique, functional MRI (fMRI) has been extensively adopted as a functional localization procedure for surgical planning. However, the information provided by preoperative fMRI (pre-fMRI) is hampered by the brain deformation that is secondary to surgical procedures. Therefore, intraoperative fMRI (i-fMRI) becomes a potential alternative that can compensate for brain shifts by updating the functional localization information during craniotomy. However, previous i-fMRI studies required that patients be under general anesthesia, preventing the wider application of such a technique as the patients cannot perform tasks unless they are awake. In this study, we propose a new technique that combines awake surgery and i-fMRI, named “awake” i-fMRI (ai-fMRI). We introduced ai-fMRI to the real-time localization of sensorimotor areas during awake craniotomy in seven patients. The results showed that ai-fMRI could successfully detect activations in the bilateral primary sensorimotor areas and supplementary motor areas for all patients, indicating the feasibility of this technique in eloquent area localization. The reliability of ai-fMRI was further validated using intraoperative stimulation mapping (ISM) in two of the seven patients. Comparisons between the pre-fMRI-derived localization result and the ai-fMRI derived result showed that the former was subject to a heavy brain shift and led to incorrect localization, while the latter solved that problem. Additionally, the approaches for the acquisition and processing of the ai-fMRI data were fully illustrated and described. Some practical issues on employing ai-fMRI in awake craniotomy were systemically discussed, and guidelines were provided. PMID:24179766

  13. Multiparametric MRI in the assessment of response of rectal cancer to neoadjuvant chemoradiotherapy: A comparison of morphological, volumetric and functional MRI parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hoetker, Andreas M. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Universitaetsmedizin Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany); Tarlinton, Lisa; Gollub, Marc J. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Mazaheri, Yousef [Memorial Sloan Kettering Cancer Center, Department of Medical Physics, New York, NY (United States); Woo, Kaitlin M.; Goenen, Mithat [Memorial Sloan Kettering Cancer Center, Department of Epidemiology and Biostatistics, New York, NY (United States); Saltz, Leonard B. [Memorial Sloan Kettering Cancer Center, Department of Medicine, Gastrointestinal Oncology Service, New York, NY (United States); Goodman, Karyn A. [Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY (United States); Garcia-Aguilar, Julio [Memorial Sloan Kettering Cancer Center, Department of Surgery, New York, NY (United States)

    2016-12-15

    To compare morphological and functional MRI metrics and determine which ones perform best in assessing response to neoadjuvant chemoradiotherapy (CRT) in rectal cancer. This retrospective study included 24 uniformly-treated patients with biopsy-proven rectal adenocarcinoma who underwent MRI, including diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) sequences, before and after completion of CRT. On all MRI exams, two experienced readers independently measured longest and perpendicular tumour diameters, tumour volume, tumour regression grade (TRG) and tumour signal intensity ratio on T2-weighted imaging, as well as tumour volume and apparent diffusion coefficient on DW-MRI and tumour volume and transfer constant K{sup trans} on DCE-MRI. These metrics were correlated with histopathological percent tumour regression in the resected specimen (%TR). Inter-reader agreement was assessed using the concordance correlation coefficient (CCC). For both readers, post-treatment DW-MRI and DCE-MRI volumetric tumour assessments were significantly associated with %TR; DCE-MRI volumetry showed better inter-reader agreement (CCC=0.700) than DW-MRI volumetry (CCC=0.292). For one reader, mrTRG, post-treatment T2 tumour volumetry and assessments of volume change made with T2, DW-MRI and DCE-MRI were also significantly associated with %TR. Tumour volumetry on post-treatment DCE-MRI and DW-MRI correlated well with %TR, with DCE-MRI volumetry demonstrating better inter-reader agreement. (orig.)

  14. Intrinsic network activity in tinnitus investigated using functional MRI

    Science.gov (United States)

    Leaver, Amber M.; Turesky, Ted K.; Seydell-Greenwald, Anna; Morgan, Susan; Kim, Hung J.; Rauschecker, Josef P.

    2016-01-01

    Tinnitus is an increasingly common disorder in which patients experience phantom auditory sensations, usually ringing or buzzing in the ear. Tinnitus pathophysiology has been repeatedly shown to involve both auditory and non-auditory brain structures, making network-level studies of tinnitus critical. In this magnetic resonance imaging (MRI) study, we used two resting-state functional connectivity (RSFC) approaches to better understand functional network disturbances in tinnitus. First, we demonstrated tinnitus-related reductions in RSFC between specific brain regions and resting-state networks (RSNs), defined by independent components analysis (ICA) and chosen for their overlap with structures known to be affected in tinnitus. Then, we restricted ICA to data from tinnitus patients, and identified one RSN not apparent in control data. This tinnitus RSN included auditory-sensory regions like inferior colliculus and medial Heschl’s gyrus, as well as classically non-auditory regions like the mediodorsal nucleus of the thalamus, striatum, lateral prefrontal and orbitofrontal cortex. Notably, patients’ reported tinnitus loudness was positively correlated with RSFC between the mediodorsal nucleus and the tinnitus RSN, indicating that this network may underlie the auditory-sensory experience of tinnitus. These data support the idea that tinnitus involves network dysfunction, and further stress the importance of communication between auditory-sensory and fronto-striatal circuits in tinnitus pathophysiology. PMID:27091485

  15. Functional MRI of music emotion processing in frontotemporal dementia.

    Science.gov (United States)

    Agustus, Jennifer L; Mahoney, Colin J; Downey, Laura E; Omar, Rohani; Cohen, Miriam; White, Mark J; Scott, Sophie K; Mancini, Laura; Warren, Jason D

    2015-03-01

    Frontotemporal dementia is an important neurodegenerative disorder of younger life led by profound emotional and social dysfunction. Here we used fMRI to assess brain mechanisms of music emotion processing in a cohort of patients with frontotemporal dementia (n = 15) in relation to healthy age-matched individuals (n = 11). In a passive-listening paradigm, we manipulated levels of emotion processing in simple arpeggio chords (mode versus dissonance) and emotion modality (music versus human emotional vocalizations). A complex profile of disease-associated functional alterations was identified with separable signatures of musical mode, emotion level, and emotion modality within a common, distributed brain network, including posterior and anterior superior temporal and inferior frontal cortices and dorsal brainstem effector nuclei. Separable functional signatures were identified post-hoc in patients with and without abnormal craving for music (musicophilia): a model for specific abnormal emotional behaviors in frontotemporal dementia. Our findings indicate the potential of music to delineate neural mechanisms of altered emotion processing in dementias, with implications for future disease tracking and therapeutic strategies. © 2014 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences.

  16. 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

  17. Structural and functional MRI in children with renal disease: first experience

    DEFF Research Database (Denmark)

    Jørgensen, Bettina; Karstoft, Kristian; Jørgensen, Troels Munch

    2010-01-01

    This MRI study demonstrates our first clinical experiences with structural and functional evaluation in children with renal dysfunction, and communicates our experience with quantitative measurements of renal function compared to reference values found employing radionucleotides....

  18. Study of acupuncture point Liv 3 with functional MRI

    International Nuclear Information System (INIS)

    Wang Wei; Li Kuncheng; Hao Jing; Yang Yanhui; Shan Baoci; Yan Bin; Li Ke; Xu Jianyang

    2006-01-01

    Objective: To investigate the mechanism of acupuncture point Liv3 (Taichong) and possible post-effect of acupuncture by using functional magnetic resonance imaging (fMRI) Methods: Eighteen healthy right-handed volunteers participated in the experiment. The experiment used single block design, including rest state, stimulation state and post effect state (PE). Everyone only received acupuncture at one of the two stimulations, that was: true acupuncture (TA) at right Liv3 or sham acupoint (SA) near Liv3, in which 10 subjects participated in TA and other 8 subjects in SA. The fMRI data were obtained from scanning the whole brain and were analyzed using SPM99. Significant changes of stimulation state or post effect state compared to rest state were accessed using t-statistics. The t-ratios were used to form the statistical parametric maps which showed brain activation areas by acupuncture above P< 0.001. In order to remove the effects of other non-acupuncture factors, we used the mask function to exclude the areas activated by SA from the areas activated by TA. Results: The brain activation areas during TA for 10 subjects exclusive by SA for 8 subjects were showed on bilateral cerebella(t value is 10.06 and 9.82, respectively), prefrontal lobe (PF), superior parietal lobule (SPL, t value is 4.36 and 4.53, respectively) and inferior parietal lobule (IPL, t value is 3.94 and 4.95, respectively), occipital lobe, parahippocampal gyms, insula( t value is 3.82 and 5.51, respectively), thalamus, lentiform nucleus (t value is 3.24 and 4.40, respectively), contralateral temporal pole, anterior cingnlate cortex (ACC), and posterior cingulate cortex (PGC, all of P<0.01). The PE of TA for 10 subjects exclusive by 'PE' of SA for 8 subjects activated bilateral cerebella, PF, SPL, IPL, occipital lobe, lentiform nucleus, parahippocampal gyrus, ipsilateral tempoaral pole, hippocampus, insula, thalamus, contralateral head of nucleus caudate, corpus callosum, ACC, and PCC. Conclusion

  19. Comparison of left ventricular function assessment between echocardiography and MRI in Duchenne muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Buddhe, Sujatha; Lewin, Mark; Olson, Aaron; Soriano, Brian D. [University of Washington School of Medicine and Seattle Children' s Hospital, Division of Cardiology, Department of Pediatrics, Seattle, WA (United States); Ferguson, Mark [University of Washington School of Medicine and Seattle Children' s Hospital, Department of Radiology, Seattle, WA (United States)

    2016-09-15

    Cardiomyopathy in Duchenne muscular dystrophy (DMD) is associated with death in approximately 40% of patients. Echocardiography is routinely used to assess left ventricular (LV) function; however, it has limitations in these patients. We compared echocardiographic measures of cardiac function assessment to cardiac MRI. We included children and young adults with DMD who had MRI performed between January 2010 and July 2015. We measured echocardiographic and MRI parameters of function assessment, including strain. Presence of late gadolinium enhancement (LGE) was assessed by MRI. Subjects were divided into two groups based on MRI left ventricular ejection fraction (LVEF): group I, LVEF ≥55% and group II, LVEF <55%. We included 41 studies in 33 subjects, with 25 in group I and 16 in group II. Mean age of subjects was 13.6 ± 2.8 years and mean duration between echocardiogram and MRI was 7.6 ± 4.1 months. Only 8 of 16 (50%) patients in group II had diminished function on echocardiogram. Echocardiographic images were suboptimal in 16 subjects (39%). Overall, echocardiographic parameters had weak correlation with MRI-derived ejection fraction percentage. MRI-derived myocardial strain assessment has better correlation with MRI ejection fraction as compared to echocardiography-derived strain parameters. Echocardiography-based ventricular functional assessment has weak correlation with MRI parameters in children and young adults with Duchenne muscular dystrophy. While this correlation improves in the subset of subjects with adequate echocardiographic image quality, it remains modest and potentially suboptimal for clinical management. Accordingly, we conclude that MRI should be performed routinely and early in children with DMD, not only for LGE imaging but also for functional assessment. (orig.)

  20. Comparison of left ventricular function assessment between echocardiography and MRI in Duchenne muscular dystrophy

    International Nuclear Information System (INIS)

    Buddhe, Sujatha; Lewin, Mark; Olson, Aaron; Soriano, Brian D.; Ferguson, Mark

    2016-01-01

    Cardiomyopathy in Duchenne muscular dystrophy (DMD) is associated with death in approximately 40% of patients. Echocardiography is routinely used to assess left ventricular (LV) function; however, it has limitations in these patients. We compared echocardiographic measures of cardiac function assessment to cardiac MRI. We included children and young adults with DMD who had MRI performed between January 2010 and July 2015. We measured echocardiographic and MRI parameters of function assessment, including strain. Presence of late gadolinium enhancement (LGE) was assessed by MRI. Subjects were divided into two groups based on MRI left ventricular ejection fraction (LVEF): group I, LVEF ≥55% and group II, LVEF <55%. We included 41 studies in 33 subjects, with 25 in group I and 16 in group II. Mean age of subjects was 13.6 ± 2.8 years and mean duration between echocardiogram and MRI was 7.6 ± 4.1 months. Only 8 of 16 (50%) patients in group II had diminished function on echocardiogram. Echocardiographic images were suboptimal in 16 subjects (39%). Overall, echocardiographic parameters had weak correlation with MRI-derived ejection fraction percentage. MRI-derived myocardial strain assessment has better correlation with MRI ejection fraction as compared to echocardiography-derived strain parameters. Echocardiography-based ventricular functional assessment has weak correlation with MRI parameters in children and young adults with Duchenne muscular dystrophy. While this correlation improves in the subset of subjects with adequate echocardiographic image quality, it remains modest and potentially suboptimal for clinical management. Accordingly, we conclude that MRI should be performed routinely and early in children with DMD, not only for LGE imaging but also for functional assessment. (orig.)

  1. Functional versus Nonfunctional Rehabilitation in Chronic Ischemic Stroke: Evidences from a Randomized Functional MRI Study

    Directory of Open Access Journals (Sweden)

    Maristela C. X. Pelicioni

    2016-01-01

    Full Text Available Motor rehabilitation of stroke survivors may include functional and/or nonfunctional strategy. The present study aimed to compare the effect of these two rehabilitation strategies by means of clinical scales and functional Magnetic Resonance Imaging (fMRI. Twelve hemiparetic chronic stroke patients were selected. Patients were randomly assigned a nonfunctional (NFS or functional (FS rehabilitation scheme. Clinical scales (Fugl-Meyer, ARA test, and modified Barthel and fMRI were applied at four moments: before rehabilitation (P1 and immediately after (P2, 1 month after (P3, and three months after (P4 the end of rehabilitation. The NFS group improved significantly and exclusively their Fugl-Meyer scores at P2, P3, and P4, when compared to P1. On the other hand, the FS group increased significantly in Fugl-Meyer at P2, when compared to P1, and also in their ARA and Barthel scores. fMRI inspection at the individual level revealed that both rehabilitation schemes most often led to decreased activation sparseness, decreased activity of contralesional M1, increased asymmetry of M1 activity to the ipsilesional side, decreased perilesional activity, and decreased SMA activity. Increased M1 asymmetry with rehabilitation was also confirmed by Lateralization Indexes. Our clinical analysis revealed subtle differences between FS and NFS.

  2. Partially Adaptive STAP Algorithm Approaches to functional MRI

    Science.gov (United States)

    Huang, Lejian; Thompson, Elizabeth A.; Schmithorst, Vincent; Holland, Scott K.; Talavage, Thomas M.

    2010-01-01

    In this work, the architectures of three partially adaptive STAP algorithms are introduced, one of which is explored in detail, that reduce dimensionality and improve tractability over fully adaptive STAP when used in construction of brain activation maps in fMRI. Computer simulations incorporating actual MRI noise and human data analysis indicate that element space partially adaptive STAP can attain close to the performance of fully adaptive STAP while significantly decreasing processing time and maximum memory requirements, and thus demonstrates potential in fMRI analysis. PMID:19272913

  3. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function

    NARCIS (Netherlands)

    Coolen, Bram F.; Abdurrachim, Desiree; Motaal, Abdallah G.; Nicolay, Klaas; Prompers, Jeanine J.; Strijkers, Gustav J.

    2013-01-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered

  4. Assessment of muscle function using hybrid PET/MRI

    DEFF Research Database (Denmark)

    Haddock, Bryan; Holm, Søren; Poulsen, Jákup M.

    2017-01-01

    in muscle T2 may be used as a surrogate marker for glucose uptake and lead to an improved insight into the metabolic changes that occur with muscle activation. Such knowledge may lead to improved treatment strategies in patients with neuromuscular pathologies such as stroke, spinal cord injuries......Purpose: The aim of this study was to determine the relationship between relative glucose uptake and MRI T2 changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Methods: Ten young healthy recreationally active men (age 21 – 28 years) were injected with 18F......-FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with 18F-FDG PET/MRI and muscle groups were evaluated for increases in 18F-FDG uptake and MRI T2...

  5. Partially Adaptive STAP Algorithm Approaches to functional MRI

    OpenAIRE

    Huang, Lejian; Thompson, Elizabeth A.; Schmithorst, Vincent; Holland, Scott K.; Talavage, Thomas M.

    2008-01-01

    In this work, the architectures of three partially adaptive STAP algorithms are introduced, one of which is explored in detail, that reduce dimensionality and improve tractability over fully adaptive STAP when used in construction of brain activation maps in fMRI. Computer simulations incorporating actual MRI noise and human data analysis indicate that element space partially adaptive STAP can attain close to the performance of fully adaptive STAP while significantly decreasing processing tim...

  6. Normal pancreatic exocrine function does not exclude MRI/MRCP chronic pancreatitis findings.

    Science.gov (United States)

    Alkaade, Samer; Cem Balci, Numan; Momtahen, Amir Javad; Burton, Frank

    2008-09-01

    Abnormal pancreatic function tests have been reported to precede the imaging findings of chronic pancreatitis. Magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) is increasingly accepted as the primary imaging modality for the detection of structural changes of early mild chronic pancreatitis. The aim of this study was to evaluate MRI/MRCP findings in patients with symptoms consistent with chronic pancreatitis who have normal Secretin Endoscopic Pancreatic Function test. A retrospective study of 32 patients referred for evaluation of chronic abdominal pain consistent with chronic pancreatitis and reported normal standard abdominal imaging (ultrasound, computed tomography, or MRI). All patients underwent Secretin Endoscopic Pancreatic Function testing and pancreatic MRI/MRCP at our institution. We reviewed the MRI/MRCP images in patients who had normal Secretin Endoscopic Pancreatic Function testing. MRI/MRCP images were assessed for pancreatic duct morphology, gland size, parenchymal signal and morphology, and arterial contrast enhancement. Of the 32 patients, 23 had normal Secretin Endoscopic Pancreatic Function testing, and 8 of them had mild to marked spectrum of abnormal MRI/MRCP findings that were predominantly focal. Frequencies of the findings were as follows: pancreatic duct stricture (n=3), pancreatic duct dilatation (n=3), side branch ectasia (n=4), atrophy (n=5), decreased arterial enhancement (n=5), decreased parenchymal signal (n=1), and cavity formation (n=1). The remaining15 patients had normal pancreatic structure on MRI/MRCP. Normal pancreatic function testing cannot exclude abnormal MRI/MRCP especially focal findings of chronic pancreatitis. Further studies needed to verify significance of these findings and establish MRI/MRCP imaging criteria for the diagnosis of chronic pancreatitis.

  7. Modelling large motion events in fMRI studies of patients with epilepsy

    DEFF Research Database (Denmark)

    Lemieux, Louis; Salek-Haddadi, Afraim; Lund, Torben E

    2007-01-01

    EEG-correlated fMRI can provide localisation information on the generators of epileptiform discharges in patients with focal epilepsy. To increase the technique's clinical potential, it is important to consider ways of optimising the yield of each experiment while minimizing the risk of false...

  8. Activated and deactivated functional brain areas in the Deqi state: A functional MRI study.

    Science.gov (United States)

    Huang, Yong; Zeng, Tongjun; Zhang, Guifeng; Li, Ganlong; Lu, Na; Lai, Xinsheng; Lu, Yangjia; Chen, Jiarong

    2012-10-25

    We compared the activities of functional regions of the brain in the Deqi versus non-Deqi state, as reported by physicians and subjects during acupuncture. Twelve healthy volunteers received sham and true needling at the Waiguan (TE5) acupoint. Real-time cerebral functional MRI showed that compared with non-sensation after sham needling, true needling activated Brodmann areas 3, 6, 8, 9, 10, 11, 13, 20, 21, 37, 39, 40, 43, and 47, the head of the caudate nucleus, the parahippocampal gyrus, thalamus and red nucleus. True needling also deactivated Brodmann areas 1, 2, 3, 4, 5, 6, 7, 9, 10, 18, 24, 31, 40 and 46.

  9. Effects of Field-Map Distortion Correction on Resting State Functional Connectivity MRI

    Directory of Open Access Journals (Sweden)

    Hiroki Togo

    2017-12-01

    Full Text Available Magnetic field inhomogeneities cause geometric distortions of echo planar images used for functional magnetic resonance imaging (fMRI. To reduce this problem, distortion correction (DC with field map is widely used for both task and resting-state fMRI (rs-fMRI. Although DC with field map has been reported to improve the quality of task fMRI, little is known about its effects on rs-fMRI. Here, we tested the influence of field-map DC on rs-fMRI results using two rs-fMRI datasets derived from 40 healthy subjects: one with DC (DC+ and the other without correction (DC−. Independent component analysis followed by the dual regression approach was used for evaluation of resting-state functional connectivity networks (RSN. We also obtained the ratio of low-frequency to high-frequency signal power (0.01–0.1 Hz and above 0.1 Hz, respectively; LFHF ratio to assess the quality of rs-fMRI signals. For comparison of RSN between DC+ and DC− datasets, the default mode network showed more robust functional connectivity in the DC+ dataset than the DC− dataset. Basal ganglia RSN showed some decreases in functional connectivity primarily in white matter, indicating imperfect registration/normalization without DC. Supplementary seed-based and simulation analyses supported the utility of DC. Furthermore, we found a higher LFHF ratio after field map correction in the anterior cingulate cortex, posterior cingulate cortex, ventral striatum, and cerebellum. In conclusion, field map DC improved detection of functional connectivity derived from low-frequency rs-fMRI signals. We encourage researchers to include a DC step in the preprocessing pipeline of rs-fMRI analysis.

  10. 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

  11. 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.

  12. EEG-fMRI integration for the study of human brain function.

    Science.gov (United States)

    Jorge, João; van der Zwaag, Wietske; Figueiredo, Patrícia

    2014-11-15

    Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) have proved to be extremely valuable tools for the non-invasive study of human brain function. Moreover, due to a notable degree of complementarity between the two modalities, the combination of EEG and fMRI data has been actively sought in the last two decades. Although initially focused on epilepsy, EEG-fMRI applications were rapidly extended to the study of healthy brain function, yielding new insights into its underlying mechanisms and pathways. Nevertheless, EEG and fMRI have markedly different spatial and temporal resolutions, and probe neuronal activity through distinct biophysical processes, many aspects of which are still poorly understood. The remarkable conceptual and methodological challenges associated with EEG-fMRI integration have motivated the development of a wide range of analysis approaches over the years, each relying on more or less restrictive assumptions, and aiming to shed further light on the mechanisms of brain function along with those of the EEG-fMRI coupling itself. Here, we present a review of the most relevant EEG-fMRI integration approaches yet proposed for the study of brain function, supported by a general overview of our current understanding of the biophysical mechanisms coupling the signals obtained from the two modalities. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Structural and functional MRI in children with renal disease. First experience

    International Nuclear Information System (INIS)

    Joergensen, Bettina; Froekiaer, Joergen; Karstoft, Kristian; Pedersen, Michael; Aarhus Univ. Hospital; Joergensen, Troels Munch; Rittig, Soeren

    2010-01-01

    This MRI study demonstrates our first clinical experiences with structural and functional evaluation in children with renal dysfunction, and communicates our experience with quantitative measurements of renal function compared to reference values found employing radionucleotides. We included renal impaired children who were recruited for clinical radioisotopic GFR measurements (n=8). MRI was performed 2 hours after Cr-EDTA measurements and was conducted using a protocol involving both anatomical/structural sequences and a dynamic contrast-enhanced sequence. Data obtained with the dynamic MRI sequence were processed using the graphical Patlak approach to obtain estimates of GFR. We were able to characterize the intrarenal configuration (cortex, medulla, pelvicalyceal arrangement) in all cases. Functional analyses of dynamic contrast-enhanced MRI revealed an overall underestimation of GFR measured by MRI compared to Cr-EDTPA measures (range: -2% to -43%). We advocate the use of MRI as a single-modality approach in the structural and functional evaluation of impaired kidneys in children, and concurrently, we presented a clinically available strategy for estimations of renal cortical volume and single kidney function. However, the use of MRI contrast agents have recently become controversial in renal patients due to the risk of NSF. (orig.)

  14. Structural and functional MRI in children with renal disease. First experience

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Bettina; Froekiaer, Joergen [Aarhus Univ. Hospital (Denmark). Inst. of Clinical Medicine; Karstoft, Kristian; Pedersen, Michael [Aarhus Univ. Hospital (Denmark). Inst. of Clinical Medicine; Aarhus Univ. Hospital (Denmark). MR Research Centre; Joergensen, Troels Munch [Aarhus Univ. Hospital (Denmark). Dept. of Urology; Rittig, Soeren [Aarhus Univ. Hospital (Denmark). Dept. of Paediatrics

    2010-07-01

    This MRI study demonstrates our first clinical experiences with structural and functional evaluation in children with renal dysfunction, and communicates our experience with quantitative measurements of renal function compared to reference values found employing radionucleotides. We included renal impaired children who were recruited for clinical radioisotopic GFR measurements (n=8). MRI was performed 2 hours after Cr-EDTA measurements and was conducted using a protocol involving both anatomical/structural sequences and a dynamic contrast-enhanced sequence. Data obtained with the dynamic MRI sequence were processed using the graphical Patlak approach to obtain estimates of GFR. We were able to characterize the intrarenal configuration (cortex, medulla, pelvicalyceal arrangement) in all cases. Functional analyses of dynamic contrast-enhanced MRI revealed an overall underestimation of GFR measured by MRI compared to Cr-EDTPA measures (range: -2% to -43%). We advocate the use of MRI as a single-modality approach in the structural and functional evaluation of impaired kidneys in children, and concurrently, we presented a clinically available strategy for estimations of renal cortical volume and single kidney function. However, the use of MRI contrast agents have recently become controversial in renal patients due to the risk of NSF. (orig.)

  15. Functional MRI study of cerebral cortical activation during volitional swallowing

    International Nuclear Information System (INIS)

    Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji

    2002-01-01

    The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

  16. Investigating repetition and change in musical rhythm by functional MRI.

    Science.gov (United States)

    Danielsen, A; Otnæss, M K; Jensen, J; Williams, S C R; Ostberg, B C

    2014-09-05

    Groove-based rhythm is a basic and much appreciated feature of Western popular music. It is commonly associated with dance, movement and pleasure and is characterized by the repetition of a basic rhythmic pattern. At various points in the musical course, drum breaks occur, representing a change compared to the repeated pattern of the groove. In the present experiment, we investigated the brain response to such drum breaks in a repetitive groove. Participants were scanned with functional magnetic resonance imaging (fMRI) while listening to a previously unheard naturalistic groove with drum breaks at uneven intervals. The rhythmic pattern and the timing of its different parts as performed were the only aspects that changed from the repetitive sections to the breaks. Differences in blood oxygen level-dependent activation were analyzed. In contrast to the repetitive parts, the drum breaks activated the left cerebellum, the right inferior frontal gyrus (RIFG), and the superior temporal gyri (STG) bilaterally. A tapping test using the same stimulus showed an increase in the standard deviation of inter-tap-intervals in the breaks versus the repetitive parts, indicating extra challenges for auditory-motor integration in the drum breaks. Both the RIFG and STG have been associated with structural irregularity and increase in musical-syntactical complexity in several earlier studies, whereas the left cerebellum is known to play a part in timing. Together these areas may be recruited in the breaks due to a prediction error process whereby the internal model is being updated. This concurs with previous research suggesting a network for predictive feed-forward control that comprises the cerebellum and the cortical areas that were activated in the breaks. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Functional MRI study of cerebral cortical activation during volitional swallowing

    Energy Technology Data Exchange (ETDEWEB)

    Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji [Okayama Univ. (Japan). Graduate School of Medicine and Dentistry

    2002-12-01

    The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

  18. 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)

  19. [Progress of clinical application of functional MRI in the localization of brain language area].

    Science.gov (United States)

    Zhang, Nan; Lu, Junfeng; Wu, Jinsong

    2016-02-01

    For surgical operation in the functional area in the brain, it's commonly demanded to resect the lesion to the maximal extent on the basis of preserve the normal neural function, thus the precise localization of functional area is extremely important. As for the advantages of being widely available, easy to grasp and non-invasive, the functional MRI (fMRI) has come into wide use, while the application of language fMRI is still in the initial stage. It's important to choose appropriate fMRI task according to the individual condition of the subject, the commonly-adopted tasks include verb generation, picture naming, word recognition, word generation, etc. However, the effectiveness of using fMRI to localize language area is not totally satisfactory, adopting multiple task is an effective approach to improve the sensitivity of this technique. The application of resting state fMRI in the localization of language area and the further research of the role of fMRI in localizing the Chinese language area are the important future directions.

  20. Automatic Recognition of fMRI-derived Functional Networks using 3D Convolutional Neural Networks.

    Science.gov (United States)

    Zhao, Yu; Dong, Qinglin; Zhang, Shu; Zhang, Wei; Chen, Hanbo; Jiang, Xi; Guo, Lei; Hu, Xintao; Han, Junwei; Liu, Tianming

    2017-06-15

    Current fMRI data modeling techniques such as Independent Component Analysis (ICA) and Sparse Coding methods can effectively reconstruct dozens or hundreds of concurrent interacting functional brain networks simultaneously from the whole brain fMRI signals. However, such reconstructed networks have no correspondences across different subjects. Thus, automatic, effective and accurate classification and recognition of these large numbers of fMRI-derived functional brain networks are very important for subsequent steps of functional brain analysis in cognitive and clinical neuroscience applications. However, this task is still a challenging and open problem due to the tremendous variability of various types of functional brain networks and the presence of various sources of noises. In recognition of the fact that convolutional neural networks (CNN) has superior capability of representing spatial patterns with huge variability and dealing with large noises, in this paper, we design, apply and evaluate a deep 3D CNN framework for automatic, effective and accurate classification and recognition of large number of functional brain networks reconstructed by sparse representation of whole-brain fMRI signals. Our extensive experimental results based on the Human Connectome Project (HCP) fMRI data showed that the proposed deep 3D CNN can effectively and robustly perform functional networks classification and recognition tasks, while maintaining a high tolerance for mistakenly labelled training instances. Our work provides a new deep learning approach for modeling functional connectomes based on fMRI data.

  1. Evaluation of a pre-surgical functional MRI workflow: From data acquisition to reporting.

    Science.gov (United States)

    Pernet, Cyril R; Gorgolewski, Krzysztof J; Job, Dominic; Rodriguez, David; Storkey, Amos; Whittle, Ian; Wardlaw, Joanna

    2016-02-01

    Present and assess clinical protocols and associated automated workflow for pre-surgical functional magnetic resonance imaging in brain tumor patients. Protocols were validated using a single-subject reliability approach based on 10 healthy control subjects. Results from the automated workflow were evaluated in 9 patients with brain tumors, comparing fMRI results to direct electrical stimulation (DES) of the cortex. Using a new approach to compute single-subject fMRI reliability in controls, we show that not all tasks are suitable in the clinical context, even if they show meaningful results at the group level. Comparison of the fMRI results from patients to DES showed good correspondence between techniques (odds ratio 36). Providing that validated and reliable fMRI protocols are used, fMRI can accurately delineate eloquent areas, thus providing an aid to medical decision regarding brain tumor surgery. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Ecological nuances in functional magnetic resonance imaging (fMRI): psychological stressors, posture, and hydrostatics.

    Science.gov (United States)

    Raz, Amir; Lieber, Baruch; Soliman, Fatima; Buhle, Jason; Posner, Jonathan; Peterson, Bradley S; Posner, Michael I

    2005-03-01

    Brain imaging techniques such as functional magnetic resonance imaging (fMRI) have forged an impressive link between psychology and neuroscience. Whereas most experiments in cognitive psychology require participants to perform while sitting upright in front of display devices, fMRI obliges participants to perform cognitive tasks while lying supine and motionless inside a narrow bore. In addition to introducing psychological and physical stressors, such as loud thumps and head restraints, fMRI procedures also alter brain hydrostatics. The ecological factors associated with current fMRI technology, such as supine posture, may skew cognitive processing and influence hemodynamic and electrophysiological measurements, especially in extreme age groups and pathological populations. Recognizing the central role of fMRI in unraveling the neural mechanisms of cognition, we outline ways to address these limitations.

  3. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function.

    Science.gov (United States)

    Coolen, Bram F; Abdurrachim, Desiree; Motaal, Abdallah G; Nicolay, Klaas; Prompers, Jeanine J; Strijkers, Gustav J

    2013-03-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal-to-noise limitations. To overcome these limitations associated with electrocardiography-triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high-resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k-space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography-triggered Cine for which a high-frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography-triggered protocols. High spatial-resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice. Copyright © 2012 Wiley Periodicals, Inc.

  4. Dynamic MRI and isotope renogram in the functional evaluation of pelviureteric junction obstruction: A comparative study.

    Science.gov (United States)

    Sivakumar, Vadivalagia Nambi; Indiran, Venkatraman; Sathyanathan, Babu Peter

    2018-01-01

    The aim of this study was to evaluate and compare the diagnostic accuracy of dynamic contrast- enhanced magnetic resonance imaging (dMRI) and isotope renogram in the functional evaluation of pelviureteric junction obstruction (PUJO). Forty-two patients included in the study were investigated with isotope renogram and subsequently, subjected to dMRI. Time-activity curves were generated for both isotope renogram and dMRI. Out of the 42 cases, 9 cases were conservatively managed. Thirty-three cases were taken up for surgical intervention. Of 33 patients taken up for surgical intervention, 12 underwent laparoscopic nephrectomy and 21 of them pyeloplasty. The mean glomerular filtration rates (GFRs) as measured by isotope renogram and dMRI were 22.5+4.2 mL/min and 23.8+3.1 mL/min respectively. The calculation of GFR by isotope renogram, showed good correlation with that of dMRI with correlation coefficient of 0.93. The dMRI was able to reveal the functional status of the renal unit accurately. dMRI did not yield false positive results with 20 of 21 patients scheduled for pyeloplasty and 11 of 12 patients scheduled for nephrectomy. Isotope renogram had a false positive result in 3 cases compared with surgical diagnosis. Analysis of renal function using dMRI yielded results comparable to those of renal scintigraphy, with superior spatial and contrast resolution. It was also better in prompting management decisions with respect to the obstructed systems. dMRI can be used as a "one stop imaging examination" that can replace different imaging methods used for morphological, etiological and functional evaluation of PUJO.

  5. Muscle MRI Findings in Childhood/Adult Onset Pompe Disease Correlate with Muscle Function.

    Directory of Open Access Journals (Sweden)

    Sebastián Figueroa-Bonaparte

    Full Text Available Enzyme replacement therapy has shown to be effective for childhood/adult onset Pompe disease (AOPD. The discovery of biomarkers useful for monitoring disease progression is one of the priority research topics in Pompe disease. Muscle MRI could be one possible test but the correlation between muscle MRI and muscle strength and function has been only partially addressed so far.We studied 34 AOPD patients using functional scales (Manual Research Council scale, hand held myometry, 6 minutes walking test, timed to up and go test, time to climb up and down 4 steps, time to walk 10 meters and Motor Function Measure 20 Scale, respiratory tests (Forced Vital Capacity seated and lying, Maximun Inspiratory Pressure and Maximum Expiratory Pressure, daily live activities scales (Activlim and quality of life scales (Short Form-36 and Individualized Neuromuscular Quality of Life questionnaire. We performed a whole body muscle MRI using T1w and 3-point Dixon imaging centered on thighs and lower trunk region.T1w whole body muscle MRI showed a homogeneous pattern of muscle involvement that could also be found in pre-symptomatic individuals. We found a strong correlation between muscle strength, muscle functional scales and the degree of muscle fatty replacement in muscle MRI analyzed using T1w and 3-point Dixon imaging studies. Moreover, muscle MRI detected mild degree of fatty replacement in paraspinal muscles in pre-symptomatic patients.Based on our findings, we consider that muscle MRI correlates with muscle function in patients with AOPD and could be useful for diagnosis and follow-up in pre-symptomatic and symptomatic patients under treatment.Muscle MRI correlates with muscle function in patients with AOPD and could be useful to follow-up patients in daily clinic.

  6. Corticospinal tract atrophy and motor fMRI predict motor preservation after functional cerebral hemispherectomy.

    Science.gov (United States)

    Wang, Anthony C; Ibrahim, George M; Poliakov, Andrew V; Wang, Page I; Fallah, Aria; Mathern, Gary W; Buckley, Robert T; Collins, Kelly; Weil, Alexander G; Shurtleff, Hillary A; Warner, Molly H; Perez, Francisco A; Shaw, Dennis W; Wright, Jason N; Saneto, Russell P; Novotny, Edward J; Lee, Amy; Browd, Samuel R; Ojemann, Jeffrey G

    2018-01-01

    OBJECTIVE The potential loss of motor function after cerebral hemispherectomy is a common cause of anguish for patients, their families, and their physicians. The deficits these patients face are individually unique, but as a whole they provide a framework to understand the mechanisms underlying cortical reorganization of motor function. This study investigated whether preoperative functional MRI (fMRI) and diffusion tensor imaging (DTI) could predict the postoperative preservation of hand motor function. METHODS Thirteen independent reviewers analyzed sensorimotor fMRI and colored fractional anisotropy (CoFA)-DTI maps in 25 patients undergoing functional hemispherectomy for treatment of intractable seizures. Pre- and postoperative gross hand motor function were categorized and correlated with fMRI and DTI findings, specifically, abnormally located motor activation on fMRI and corticospinal tract atrophy on DTI. RESULTS Normal sensorimotor cortical activation on preoperative fMRI was significantly associated with severe decline in postoperative motor function, demonstrating 92.9% sensitivity (95% CI 0.661-0.998) and 100% specificity (95% CI 0.715-1.00). Bilaterally robust, symmetric corticospinal tracts on CoFA-DTI maps were significantly associated with severe postoperative motor decline, demonstrating 85.7% sensitivity (95% CI 0.572-0.982) and 100% specificity (95% CI 0.715-1.00). Interpreting the fMR images, the reviewers achieved a Fleiss' kappa coefficient (κ) for interrater agreement of κ = 0.69, indicating good agreement (p motor function can be identified prior to hemispherectomy, where fMRI or DTI suggests that cortical reorganization of motor function has occurred prior to the operation.

  7. Functional brain hubs and their test-retest reliability: a multiband resting-state functional MRI study.

    Science.gov (United States)

    Liao, Xu-Hong; Xia, Ming-Rui; Xu, Ting; Dai, Zheng-Jia; Cao, Xiao-Yan; Niu, Hai-Jing; Zuo, Xi-Nian; Zang, Yu-Feng; He, Yong

    2013-12-01

    Resting-state functional MRI (R-fMRI) has emerged as a promising neuroimaging technique used to identify global hubs of the human brain functional connectome. However, most R-fMRI studies on functional hubs mainly utilize traditional R-fMRI data with relatively low sampling rates (e.g., repetition time [TR]=2 s). R-fMRI data scanned with higher sampling rates are important for the characterization of reliable functional connectomes because they can provide temporally complementary information about functional integration among brain regions and simultaneously reduce the effects of high frequency physiological noise. Here, we employed a publicly available multiband R-fMRI dataset with a sub-second sampling rate (TR=645 ms) to identify global hubs in the human voxel-wise functional networks, and further examined their test-retest (TRT) reliability over scanning time. We showed that the functional hubs of human brain networks were mainly located at the default-mode regions (e.g., medial prefrontal and parietal cortex as well as the lateral parietal and temporal cortex) and the sensorimotor and visual cortex. These hub regions were highly anatomically distance-dependent, where short-range and long-range hubs were primarily located at the primary cortex and the multimodal association cortex, respectively. We found that most functional hubs exhibited fair to good TRT reliability using intraclass correlation coefficients. Interestingly, our analysis suggested that a 6-minute scan duration was able to reliably detect these functional hubs. Further comparison analysis revealed that these results were approximately consistent with those obtained using traditional R-fMRI scans of the same subjects with TR=2500 ms, but several regions (e.g., lateral frontal cortex, paracentral lobule and anterior temporal lobe) exhibited different TRT reliability. Finally, we showed that several regions (including the medial/lateral prefrontal cortex and lateral temporal cortex) were

  8. Functional MRI of the brain: localisation of eloquent cortex in focal brain lesion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dymarkowski, S.; Sunaert, S.; Oostende, S. van; Hecke, P. van; Wilms, G.; Demaerel, P.; Marchal, G. [Department of Radiology, University Hospitals, Leuven (Belgium); Nuttin, B.; Plets, C. [Department of Neurosurgery, University Hospitals, Leuven (Belgium)

    1998-12-01

    The aim of this study was to assess the feasibility of functional MRI (fMRI) in a clinical environment on a large patient group, and to evaluate the pretherapeutic value of localisation of eloquent cortex. Forty patients with focal brain lesions of different origin were studied using fMRI. Functional information was obtained using motor, somatosensory, auditory and phonological stimuli depending on the localisation of the lesions. To obtain information about the spatial accuracy of fMRI, the results were compared with postoperative electrocortical stimulation. Two patients with secondary trigeminal neuralgia were scanned using a motor protocol and were implanted with an extradural plate electrode. Imaging was successful in 40 of 42 patients (including the 2 with trigeminal neuralgia). These patients were analysed for strength of activation, the relation of the lesion to activation sites and the presence of mass effect. The correlation between these data and surgical findings provided significant additional clinical information. Functional MRI can be accurately performed in patients with focal brain lesions using a dedicated approach. Functional MRI offers important clinical information as a contribution to a decrease in posttherapeutic morbidity. The accuracy of the technique can be confirmed by other modalities, including invasive cortical electrostimulation. (orig.) With 7 figs., 2 tabs., 25 refs.

  9. An optical 6-axis force sensor for brain function analysis using fMRI

    International Nuclear Information System (INIS)

    Takahashi, Norihisa; Tada, Mitsunori; Ueda, Jun; Matsumoto, Yoshio; Ogasawara, Tsukasa

    2004-01-01

    This paper presents an 6-axis optical force sensor which can be used in functional MRI (fMRI). Recently, fMRI are widely used for studying human brain function. Simultaneous measurement of brain activity and peripheral information, such as grip force, enables more precise investigations in studies of motor function. However, conventional force sensors cannot be used in fMRI environment, since metal elements generate noise which severely contaminate the signals of fMRI. An optical 2-axis force sensor has been developed using photo sensors and optical fibers by Tada et al., that resolved these problems. The developed force sensor removed all magnetic components from the sensing part. It detected minute displacements by measure amount of light and light traveled through the optical fibers. However, there still remain several problems on this optical force sensor. Firstly, the accuracy is not high compared to the conventional force sensors. Secondly, the robustness is not enough against the contact force to the optical fibers. In this paper, the problems concerning to the acturacy and the sensor output stability has been improved by novel methods of fixing fibers and arithmetic circuit. An optical 6-axis force is developed based on these improvements, and usefulness of our sensor for brain function analysis is confirmed in fMRI experimentations. (author)

  10. 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....... 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...

  11. Preoperative functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS)

    DEFF Research Database (Denmark)

    Hartwigsen, G.; Siebner, Hartwig R.; Stippich, C.

    2010-01-01

    of essential cortex, it cannot provide information preoperatively for surgical planning.Brain imaging techniques such as functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS) are increasingly being used to localize functionally critical cortical......, if the stimulated cortex makes a critical contribution to the brain functions subserving the task. While the relationship between task and functional activation as revealed by fMRI is correlative in nature, the neurodisruptive effect of TMS reflects a causal effect on brain activity.The use of preoperative f...

  12. Functional Topography of Human Corpus Callosum: An fMRI Mapping Study

    OpenAIRE

    Fabri, Mara; Polonara, Gabriele

    2013-01-01

    The concept of a topographical map of the corpus callosum (CC) has emerged from human lesion studies and from electrophysiological and anatomical tracing investigations in other mammals. Over the last few years a rising number of researchers have been reporting functional magnetic resonance imaging (fMRI) activation in white matter, particularly the CC. In this study the scope for describing CC topography with fMRI was explored by evoking activation through simple sensory stimulation and moto...

  13. Gait improvement after treadmill training in ischemic stroke survivors: A critical review of functional MRI studies ☆

    OpenAIRE

    Xiao, Xiang; Huang, Dongfeng; O’Young, Bryan

    2012-01-01

    Stroke survivors often present with abnormal gait, movement training can improve the walking performance post-stroke, and functional MRI can objectively evaluate the brain functions before and after movement training. This paper analyzes the functional MRI changes in patients with ischemic stroke after treadmill training with voluntary and passive ankle dorsiflexion. Functional MRI showed that there are some changes in some regions of patients with ischemic stroke including primary sensorimot...

  14. 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

  15. 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

  16. Functional MRI of the pharynx in obstructive sleep apnea (OSA) with rapid 2-D flash sequences

    International Nuclear Information System (INIS)

    Jaeger, L.; Guenther, E.; Gauger, J.; Nitz, W.; Kastenbauer, E.; Reiser, M.

    1996-01-01

    Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager ('Vision', Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an in-plane resolution of 2.67x1.8 mm were achieved. The mobility of the tongue, soft palate and pharyngeal surface could be clearly delineated. The MRI findings correlated well with the clinical examinations. We propose ultrafast MRI as a reliable and non-invasive method of evaluating pharyngeal obstruction and their levels. (orig.) [de

  17. Large-scale functional MRI analysis to accumulate knowledge on brain functions

    International Nuclear Information System (INIS)

    Schwartz, Yannick

    2015-01-01

    How can we accumulate knowledge on brain functions? How can we leverage years of research in functional MRI to analyse finer-grained psychological constructs, and build a comprehensive model of the brain? Researchers usually rely on single studies to delineate brain regions recruited by mental processes. They relate their findings to previous works in an informal way by defining regions of interest from the literature. Meta-analysis approaches provide a more principled way to build upon the literature. This thesis investigates three ways to assemble knowledge using activation maps from a large amount of studies. First, we present an approach that uses jointly two similar fMRI experiments, to better condition an analysis from a statistical standpoint. We show that it is a valuable data-driven alternative to traditional regions of interest analyses, but fails to provide a systematic way to relate studies, and thus does not permit to integrate knowledge on a large scale. Because of the difficulty to associate multiple studies, we resort to using a single dataset sampling a large number of stimuli for our second contribution. This method estimates functional networks associated with functional profiles, where the functional networks are interacting brain regions and the functional profiles are a weighted set of cognitive descriptors. This work successfully yields known brain networks and automatically associates meaningful descriptions. Its limitations lie in the unsupervised nature of this method, which is more difficult to validate, and the use of a single dataset. It however brings the notion of cognitive labels, which is central to our last contribution. Our last contribution presents a method that learns functional atlases by combining several datasets. [Henson 2006] shows that forward inference, i.e. the probability of an activation given a cognitive process, is often not sufficient to conclude on the engagement of brain regions for a cognitive process

  18. Relationship between DCE-MRI morphological and functional features and histopathological characteristics of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Montemurro, Filippo; Redana, Stefania; Aglietta, Massimo [Institute for Cancer Research and Treatment, Unit of Medical Oncology, Candiolo, Torino (Italy); Martincich, Laura; Bertotto, Ilaria; Cellini, Lisa [Institute for Cancer Research and Treatment, Unit of Diagnostic Imaging, Candiolo, Torino (Italy); Sarotto, Ivana [Institute for Cancer Research and Treatment, Unit of Surgical Pathology, Candiolo, Torino (Italy); Ponzone, Riccardo; Sismondi, Piero [Institute for Cancer Research and Treatment, Unit of Gynaecological Oncology, Candiolo, Torino (Italy); Regge, Daniele [Institute for Science Interchange Foundation, Torino (Italy)

    2007-06-15

    We studied whether dynamic contrast-enhanced MRI (DCE-MRI) could identify histopathological characteristics of breast cancer. Seventy-five patients with breast cancer underwent DCE-MRI followed by core biopsy. DCE-MRI findings were evaluated following the scoring system published by Fischer in 1999. In this scoring system, five DCE-MRI features, three morphological (shape, margins, enhancement kinetic) and two functional (initial peak of signal intensity (SI) increase and behavior of signal intensity curve), are defined by 14 parameters. Each parameter is assigned points ranging from 0 to 1 or 0 to 2, with higher points for those that are more likely to be associated with malignancy. The sum of all the points defines the degree of suspicion of malignancy, with a score 0 representing the lowest and 8 the highest degree of suspicion. Associations between DCE-MRI features and tumor histopathological characteristics assessed on core biopsies (histological type, grading, estrogen and progesterone receptor status, Ki67 and HER2 status) were studied by contingency tables and logistic regression analysis. We found a significant inverse association between the Fischer's score and HER2-overexpression (odds ratio-OR 0.608, p = 0.02). Based on our results, we suggest that lesions with intermediate-low suspicious DCE-MRI parameters may represent a subset of tumor with poor histopathological characteristics. (orig.)

  19. MRI tools for assessment of microstructure and nephron function of the kidney

    Science.gov (United States)

    Bennett, Kevin M.; Liu, Chunlei; Johnson, G. Allan; Zhang, Jeff Lei; Lee, Vivian S.

    2016-01-01

    MRI can provide excellent detail of renal structure and function. Recently, novel MR contrast mechanisms and imaging tools have been developed to evaluate microscopic kidney structures including the tubules and glomeruli. Quantitative MRI can assess local tubular function and is able to determine the concentrating mechanism of the kidney noninvasively in real time. Measuring single nephron function is now a near possibility. In parallel to advancing imaging techniques for kidney microstructure is a need to carefully understand the relationship between the local source of MRI contrast and the underlying physiological change. The development of these imaging markers can impact the accurate diagnosis and treatment of kidney disease. This study reviews the novel tools to examine kidney microstructure and local function and demonstrates the application of these methods in renal pathophysiology. PMID:27630064

  20. On the Averaging of Cardiac Diffusion Tensor MRI Data: The Effect of Distance Function Selection

    Science.gov (United States)

    Giannakidis, Archontis; Melkus, Gerd; Yang, Guang; Gullberg, Grant T.

    2016-01-01

    Diffusion tensor magnetic resonance imaging (DT-MRI) allows a unique insight into the microstructure of highly-directional tissues. The selection of the most proper distance function for the space of diffusion tensors is crucial in enhancing the clinical application of this imaging modality. Both linear and nonlinear metrics have been proposed in the literature over the years. The debate on the most appropriate DT-MRI distance function is still ongoing. In this paper, we presented a framework to compare the Euclidean, affine-invariant Riemannian and log-Euclidean metrics using actual high-resolution DT-MRI rat heart data. We employed temporal averaging at the diffusion tensor level of three consecutive and identically-acquired DT-MRI datasets from each of five rat hearts as a means to rectify the background noise-induced loss of myocyte directional regularity. This procedure is applied here for the first time in the context of tensor distance function selection. When compared with previous studies that used a different concrete application to juxtapose the various DT-MRI distance functions, this work is unique in that it combined the following: (i) Metrics were judged by quantitative –rather than qualitative– criteria, (ii) the comparison tools were non-biased, (iii) a longitudinal comparison operation was used on a same-voxel basis. The statistical analyses of the comparison showed that the three DT-MRI distance functions tend to provide equivalent results. Hence, we came to the conclusion that the tensor manifold for cardiac DT-MRI studies is a curved space of almost zero curvature. The signal to noise ratio dependence of the operations was investigated through simulations. Finally, the “swelling effect” occurrence following Euclidean averaging was found to be too unimportant to be worth consideration. PMID:27754986

  1. On the averaging of cardiac diffusion tensor MRI data: the effect of distance function selection

    Science.gov (United States)

    Giannakidis, Archontis; Melkus, Gerd; Yang, Guang; Gullberg, Grant T.

    2016-11-01

    Diffusion tensor magnetic resonance imaging (DT-MRI) allows a unique insight into the microstructure of highly-directional tissues. The selection of the most proper distance function for the space of diffusion tensors is crucial in enhancing the clinical application of this imaging modality. Both linear and nonlinear metrics have been proposed in the literature over the years. The debate on the most appropriate DT-MRI distance function is still ongoing. In this paper, we presented a framework to compare the Euclidean, affine-invariant Riemannian and log-Euclidean metrics using actual high-resolution DT-MRI rat heart data. We employed temporal averaging at the diffusion tensor level of three consecutive and identically-acquired DT-MRI datasets from each of five rat hearts as a means to rectify the background noise-induced loss of myocyte directional regularity. This procedure is applied here for the first time in the context of tensor distance function selection. When compared with previous studies that used a different concrete application to juxtapose the various DT-MRI distance functions, this work is unique in that it combined the following: (i) metrics were judged by quantitative—rather than qualitative—criteria, (ii) the comparison tools were non-biased, (iii) a longitudinal comparison operation was used on a same-voxel basis. The statistical analyses of the comparison showed that the three DT-MRI distance functions tend to provide equivalent results. Hence, we came to the conclusion that the tensor manifold for cardiac DT-MRI studies is a curved space of almost zero curvature. The signal to noise ratio dependence of the operations was investigated through simulations. Finally, the ‘swelling effect’ occurrence following Euclidean averaging was found to be too unimportant to be worth consideration.

  2. Individual preferences modulate incentive values: Evidence from functional MRI

    Directory of Open Access Journals (Sweden)

    Bosch Volker

    2008-11-01

    Full Text Available Abstract Background In most studies on human reward processing, reward intensity has been manipulated on an objective scale (e.g., varying monetary value. Everyday experience, however, teaches us that objectively equivalent rewards may differ substantially in their subjective incentive values. One factor influencing incentive value in humans is branding. The current study explores the hypothesis that individual brand preferences modulate activity in reward areas similarly to objectively measurable differences in reward intensity. Methods A wheel-of-fortune game comprising an anticipation phase and a subsequent outcome evaluation phase was implemented. Inside a 3 Tesla MRI scanner, 19 participants played for chocolate bars of three different brands that differed in subjective attractiveness. Results Parametrical analysis of the obtained fMRI data demonstrated that the level of activity in anatomically distinct neural networks was linearly associated with the subjective preference hierarchy of the brands played for. During the anticipation phases, preference-dependent neural activity has been registered in premotor areas, insular cortex, orbitofrontal cortex, and in the midbrain. During the outcome phases, neural activity in the caudate nucleus, precuneus, lingual gyrus, cerebellum, and in the pallidum was influenced by individual preference. Conclusion Our results suggest a graded effect of differently preferred brands onto the incentive value of objectively equivalent rewards. Regarding the anticipation phase, the results reflect an intensified state of wanting that facilitates action preparation when the participants play for their favorite brand. This mechanism may underlie approach behavior in real-life choice situations.

  3. Reviews of Functional MRI: The Ethical Dimensions of Methodological Critique

    Science.gov (United States)

    Anderson, James; Mizgalewicz, Ania; Illes, Judy

    2012-01-01

    Neuroimaging studies involving human subjects raise a range of ethics issues. Many of these issues are heightened in the context of neuroimaging research involving persons with mental health disorders. There has been growing interest in these issues among legal scholars, philosophers, social scientists, and as well as neuroimagers over the last decade. Less clear, however, is the extent to which members of the neuroimaging community are engaged with these issues when they undertake their research and report results. In this study, we analyze the peer-reviewed review literature involving fMRI as applied to the study of mental health disorders. Our hypothesis is that, due to the critical orientation of reviews, and the vulnerability of mental health population, the penetrance of neuroethics will be higher in the review literature in this area than it is in the primary fMRI research literature more generally. We find that while authors of reviews do focus a great deal of attention on the methodological limitations of the studies they discussed, contrary to our hypothesis, they do not frame concerns in ethical terms despite their ethical significance. We argue that an ethics lens on such discussion would increase the knowledge-value of this scholarly work. PMID:22952615

  4. Reviews of functional MRI: the ethical dimensions of methodological critique.

    Directory of Open Access Journals (Sweden)

    James Anderson

    Full Text Available Neuroimaging studies involving human subjects raise a range of ethics issues. Many of these issues are heightened in the context of neuroimaging research involving persons with mental health disorders. There has been growing interest in these issues among legal scholars, philosophers, social scientists, and as well as neuroimagers over the last decade. Less clear, however, is the extent to which members of the neuroimaging community are engaged with these issues when they undertake their research and report results. In this study, we analyze the peer-reviewed review literature involving fMRI as applied to the study of mental health disorders. Our hypothesis is that, due to the critical orientation of reviews, and the vulnerability of mental health population, the penetrance of neuroethics will be higher in the review literature in this area than it is in the primary fMRI research literature more generally. We find that while authors of reviews do focus a great deal of attention on the methodological limitations of the studies they discussed, contrary to our hypothesis, they do not frame concerns in ethical terms despite their ethical significance. We argue that an ethics lens on such discussion would increase the knowledge-value of this scholarly work.

  5. Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

    International Nuclear Information System (INIS)

    Anazodo, Udunna; Kewin, Matthew; Finger, Elizabeth; Thiessen, Jonathan; Hadway, Jennifer; Butler, John; Pavlosky, William; Prato, Frank; Thompson, Terry; St Lawrence, Keith

    2015-01-01

    PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

  6. Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Anazodo, Udunna; Kewin, Matthew [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Finger, Elizabeth [Department of Clinical Neurological Sciences, Western University, London, Ontario (Canada); Thiessen, Jonathan; Hadway, Jennifer; Butler, John [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Pavlosky, William [Diagnostic Imaging, St Joseph' s Health Care, London, Ontario (Canada); Prato, Frank; Thompson, Terry; St Lawrence, Keith [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada)

    2015-05-18

    PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

  7. Would the field of cognitive neuroscience be advanced by sharing functional MRI data?

    Directory of Open Access Journals (Sweden)

    Weissman Daniel H

    2011-04-01

    Full Text Available Abstract During the past two decades, the advent of functional magnetic resonance imaging (fMRI has fundamentally changed our understanding of brain-behavior relationships. However, the data from any one study add only incrementally to the big picture. This fact raises important questions about the dominant practice of performing studies in isolation. To what extent are the findings from any single study reproducible? Are researchers who lack the resources to conduct a fMRI study being needlessly excluded? Is pre-existing fMRI data being used effectively to train new students in the field? Here, we will argue that greater sharing and synthesis of raw fMRI data among researchers would make the answers to all of these questions more favorable to scientific discovery than they are today and that such sharing is an important next step for advancing the field of cognitive neuroscience.

  8. Changes of functional MRI findings in a patient whose pathological gambling improved with fluvoxamine.

    Science.gov (United States)

    Chung, Sang-Keun; You, Il-Han; Cho, Gwang-Hyun; Chung, Gyung-Ho; Shin, Young-Chul; Kim, Dai-Jin; Choi, Sam-Wook

    2009-06-30

    Legalized gambling is a growing industry, and is probably a factor in the presently increasing prevalence of pathological gambling. We present a case of a 36-year-old pathological gambler who was treated with fluvoxamine, a selective serotonin reuptake inhibitor, and who was assessed by functional MRI before and after drug administration. During activation periods, the pathological gambler was shown cards as stimuli, and fMRI results in several brain regions showed differential effects before and after medication and a maintenance period. This case demonstrates that the treatment response to fluvoxamine in a pathological gambler was observed not only by subjective self-report, but also by objective fMRI results. Therefore, fMRI may be a useful tool in the diagnosis and prediction of treatment response in patients afflicted with pathological gambling.

  9. Comparison of brain MRI findings with language and motor function in the dystroglycanopathies.

    Science.gov (United States)

    Brun, Brianna N; Mockler, Shelley R H; Laubscher, Katie M; Stephan, Carrie M; Wallace, Anne M; Collison, Julia A; Zimmerman, M Bridget; Dobyns, William B; Mathews, Katherine D

    2017-02-14

    To describe the spectrum of brain MRI findings in a cohort of individuals with dystroglycanopathies (DGs) and relate MRI results to function. All available brain MRIs done for clinical indications on individuals enrolled in a DG natural history study (NCT00313677) were reviewed. Reports were reviewed when MRI was not available. MRIs were categorized as follows: (1) cortical, brainstem, and cerebellar malformations; (2) cortical and cerebellar malformations; or (3) normal. Language development was assigned to 1 of 3 categories by a speech pathologist. Maximal motor function and presence of epilepsy were determined by history or examination. Twenty-five MRIs and 9 reports were reviewed. The most common MRI abnormalities were cobblestone cortex or dysgyria with an anterior-posterior gradient and cerebellar hypoplasia. Seven individuals had MRIs in group 1, 8 in group 2, and 19 in group 3. Language was impaired in 100% of those in MRI groups 1 and 2, and degree of language impairment correlated with severity of imaging. Eighty-five percent of the whole group achieved independent walking, but only 33% did in group 1. Epilepsy was present in 8% of the cohort and rose to 37% of those with an abnormal MRI. Developmental abnormalities of the brain such as cobblestone lissencephaly, cerebellar cysts, pontine hypoplasia, and brainstem bowing are hallmarks of DG and should prompt consideration of these diagnoses. Brain imaging in individuals with DG helps to predict outcomes, especially language development, aiding clinicians in prognostic counseling. © 2017 American Academy of Neurology.

  10. [Dynamics of functional MRI and speech function in patients after resection of frontal and temporal lobe tumors].

    Science.gov (United States)

    Buklina, S B; Batalov, A I; Smirnov, A S; Poddubskaya, A A; Pitskhelauri, D I; Kobyakov, G L; Zhukov, V Yu; Goryaynov, S A; Kulikov, A S; Ogurtsova, A A; Golanov, A V; Varyukhina, M D; Pronin, I N

    2017-01-01

    There are no studies on application of functional MRI (fMRI) for long-term monitoring of the condition of patients after resection of frontal and temporal lobe tumors. The study purpose was to correlate, using fMRI, reorganization of the speech system and dynamics of speech disorders in patients with left hemisphere gliomas before surgery and in the early and late postoperative periods. A total of 20 patients with left hemisphere gliomas were dynamically monitored using fMRI and comprehensive neuropsychological testing. The tumor was located in the frontal lobe in 12 patients and in the temporal lobe in 8 patients. Fifteen patients underwent primary surgery; 5 patients had repeated surgery. Sixteen patients had WHO Grade II and Grade III gliomas; the others had WHO Grade IV gliomas. Nineteen patients were examined preoperatively; 20 patients were examined at different times after surgery. Speech functions were assessed by a Luria's test; the dominant hand was determined using the Annette questionnaire; a family history of left-handedness was investigated. Functional MRI was performed on an HDtx 3.0 T scanner using BrainWavePA 2.0, Z software for fMRI data processing program for all calculations >7, pfrontal lobe tumors than in those with temporal lobe tumors. No additional activation foci in the left hemisphere were found at the thresholds used to process fMRI data. Recovery of the speech function, to a certain degree, occurred in all patients, but no clear correlation with fMRI data was found. Complex fMRI and neuropsychological studies in 20 patients after resection of frontal and temporal lobe tumors revealed individual features of speech system reorganization within one year follow-up. Probably, activation of right-sided homologues of the speech areas in the presence of left hemisphere tumors depends not only on the severity of speech disorder but also reflects individual involvement of the right hemisphere in enabling speech function. This is confirmed by

  11. Fusing Simultaneous EEG and fMRI Using Functional and Anatomical Information

    DEFF Research Database (Denmark)

    Hansen, Sofie Therese; Winkler, Irene; Hansen, Lars Kai

    2015-01-01

    SPoC), to not only use functional but also anatomical information. The goal is to extract correlated source components from electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Anatomical information enters our proposed extension to mSPoC via the forward model, which relates the activity...

  12. Preoperative MRI findings and functional outcome after selective dorsal rhizotomy in children with bilateral spasticity

    NARCIS (Netherlands)

    Grunt, S.; Becher, J.G.S.J.S.; van Schie, P.E.M.; van Ouwerkerk, W.J.R.; Ahmadi, N.; Vermeulen, R.J.

    2010-01-01

    Purpose: To identify MRI characteristics that may predict the functional effect of selective dorsal rhizotomy (SDR) in children with bilateral spastic paresis. Methods: We performed SDR in a group of 36 patients. The gross motor functioning measure-66 (GMFM-66) was applied before and after SDR.

  13. 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)

  14. Functional MRI evidence for fine motor praxis dysfunction in children with persistent speech disorders

    Science.gov (United States)

    Redle, Erin; Vannest, Jennifer; Maloney, Thomas; Tsevat, Rebecca K.; Eikenberry, Sarah; Lewis, Barbara; Shriberg, Lawrence D.; Tkach, Jean; Holland, Scott K.

    2014-01-01

    Children with persistent speech disorders (PSD) often present with overt or subtle motor deficits; the possibility that speech disorders and motor deficits could arise from a shared neurological base is currently unknown. Functional MRI (fMRI) was used to examine the brain networks supporting fine motor praxis in children with PSD and without clinically identified fine motor deficits. Methods This case-control study included 12 children with PSD (mean age 7.42 years, 4 female) and 12 controls (mean age 7.44 years, 4 female). Children completed behavioral evaluations using standardized motor assessments and parent reported functional measures. During fMRI scanning, participants completed a cued finger tapping task contrasted passive listening. A general linear model approach identified brain regions associated with finger tapping in each group and regions that differed between groups. The relationship between regional fMRI activation and fine motor skill was assessed using a regression analysis. Results Children with PSD had significantly poorer results for rapid speech production and fine motor praxis skills, but did not differ on classroom functional skills. Functional MRI results showed that children with PSD had significantly more activation in the cerebellum during finger tapping. Positive correlations between performance on a fine motor praxis test and activation multiple cortical regions were noted for children with PSD but not for controls. Conclusions Over-activation in the cerebellum during a motor task may reflect a subtle abnormality in the non-speech motor neural circuitry in children with PSD. PMID:25481413

  15. Cognitive function and MRI findings in very low birth weight infants

    International Nuclear Information System (INIS)

    Imamura, Atsuko; Takagishi, Yuka; Takada, Satoru; Uetani, Yoshiyuki; Nakamura, Toru; Nakamura, Hajime; Inagaki, Yuko.

    1996-01-01

    Twenty-two very low birth weight infants at preschool ages of 5-6 years were studied to clarify the correlation between cognitive function and MRI findings. Cognitive function was evaluated by the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Frostig developmental test of visual perception. Ventricular enlargement, assessed by the bioccipital index (B.I.) measured on MRI, was correlated to cognitive disorders. Children with periventricular high intensity areas (T 2 -weighted images) extending from the posterior periventricular region to the parietal lobe tend to highly suffer from cerebral palsy and visuoperceptual impairment. These results indicate that the disorders of cognitive function in very low birth weight infants were caused by a damage of association fibers in periventricular areas which was detectable by MRI. (author)

  16. Cognitive function and MRI findings in very low birth weight infants

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Atsuko; Takagishi, Yuka; Takada, Satoru; Uetani, Yoshiyuki; Nakamura, Toru; Nakamura, Hajime [Kobe Univ. (Japan). School of Medicine; Inagaki, Yuko

    1996-07-01

    Twenty-two very low birth weight infants at preschool ages of 5-6 years were studied to clarify the correlation between cognitive function and MRI findings. Cognitive function was evaluated by the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Frostig developmental test of visual perception. Ventricular enlargement, assessed by the bioccipital index (B.I.) measured on MRI, was correlated to cognitive disorders. Children with periventricular high intensity areas (T{sub 2}-weighted images) extending from the posterior periventricular region to the parietal lobe tend to highly suffer from cerebral palsy and visuoperceptual impairment. These results indicate that the disorders of cognitive function in very low birth weight infants were caused by a damage of association fibers in periventricular areas which was detectable by MRI. (author)

  17. Pharmaco fMRI: Determining the functional anatomy of the effects of medication.

    Science.gov (United States)

    Wandschneider, Britta; Koepp, Matthias J

    2016-01-01

    Functional MRI studies have helped to elucidate underlying mechanisms in complex neurological and neuropsychiatric disorders. Disease processes often involve complex large-scale network interactions, extending beyond the presumed main disease focus. Given both the complexity of the clinical phenotype and the underlying dysfunctional brain circuits, so called pharmaco-fMRI (ph-MRI) studies probe pharmacological effects on functional neuro-anatomy, and can help to determine early treatment response, mechanisms of drug efficacy and side effects, and potentially advance CNS drug development. In this review, we discuss recent ph-MRI research in three major neuropsychiatric and neurological disorders and associated network alterations, namely selective serotonin and noradrenergic reuptake inhibitors in affective disorders and emotional processing circuits; antiepileptic drugs in epilepsy and cognitive networks; and stimulants in attention-deficit/hyperactivity disorder and networks of attention control. We conclude that ph-MRI studies show consistent and reproducible changes on disease relevant networks, and prove sensitive to early pharmacological effects on functional anatomy associated with disease. Further CNS drug research and development would benefit greatly from improved disease phenotyping, or biomarkers, using advanced imaging techniques.

  18. Functional correlates of cognitive dysfunction in multiple sclerosis: A multicenter fMRI Study.

    Science.gov (United States)

    Rocca, Maria A; Valsasina, Paola; Hulst, Hanneke E; Abdel-Aziz, Khaled; Enzinger, Christian; Gallo, Antonio; Pareto, Debora; Riccitelli, Gianna; Muhlert, Nils; Ciccarelli, Olga; Barkhof, Frederik; Fazekas, Franz; Tedeschi, Gioacchino; Arévalo, Maria J; Filippi, Massimo

    2014-12-01

    In this multicenter study, we applied functional magnetic resonance imaging (fMRI) to define the functional correlates of cognitive dysfunction in patients with multiple sclerosis (MS). fMRI scans during the performance of the N-back task were acquired from 42 right-handed relapsing remitting (RR) MS patients and 52 sex-matched right-handed healthy controls, studied at six European sites using 3.0 Tesla scanners. Patients with at least two abnormal (function of increasing task difficulty, CI MS patients had reduced activations of several areas located in the fronto-parieto-temporal lobes as well as reduced deactivations of regions which are part of the default mode network compared to the other two groups. Significant correlations were found between abnormal fMRI patterns of activations and deactivations and behavioral measures, cognitive performance, and brain T2 and T1 lesion volumes. This multicenter study supports the theory that a preserved fMRI activity of the frontal lobe is associated with a better cognitive profile in MS patients. It also indicates the feasibility of fMRI to monitor disease evolution and treatment effects in future studies. © 2014 Wiley Periodicals, Inc.

  19. The detection of the dynamic renal function using MRI by gadolinium-DTPA

    International Nuclear Information System (INIS)

    Torii, Shinichiro; Machida, Toyohei; Ohoishi, Yukihiko; Tateno, Yukio; Fukuda, Nobuo.

    1988-01-01

    The mathematical study of dynamic renal function and the simulation of renal disorder in rabbit kidney using MRI by Gd-DTPA were performed. T1 of rabbit kidney, which had been operated (complete unilateral ureteral occlusion or incomplete unilateral occlusion of renal artery) was calculated before and after intravenous injection of 0.05 mmol/kg Gd-DTPA, continuously for 90 minutes. All images were obtained by the 0.1 Tesla resistive type MRI. The changes of 1/T1 of cortex and medulla of both kidneys were calculated (MRI renogram). The 4 compartment model of bilateral kidneys was established by 6 normal MRI renogram and renal blood flow-glommelurar function parameter and tubural excration function parameter were calculated by the Runge-Kutta-Gill method and the nonlinear least squares method (Simplex method). The change of renogram pattern was observed by the mathematical change of such parameters and comparative study was performed between such mathematical simulation and practical cases. The actual change of such parameters were calculated by the experimental model of rabbit kidney. It was concluded that the change of MRI renogram pattern was sensitive for unilateral hydronephrosis, renal parenchymal dysfunction by obstructive uropathy and unilateral renal arterial stenosis. Quantitative observation of focal renal parenchymal dysfunction, which was induced by ureteral obstruction, was possible. In the near future it will be also possible to detect acculate ERBF and GFR by the measurement of T1 of human kidney. (author)

  20. Structural and functional MRI correlates of Stroop control in benign MS.

    Science.gov (United States)

    Rocca, Maria A; Valsasina, Paola; Ceccarelli, Antonia; Absinta, Martina; Ghezzi, Angelo; Riccitelli, Gianna; Pagani, Elisabetta; Falini, Andrea; Comi, Giancarlo; Scotti, Giuseppe; Filippi, Massimo

    2009-01-01

    The objective of this study was to assess the functional and structural substrates of cognitive network changes in patients with benign multiple sclerosis (BMS), using an analysis of effective connectivity and MR tractography. Using a 3-Tesla scanner, we acquired dual-echo, diffusion tensor (DT) and functional MRI during the performance of the Stroop task from 15 BMS patients and 19 healthy controls. DT MRI tractography was used to calculate DT derived metrics from several white matter (WM) fiber bundles, thought to be involved in cognitive performance. DT MRI metrics from WM fiber bundles not directly related with cognitive performance were also derived. Effective connectivity analysis was performed using statistical parametric mapping. MS patients had significantly abnormal DT MRI metrics in all the structures analyzed. Compared with controls, MS patients had more significant activations of several areas of the cognitive network involved in Stroop performance, bilaterally. Compared with controls, BMS patients also had increased connectivity strengths between several cortical areas of the sensorimotor network and the right (R) inferior frontal gyrus and the R cerebellum, as well as decreased connectivity strengths with the anterior cingulate cortex. Coefficients of altered connectivity were moderately correlated with structural MRI metrics of tissue damage within intra- and inter-hemispheric cognitive-related WM fiber bundles, while no correlations were found with the remaining fiber bundles studied, suggesting that functional cortical changes in patients with BMS might represent an adaptive response driven by damage of specific WM structures. (c) 2007 Wiley-Liss, Inc.

  1. Assessment of language lateralization with functional magnetic resonance imaging (fMRI)

    International Nuclear Information System (INIS)

    Salagierska-Barwinska, A.; Goraj, B.

    2004-01-01

    fMRI offers powerful methods to delineate which brain regions are engaged in language processing in the intact brain. Until now hemisphere dominance for language has been usually assessed by means of the intraoperative methods: the Wada test or electrocortical stimulation mapping. Recently functional MRI becomes the valuable method in determining hemisphere dominance for language. fMRI study was proved to be concordant with invasive measures. fMRI was carried out in 30 healthy selected participants (15 females: 10 strongly right-handed and 5 strongly left-handed; 15 males: 10 strongly right-handed and 5 strongly left-handed). The subject's handedness was assessed by standardized psychological tests inter alia the 'lateralization inventory'. Two different language tasks were used: a verb generation task and a phonological task. Subjects were scanned,while performing experimental block. The block contained alternately 8 active (language task) and 8 control conditions. Statistical analysis of evoked blood oxygenation level-dependent BOLD) responses, measured with echo planar imagining (1.5 T) were used. During a verb generation task in strongly right or left handed subjects the inferior frontal region was activated on the side opposite to the subject's handedness determined by the psychological test. Our fMRI studies demonstrated no gender effects on brain during these language tasks. Our study suggests that fMRI is a good device for the study of the language organization. The advantage of fMRI is its capacity for exact localization of activated areas. fMRI together with adequate neurolinguistic test could be promising routine preoperative tool in identification hemisphere dominance for language. These results encourage to further investigation for evaluating correlation in patients with brain injuries. (author)

  2. Low-Functioning Autism and Nonsyndromic Intellectual Disability: Magnetic Resonance Imaging (MRI) Findings.

    Science.gov (United States)

    Erbetta, Alessandra; Bulgheroni, Sara; Contarino, Valeria Elisa; Chiapparini, Luisa; Esposito, Silvia; Annunziata, Silvia; Riva, Daria

    2015-10-01

    Previous neuroradiologic studies reported a high incidence of abnormalities in low-functioning autistic children. In this population, it is difficult to know which abnormality depends on autism itself and which is related to intellectual disability associated with autism. The aim of this study was to evaluate the frequency of neuroradiologic abnormalities in low-functioning autistic children compared to Intellectual Quotient and age-matched nonsyndromic children, using the same set of magnetic resonance imaging (MRI) sequences. MRI was rated as abnormal in 44% of autistic and 54% of children with intellectual disability. The main results were mega cisterna magna in autism and hypoplastic corpus callosum in intellectual disability. These abnormalities are morphologically visible signs of altered brain development. These findings, more frequent than expected, are not specific to the 2 conditions. Although MRI cannot be considered mandatory, it allows an in-depth clinical assessment in nonsyndromic intellectual-disabled and autistic children. © The Author(s) 2015.

  3. Relationship between functional connectivity and motor function assessment in stroke patients with hemiplegia: a resting-state functional MRI study

    International Nuclear Information System (INIS)

    Zhang, Ye; Wang, Li; Zhang, Jingna; Sang, Linqiong; Li, Pengyue; Qiu, Mingguo; Liu, Hongliang; Yan, Rubing; Yang, Jun; Wang, Jian

    2016-01-01

    Resting-state functional magnetic resonance imaging (fMRI) has been used to examine the brain mechanisms of stroke patients with hemiplegia, but the relationship between functional connectivity (FC) and treatment-induced motor function recovery has not yet been fully investigated. This study aimed to identify the brain FC changes in stroke patients and study the relationship between FC and motor function assessment using the resting-state fMRI. Seventeen stroke patients with hemiplegia and fifteen healthy control subjects (HCSs) were recruited in this study. We compared the FC between the ipsilesional primary motor cortex (M1) and the whole brain of the patients with the FC of the HCSs and studied the FC changes in the patients before and after conventional rehabilitation and motor imagery therapy. Additionally, correlations between the FC change and motor function of the patients were studied. Compared to the HCSs, the FC in the patient group was significantly increased between the ipsilesional M1 and the ipsilesional inferior parietal cortex, frontal gyrus, supplementary motor area (SMA), and contralesional angular and decreased between the ipsilesional M1 and bilateral M1. After the treatment, the FC between the ipsilesional M1 and contralesional M1 increased while the FC between the ipsilesional M1 and ipsilesional SMA and paracentral lobule decreased. A statistically significant correlation was found between the FC change in the bilateral M1 and the Fugl-Meyer assessment (FMA) score change. Our results revealed an abnormal motor network after stroke and suggested that the FC could serve as a biomarker of motor function recovery in stroke patients with hemiplegia. (orig.)

  4. Bayesian Inference for Functional Dynamics Exploring in fMRI Data

    Directory of Open Access Journals (Sweden)

    Xuan Guo

    2016-01-01

    Full Text Available This paper aims to review state-of-the-art Bayesian-inference-based methods applied to functional magnetic resonance imaging (fMRI data. Particularly, we focus on one specific long-standing challenge in the computational modeling of fMRI datasets: how to effectively explore typical functional interactions from fMRI time series and the corresponding boundaries of temporal segments. Bayesian inference is a method of statistical inference which has been shown to be a powerful tool to encode dependence relationships among the variables with uncertainty. Here we provide an introduction to a group of Bayesian-inference-based methods for fMRI data analysis, which were designed to detect magnitude or functional connectivity change points and to infer their functional interaction patterns based on corresponding temporal boundaries. We also provide a comparison of three popular Bayesian models, that is, Bayesian Magnitude Change Point Model (BMCPM, Bayesian Connectivity Change Point Model (BCCPM, and Dynamic Bayesian Variable Partition Model (DBVPM, and give a summary of their applications. We envision that more delicate Bayesian inference models will be emerging and play increasingly important roles in modeling brain functions in the years to come.

  5. Detection of Brain Reorganization in Pediatric Multiple Sclerosis Using Functional MRI

    Science.gov (United States)

    2015-10-01

    Page | 2 AWARD NUMBER: W81XWH-13-1-0464 TITLE: Detection of Brain Reorganization in Pediatric Multiple Sclerosis Using Functional MRI...Sep 2014 – 29 Sep 2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Detection of Brain Reorganization in Pediatric Multiple Sclerosis Using Functional...adaptive functional reorganization as a way to explain how some early-stage MS patients are able to perform well in clinical cognitive testing

  6. Model-free functional MRI analysis for detecting low-frequency functional connectivity in the human brain

    Science.gov (United States)

    Wismueller, Axel; Lange, Oliver; Auer, Dorothee; Leinsinger, Gerda

    2010-03-01

    Slowly varying temporally correlated activity fluctuations between functionally related brain areas have been identified by functional magnetic resonance imaging (fMRI) research in recent years. These low-frequency oscillations of less than 0.08 Hz appear to play a major role in various dynamic functional brain networks, such as the so-called 'default mode' network. They also have been observed as a property of symmetric cortices, and they are known to be present in the motor cortex among others. These low-frequency data are difficult to detect and quantify in fMRI. Traditionally, user-based regions of interests (ROI) or 'seed clusters' have been the primary analysis method. In this paper, we propose unsupervised clustering algorithms based on various distance measures to detect functional connectivity in resting state fMRI. The achieved results are evaluated quantitatively for different distance measures. The Euclidian metric implemented by standard unsupervised clustering approaches is compared with a non-metric topographic mapping of proximities based on the the mutual prediction error between pixel-specific signal dynamics time-series. It is shown that functional connectivity in the motor cortex of the human brain can be detected based on such model-free analysis methods for resting state fMRI.

  7. Functional alterations of V1 cortex in patients with primary open angle glaucoma using functional MRI retinotopic mapping

    International Nuclear Information System (INIS)

    Shi Linping; Cai Ping; Li Changying; Li Xueqin; Xie Bing; Li Sha; Liu Ting; Chen Xing; Shi Yanshu; Wang Jian

    2011-01-01

    Objective: To evaluate the functional changes of visual cortex (V1) in patients with primary open angle glaucoma (POAG) by fMRI retinotopic mapping technology. Methods: Fifteen POAG patients and 15 healthy volunteers underwent stimulations with fMRI retinotopic mapping stimulus and contrast-reversing checkerboard patterns stimulus on a Siemens Trio 3.0 T MRI whole-body scanner for functional data collection. Comparisons of V1 fMRI responses between the glaucomatous eyes and the healthy eyes of the patients were carried out using paired samples t-test, while independent samples t-test was used to compare V1 fMRI responses and activations between the healthy eyes of patients and the age-, gender- and side- matched eyes of normal people. Differences of V1 cortical functions and visual functions were analyzed by linear correlation analysis when the glaucomatous and the healthy eyes were simulated individually., Results: (1) V1 fMRI responses of the individually stimulated glaucomatous eyes [(1.24±0.72)%] were weaker than those of the healthy eyes [(2.18±0.93)%] (t=4.757, P 0.05). (2) Differences of V1 cortical functions were negatively correlated with those of visual functions in the individually stimulated glaucomatous and healthy eyes (r=-0.887, P< 0.01). (3) The activated area indexes of V1 cortexes in the healthy eyes from patients (0.72±0.12) were lower than those in the matched eyes of normal people (0.85±0.09) (t=-3.801, P<0.01) . Conclusion: Cortical function impairment was in accordance with visual function impairment in glaucoma. Located and quantified measurement with fMRI retinotopic mapping was a useful method for clinical follow-up and evaluation of functional alteration of glaucomatous visual cortex, and a potentially useful means of studying trans-synaptic degeneration of visual pathways of in vivo glaucoma. (authors)

  8. Comparison of quantitative regional ventilation-weighted fourier decomposition MRI with dynamic fluorinated gas washout MRI and lung function testing in COPD patients.

    Science.gov (United States)

    Kaireit, Till F; Gutberlet, Marcel; Voskrebenzev, Andreas; Freise, Julia; Welte, Tobias; Hohlfeld, Jens M; Wacker, Frank; Vogel-Claussen, Jens

    2017-11-21

    Ventilation-weighted Fourier decomposition-MRI (FD-MRI) has matured as a reliable technique for quantitative measures of regional lung ventilation in recent years, but has yet not been validated in COPD patients. To compare regional fractional lung ventilation obtained by ventilation-weighted FD-MRI with dynamic fluorinated gas washout MRI ( 19 F-MRI) and lung function test parameters. Prospective study. Twenty-seven patients with chronic obstructive pulmonary disease (COPD, median age 61 [54-67] years) were included. For FD-MRI and for 19 F-MRI a spoiled gradient echo sequence was used at 1.5T. FD-MRI coronal slices were acquired in free breathing. Dynamic 19 F-MRI was performed after inhalation of 25-30 L of a mixture of 79% fluorinated gas (C 3 F 8 ) and 21% oxygen via a closed face mask tubing using a dedicated coil tuned to 59.9 MHz. 19 F washout times in numbers of breaths ( 19 F-n breaths ) as well as fractional ventilation maps for both methods (FD-FV, 19 F-FV) were calculated. Slices were matched using a landmark driven algorithm, and only corresponding slices with an overlap of >90% were coregistered for evaluation. The obtained parameters were correlated with each other using Spearman's correlation coefficient (r). FD-FV strongly correlated with 19 F-n breaths on a global (r = -0.72, P Fourier decomposition-MRI is a promising noninvasive, radiation-free tool for quantification of regional ventilation in COPD patients. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

  9. Motor function deficits in schizophrenia: an fMRI and VBM study

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sadhana; Modi, Shilpi; Kumar, Pawan; Singh, Namita; Khushu, Subash [Institute of Nuclear Medicine and Allied Sciences (INMAS), NMR Research Center, Delhi (India); Goyal, Satnam; Bhatia, Triptish; Deshpande, Smita N. [RML Hospital, PGIMER, New Delhi (India)

    2014-05-15

    To investigate whether the motor functional alterations in schizophrenia (SZ) are also associated with structural changes in the related brain areas using functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM). A sample of 14 right-handed SZ patients and 14 right-handed healthy control subjects matched for age, sex, and education were examined with structural high-resolution T1-weighted MRI; fMRI images were obtained during right index finger-tapping task in the same session. fMRI results showed reduced functional activation in the motor areas (contralateral precentral and postcentral gyrus) and ipsilateral cerebellum in SZ subjects as compared to healthy controls (n = 14). VBM analysis also revealed reduced grey matter in motor areas and white matter reduction in cerebellum of SZ subjects as compared to controls. The present study provides an evidence for a possible association between structural alterations in the motor cortex and disturbed functional activation in the motor areas in persons affected with SZ during a simple finger-tapping task. (orig.)

  10. Secretin-stimulated MRI characterization of pancreatic morphology and function in patients with chronic pancreatitis.

    Science.gov (United States)

    Madzak, Adnan; Olesen, Søren Schou; Haldorsen, Ingfrid Salvesen; Drewes, Asbjørn Mohr; Frøkjær, Jens Brøndum

    Chronic pancreatitis (CP) is characterized by abnormal pancreatic morphology and impaired endocrine and exocrine function. However, little is known about the relationship between pancreatic morphology and function, and also the association with the etiology and clinical manifestations of CP. The aim was to explore pancreatic morphology and function with advanced MRI in patients with CP and healthy controls (HC) METHODS: Eighty-two patients with CP and 22 HC were enrolled in the study. Morphological imaging parameters included pancreatic main duct diameter, gland volume, fat signal fraction and apparent diffusion coefficient (ADC) values. Functional secretin-stimulated MRI (s-MRI) parameters included pancreatic secretion (bowel fluid volume) and changes in pancreatic ADC value before and after secretin stimulation. Patients were classified according to the modified Cambridge and M-ANNHEIM classification system and fecal elastase was collected. All imaging parameters differentiated CP patients from HC; however, correlations between morphological and functional parameters in CP were weak. Patients with alcoholic and non-alcoholic etiology had comparable s-MRI findings. Fecal elastase was positively correlated to pancreatic gland volume (r = 0.68, P = 0.0016) and negatively correlated to Cambridge classification (r = -0.35, P gland volume was negatively correlated to the duration of CP (r = -0.39, P gland volume was significantly decreased in the severe stages of CP (P = 0.001). S-MRI provides detailed information about pancreatic morphology and function and represents a promising non-invasive imaging method to characterize pancreatic pathophysiology and may enable monitoring of disease progression in patients with CP. Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  11. Central sensitization in fibromyalgia? A systematic review on structural and functional brain MRI.

    Science.gov (United States)

    Cagnie, Barbara; Coppieters, Iris; Denecker, Sien; Six, Jasmien; Danneels, Lieven; Meeus, Mira

    2014-08-01

    The aim of the present study was to systematically review the literature addressing pain-induced changes in the brain related to central sensitization in patients with fibromyalgia (FM) using specific functional (rs-fMRI and fMRI) and structural (voxel-based morphometry-VBM) brain MRI techniques. PubMed and Web of Science were searched for relevant literature using different key word combinations related to FM, brain MRI, and central sensitization. Full-text reports fulfilling the inclusion criteria were assessed on risk of bias and reviewed by two independent reviewers. From the 61 articles that were identified, 22 met the inclusion criteria and achieved sufficient methodological quality. Overall, eight articles examined structural brain (VBM) changes in patients with FM, showing moderate evidence that central sensitization is correlated with gray matter volume decrease in specific brain regions (mainly anterior cingulate cortex and prefrontal cortex). However, global gray matter volume remains unchanged. A total of 13 articles evaluated brain activity (fMRI) in response to a nociceptive stimulus. Findings suggest a higher but similar pattern of activation of the pain matrix in FM patients compared to controls. There is also evidence of decreased functional connectivity in the descending pain-modulating system in FM patients. Overall, two articles examined intrinsic brain connectivity in FM patients with rs-fMRI. In conclusion, there is moderate evidence for a significant imbalance of the connectivity within the pain network during rest in patients with FM. The included studies showed a moderate evidence for region-specific changes in gray matter volume, a decreased functional connectivity in the descending pain-modulating system, and an increased activity in the pain matrix related to central sensitization. More research is needed to evaluate the cause-effect relationship. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Functional MRI, DTI and neurophysiology in horizontal gaze palsy with progressive scoliosis.

    Science.gov (United States)

    Haller, Sven; Wetzel, Stephan G; Lütschg, Jürg

    2008-05-01

    Horizontal gaze palsy with progressive scoliosis (HGPPS) is an autosomal recessive disease due to a mutation in the ROBO3 gene. This rare disease is of particular interest because the absence, or at least reduction, of crossing of the ascending lemniscal and descending corticospinal tracts in the medulla predicts abnormal ipsilateral sensory and motor systems. We evaluated the use of functional magnetic resonance imaging (fMRI) for the first time in this disease and compared it to diffusion tensor imaging (DTI) tractography and neurophysiological findings in the same patient with genetically confirmed ROBO3 mutation. As expected, motor fMRI, somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP) were dominantly ipsilateral to the stimulation side. DTI tractography revealed ipsilateral ascending and descending connectivity in the brainstem yet normal interhemispheric connections in the corpus callosum. Auditory fMRI revealed bilateral auditory activation to monaural left-sided auditory stimulation. No significant cortical activation was observed after monaural right-sided stimulation, a hearing defect having been excluded. Prosaccades fMRI showed no activations in the eye-movement network. Motor fMRI confirmed the established findings of DTI and neurophysiology in the same patient. In suspected HGPPS, any technique appears appropriate for further investigation. Auditory fMRI suggests that a monaural auditory system with bilateral auditory activations might be a physiological advantage as compared to a binaural yet only unilateral auditory system, in analogy to anisometropic amblyopia. Moving-head fMRI studies in the future might show whether the compensatory head movements instead of normal eye movements activate the eye-movement network.

  13. Functional MRI, DTI and neurophysiology in horizontal gaze palsy with progressive scoliosis

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Sven; Wetzel, Stephan G. [University Hospital Basel, Institute of Radiology, Department of Neuroradiology, Basel (Switzerland); Luetschg, Juerg [University Children' s Hospital (UKBB), Basel (Switzerland)

    2008-05-15

    Horizontal gaze palsy with progressive scoliosis (HGPPS) is an autosomal recessive disease due to a mutation in the ROBO3 gene. This rare disease is of particular interest because the absence, or at least reduction, of crossing of the ascending lemniscal and descending corticospinal tracts in the medulla predicts abnormal ipsilateral sensory and motor systems. We evaluated the use of functional magnetic resonance imaging (fMRI) for the first time in this disease and compared it to diffusion tensor imaging (DTI) tractography and neurophysiological findings in the same patient with genetically confirmed ROBO3 mutation. As expected, motor fMRI, somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP) were dominantly ipsilateral to the stimulation side. DTI tractography revealed ipsilateral ascending and descending connectivity in the brainstem yet normal interhemispheric connections in the corpus callosum. Auditory fMRI revealed bilateral auditory activation to monaural left-sided auditory stimulation. No significant cortical activation was observed after monaural right-sided stimulation, a hearing defect having been excluded. Prosaccades fMRI showed no activations in the eye-movement network. Motor fMRI confirmed the established findings of DTI and neurophysiology in the same patient. In suspected HGPPS, any technique appears appropriate for further investigation. Auditory fMRI suggests that a monaural auditory system with bilateral auditory activations might be a physiological advantage as compared to a binaural yet only unilateral auditory system, in analogy to anisometropic amblyopia. Moving-head fMRI studies in the future might show whether the compensatory head movements instead of normal eye movements activate the eye-movement network. (orig.)

  14. Functional MRI, DTI and neurophysiology in horizontal gaze palsy with progressive scoliosis

    International Nuclear Information System (INIS)

    Haller, Sven; Wetzel, Stephan G.; Luetschg, Juerg

    2008-01-01

    Horizontal gaze palsy with progressive scoliosis (HGPPS) is an autosomal recessive disease due to a mutation in the ROBO3 gene. This rare disease is of particular interest because the absence, or at least reduction, of crossing of the ascending lemniscal and descending corticospinal tracts in the medulla predicts abnormal ipsilateral sensory and motor systems. We evaluated the use of functional magnetic resonance imaging (fMRI) for the first time in this disease and compared it to diffusion tensor imaging (DTI) tractography and neurophysiological findings in the same patient with genetically confirmed ROBO3 mutation. As expected, motor fMRI, somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP) were dominantly ipsilateral to the stimulation side. DTI tractography revealed ipsilateral ascending and descending connectivity in the brainstem yet normal interhemispheric connections in the corpus callosum. Auditory fMRI revealed bilateral auditory activation to monaural left-sided auditory stimulation. No significant cortical activation was observed after monaural right-sided stimulation, a hearing defect having been excluded. Prosaccades fMRI showed no activations in the eye-movement network. Motor fMRI confirmed the established findings of DTI and neurophysiology in the same patient. In suspected HGPPS, any technique appears appropriate for further investigation. Auditory fMRI suggests that a monaural auditory system with bilateral auditory activations might be a physiological advantage as compared to a binaural yet only unilateral auditory system, in analogy to anisometropic amblyopia. Moving-head fMRI studies in the future might show whether the compensatory head movements instead of normal eye movements activate the eye-movement network. (orig.)

  15. Effect of acupuncture in mild cognitive impairment and Alzheimer disease: a functional MRI study.

    Directory of Open Access Journals (Sweden)

    Zhiqun Wang

    Full Text Available We aim to clarify the mechanisms of acupuncture in treating mild cognitive impairment (MCI and Alzheimer disease (AD by using functional magnetic resonance imaging (fMRI. Thirty-six right-handed subjects (8 MCI patients, 14 AD patients, and 14 healthy elders participated in this study. Clinical and neuropsychological examinations were performed on all the subjects. MRI data acquisition was performed on a SIEMENS verio 3-Tesla scanner. The fMRI study used a single block experimental design. We first acquired the baseline resting state data in the initial 3 minutes; we then acquired the fMRI data during the procession of acupuncture stimulation on the acupoints of Tai chong and Hegu for the following 3 minutes. Last, we acquired fMRI data for another 10 minutes after the needle was withdrawn. The preprocessing and data analysis were performed using the statistical parametric mapping (SPM8 software. Then the two-sample t-tests were performed between each two groups of different states. We found that during the resting state, brain activities in AD and MCI patients were different from those of control subjects. During the acupuncture and the second resting state after acupuncture, when comparing to resting state, there are several regions showing increased or decreased activities in MCI, AD subjects compared to normal subjects. Most of the regions were involved in the temporal lobe and the frontal lobe, which were closely related to the memory and cognition. In conclusion, we investigated the effect of acupuncture in AD and MCI patients by combing fMRI and traditional acupuncture. Our fMRI study confirmed that acupuncture at Tai chong (Liv3 and He gu (LI4 can activate certain cognitive-related regions in AD and MCI patients.

  16. 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.)

  17. 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.)

  18. A functional MRI study of somatotopic representation of somatosensory stimulation in the cerebellum

    Energy Technology Data Exchange (ETDEWEB)

    Takanashi, M.; Abe, K.; Yanagihara, T.; Sakoda, S. [Dept. of Neurology D4, Osaka Univ. Graduate School of Medicine, Suita City, Osaka (Japan); Tanaka, H.; Hirabuki, N.; Nakamura, H.; Fujita, N. [Dept. of Radiology, Osaka Univ. Graduate School of Medicine, Suita City, Osaka (Japan)

    2003-03-01

    Somatotopic representation in the cerebral cortex of somatosensory stimulation has been widely reported, but that in the cerebellum has not. We investigated the latter in the human cerebellum by functional MRI (fMRI). Using a 1.5 tesla imager, we obtained multislice blood oxygen level-dependent fMRI with single-shot gradient-echo echoplanar imaging in seven right-handed volunteers during electrical stimulation of the left index finger and big toe. In the anterior and posterior cerebellum, activated pixels for the index finger were separate from those for the toe. This suggests that somatosensory stimulation of different parts of the body may involve distinct areas of in the cerebellum as well as the cerebral cortex. (orig.)

  19. Functional magnetic resonance imaging (fMRI) of motor deficits in schizophrenia

    International Nuclear Information System (INIS)

    Wenz, F.; Floemer, F.; Kaick, G. van

    1995-01-01

    The purpose of this study was to investigate differences in the cerebral activation pattern in ten schizophrenic patients and ten healthy volunteers using functional MRI. fMRI was performed using a modified FLASH sequence (TR/TE/α=100/60/40 ) and a conventional 1.5 T MR scanner. Colorcoded statistical parametric maps based on Student's t-test were calculated. Activation strength was quantified using a 5x6 grid overlay. The volunteers showed a higher activation strength during left hand movement compared to right hand movement. This lateralization effect was reversed in patients who showed overall reduced activation strength. Disturbed interhemispheric balance in schizophrenic patients during motor task performance can be demonstrated using fMRI. (orig.) [de

  20. Hemodynamic response based mixture model to estimate micro- and macro-vasculature contributions in functional MRI

    CERN Document Server

    Singh, Manbir; Sungkarat, Witaya; Zhou, Yongxia

    2003-01-01

    A multi-componet model reflecting the temporal characteristics of micro- and macro-vasculature hemodynamic responses was used to fit the time-course of voxels in functional MRI (fMRI). The number of relevant components, the latency of the first component, the time- separation among the components, their relative amplitude and possible interpretation in terms of partial volume contributions of micro- and macro-components to the time-course data were investigated. Analysis of a reversing checkerboard experiment revealed that there was no improvement in the filing beyond two components. Using a two-component model, the fractional abundances of the micro- and macro-vasculature were estimated in individual voxels. These results suggest the potential of a mixture-model approach to mitigate partial volume effects and separate contributions of vascular components within a voxel in fMRI.

  1. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...... to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...

  2. Usefulness and limitation of functional MRI with echo planar imaging using clinical MR apparatus

    International Nuclear Information System (INIS)

    Kusunoki, Katsusuke; Zenke, Kiichiro; Saito, Masahiro; Sadamoto, Kazuhiko; Ohue, Shiro; Sakaki, Saburo; Kumon, Yoshiaki; Kabasawa, Hiroyuki; Nagasawa, Kiyoshi

    1998-01-01

    We studied blood oxygen level-dependent (BOLD) functional MRI (fMRI) with EPI sequence in 21 normal volunteers and 8 presurgical clinical patients using a 1.5 T clinical MRI apparatus. To optimize the imaging parameters, we compared the fMRI images obtained by GFE-EPI and by SE-EPI in normal volunteers while each squeezed a sponge ball. We identified the motor cortex in 85.7% of normal volunteers by GFE-EPI in contrast to only 28.6% by SE-EPI. In addition, our clinical MR apparatus, using optimized parameters, maximally provides 15 slices per 5 seconds. In patients with brain tumor close to the sensorimotor cortex, we attempted to identify the motor cortex preoperatively by this procedure and found a significant increase of signal intensity in the motor cortex in 5 of 8 patients. In conclusion, fMRI using EPI may be useful for identifying the motor cortex preoperatively. However, further development of the apparatus is needed to obtain better temporal and spatial resolution for clinical applications. (author)

  3. 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

  4. Functional and molecular imaging with MRI: potential applications in paediatric radiology

    International Nuclear Information System (INIS)

    Arthurs, Owen J.; Gallagher, Ferdia A.

    2011-01-01

    MRI is a very versatile tool for noninvasive imaging and it is particularly attractive as an imaging technique in paediatric patients given the absence of ionizing radiation. Recent advances in the field of MRI have enabled tissue function to be probed noninvasively, and increasingly MRI is being used to assess cellular and molecular processes. For example, dynamic contrast-enhanced MRI has been used to assess tissue vascularity, diffusion-weighted imaging can quantify molecular movements of water in tissue compartments and MR spectroscopy provides a quantitative assessment of metabolite levels. A number of targeted contrast agents have been developed that bind specifically to receptors on the vascular endothelium or cell surface and there are several MR methods for labelling cells and tracking cellular movements. Hyperpolarization techniques have the capability of massively increasing the sensitivity of MRI and these have been used to image tissue pH, successful response to drug treatment as well as imaging the microstructure of the lungs. Although there are many challenges to be overcome before these techniques can be translated into routine paediatric imaging, they could potentially be used to aid diagnosis, predict disease outcome, target biopsies and determine treatment response noninvasively. (orig.)

  5. Functional connectivity analysis of resting-state fMRI networks in nicotine dependent patients

    Science.gov (United States)

    Smith, Aria; Ehtemami, Anahid; Fratte, Daniel; Meyer-Baese, Anke; Zavala-Romero, Olmo; Goudriaan, Anna E.; Schmaal, Lianne; Schulte, Mieke H. J.

    2016-03-01

    Brain imaging studies identified brain networks that play a key role in nicotine dependence-related behavior. Functional connectivity of the brain is dynamic; it changes over time due to different causes such as learning, or quitting a habit. Functional connectivity analysis is useful in discovering and comparing patterns between functional magnetic resonance imaging (fMRI) scans of patients' brains. In the resting state, the patient is asked to remain calm and not do any task to minimize the contribution of external stimuli. The study of resting-state fMRI networks have shown functionally connected brain regions that have a high level of activity during this state. In this project, we are interested in the relationship between these functionally connected brain regions to identify nicotine dependent patients, who underwent a smoking cessation treatment. Our approach is on the comparison of the set of connections between the fMRI scans before and after treatment. We applied support vector machines, a machine learning technique, to classify patients based on receiving the treatment or the placebo. Using the functional connectivity (CONN) toolbox, we were able to form a correlation matrix based on the functional connectivity between different regions of the brain. The experimental results show that there is inadequate predictive information to classify nicotine dependent patients using the SVM classifier. We propose other classification methods be explored to better classify the nicotine dependent patients.

  6. Large-scale Granger causality analysis on resting-state functional MRI

    Science.gov (United States)

    D'Souza, Adora M.; Abidin, Anas Zainul; Leistritz, Lutz; Wismüller, Axel

    2016-03-01

    We demonstrate an approach to measure the information flow between each pair of time series in resting-state functional MRI (fMRI) data of the human brain and subsequently recover its underlying network structure. By integrating dimensionality reduction into predictive time series modeling, large-scale Granger Causality (lsGC) analysis method can reveal directed information flow suggestive of causal influence at an individual voxel level, unlike other multivariate approaches. This method quantifies the influence each voxel time series has on every other voxel time series in a multivariate sense and hence contains information about the underlying dynamics of the whole system, which can be used to reveal functionally connected networks within the brain. To identify such networks, we perform non-metric network clustering, such as accomplished by the Louvain method. We demonstrate the effectiveness of our approach to recover the motor and visual cortex from resting state human brain fMRI data and compare it with the network recovered from a visuomotor stimulation experiment, where the similarity is measured by the Dice Coefficient (DC). The best DC obtained was 0.59 implying a strong agreement between the two networks. In addition, we thoroughly study the effect of dimensionality reduction in lsGC analysis on network recovery. We conclude that our approach is capable of detecting causal influence between time series in a multivariate sense, which can be used to segment functionally connected networks in the resting-state fMRI.

  7. Mapping of cognitive functions in chronic intractable epilepsy: Role of fMRI

    International Nuclear Information System (INIS)

    Chaudhary, Kapil; Kumaran, S Senthil; Chandra, Sarat P; Wadhawan, Ashima Nehra; Tripathi, Manjari

    2014-01-01

    Functional magnetic resonance imaging (fMRI), a non-invasive technique with high spatial resolution and blood oxygen level dependent (BOLD) contrast, has been applied to localize and map cognitive functions in the clinical condition of chronic intractable epilepsy. fMRI was used to map the language and memory network in patients of chronic intractable epilepsy pre- and post-surgery. After obtaining approval from the institutional ethics committee, six patients with intractable epilepsy with an equal number of age-matched controls were recruited in the study. A 1.5 T MR scanner with 12-channel head coil, integrated with audio-visual fMRI accessories was used. Echo planar imaging sequence was used for BOLD studies. There were two sessions in TLE (pre- and post-surgery). In TLE patients, BOLD activation increased post-surgery in comparison of pre-surgery in inferior frontal gyrus (IFG), middle frontal gyrus (MFG), and superior temporal gyrus (STG), during semantic lexical, judgment, comprehension, and semantic memory tasks. Functional MRI is useful to study the basic concepts related to language and memory lateralization in TLE and guide surgeons for preservation of important brain areas during ATLR. This will help in understanding future directions for the diagnosis and treatment of such disease

  8. BOLDSync: a MATLAB-based toolbox for synchronized stimulus presentation in functional MRI.

    Science.gov (United States)

    Joshi, Jitesh; Saharan, Sumiti; Mandal, Pravat K

    2014-02-15

    Precise and synchronized presentation of paradigm stimuli in functional magnetic resonance imaging (fMRI) is central to obtaining accurate information about brain regions involved in a specific task. In this manuscript, we present a new MATLAB-based toolbox, BOLDSync, for synchronized stimulus presentation in fMRI. BOLDSync provides a user friendly platform for design and presentation of visual, audio, as well as multimodal audio-visual (AV) stimuli in functional imaging experiments. We present simulation experiments that demonstrate the millisecond synchronization accuracy of BOLDSync, and also illustrate the functionalities of BOLDSync through application to an AV fMRI study. BOLDSync gains an advantage over other available proprietary and open-source toolboxes by offering a user friendly and accessible interface that affords both precision in stimulus presentation and versatility across various types of stimulus designs and system setups. BOLDSync is a reliable, efficient, and versatile solution for synchronized stimulus presentation in fMRI study. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Synthesis of functionalized magnetite nanoparticles to use as liver targeting MRI contrast agent

    Science.gov (United States)

    Yazdani, Farshad; Fattahi, Bahare; Azizi, Najmodin

    2016-05-01

    The aim of this research was the preparation of functionalized magnetite nanoparticles to use as a liver targeting contrast agent in magnetic resonance imaging (MRI). For this purpose, Fe3O4 nanoparticles were synthesized via the co-precipitation method. The synthesized nanoparticles were coated with silica via the Stober method and finally the coated nanoparticles were functionalized with mebrofenin. Formation of crystalline magnetite particles was confirmed by X-ray diffraction (XRD) analysis. The Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray analyzer (EDX) of the final product showed that silica had been effectively bonded onto the surface of the magnetite nanoparticles and the coated nanoparticles functionalized with mebrofenin. The magnetic resonance imaging of the functional nanoparticles showed that the Fe3O4-SiO2-mebrofenin composite is an effective MRI contrast agent for liver targeting.

  10. Genetic and Diagnostic Biomarker Development in ASD Toddlers Using Resting State Functional MRI

    Science.gov (United States)

    2016-09-01

    imagining ,  and   functional  connectivity,  typically  measured...Toddlers  Using  Resting-­‐State   Functional  MRI   PRINCIPAL  INVESTIGATOR:      David  C.  Glahn CONTRACTING  ORGANIZATION...Yale  University   New Haven, CT 06520-8047 REPORT  DATE:   September 2016   TYPE  OF  REPORT:        Annual

  11. Altered resting-state functional connectivity in post-traumatic stress disorder: a perfusion MRI study

    Science.gov (United States)

    Li, Baojuan; Liu, Jian; Liu, Yang; Lu, Hong-Bing; Yin, Hong

    2013-03-01

    The majority of studies on posttraumatic stress disorder (PTSD) so far have focused on delineating patterns of activations during cognitive processes. Recently, more and more researches have started to investigate functional connectivity in PTSD subjects using BOLD-fMRI. Functional connectivity analysis has been demonstrated as a powerful approach to identify biomarkers of different brain diseases. This study aimed to detect resting-state functional connectivity abnormities in patients with PTSD using arterial spin labeling (ASL) fMRI. As a completely non-invasive technique, ASL allows quantitative estimates of cerebral blood flow (CBF). Compared with BOLD-fMRI, ASL fMRI has many advantages, including less low-frequency signal drifts, superior functional localization, etc. In the current study, ASL images were collected from 10 survivors in mining disaster with recent onset PTSD and 10 survivors without PTSD. Decreased regional CBF in the right middle temporal gyrus, lingual gyrus, and postcentral gyrus was detected in the PTSD patients. Seed-based resting-state functional connectivity analysis was performed using an area in the right middle temporal gyrus as region of interest. Compared with the non-PTSD group, the PTSD subjects demonstrated increased functional connectivity between the right middle temporal gyrus and the right superior temporal gyrus, the left middle temporal gyrus. Meanwhile, decreased functional connectivity between the right middle temporal gyrus and the right postcentral gyrus, the right superior parietal lobule was also found in the PTSD patients. This is the first study which investigated resting-state functional connectivity in PTSD using ASL images. The results may provide new insight into the neural substrates of PTSD.

  12. Evidence of a Christmas spirit network in the brain: functional MRI study

    OpenAIRE

    Hougaard, Anders; Lindberg, Ulrich; Arngrim, Nanna; Larsson, Henrik B W; Olesen, Jes; Amin, Faisal Mohammad; Ashina, Messoud; Haddock, Bryan T

    2015-01-01

    Objective?To detect and localise the Christmas spirit in the human brain. Design?Single blinded, cross cultural group study with functional magnetic resonance imaging (fMRI). Setting?Functional imaging unit and department of clinical physiology, nuclear medicine and PET in Denmark. Participants?10 healthy people from the Copenhagen area who routinely celebrate Christmas and 10 healthy people living in the same area who have no Christmas traditions. Main outcome measures?Brain activation uniqu...

  13. Functional MRI studies in human Ecstasy and cannabis users

    NARCIS (Netherlands)

    Jager, G.

    2006-01-01

    Cannabis and ecstasy are among the most widely used illicit drugs in the world. However, there are substantial concerns about their neurotoxic potential for brain and brain function. Despite previous research, some crucial questions regarding the causality, course and clinical relevance have

  14. Functional MRI of food-induced brain responses

    NARCIS (Netherlands)

    Smeets, P.A.M.

    2006-01-01

    The ultimate goal of this research was to find central biomarkers of satiety, i.e., physiological measures in the brain that relate to subjectively rated appetite, actual food intake, or both. This thesis describes the changes in brain activity in response to food stimuli as measured by functional

  15. Impaired sensory processing measured by functional MRI in Bipolar disorder manic and depressed mood states.

    Science.gov (United States)

    Shaffer, Joseph J; Johnson, Casey P; Fiedorowicz, Jess G; Christensen, Gary E; Wemmie, John A; Magnotta, Vincent A

    2017-07-03

    Bipolar disorder is characterized by recurring episodes of depression and mania. Defining differences in brain function during these states is an important goal of bipolar disorder research. However, few imaging studies have directly compared brain activity between bipolar mood states. Herein, we compare functional magnetic resonance imaging (fMRI) responses during a flashing checkerboard stimulus between bipolar participants across mood states (euthymia, depression, and mania) in order to identify functional differences between these states. 40 participants with bipolar I disorder and 33 healthy controls underwent fMRI during the presentation of the stimulus. A total of 23 euthymic-state, 16 manic-state, 15 depressed-state, and 32 healthy control imaging sessions were analyzed in order to compare functional activation during the stimulus between mood states and with healthy controls. A reduced response was identified in the visual cortex in both the depressed and manic groups compared to euthymic and healthy participants. Functional differences between bipolar mood states were also observed in the cerebellum, thalamus, striatum, and hippocampus. Functional differences between mood states occurred in several brain regions involved in visual and other sensory processing. These differences suggest that altered visual processing may be a feature of mood states in bipolar disorder. The key limitations of this study are modest mood-state group size and the limited temporal resolution of fMRI which prevents the segregation of primary visual activity from regulatory feedback mechanisms.

  16. Synthesis of functionalized magnetite nanoparticles to use as liver targeting MRI contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, Farshad, E-mail: fyazdani@ccerci.ac.ir; Fattahi, Bahare; Azizi, Najmodin

    2016-05-15

    The aim of this research was the preparation of functionalized magnetite nanoparticles to use as a liver targeting contrast agent in magnetic resonance imaging (MRI). For this purpose, Fe{sub 3}O{sub 4} nanoparticles were synthesized via the co-precipitation method. The synthesized nanoparticles were coated with silica via the Stober method and finally the coated nanoparticles were functionalized with mebrofenin. Formation of crystalline magnetite particles was confirmed by X-ray diffraction (XRD) analysis. The Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray analyzer (EDX) of the final product showed that silica had been effectively bonded onto the surface of the magnetite nanoparticles and the coated nanoparticles functionalized with mebrofenin. The magnetic resonance imaging of the functional nanoparticles showed that the Fe{sub 3}O{sub 4}–SiO{sub 2}-mebrofenin composite is an effective MRI contrast agent for liver targeting. - Highlights: • Superparamagnetic magnetite nanoparticles have been synthesized by simple and economical method. • Preperation of functional MNPs as a MRI contrast agent for liver targeting. • Gaining a good r{sub 2} relaxivity of the coated functional nanoparticles.

  17. Functional MRI for immediate monitoring stereotactic thalamotomy in a patient with essential tremor

    Energy Technology Data Exchange (ETDEWEB)

    Hesselmann, Volker; Schaaf, Maike; Krug, Barbara; Lackner, Klaus [University of Cologne, Department of Radiology, Cologne (Germany); Maarouf, Mohammed; Hunsche, Stefan; Sturm, Volker [University of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Lasek, Kathrin [Universitaetsklinikum Schleswig Holstein, Klinik fuer Neurologie, Luebeck (Germany); Wedekind, Christoph [Akademisches Lehrkrankenhaus der Universitaet Erlangen-Nuernberg, Belegabteilung fuer Neurochirurgie, Klinikum Bamberg, Bamberg (Germany)

    2006-10-15

    The effect of stereotactic thalamotomy was assessed with pre- and postoperative functional magnetic resonance imaging (fMRI) under motor stimulation. A patient with unilateral essential tremor (ET) of the left arm underwent stereotactically guided thalamotomy of the right ventral intermediate thalamic nucleus (VIM). FMRI was done directly before and after surgery on a 1.5-Tesla scanner. The stimulation paradigm was maintainance of the affected arm in an extended position and hand clenching being performed in a block design manner. Statistical analysis was done with Brain Voyager 2000. After thalamotomy the tremor diminished completely. As a difference between the pre- and postoperative fMRI, a significant activation was found in the VIM contralateral to the activation site, adjacent to the inferior olivary nucleus contralateral to the activation site and in the dorsal cingulum. In conclusion, fMRI can detect the functional effect of thalamotomy for tremor treatment. Direct postoperative fMRI provides a sufficient method for estimating the effect of thalamotomy immediately after intervention. The importance of the intermediate thalamic nucleus and the olivary nucleus in tremor generation is supported by our findings. (orig.)

  18. 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.

  19. A functional MRI study of the influence of sleep deprivation on digital memory in human brain

    Directory of Open Access Journals (Sweden)

    FAN Shuang-yi

    2013-05-01

    Full Text Available Background Working for long hours often leads to mental fatigue. There is evidence that mental fatigue is serious damage to cognitive function and behavior of the operator. Revealing the mechanism of continuous operation and sleep deprivation (SD on cognitive function, will help to combat the fatigue caused by continuous operation and to improve capacity of operators. This functional magnetic resonance imaging (fMRI study focused on the influence of sleep deprivation on digital memory in human brain. Methods Totally 6 healthy subjects underwent a digital memory encoding, maintenance and retrieval session during fMRI scanning before and after 48 h sleep deprivation. Results The digital memory test had the same error rate before and after sleep deprivation (P > 0.05, for all, but the reponse time of seven-number memory was longer after sleep deprivation (P = 0.005. During encoding trials decreased fMRI regions of significant activation between sleep control and sleep deprivation were in left parahippocampal gyrus Brodmann 30, left superior temporal gyrus Brodmann 42, left insular lobe Brodmann 41 and left frontal lobe Brodmann 6. During maintenance trials decreased fMRI regions of significant activation were at left superior temporal gyrus Brodmann 38, left middle temporal gyrus Brodmann 21, left parahippocampus and amygdaloid nucleus Brodmann 30, left middle frontal gyrus Brodmann 47, left lenticular nucleus and thalamus, right lenticular nucleus, left retrosplenial granular cortex Brodmann 30, right retrosplenial granular cortex Brodmann 30, bilateral cingulate gyrus Brodmann 24 and bilateral middle frontal gyrus, medial frontal gyrus Brodmann 6. During retrieval trials decreased fMRI regions of significantly positive activation were at bilateral hippocampus, right amygdaloid nucleus and inferior parietal lobule Brodmann 40, left precuneus Brodmann 19 and thalamus. Conclusion Different brain regions are activated at different stages of the

  20. American Society of Functional Neuroradiology-Recommended fMRI Paradigm Algorithms for Presurgical Language Assessment.

    Science.gov (United States)

    Black, D F; Vachha, B; Mian, A; Faro, S H; Maheshwari, M; Sair, H I; Petrella, J R; Pillai, J J; Welker, K

    2017-10-01

    Functional MR imaging is increasingly being used for presurgical language assessment in the treatment of patients with brain tumors, epilepsy, vascular malformations, and other conditions. The inherent complexity of fMRI, which includes numerous processing steps and selective analyses, is compounded by institution-unique approaches to patient training, paradigm choice, and an eclectic array of postprocessing options from various vendors. Consequently, institutions perform fMRI in such markedly different manners that data sharing, comparison, and generalization of results are difficult. The American Society of Functional Neuroradiology proposes widespread adoption of common fMRI language paradigms as the first step in countering this lost opportunity to advance our knowledge and improve patient care. A taskforce of American Society of Functional Neuroradiology members from multiple institutions used a broad literature review, member polls, and expert opinion to converge on 2 sets of standard language paradigms that strike a balance between ease of application and clinical usefulness. The taskforce generated an adult language paradigm algorithm for presurgical language assessment including the following tasks: Sentence Completion, Silent Word Generation, Rhyming, Object Naming, and/or Passive Story Listening. The pediatric algorithm includes the following tasks: Sentence Completion, Rhyming, Antonym Generation, or Passive Story Listening. Convergence of fMRI language paradigms across institutions offers the first step in providing a "Rosetta Stone" that provides a common reference point with which to compare and contrast the usefulness and reliability of fMRI data. From this common language task battery, future refinements and improvements are anticipated, particularly as objective measures of reliability become available. Some commonality of practice is a necessary first step to develop a foundation on which to improve the clinical utility of this field. © 2017 by

  1. Self-gated golden angle spiral cine MRI for coronary endothelial function assessment.

    Science.gov (United States)

    Bonanno, Gabriele; Hays, Allison G; Weiss, Robert G; Schär, Michael

    2018-08-01

    Depressed coronary endothelial function (CEF) is a marker for atherosclerotic disease, an independent predictor of cardiovascular events, and can be quantified non-invasively with ECG-triggered spiral cine MRI combined with isometric handgrip exercise (IHE). However, MRI-CEF measures can be hindered by faulty ECG-triggering, leading to prolonged breath-holds and degraded image quality. Here, a self-gated golden angle spiral method (SG-GA) is proposed to eliminate the need for ECG during cine MRI. SG-GA was tested against retrospectively ECG-gated golden angle spiral MRI (ECG-GA) and gold-standard ECG-triggered spiral cine MRI (ECG-STD) in 10 healthy volunteers. CEF data were obtained from cross-sectional images of the proximal right and left coronary arteries in a 3T scanner. Self-gating heart rates were compared to those from simultaneous ECG-gating. Coronary vessel sharpness and cross-sectional area (CSA) change with IHE were compared among the 3 methods. Self-gating precision, accuracy, and correlation-coefficient were 7.7 ± 0.5 ms, 9.1 ± 0.7 ms, and 0.93 ± 0.01, respectively (mean ± standard error). Vessel sharpness by SG-GA was equal or higher than ECG-STD (rest: 63.0 ± 1.7% vs. 61.3 ± 1.3%; exercise: 62.6 ± 1.3% vs. 56.7 ± 1.6%, P cine MRI method even when ECG is faulty or not available. Magn Reson Med 80:560-570, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  2. Arcuate fasciculus laterality by diffusion tensor imaging correlates with language laterality by functional MRI in preadolescent children.

    Science.gov (United States)

    Sreedharan, Ruma Madhu; Menon, Amitha C; James, Jija S; Kesavadas, Chandrasekharan; Thomas, Sanjeev V

    2015-03-01

    Language lateralization is unique to humans. Functional MRI (fMRI) and diffusion tensor imaging (DTI) enable the study of language areas and white matter fibers involved in language, respectively. The objective of this study was to correlate arcuate fasciculus (AF) laterality by diffusion tensor imaging with that by fMRI in preadolescent children which has not yet been reported. Ten children between 8 and 12 years were subjected to fMRI and DTI imaging using Siemens 1.5 T MRI. Two language fMRI paradigms--visual verb generation and word pair task--were used. Analysis was done using SPM8 software. In DTI, the fiber volume of the arcuate fasciculus (AFV) and fractional anisotropy (FA) was measured. The fMRI Laterality Index (fMRI-LI) and DTI Laterality Index (DTI-LI) were calculated and their correlation assessed using the Pearson Correlation Index. Of ten children, mean age 10.6 years, eight showed left lateralization while bilateral language lateralization was seen in two. AFV by DTI was more on the left side in seven of the eight children who had left lateralization by fMRI. DTI could not trace the AF in one child. Of the two with bilateral language lateralization on fMRI, one showed larger AFV on the right side while the other did not show any asymmetry. There was a significant correlation (p laterality in children with a high degree of correlation between the two imaging modalities.

  3. Functional MRI of the olfactory system in conscious dogs.

    Directory of Open Access Journals (Sweden)

    Hao Jia

    Full Text Available We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology.

  4. Functional MRI of the olfactory system in conscious dogs.

    Science.gov (United States)

    Jia, Hao; Pustovyy, Oleg M; Waggoner, Paul; Beyers, Ronald J; Schumacher, John; Wildey, Chester; Barrett, Jay; Morrison, Edward; Salibi, Nouha; Denney, Thomas S; Vodyanoy, Vitaly J; Deshpande, Gopikrishna

    2014-01-01

    We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology.

  5. Motion correction for functional MRI with three-dimensional hybrid radial-Cartesian EPI.

    Science.gov (United States)

    Graedel, Nadine N; McNab, Jennifer A; Chiew, Mark; Miller, Karla L

    2017-08-01

    Subject motion is a major source of image degradation for functional MRI (fMRI), especially when using multishot sequences like three-dimensional (3D EPI). We present a hybrid radial-Cartesian 3D EPI trajectory enabling motion correction in k-space for functional MRI. The EPI "blades" of the 3D hybrid radial-Cartesian EPI sequence, called TURBINE, are rotated about the phase-encoding axis to fill out a cylinder in 3D k-space. Angular blades are acquired over time using a golden-angle rotation increment, allowing reconstruction at flexible temporal resolution. The self-navigating properties of the sequence are used to determine motion parameters from a high temporal-resolution navigator time series. The motion is corrected in k-space as part of the image reconstruction, and evaluated for experiments with both cued and natural motion. We demonstrate that the motion correction works robustly and that we can achieve substantial artifact reduction as well as improvement in temporal signal-to-noise ratio and fMRI activation in the presence of both severe and subtle motion. We show the potential for hybrid radial-Cartesian 3D EPI to substantially reduce artifacts for application in fMRI, especially for subject groups with significant head motion. The motion correction approach does not prolong the scan, and no extra hardware is required. Magn Reson Med 78:527-540, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  6. Tablet-Based Functional MRI of the Trail Making Test: Effect of Tablet Interaction Mode

    Directory of Open Access Journals (Sweden)

    Mahta Karimpoor

    2017-10-01

    Full Text Available The Trail Making Test (TMT is widely used for assessing executive function, frontal lobe abilities, and visual motor skills. Part A of this pen-and-paper test (TMT-A involves linking numbers randomly distributed in space, in ascending order. Part B (TMT-B alternates between linking numbers and letters. TMT-B is more demanding than TMT-A, but the mental processing that supports the performance of this test remains incompletely understood. Functional MRI (fMRI may help to clarify the relationship between TMT performance and brain activity, but providing an environment that supports real-world pen-and-paper interactions during fMRI is challenging. Previously, an fMRI-compatible tablet system was developed for writing and drawing with two modes of interaction: the original cursor-based, proprioceptive approach, and a new mode involving augmented reality to provide visual feedback of hand position (VFHP for enhanced user interaction. This study characterizes the use of the tablet during fMRI of young healthy adults (n = 22, with half of the subjects performing TMT with VFHP and the other half performing TMT without VFHP. Activation maps for both TMT-A and TMT-B performance showed considerable overlap between the two tablet modes, and no statistically differences in brain activity were detected when contrasting TMT-B vs. TMT-A for the two tablet modes. Behavioral results also showed no statistically different interaction effects for TMT-B vs. TMT-A for the two tablet modes. Tablet-based TMT scores showed reasonable convergent validity with those obtained by administering the standard pen-and-paper TMT to the same subjects. Overall, the results suggest that despite the slightly different mechanisms involved for the two modes of tablet interaction, both are suitable for use in fMRI studies involving TMT performance. This study provides information for using tablet-based TMT methods appropriately in future fMRI studies involving patients and healthy

  7. Functional significance of MRI defined mesial temporal sclerosis in temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Elza Márcia T. Yacubian

    1994-09-01

    Full Text Available The functional significance of MRI-defined mesial temporal sclerosis in temporal lobe epilepsy (TLE is not completely established. In order to study the possible relationship between signals of mesial temporal sclerosis on MRI and interictal SPECT findings we selected 18 patients with complex partial seizures, unilateral temporal EEG focus and normal CT. The EEG focus was defined by the presence of interictal sharp waves and slow background on several scalp EEG obtained during many years of follow up in all patients and by ictal recordings with sphenoidal electrodes in 12 patients. Group I comprised patients (n=11 in whom MRI showed mesial temporal sclerosis; group II patients (n=7 had normal MRIs. All patients were submitted to interictal 99m-Tc HMPAO injections with concomitant EEG monitoring. Lateralized hypoperfusion ipsilateral to the EEG was found in 13 patients (72%. In all Group II and in 6 Group I patients a temporal hypoperfusion was found. This SPECT study showed a higher positivity rate in patients with normal MRI than previously reported. On the other hand, in all these group II patients a neocortical origin of epileptic focus was suspected on clinical or electroencephalographic basis. Positive SPECT findings may be at least as prevalent in neocortical as in mesiolimbic epilepsy.

  8. Study on cerebral activation areas during repetition with functional MRI in normal adults

    International Nuclear Information System (INIS)

    Koseki, Yohju

    2009-01-01

    For cerebral activation of speech areas in functional MRI (f-MRI) study, the usefulness of an optical microphone, which made it possible to perform task repetition at real time during scanning, was examined. Subjects were 25 healthy adults (mean age, 27.1±5.6 years), who consisted of 15 right-handed and 10 left-handed or ambidextrous persons. Tasks comprised repetition of monosyllables, non-words, words and sentences. The repetition tasks were covertly performed during scanning of f-MRI by using an optical microphone. In both the right-handed and non-right-handed groups, activations in the left superior temporal gyrus (sensory speech area) were most frequently observed during all of the tasks. In the right-handed group, activations in the left inferior frontal (motor speech area) and superior temporal gyri were significantly more often observed than those in the right inferior frontal and superior temporal gyri. From an assessment of the laterality index (LI), left-side dominant activation was frequently seen in most of the cerebral regions including sensory and motor speech areas, although right-side and bilateral dominant activations were observed in a few cases. In both groups, activations in regions associated with sensory speech were significantly more often seen than those in regions associated with motor speech. The present predominant activations in regions involved in sensory speech indicate that the optical microphone is useful in f-MRI studies using task repetition. (author)

  9. Identification by functional MRI of human cerebral region activated by taste stimulation

    International Nuclear Information System (INIS)

    Kakimoto, Naoya

    2000-01-01

    The purpose of this study was the examination of possible imaging of the primary taste region of human cerebral cortex by functional MRI (fMRI). Subjects were 19-36 years old, healthy adult male and female volunteers given information concerning the purpose, significance and method of the study. MRI equipment was 1.5 T Signa Horizon (GE) with Head Coil. Images were processed by the software FuncTool on the Advantage Windows Workstation (GE). Taste stimulation was done by swab bearing the solution of 4% quinine hydrochloride, 20% sodium chloride or distilled water (control) or by dripping from the syringe of the solutions, 8% tartaric acid or 80% sugar. Preliminary examinations with the swab suggested the possibility of the identification. Further, with use of dripping apparatus, the taste active region was shown to be identified by fMRI and of which area tended to be larger in male than in female: a significant difference was seen for the quinine hydrochloride. As above, the method was suggested to be a diagnostic mean for the taste perception. (K.H.)

  10. Functional connectivity in resting-state fMRI: Is linear correlation sufficient?

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav; Paluš, Milan; Vejmelka, Martin; Mantini, D.; Corbetta, M.

    2011-01-01

    Roč. 54, č. 3 (2011), s. 2218-2225 ISSN 1053-8119 R&D Projects: GA MŠk 7E08027 EU Projects: European Commission(XE) 200728 - BRAINSYNC Institutional research plan: CEZ:AV0Z10300504 Keywords : fMRI * functional connectivity * Gaussianity * nonlinearity * correlation * mutual information Subject RIV: FH - Neurology Impact factor: 5.895, year: 2011

  11. Scanning fast and slow: current limitations of 3 Tesla functional MRI and future potential

    Directory of Open Access Journals (Sweden)

    Roland N Boubela

    2014-02-01

    Full Text Available Functional MRI at 3T has become a workhorse for the neurosciences, e.g., neurology, psychology, and psychiatry, enabling non-invasive investigation of brain function and connectivity. However, BOLD-based fMRI is a rather indirect measure of brain function, confounded by fluctuation related signals, e.g. head or brain motion, brain pulsation, blood flow, intermixed with susceptibility differences close or distant to the region of neuronal activity. Even though a plethora of preprocessing strategies have been published to address these confounds, their efficiency is still under discussion. In particular, physiological signal fluctuations closely related to brain supply may mask BOLD signal changes related to true neuronal activation. Here we explore recent technical and methodological advancements aimed at disentangling the various components, employing fast multiband vs. standard EPI, in combination with fast temporal ICA.Our preliminary results indicate that fast (TR< 0.5s scanning may help to identify and eliminate physiologic components, increasing tSNR and functional contrast. In addition, biological variability can be studied and task performance better correlated to other measures. This should increase specificity and reliability in fMRI studies. Furthermore, physiological signal changes during scanning may then be recognized as a source of information rather than a nuisance. As we are currently still undersampling the complexity of the brain, even at a rather coarse macroscopic level, we should be very cautious in the interpretation of neuroscientific findings, in particular when comparing different groups (e.g., age, sex, medication, pathology, etc.. From a technical point of view our goal should be to sample brain activity at layer specific resolution with low TR, covering as much of the brain as possible without violating SAR limits. We hope to stimulate discussion towards a better understanding and a more quantitative use of fMRI.

  12. Scanning fast and slow: current limitations of 3 Tesla functional MRI and future potential

    Science.gov (United States)

    Boubela, Roland N.; Kalcher, Klaudius; Nasel, Christian; Moser, Ewald

    2017-01-01

    Functional MRI at 3T has become a workhorse for the neurosciences, e.g., neurology, psychology, and psychiatry, enabling non-invasive investigation of brain function and connectivity. However, BOLD-based fMRI is a rather indirect measure of brain function, confounded by physiology related signals, e.g., head or brain motion, brain pulsation, blood flow, intermixed with susceptibility differences close or distant to the region of neuronal activity. Even though a plethora of preprocessing strategies have been published to address these confounds, their efficiency is still under discussion. In particular, physiological signal fluctuations closely related to brain supply may mask BOLD signal changes related to “true” neuronal activation. Here we explore recent technical and methodological advancements aimed at disentangling the various components, employing fast multiband vs. standard EPI, in combination with fast temporal ICA. Our preliminary results indicate that fast (TR <0.5 s) scanning may help to identify and eliminate physiologic components, increasing tSNR and functional contrast. In addition, biological variability can be studied and task performance better correlated to other measures. This should increase specificity and reliability in fMRI studies. Furthermore, physiological signal changes during scanning may then be recognized as a source of information rather than a nuisance. As we are currently still undersampling the complexity of the brain, even at a rather coarse macroscopic level, we should be very cautious in the interpretation of neuroscientific findings, in particular when comparing different groups (e.g., age, sex, medication, pathology, etc.). From a technical point of view our goal should be to sample brain activity at layer specific resolution with low TR, covering as much of the brain as possible without violating SAR limits. We hope to stimulate discussion toward a better understanding and a more quantitative use of fMRI. PMID:28164083

  13. Insights into the mechanisms of absence seizure generation provided by EEG with Functional MRI.

    Directory of Open Access Journals (Sweden)

    Patrick William Carney

    2014-09-01

    Full Text Available Absence seizures are brief epileptic events characterized by loss of awareness with subtle motor features. They may be very frequent, and impact on attention, learning and memory. A number of pathophysiological models have been developed to explain the mechanism of absence seizure generation which rely heavily on observations from animal studies. Studying the structural and functional relationships between large-scale brain networks in humans is only practical with non-invasive whole brain techniques. EEG with functional MRI (EEG-fMRI is one such technique that provides an opportunity to explore the interactions between brain structures involved in AS generation. A number of fMRI techniques including event-related analysis, time course analysis and functional connectivity have identified a common network of structures involved in AS seizures. This network comprises the thalamus, midline and lateral parietal cortex (the default mode network [DMN], caudate nuclei and the reticular structures of the pons. The main component displaying an increase in BOLD signal relative to the resting state, in group studies, is the thalamus while the most consistent cortical change is reduced BOLD signal in the DMN. Time course analysis shows that, rather than some structures being activated or inactivated during AS, there appears to be increase in activity across components of the network preceding or following the electro-clinical onset of the seizure. The earliest change in BOLD signal occurs in the DMN, prior to the onset of epileptiform events. This region also shows altered functional connectivity in patients with absence seizures. Hence it appears that engagement of this network is central to absence seizures. In this review we will explore the insights EEG-fMRI studies into the mechanisms of AS and considers how the DMN is likely to be the major large scale brain network central to both seizure generation and the seizure manifestations.

  14. Multimodality Functional Imaging in Radiation Therapy Planning: Relationships between Dynamic Contrast-Enhanced MRI, Diffusion-Weighted MRI, and 18F-FDG PET

    Directory of Open Access Journals (Sweden)

    Moisés Mera Iglesias

    2015-01-01

    Full Text Available Objectives. Biologically guided radiotherapy needs an understanding of how different functional imaging techniques interact and link together. We analyse three functional imaging techniques that can be useful tools for achieving this objective. Materials and Methods. The three different imaging modalities from one selected patient are ADC maps, DCE-MRI, and 18F-FDG PET/CT, because they are widely used and give a great amount of complementary information. We show the relationship between these three datasets and evaluate them as markers for tumour response or hypoxia marker. Thus, vascularization measured using DCE-MRI parameters can determine tumour hypoxia, and ADC maps can be used for evaluating tumour response. Results. ADC and DCE-MRI include information from 18F-FDG, as glucose metabolism is associated with hypoxia and tumour cell density, although 18F-FDG includes more information about the malignancy of the tumour. The main disadvantage of ADC maps is the distortion, and we used only low distorted regions, and extracellular volume calculated from DCE-MRI can be considered equivalent to ADC in well-vascularized areas. Conclusion. A dataset for achieving the biologically guided radiotherapy must include a tumour density study and a hypoxia marker. This information can be achieved using only MRI data or only PET/CT studies or mixing both datasets.

  15. Study of human brain functions by functional magnetic resonance imaging (fMRI) and spectroscopy (fMRS)

    International Nuclear Information System (INIS)

    Jagannathan, N.R.

    1998-01-01

    Functional magnetic resonance imaging (fMRI) has become a powerful tool in the detection and assessment of cerebral pathophysiology and the regional mapping and characterization of cognitive processes such as motor skills, vision, language and memory. The results of the effect of motor cortex stimulation during repetitive hand squeezing task activation using in-vivo single voxel NMR spectroscopy carried out on normal volunteer subjects are presented

  16. Aging effects on functional auditory and visual processing using fMRI with variable sensory loading.

    Science.gov (United States)

    Cliff, Michael; Joyce, Dan W; Lamar, Melissa; Dannhauser, Thomas; Tracy, Derek K; Shergill, Sukhwinder S

    2013-05-01

    Traditionally, studies investigating the functional implications of age-related structural brain alterations have focused on higher cognitive processes; by increasing stimulus load, these studies assess behavioral and neurophysiological performance. In order to understand age-related changes in these higher cognitive processes, it is crucial to examine changes in visual and auditory processes that are the gateways to higher cognitive functions. This study provides evidence for age-related functional decline in visual and auditory processing, and regional alterations in functional brain processing, using non-invasive neuroimaging. Using functional magnetic resonance imaging (fMRI), younger (n=11; mean age=31) and older (n=10; mean age=68) adults were imaged while observing flashing checkerboard images (passive visual stimuli) and hearing word lists (passive auditory stimuli) across varying stimuli presentation rates. Younger adults showed greater overall levels of temporal and occipital cortical activation than older adults for both auditory and visual stimuli. The relative change in activity as a function of stimulus presentation rate showed differences between young and older participants. In visual cortex, the older group showed a decrease in fMRI blood oxygen level dependent (BOLD) signal magnitude as stimulus frequency increased, whereas the younger group showed a linear increase. In auditory cortex, the younger group showed a relative increase as a function of word presentation rate, while older participants showed a relatively stable magnitude of fMRI BOLD response across all rates. When analyzing participants across all ages, only the auditory cortical activation showed a continuous, monotonically decreasing BOLD signal magnitude as a function of age. Our preliminary findings show an age-related decline in demand-related, passive early sensory processing. As stimulus demand increases, visual and auditory cortex do not show increases in activity in older

  17. Blood oxygen-level dependent functional assessment of cerebrovascular reactivity: Feasibility for intraoperative 3 Tesla MRI.

    Science.gov (United States)

    Fierstra, Jorn; Burkhardt, Jan-Karl; van Niftrik, Christiaan Hendrik Bas; Piccirelli, Marco; Pangalu, Athina; Kocian, Roman; Neidert, Marian Christoph; Valavanis, Antonios; Regli, Luca; Bozinov, Oliver

    2017-02-01

    To assess the feasibility of functional blood oxygen-level dependent (BOLD) MRI to evaluate intraoperative cerebrovascular reactivity (CVR) at 3 Tesla field strength. Ten consecutive neurosurgical subjects scheduled for a clinical intraoperative MRI examination were enrolled in this study. In addition to the clinical protocol a BOLD sequence was implemented with three cycles of 44 s apnea to calculate CVR values on a voxel-by-voxel basis throughout the brain. The CVR range was then color-coded and superimposed on an anatomical volume to create high spatial resolution CVR maps. Ten subjects (mean age 34.8 ± 13.4; 2 females) uneventfully underwent the intraoperative BOLD protocol, with no complications occurring. Whole-brain CVR for all subjects was (mean ± SD) 0.69 ± 0.42, whereas CVR was markedly higher for tumor subjects as compared to vascular subjects, 0.81 ± 0.44 versus 0.33 ± 0.10, respectively. Furthermore, color-coded functional maps could be robustly interpreted for a whole-brain assessment of CVR. We demonstrate that intraoperative BOLD MRI is feasible in creating functional maps to assess cerebrovascular reactivity throughout the brain in subjects undergoing a neurosurgical procedure. Magn Reson Med 77:806-813, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  18. The effect of fMRI task combinations on determining the hemispheric dominance of language functions

    Energy Technology Data Exchange (ETDEWEB)

    Niskanen, Eini [University of Eastern Finland, Department of Applied Physics, Kuopio (Finland); Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Koenoenen, Mervi [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Kuopio University Hospital, Department of Clinical Neurophysiology, Kuopio (Finland); Villberg, Ville; Aeikiae, Marja [Kuopio University Hospital, Department of Neurology, Kuopio (Finland); Nissi, Mikko; Ranta-aho, Perttu; Karjalainen, Pasi [University of Eastern Finland, Department of Applied Physics, Kuopio (Finland); Saeisaenen, Laura; Mervaala, Esa [Kuopio University Hospital, Department of Clinical Neurophysiology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Clinical Neurophysiology, Kuopio (Finland); Kaelviaeinen, Reetta [Kuopio University Hospital, Department of Neurology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Neurology, Kuopio (Finland); Vanninen, Ritva [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Clinical Radiology, Kuopio (Finland)

    2012-04-15

    The purpose of this study is to establish the most suitable combination of functional magnetic resonance imaging (fMRI) language tasks for clinical use in determining language dominance and to define the variability in laterality index (LI) and activation power between different combinations of language tasks. Activation patterns of different fMRI analyses of five language tasks (word generation, responsive naming, letter task, sentence comprehension, and word pair) were defined for 20 healthy volunteers (16 right-handed). LIs and sums of T values were calculated for each task separately and for four combinations of tasks in predefined regions of interest. Variability in terms of activation power and lateralization was defined in each analysis. In addition, the visual assessment of lateralization of language functions based on the individual fMRI activation maps was conducted by an experienced neuroradiologist. A combination analysis of word generation, responsive naming, and sentence comprehension was the most suitable in terms of activation power, robustness to detect essential language areas, and scanning time. In general, combination analyses of the tasks provided higher overall activation levels than single tasks and reduced the number of outlier voxels disturbing the calculation of LI. A combination of auditory and visually presented tasks that activate different aspects of language functions with sufficient activation power may be a useful task battery for determining language dominance in patients. (orig.)

  19. Functional MRI of the cervical spine after distortion injury; MR-Funktionsdiagnostik der Halswirbelsaeule nach Schleudertrauma

    Energy Technology Data Exchange (ETDEWEB)

    Schnarkowski, P. [Muenchen Univ. (Germany). Inst. fuer Radiologische Diagnostik; Weidenmaier, W. [Muenchen Univ. (Germany). Inst. fuer Radiologische Diagnostik; Heuck, A. [Muenchen Univ. (Germany). Inst. fuer Radiologische Diagnostik; Reiser, M.F. [Muenchen Univ. (Germany). Inst. fuer Radiologische Diagnostik

    1995-04-01

    50 patients with a history of distortion injury of the cervical spine were examined with static and functional MRI. Functional MRI consisted of different patient`s positions from maximal extension to maximal flexion (30 , 0 , 25 , 40 , 50 ). T{sub 2}*-weighted gradient echo sequences were performed in a sagittal view for the different positions. Ligamentous instabilities and disc protrusions were seen only in functional MRI in 17 patients. These findings correlated with the neurological symptoms. Two patients were treated by operative fusion because of these findings. (orig.) [Deutsch] Bei 50 Patienten mit einem Schleudertrauma der Halswirbelsaeule wurden zu den statischen Magnetresonanztomogrammen der Halswirbelsaeule MR-Funktionsaufnahmen durchgefuehrt. Diese Funktionsaufnahmen erfolgten in 5 verschiedenen Flexionsgraden von maximaler Reklination bis zur maximalen Inklination (30 , 0 , 25 , 40 , 50 ). T{sub 2}*-gewichtete Gradienten-Echo-Sequenzen in sagittaler Schnittfuehrung wurden fuer jeden Flexionsgrad angefertigt. Bandinstabilitaeten und Bandscheibenvorwoelbungen konnten bei 17 Patienten nur in bestimmten Flexionsgraden erfasst werden. Diese 17 Patienten zeigten eine umschriebene neurologische Symptomatik, die von ihrer Lokalisation mit den in der MR-Funktionsdiagnostik erhobenen Befunden korrelierten. Zwei Patienten wurden aufgrund diese Befunde mit einer operativen Fusion therapiert. (orig.)

  20. Multimodal functional network connectivity: an EEG-fMRI fusion in network space.

    Directory of Open Access Journals (Sweden)

    Xu Lei

    Full Text Available EEG and fMRI recordings measure the functional activity of multiple coherent networks distributed in the cerebral cortex. Identifying network interaction from the complementary neuroelectric and hemodynamic signals may help to explain the complex relationships between different brain regions. In this paper, multimodal functional network connectivity (mFNC is proposed for the fusion of EEG and fMRI in network space. First, functional networks (FNs are extracted using spatial independent component analysis (ICA in each modality separately. Then the interactions among FNs in each modality are explored by Granger causality analysis (GCA. Finally, fMRI FNs are matched to EEG FNs in the spatial domain using network-based source imaging (NESOI. Investigations of both synthetic and real data demonstrate that mFNC has the potential to reveal the underlying neural networks of each modality separately and in their combination. With mFNC, comprehensive relationships among FNs might be unveiled for the deep exploration of neural activities and metabolic responses in a specific task or neurological state.

  1. Functional connectivity analysis of fMRI data based on regularized multiset canonical correlation analysis.

    Science.gov (United States)

    Deleus, Filip; Van Hulle, Marc M

    2011-04-15

    In this paper we describe a method for functional connectivity analysis of fMRI data between given brain regions-of-interest (ROIs). The method relies on nonnegativity constrained- and spatially regularized multiset canonical correlation analysis (CCA), and assigns weights to the fMRI signals of the ROIs so that their representative signals become simultaneously maximally correlated. The different pairwise correlations between the representative signals of the ROIs are combined using the maxvar approach for multiset CCA, which has been shown to be equivalent to the generalized eigenvector formulation of CCA. The eigenvector in the maxvar approach gives an indication of the relative importance of each ROI in obtaining a maximal overall correlation, and hence, can be interpreted as a functional connectivity pattern of the ROIs. The successive canonical correlations define subsequent functional connectivity patterns, in decreasing order of importance. We apply our method on synthetic data and real fMRI data and show its advantages compared to unconstrained CCA and to PCA. Furthermore, since the representative signals for the ROIs are optimized for maximal correlation they are also ideally suited for further effective connectivity analyses, to assess the information flows between the ROIs in the brain. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. The effect of fMRI task combinations on determining the hemispheric dominance of language functions

    International Nuclear Information System (INIS)

    Niskanen, Eini; Koenoenen, Mervi; Villberg, Ville; Aeikiae, Marja; Nissi, Mikko; Ranta-aho, Perttu; Karjalainen, Pasi; Saeisaenen, Laura; Mervaala, Esa; Kaelviaeinen, Reetta; Vanninen, Ritva

    2012-01-01

    The purpose of this study is to establish the most suitable combination of functional magnetic resonance imaging (fMRI) language tasks for clinical use in determining language dominance and to define the variability in laterality index (LI) and activation power between different combinations of language tasks. Activation patterns of different fMRI analyses of five language tasks (word generation, responsive naming, letter task, sentence comprehension, and word pair) were defined for 20 healthy volunteers (16 right-handed). LIs and sums of T values were calculated for each task separately and for four combinations of tasks in predefined regions of interest. Variability in terms of activation power and lateralization was defined in each analysis. In addition, the visual assessment of lateralization of language functions based on the individual fMRI activation maps was conducted by an experienced neuroradiologist. A combination analysis of word generation, responsive naming, and sentence comprehension was the most suitable in terms of activation power, robustness to detect essential language areas, and scanning time. In general, combination analyses of the tasks provided higher overall activation levels than single tasks and reduced the number of outlier voxels disturbing the calculation of LI. A combination of auditory and visually presented tasks that activate different aspects of language functions with sufficient activation power may be a useful task battery for determining language dominance in patients. (orig.)

  3. Unsupervised learning of functional network dynamics in resting state fMRI.

    Science.gov (United States)

    Eavani, Harini; Satterthwaite, Theodore D; Gur, Raquel E; Gur, Ruben C; Davatzikos, Christos

    2013-01-01

    Research in recent years has provided some evidence of temporal non-stationarity of functional connectivity in resting state fMRI. In this paper, we present a novel methodology that can decode connectivity dynamics into a temporal sequence of hidden network "states" for each subject, using a Hidden Markov Modeling (HMM) framework. Each state is characterized by a unique covariance matrix or whole-brain network. Our model generates these covariance matrices from a common but unknown set of sparse basis networks, which capture the range of functional activity co-variations of regions of interest (ROIs). Distinct hidden states arise due to a variation in the strengths of these basis networks. Thus, our generative model combines a HMM framework with sparse basis learning of positive definite matrices. Results on simulated fMRI data show that our method can effectively recover underlying basis networks as well as hidden states. We apply this method on a normative dataset of resting state fMRI scans. Results indicate that the functional activity of a subject at any point during the scan is composed of combinations of overlapping task-positive/negative pairs of networks as revealed by our basis. Distinct hidden temporal states are produced due to a different set of basis networks dominating the covariance pattern in each state.

  4. The Use of Functional MRI to Study Appetite Control in the CNS

    Directory of Open Access Journals (Sweden)

    Akila De Silva

    2012-01-01

    Full Text Available Functional magnetic resonance imaging (fMRI has provided the opportunity to safely investigate the workings of the human brain. This paper focuses on its use in the field of human appetitive behaviour and its impact in obesity research. In the present absence of any safe or effective centrally acting appetite suppressants, a better understanding of how appetite is controlled is vital for the development of new antiobesity pharmacotherapies. Early functional imaging techniques revealed an attenuation of brain reward area activity in response to visual food stimuli when humans are fed—in other words, the physiological state of hunger somehow increases the appeal value of food. Later studies have investigated the action of appetite modulating hormones on the fMRI signal, showing how the attenuation of brain reward region activity that follows feeding can be recreated in the fasted state by the administration of anorectic gut hormones. Furthermore, differences in brain activity between obese and lean individuals have provided clues about the possible aetiology of overeating. The hypothalamus acts as a central gateway modulating homeostatic and nonhomeostatic drives to eat. As fMRI techniques constantly improve, functional data regarding the role of this small but hugely important structure in appetite control is emerging.

  5. Cerebral activation during Chinese semantic associative task in Xinjiang' Uyghurs: a functional MRI study

    International Nuclear Information System (INIS)

    Yang Lixia; Jia Wenxiao; Tang Weijun; Wang Hong; Ding Shuang; Wang Hao

    2010-01-01

    Objective: To explore the cerebral activation in Xinjiang' Uyghurs when performing a Chinese word tasks by the functional magnetic resonance image (fMRI). Methods: Twenty-one healthy Xinjiang' Uyghurs and 11 healthy Hans were scanned using functional magnetic resonance imaging (fMRI) on a 1.5 T MRI scanner with a single run. Different Chinese words were displayed in each block to avoid any practice effect. SPM5.0 software was used for image data processing. To evaluate the inter subject consistency of brain activations associated with Chinese character and word reading, we created penetrance maps by combining binary individual functional maps. Results: For Uyghur-Chinese bilingual subjects, activations related to generated a word that was semantically related to each stimulus. The results indicated that reading Chinese is characterized by extensive activity of the neural systems. Peak activations occurred in the left middle frontal cortex at Brodmann Areas (BA9 and BA47). The left temporal (BA37) cortices were also strongly activated. Other important activated areas included bilateral visual systems (BA17-19) and cerebellum. The location of peak activation in the left frontal regions was similar in Native Uyghurs and Hans. But the active areas in Uyghurs are more extensive than that of Hans. Conclusions: The location of peak activation in the left frontal regions was similar in Native Uyghurs and Hans. More brain areas were needed for Xinjiang' Uyghur speakers during processing Chinese words. (authors)

  6. Scanning fast and slow: current limitations of 3 Tesla functional MRI and future potential

    Science.gov (United States)

    Boubela, Roland N.; Kalcher, Klaudius; Nasel, Christian; Moser, Ewald

    2014-02-01

    Functional MRI at 3T has become a workhorse for the neurosciences, e.g., neurology, psychology, and psychiatry, enabling non-invasive investigation of brain function and connectivity. However, BOLD-based fMRI is a rather indirect measure of brain function, confounded by fluctuation related signals, e.g. head or brain motion, brain pulsation, blood flow, intermixed with susceptibility differences close or distant to the region of neuronal activity. Even though a plethora of preprocessing strategies have been published to address these confounds, their efficiency is still under discussion. In particular, physiological signal fluctuations closely related to brain supply may mask BOLD signal changes related to "true" neuronal activation. Here we explore recent technical and methodological advancements aimed at disentangling the various components, employing fast multiband vs. standard EPI, in combination with fast temporal ICA.Our preliminary results indicate that fast (TRgroups (e.g., age, sex, medication, pathology, etc.). From a technical point of view our goal should be to sample brain activity at layer specific resolution with low TR, covering as much of the brain as possible without violating SAR limits. We hope to stimulate discussion towards a better understanding and a more quantitative use of fMRI.

  7. Neural correlates of the popular music phenomenon: evidence from functional MRI and PET imaging

    International Nuclear Information System (INIS)

    Chen, Qiaozhen; Zhang, Ying; Hou, Haifeng; Du, Fenglei; Wu, Shuang; Chen, Lin; Shen, Yehua; Chao, Fangfang; Zhang, Hong; Tian, Mei; Chung, June-key

    2017-01-01

    Music can induce different emotions. However, its neural mechanism remains unknown. The aim of this study was to use functional magnetic resonance imaging (fMRI) and position emission tomography (PET) imaging for mapping of neural changes under the most popular music in healthy volunteers. Blood-oxygen-level-dependent (BOLD) fMRI and monoamine receptor PET imaging with 11 C-N-methylspiperone ( 11 C-NMSP) were conducted under the popular music Gangnam Style and light music A Comme Amour in healthy subjects. PET and fMRI images were analyzed by using the Statistical Parametric Mapping software (SPM). Significantly increased fMRI BOLD signals were found in the bilateral superior temporal cortices, left cerebellum, left putamen and right thalamus cortex. Monoamine receptor availability was increased significantly in the left superior temporal gyrus and left putamen, but decreased in the bilateral superior occipital cortices under the Gangnam Style compared with the light music condition. Significant positive correlation was found between 11 C-NMSP binding and fMRI BOLD signals in the left temporal cortex. Furthermore, increased 11 C-NMSP binding in the left putamen was positively correlated with the mood arousal level score under the Gangnam Style condition. Popular music Gangnam Style can arouse pleasure experience and strong emotional response. The left putamen is positively correlated with the mood arousal level score under the Gangnam Style condition. Our results revealed characteristic patterns of brain activity associated with Gangnam Style, and may also provide more general insights into the music-induced emotional processing. (orig.)

  8. Enhancing motor network activity using real-time functional MRI neurofeedback of left premotor cortex

    Directory of Open Access Journals (Sweden)

    Theo Ferreira Marins

    2015-12-01

    Full Text Available Neurofeedback by functional Magnetic Resonance Imaging (fMRI is a technique of potential therapeutic relevance that allows individuals to be aware of their own neurophysiological responses and to voluntarily modulate the activity of specific brain regions, such as the premotor cortex (PMC, important for motor recovery after brain injury. We investigated (i whether healthy human volunteers are able to up-regulate the activity of the left PMC during a right hand finger tapping motor imagery (MI task while receiving continuous fMRI-neurofeedback, and (ii whether successful modulation of brain activity influenced non-targeted motor control regions. During the MI task, participants of the neurofeedback group (NFB received ongoing visual feedback representing the level of fMRI responses within their left PMC. Control (CTL group participants were shown similar visual stimuli, but these were non-contingent on brain activity. Both groups showed equivalent levels of behavioral ratings on arousal and motor imagery, before and during the fMRI protocol. In the NFB, but not in CLT group, brain activation during the last run compared to the first run revealed increased activation in the left PMC. In addition, the NFB group showed increased activation in motor control regions extending beyond the left PMC target area, including the supplementary motor area, basal ganglia and cerebellum. Moreover, in the last run, the NFB group showed stronger activation in the left PMC/inferior frontal gyrus when compared to the CTL group. Our results indicate that modulation of PMC and associated motor control areas can be achieved during a single neurofeedback-fMRI session. These results contribute to a better understanding of the underlying mechanisms of MI-based neurofeedback training, with direct implications for rehabilitation strategies in severe brain disorders, such as stroke.

  9. Neural correlates of the popular music phenomenon: evidence from functional MRI and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qiaozhen [The Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Psychiatry, Hangzhou (China); Zhejiang University Medical PET Center, Hangzhou (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou (China); The Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Zhang, Ying; Hou, Haifeng; Du, Fenglei; Wu, Shuang; Chen, Lin; Shen, Yehua; Chao, Fangfang; Zhang, Hong; Tian, Mei [Zhejiang University Medical PET Center, Hangzhou (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou (China); The Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Chung, June-key [Seoul National University Hospital, Department of Nuclear Medicine, Seoul (Korea, Republic of)

    2017-06-15

    Music can induce different emotions. However, its neural mechanism remains unknown. The aim of this study was to use functional magnetic resonance imaging (fMRI) and position emission tomography (PET) imaging for mapping of neural changes under the most popular music in healthy volunteers. Blood-oxygen-level-dependent (BOLD) fMRI and monoamine receptor PET imaging with {sup 11}C-N-methylspiperone ({sup 11}C-NMSP) were conducted under the popular music Gangnam Style and light music A Comme Amour in healthy subjects. PET and fMRI images were analyzed by using the Statistical Parametric Mapping software (SPM). Significantly increased fMRI BOLD signals were found in the bilateral superior temporal cortices, left cerebellum, left putamen and right thalamus cortex. Monoamine receptor availability was increased significantly in the left superior temporal gyrus and left putamen, but decreased in the bilateral superior occipital cortices under the Gangnam Style compared with the light music condition. Significant positive correlation was found between {sup 11}C-NMSP binding and fMRI BOLD signals in the left temporal cortex. Furthermore, increased {sup 11}C-NMSP binding in the left putamen was positively correlated with the mood arousal level score under the Gangnam Style condition. Popular music Gangnam Style can arouse pleasure experience and strong emotional response. The left putamen is positively correlated with the mood arousal level score under the Gangnam Style condition. Our results revealed characteristic patterns of brain activity associated with Gangnam Style, and may also provide more general insights into the music-induced emotional processing. (orig.)

  10. Neural correlates of the popular music phenomenon: evidence from functional MRI and PET imaging.

    Science.gov (United States)

    Chen, Qiaozhen; Zhang, Ying; Hou, Haifeng; Du, Fenglei; Wu, Shuang; Chen, Lin; Shen, Yehua; Chao, Fangfang; Chung, June-Key; Zhang, Hong; Tian, Mei

    2017-06-01

    Music can induce different emotions. However, its neural mechanism remains unknown. The aim of this study was to use functional magnetic resonance imaging (fMRI) and position emission tomography (PET) imaging for mapping of neural changes under the most popular music in healthy volunteers. Blood-oxygen-level-dependent (BOLD) fMRI and monoamine receptor PET imaging with 11 C-N-methylspiperone ( 11 C-NMSP) were conducted under the popular music Gangnam Style and light music A Comme Amour in healthy subjects. PET and fMRI images were analyzed by using the Statistical Parametric Mapping software (SPM). Significantly increased fMRI BOLD signals were found in the bilateral superior temporal cortices, left cerebellum, left putamen and right thalamus cortex. Monoamine receptor availability was increased significantly in the left superior temporal gyrus and left putamen, but decreased in the bilateral superior occipital cortices under the Gangnam Style compared with the light music condition. Significant positive correlation was found between 11 C-NMSP binding and fMRI BOLD signals in the left temporal cortex. Furthermore, increased 11 C-NMSP binding in the left putamen was positively correlated with the mood arousal level score under the Gangnam Style condition. Popular music Gangnam Style can arouse pleasure experience and strong emotional response. The left putamen is positively correlated with the mood arousal level score under the Gangnam Style condition. Our results revealed characteristic patterns of brain activity associated with Gangnam Style, and may also provide more general insights into the music-induced emotional processing.

  11. Functional MRI-navigated repetitive transcranial magnetic stimulation over supplementary motor area in chronic tic disorders.

    Science.gov (United States)

    Wu, Steve W; Maloney, Thomas; Gilbert, Donald L; Dixon, Stephan G; Horn, Paul S; Huddleston, David A; Eaton, Kenneth; Vannest, Jennifer

    2014-01-01

    Open label studies have shown repetitive transcranial magnetic stimulation to be effective in reducing tics. To determine whether 8 sessions of continuous theta burst stimulation (cTBS) over supplementary motor area (SMA) given over 2 days may reduce tics and motor cortical network activity in Tourette syndrome/chronic tic disorders. This was a randomized (1:1), double-blind, sham-controlled trial of functional MRI (fMRI)-navigated, 30 Hz cTBS at 90% of resting motor threshold (RMT) over SMA in 12 patients ages 10-22 years. Comorbid ADHD (n = 8), OCD (n = 8), and stable concurrent medications (n = 9) were permitted. Neuro-navigation utilized each individual's event-related fMRI signal. Primary clinical and cortical outcomes were: 1) Yale Global Tic Severity Scale (YGTSS) at one week; 2) fMRI event-related signal in SMA and primary motor cortex (M1) during a finger-tapping motor task. Baseline characteristics were not statistically different between groups (age, current tic/OCD/ADHD severities, tic-years, number of prior medication trials, RMT). Mean YGTSS scores decreased in both active (27.5 ± 7.4 to 23.2 ± 9.8) and sham (26.8 ± 4.8 to 21.7 ± 7.7) groups. However, no significant difference in video-based tic severity rating was detected between the two groups. Two-day post-treatment fMRI activation during finger tapping decreased significantly in active vs. sham groups for SMA (P = 0.02), left M1 (P = 0.0004), and right M1 (P tic reduction at 7 days. Larger sample size and protocol modifications may be needed to produce clinically significant tic reduction beyond placebo effect. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Clinical application of functional MRI for chronic epilepsy; Klinischer Einsatz der funktionellen MRT bei chronischer Epilepsie

    Energy Technology Data Exchange (ETDEWEB)

    Woermann, F.G.; Labudda, K. [Krankenhaus Mara, Epilepsiezentrum Bethel, Abteilung fuer Magentresonanztomographie, Bielefeld (Germany)

    2010-02-15

    Functional magnetic resonance imaging (fMRI) is frequently used in the presurgical diagnostic procedure of epilepsy patients, in particular for lateralization of speech and memory and for localization of the primary motor cortex to delineate the epileptogenic lesion from eloquent brain areas. fMRI is one of the non-invasive procedures in the presurgical diagnostic process, together with medical history, seizure semiology, neurological examination, interictal and ictal EEG, structural MRI, video EEG monitoring and neuropsychology. This diagnostic sequence leads either to the decision for or against elective epilepsy surgery or to the decision to proceed with invasive diagnostic techniques (Wada test, intra-operative or extra-operative cortical stimulation). It is difficult to evaluate the contribution of the fMRI test in isolation to the validity of the entire diagnostic sequence. Complications such as memory loss and aphasia in temporal lobe resections or paresis after frontal lobe resections are rare and rarely of disastrous extent. This further complicates the evaluation of the clinical relevance of fMRI as a predictive tool. In this article studies which investigated the concordance between fMRI and other diagnostic gold standards will be presented as well as the association between presurgical fMRI and postsurgical morbidity. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) wird im Rahmen der Epilepsiediagnostik vor epilepsiechirurgischen Eingriffen insbesondere zur Lateralisation von Sprache und Gedaechtnis und zur Lokalisation der Zentralregion eingesetzt, um den eloquenten Kortex von der epilepsieverursachenden, chirurgisch zugaenglichen Laesion abzugrenzen. Dabei ist die fMRT Teil einer Sequenz nichtinvasiver klinischer Tests (Anamnese, Anfall-Semiologie, neurologischer Status, interiktales und iktales EEG, strukturelles MRT, Video-EEG-Monitoring, Neuropsychologie). Das Ergebnis dieser Sequenz ist die Entscheidung fuer oder gegen einen

  13. Compromised fronto-striatal functioning in HIV: an fMRI investigation of semantic event sequencing.

    Science.gov (United States)

    Melrose, Rebecca J; Tinaz, Sule; Castelo, J Mimi Boer; Courtney, Maureen G; Stern, Chantal E

    2008-04-09

    The human immunodeficiency virus (HIV) damages fronto-striatal regions, and is associated with deficits in executive functioning. We recently developed a semantic event sequencing task based on the Picture Arrangement subtest of the Wechsler Adult Intelligence Scale-III for use with functional magnetic resonance imaging (fMRI) and found recruitment of dorsolateral prefrontal cortex and basal ganglia in healthy participants. To assess the impact of HIV on the functioning of the basal ganglia and prefrontal cortex, we administered this task to 11 HIV+ and 11 Control participants matched for age and education. Neuropsychological evaluation demonstrated that the HIV+ group had mild impairment in memory retrieval and motor functioning, but was not demented. Morphometric measurements suggested no atrophy in basal ganglia regions. The results of the fMRI analysis revealed hypoactivation of the left caudate, left dorsolateral prefrontal cortex, and bilateral ventral prefrontal cortex in the HIV+ group. Functional connectivity analysis demonstrated less functional connectivity between the caudate and prefrontal cortex and basal ganglia regions in the HIV+ group. In contrast, the HIV+ group demonstrated increased activation of right postcentral/supramarginal gyrus, and greater connectivity between the caudate and this same anterior parietal region. The results of this study extend previous investigations by demonstrating compromised function of the caudate and connected prefrontal regions in HIV during cognition. This disruption of fronto-striatal circuitry likely precedes the development of cognitive impairment in HIV.

  14. Arcuate fasciculus laterality by diffusion tensor imaging correlates with language laterality by functional MRI in preadolescent children

    Energy Technology Data Exchange (ETDEWEB)

    Sreedharan, Ruma Madhu [Government Medical College Hospital, Department of Radiology, Trivandrum, Kerala (India); Menon, Amitha C.; Thomas, Sanjeev V. [Sree Chitra, Thirunal Institute for Medical Sciences and Technology, Department of Neurology, Thiruvananthapuram, Kerala (India); James, Jija S.; Kesavadas, Chandrasekharan [SCTIMST, Department of Imaging Science and Interventional Radiology, Trivandrum, Kerala (India)

    2015-03-01

    Language lateralization is unique to humans. Functional MRI (fMRI) and diffusion tensor imaging (DTI) enable the study of language areas and white matter fibers involved in language, respectively. The objective of this study was to correlate arcuate fasciculus (AF) laterality by diffusion tensor imaging with that by fMRI in preadolescent children which has not yet been reported. Ten children between 8 and 12 years were subjected to fMRI and DTI imaging using Siemens 1.5 T MRI. Two language fMRI paradigms - visual verb generation and word pair task - were used. Analysis was done using SPM8 software. In DTI, the fiber volume of the arcuate fasciculus (AFV) and fractional anisotropy (FA) was measured. The fMRI Laterality Index (fMRI-LI) and DTI Laterality Index (DTI-LI) were calculated and their correlation assessed using the Pearson Correlation Index. Of ten children, mean age 10.6 years, eight showed left lateralization while bilateral language lateralization was seen in two. AFV by DTI was more on the left side in seven of the eight children who had left lateralization by fMRI. DTI could not trace the AF in one child. Of the two with bilateral language lateralization on fMRI, one showed larger AFV on the right side while the other did not show any asymmetry. There was a significant correlation (p < 0.02) between fMRI-LI and DTI-LI. Group mean of AFV by DTI was higher on the left side (2659.89 ± 654.75 mm{sup 3}) as compared to the right (1824.11 ± 582.81 mm{sup 3}) (p < 0.01). Like fMRI, DTI also reveals language laterality in children with a high degree of correlation between the two imaging modalities. (orig.)

  15. Arcuate fasciculus laterality by diffusion tensor imaging correlates with language laterality by functional MRI in preadolescent children

    International Nuclear Information System (INIS)

    Sreedharan, Ruma Madhu; Menon, Amitha C.; Thomas, Sanjeev V.; James, Jija S.; Kesavadas, Chandrasekharan

    2015-01-01

    Language lateralization is unique to humans. Functional MRI (fMRI) and diffusion tensor imaging (DTI) enable the study of language areas and white matter fibers involved in language, respectively. The objective of this study was to correlate arcuate fasciculus (AF) laterality by diffusion tensor imaging with that by fMRI in preadolescent children which has not yet been reported. Ten children between 8 and 12 years were subjected to fMRI and DTI imaging using Siemens 1.5 T MRI. Two language fMRI paradigms - visual verb generation and word pair task - were used. Analysis was done using SPM8 software. In DTI, the fiber volume of the arcuate fasciculus (AFV) and fractional anisotropy (FA) was measured. The fMRI Laterality Index (fMRI-LI) and DTI Laterality Index (DTI-LI) were calculated and their correlation assessed using the Pearson Correlation Index. Of ten children, mean age 10.6 years, eight showed left lateralization while bilateral language lateralization was seen in two. AFV by DTI was more on the left side in seven of the eight children who had left lateralization by fMRI. DTI could not trace the AF in one child. Of the two with bilateral language lateralization on fMRI, one showed larger AFV on the right side while the other did not show any asymmetry. There was a significant correlation (p < 0.02) between fMRI-LI and DTI-LI. Group mean of AFV by DTI was higher on the left side (2659.89 ± 654.75 mm 3 ) as compared to the right (1824.11 ± 582.81 mm 3 ) (p < 0.01). Like fMRI, DTI also reveals language laterality in children with a high degree of correlation between the two imaging modalities. (orig.)

  16. Functional MRI of the pelvic floor: postpartum changes of primiparous women after spontaneous vaginal delivery

    International Nuclear Information System (INIS)

    Lienemann, A.; Fischer, T.; Reiser, M.; Anthuber, C.

    2003-01-01

    Purpose: Detection of morphological and functional changes of the pelvic floor with functional MRI in primiparous women after spontaneous vaginal delivery. Methods and Materials: The study comprises 26 primiparous women after vaginal delivery and a control group of 41 healthy asymptomatic nulliparous volunteers. MRI was performed on a 1.5 T system in supine position with vagina and rectum opacified with Sonogel. The static images consisted of sagittal and axial T 2 -weighted SE sequences and functional images of true FISP sequences in midsagittal and axial planes acquired with the patient at rest, straining and during defecation. Evaluation of morphometric parameters included pelvimetry, thickness of the puborectal muscle and width of the urogenital hiatus as well as position and movement of the pelvic organs relative to the pubococcygeal reference line. Results: The configuration of the bony pelvis did not differ for both groups. The puborectal muscle was significantly thinner in the study group (0.8 cm vs 0.6 cm). The functional images showed no significant differences between both groups at rest but a significantly increased incidence in the descent of the bladder neck, vaginal fornix and anorectal junction in the study group during straining. In addition, the primiparous women had more prominent rectoceles (0.6 cm vs 1.5 cm). Conclusion: Static imaging alone fails to demonstrate relevant pelvic floor changes and a functional method is necessary to evaluate the interactions of the pelvic organs regarding organ descent. Functional MRI of the pelvic floor is an excellent method to reveal the significant changes of the pelvic floor after vaginal birth without exposing the uterus to radiation. (orig.) [de

  17. Motor association cortex activity in Parkinson's disease. A functional MRI study

    International Nuclear Information System (INIS)

    Tada, Yukiko

    1998-01-01

    The purpose of this study was to examine the activation of motor association cortex using functional magnetic resonance imaging (fMRI) in patients with Parkinson's disease (PD) and control subjects during performed hand movements. There were 26 patients with PD (12 patients with Hoehn and Yahr stage I-II, 14 patients with stage III) and 8 control subjects. Functional imaging was performed using a 1.5 tesla MRI system equipped with a single-shot, echo-planar pulse sequence. The significant signal changes were observed within the primary sensorimotor area, the supplementary motor area (SMA), and the parietal association area in both PD and control subjects. In PD subjects, the SMA was less activated than in control subjects; there were significant differences in the number of pixels activated in SMA between control and Yahr III group (p<0.01), and between Yahr I-II and Yahr III group (p<0.01). Our results demonstrated that movement related cerebral activity in the SMA is reduced in PD subjects, consistent with previously published data using other methods. It is well known from anatomical studies that one of the major cortical outputs of the basal ganglia is the SMA. This may explain the hypoactivation of the SMA in PD. Studies using fMRI provide a promising method not only for localizing cortical activation related to voluntary movements but also for investigating pathophysiology of movement disorders. (author)

  18. Study of physiology of visual cortex activated by rotating grating with functional MRI

    International Nuclear Information System (INIS)

    Liang Ping; Shao Qing; Zhang Zhiqiang; Lu Guangming

    2004-01-01

    Objective: To research the physiology of visual cortex activated by rotating grating with functional-MRI (fMRI), and to identify the components of the activation. Methods: Functional MRI was performed in 9 healthy volunteers by using GRE-EPI sequences on a 1.5 T MR scanner. In the block designing, rotating grating, static grating, and luminance were plotted as task states, while static grating, luminance, and darkness were set as control states. The stimuli tasks included six steps. Imaging processing and statistical analysis was carried out off-line using SPM99 in single-subject method. Results: Some respective areas of visual cortex were activated by the various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe located at primary vision area was related to the stimuli of white luminance. Its average maximum points were at 13, -98, -2 and 11, -100, -41 The bilateral activations of Brodmann 19th area located at MT area were related to visual motion perception. Its average maximum points were at 46, -72, -2 and -44, -74, 0. The mild activation in the middle of occipital lobe was related to form perception. Its average maximum points were at -12, -98, -6 and -16, -96, -6. Conclusion: The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception, and form perception. FMRI has potential as a tool for studying the basic physiology of visual cortex. (authors)

  19. Memory Deficits in Schizophrenia: A Selective Review of Functional Magnetic Resonance Imaging (fMRI Studies

    Directory of Open Access Journals (Sweden)

    Adrienne C. Lahti

    2013-06-01

    Full Text Available Schizophrenia is a complex chronic mental illness that is characterized by positive, negative and cognitive symptoms. Cognitive deficits are most predictive of long-term outcomes, with abnormalities in memory being the most robust finding. The advent of functional magnetic resonance imaging (fMRI has allowed exploring neural correlates of memory deficits in vivo. In this article, we will give a selective review of fMRI studies probing brain regions and functional networks that are thought to be related to abnormal memory performance in two memory systems prominently affected in schizophrenia; working memory and episodic memory. We revisit the classic “hypofrontality” hypothesis of working memory deficits and explore evidence for frontotemporal dysconnectivity underlying episodic memory abnormalities. We conclude that fMRI studies of memory deficits in schizophrenia are far from universal. However, the current literature does suggest that alterations are not isolated to a few brain regions, but are characterized by abnormalities within large-scale brain networks.

  20. Altered Structural and Functional Connectivity of Juvenile Myoclonic Epilepsy: An fMRI Study

    Directory of Open Access Journals (Sweden)

    Chengqing Zhong

    2018-01-01

    Full Text Available The aim of this study was to investigate the structural and functional connectivity (FC of juvenile myoclonic epilepsy (JME using resting state functional magnetic resonance imaging (rs-fMRI. High-resolution T1-weighted magnetic resonance imaging (MRI and rs-fMRI data were collected in 25 patients with JME and in 24 control subjects. A FC analysis was subsequently performed, with seeding at the regions that demonstrated between-group differences in gray matter volume (GMV. Then, the observed structural and FCs were associated with the clinical manifestations. The decreased GMV regions were found in the bilateral anterior cerebellum, the right orbital superior frontal gyrus, the left middle temporal gyrus, the left putamen, the right hippocampus, the bilateral caudate, and the right thalamus. The changed FCs were mainly observed in the motor-related areas and the cognitive-related areas. The significant findings of this study revealed an important role for the cerebellum in motor control and cognitive regulation in JME patients, which also have an effect on the activity of the occipital lobe. In addition, the changed FCs were related to the clinical features of JME patients. The current observations may contribute to the understanding of the pathogenesis of JME.

  1. Bayesian spatiotemporal model of fMRI data using transfer functions.

    Science.gov (United States)

    Quirós, Alicia; Diez, Raquel Montes; Wilson, Simon P

    2010-09-01

    This research describes a new Bayesian spatiotemporal model to analyse BOLD fMRI studies. In the temporal dimension, we describe the shape of the hemodynamic response function (HRF) with a transfer function model. The spatial continuity and local homogeneity of the evoked responses are modelled by a Gaussian Markov random field prior on the parameter indicating activations. The proposal constitutes an extension of the spatiotemporal model presented in a previous approach [Quirós, A., Montes Diez, R. and Gamerman, D., 2010. Bayesian spatiotemporal model of fMRI data, Neuroimage, 49: 442-456], offering more flexibility in the estimation of the HRF and computational advantages in the resulting MCMC algorithm. Simulations from the model are performed in order to ascertain the performance of the sampling scheme and the ability of the posterior to estimate model parameters, as well as to check the model sensitivity to signal to noise ratio. Results are shown on synthetic data and on a real data set from a block-design fMRI experiment. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  2. Functional circuit mapping of striatal output nuclei using simultaneous deep brain stimulation and fMRI.

    Science.gov (United States)

    Van Den Berge, Nathalie; Albaugh, Daniel L; Salzwedel, Andrew; Vanhove, Christian; Van Holen, Roel; Gao, Wei; Stuber, Garret D; Ian Shih, Yen-Yu

    2017-02-01

    The substantia nigra pars reticulata (SNr) and external globus pallidus (GPe) constitute the two major output targets of the rodent striatum. Both the SNr and GPe converge upon thalamic relay nuclei (directly or indirectly, respectively), and are traditionally modeled as functionally antagonistic relay inputs. However, recent anatomical and functional studies have identified unanticipated circuit connectivity in both the SNr and GPe, demonstrating their potential as far more than relay nuclei. In the present study, we employed simultaneous deep brain stimulation and functional magnetic resonance imaging (DBS-fMRI) with cerebral blood volume (CBV) measurements to functionally and unbiasedly map the circuit- and network level connectivity of the SNr and GPe. Sprague-Dawley rats were implanted with a custom-made MR-compatible stimulating electrode in the right SNr (n=6) or GPe (n=7). SNr- and GPe-DBS, conducted across a wide range of stimulation frequencies, revealed a number of surprising evoked responses, including unexpected CBV decreases within the striatum during DBS at either target, as well as GPe-DBS-evoked positive modulation of frontal cortex. Functional connectivity MRI revealed global modulation of neural networks during DBS at either target, sensitive to stimulation frequency and readily reversed following cessation of stimulation. This work thus contributes to a growing literature demonstrating extensive and unanticipated functional connectivity among basal ganglia nuclei. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. 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...... significant ventral and dorsal striatal reactivity when participants won a point and removed one from the opponent. Provocations significantly activated the amygdala, dorsal striatum, insula, and prefrontal areas. Task-related aggressive behavior was positively correlated with neural reactivity...... to provocations in the insula, the dorsal striatum, and prefrontal areas. Our findings suggest the PSAP within an fMRI environment may be a useful tool for probing aggression-related neural pathways. Activity in the amygdala, dorsal striatum, insula, and prefrontal areas during provocations is consistent...

  4. A functional MRI study of language networks in left medial temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Yu Aihong; Wang Xiaoyi; Xu Guoqing; Li Yongjie; Qin Wen; Li Kuncheng; Wang, Yuping

    2011-01-01

    Purpose: The purpose of this study was to investigate the abnormality of language networks in left medial temporal lobe epilepsy (MTLE) using fMRI. Materials and methods: Eight patients with left MTLE and 15 healthy subjects were evaluated. An auditory semantic judgment (AJ) paradigm was used. The fMRI data were collected on a 3T MR system and analyzed by AFNI (analysis of functional neuroimages) to generate the activation map. Results: Behavioral data showed that the reaction time of the left MTLE patients was significantly longer than that of controls on the AJ task (t = -3.396, P < 0.05). The left MTLE patients also exhibited diffusively decreased activation in the AJ task. Right hemisphere dominance of Broca's and Wernicke's areas was demonstrated in left MTLE patients. Conclusions: Long-term activation of spikes in left MTLE patients results in language impairment, which is associated with an abnormality of the brain neural network.

  5. A nonlinear identification method to study effective connectivity in functional MRI.

    Science.gov (United States)

    Li, Xingfeng; Marrelec, Guillaume; Hess, Robert F; Benali, Habib

    2010-02-01

    In this paper we propose a novel approach for characterizing effective connectivity in functional magnetic resonance imaging (fMRI) data. Unlike most other methods, our approach is nonlinear and does not rely on a priori specification of a model that contains structural information of neuronal populations. Instead, it relies on a nonlinear autoregressive exogenous model and nonlinear system identification theory; the model's nonlinear connectivities are determined using a least squares method. A statistical test was developed to quantify the significance of the influence that regions exert on one another. We compared this approach with a linear method and applied it to the human visual cortex network. Results show that this method can be used to model nonlinear interaction between different regions for fMRI data.

  6. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...... a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...

  7. Quantifying functional connectivity in multi-subject fMRI data using component models

    DEFF Research Database (Denmark)

    Madsen, Kristoffer Hougaard; Churchill, Nathan William; Mørup, Morten

    2017-01-01

    in the brain among groups of subjects. Component models can be used to define subspace representations of functional connectivity that are more interpretable. It is, however, unclear which component model provides the optimal representation of functional networks for multi-subject fMRI datasets. A flexible......-generalizing models account for subject variability within a common spatial subspace. Within this set of models, spatial Independent Component Analysis (sICA) on concatenated data provides more interpretable brain patterns, whereas a consistent-covariance model that accounts for subject-specific network scaling...

  8. Resting-state functional MRI as a tool for evaluating brain hemodynamic responsiveness to external stimuli in rats.

    Science.gov (United States)

    Paasonen, Jaakko; Salo, Raimo A; Huttunen, Joanna K; Gröhn, Olli

    2017-09-01

    Anesthesia is a major confounding factor in functional MRI (fMRI) experiments attributed to its effects on brain function. Recent evidence suggests that parameters obtained with resting-state fMRI (rs-fMRI) are coupled with anesthetic depth. Therefore, we investigated whether parameters obtained with rs-fMRI, such as functional connectivity (FC), are also directly related to blood-oxygen-level-dependent (BOLD) responses. A simple rs-fMRI protocol was implemented in a pharmacological fMRI study to evaluate the coupling between hemodynamic responses and FC under five anesthetics (α-chloralose, isoflurane, medetomidine, thiobutabarbital, and urethane). Temporal change in the FC was evaluated at 1-hour interval. Supplementary forepaw stimulation experiments were also conducted. Under thiobutabarbital anesthesia, FC was clearly coupled with nicotine-induced BOLD responses. Good correlation values were also obtained under isoflurane and medetomidine anesthesia. The observations in the thiobutabarbital group were supported by forepaw stimulation experiments. Additionally, the rs-fMRI protocol revealed significant temporal changes in the FC in the α-chloralose, thiobutabarbital, and urethane groups. Our results suggest that FC can be used to estimate brain hemodynamic responsiveness to stimuli and evaluate the level and temporal changes of anesthesia. Therefore, analysis of the fMRI baseline signal may be highly valuable tool for controlling the outcome of preclinical fMRI experiments. Magn Reson Med 78:1136-1146, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  9. Diffusion Weighted/Tensor Imaging, Functional MRI and Perfusion Weighted Imaging in Glioblastoma—Foundations and Future

    Directory of Open Access Journals (Sweden)

    Gayle R. Salama

    2018-01-01

    Full Text Available In this article, we review the basics of diffusion tensor imaging and functional MRI, their current utility in preoperative neurosurgical mapping, and their limitations. We also discuss potential future applications, including implementation of resting state functional MRI. We then discuss perfusion and diffusion-weighted imaging and their application in advanced neuro-oncologic practice. We explain how these modalities can be helpful in guiding surgical biopsies and differentiating recurrent tumor from treatment related changes.

  10. Auditory Related Resting State fMRI Functional Connectivity in Tinnitus Patients: Tinnitus Diagnosis Performance.

    Science.gov (United States)

    Minami, Shujiro B; Oishi, Naoki; Watabe, Takahisa; Uno, Kimiichi; Ogawa, Kaoru

    2018-01-01

    The purpose of the present study was to investigate functional connectivity in tinnitus patients with and without hearing loss, and design the tinnitus diagnosis performance by resting state functional magnetic resonance imaging (rs-fMRI). Nineteen volunteers with normal hearing without tinnitus, 18 tinnitus patients with hearing loss, and 11 tinnitus patients without hearing loss were enrolled in this study. The subjects were evaluated with rs-fMRI, and region of interests (ROIs) based correlation analyses were performed using the CONN toolbox version 16 and SPM version 8. The correlation coefficients from individual level results were converted into beta values. With a beta threshold of more than 0.2, 91% of all possible connections between auditory-related ROIs (Heschl's gyrus, planum temporale, planum polare, operculum, insular cortex, superior temporal gyrus) in the control group remained intact, whereas 83 and 66% of such connections were present in the hearing loss and the normal-hearing tinnitus group. However, between non-auditory-related ROIs, the rates of intact connections at a beta threshold of more than 0.2 were 17% in the control group, and 16 and 15% in the tinnitus groups. When resting state fMRI positive is defined as less than 9% of all possible connections between auditory-related ROIs with a beta threshold of more than 0.7, the sensitivity and specificity of tinnitus diagnosis is 86 and 74%, respectively. The associations between auditory-related networks are weakened in tinnitus patients, even if they have normal hearing. It is possible that rs-fMRI can be a tool for objective examination of tinnitus, by focusing the auditory-related areas.

  11. Functional inferences vary with the method of analysis in fMRI.

    Science.gov (United States)

    Machulda, M M; Ward, H A; Cha, R; O'Brien, P; Jack, C R

    2001-11-01

    Neuroanatomic substrates of specific cognitive functions have been inferred from anatomic distributions of activated pixels during fMRI studies. With declarative memory tasks, interest has focused on the extent to which various medial temporal lobe anatomic structures are activated while subjects encode new information. The aim of this project was to examine how commonly used variations in fMRI data processing methods affect the distribution of activation in anatomically defined medial temporal lobe regions of interest (ROIs) during a complex scene-encoding task. ROIs were drawn on an MRI anatomic template formed from 3D SPGR scans of eight subjects combined in Talairach space. Separate ROIs were drawn for the posterior and anterior hippocampal formation, parahippocampal gyrus, and entorhinal cortex. Twelve different activation maps were created for each subject by using four correlation coefficients and three cluster volumes. Friedman's two-way ANOVA by ranks was used to test the hypothesis that the distribution of activated pixels among defined anatomic ROIs varied as a function of the data processing method. By simply varying the combination of correlation coefficient and cluster volume, significantly different distributions of activation within named medial temporal lobe structures were obtained from the same fMRI datasets (P < 0.015; P < 0.001). The number of subjects studied (n = 8) is in a range commonly found in the literature yet this clearly resulted in spurious associations between processing parameter variations and activation distribution. Using data processing methods that are independent of the arbitrary selection of cutoff values for thresholding activation maps may reduce the likelihood of obtaining spurious results. Copyright 2001 Academic Press.

  12. Assessment of renal function after conformal radiotherapy and intensity-modulated radiotherapy by functional 1H-MRI and 23Na-MRI

    International Nuclear Information System (INIS)

    Haneder, S.; Michaely, H.J.; Schoenberg, S.O.; Konstandin, S.; Schad, L.R.; Siebenlist, K.; Wertz, H.; Wenz, F.; Lohr, F.; Boda-Heggemann, J.

    2012-01-01

    Purpose: Adjuvant radiochemotherapy (RCHT) improves survival of patients with locally advanced gastric cancer. Conventional three-dimensional conformal radiotherapy (3D-CRT) results in ablative doses to a significant amount of the left kidney, while image-guided intensity-modulated radiotherapy (IG-IMRT) provides excellent target coverage with improved kidney sparing. Few long-term results on IMRT for gastric cancer, however, have been published. Functional magnetic resonance imaging (fMRI) at 3.0 T including blood oxygenation-level dependent (BOLD) imaging, diffusion-weighted imaging (DWI) and, for the first time, 23 Na imaging was used to evaluate renal status after radiotherapy with 3D-CRT or IG-IMRT. Patients and methods Four disease-free patients (2 after 3D-CRT and 2 after IMRT; FU for all patients > 5 years) were included in this feasibility study. Morphological sequences, axial DWI images, 2D-gradient echo (GRE)-BOLD images, and 23 Na images were acquired. Mean values/standard deviations for ( 23 Na), the apparent diffusion coefficient (ADC), and R2 * values were calculated for the upper/middle/lower parts of both kidneys. Corticomedullary 23 Na-concentration gradients were determined. Results: Surprisingly, IG-IMRT patients showed no morphological alterations and no statistically significant differences of ADC and R2 * values in all renal parts. Values for mean corticomedullary 23 Na-concentration matched those for healthy volunteers. Results were similar in 3D-CRT patients, except for the cranial part of the left kidney. This was atrophic and presented significantly reduced functional parameters (p = 0.001 - p = 0.033). Reduced ADC values indicated reduced cell density and reduced extracellular space. Cortical and medullary R2 * values of the left cranial kidney in the 3D-CRT group were higher, indicating more deoxygenated hemoglobin due to reduced blood flow/oxygenation. ( 23 Na) of the renal cranial parts in the 3D-CRT group was significantly reduced

  13. The Brain Functional State of Music Creation: an fMRI Study of Composers.

    Science.gov (United States)

    Lu, Jing; Yang, Hua; Zhang, Xingxing; He, Hui; Luo, Cheng; Yao, Dezhong

    2015-07-23

    In this study, we used functional magnetic resonance imaging (fMRI) to explore the functional networks in professional composers during the creation of music. We compared the composing state and resting state imagery of 17 composers and found that the functional connectivity of primary networks in the bilateral occipital lobe and bilateral postcentral cortex decreased during the composing period. However, significantly stronger functional connectivity appeared between the anterior cingulate cortex (ACC), the right angular gyrus and the bilateral superior frontal gyrus during composition. These findings indicate that a specific brain state of musical creation is formed when professional composers are composing, in which the integration of the primary visual and motor areas is not necessary. Instead, the neurons of these areas are recruited to enhance the functional connectivity between the ACC and the default mode network (DMN) to plan the integration of musical notes with emotion.

  14. Test-retest reliability of graph metrics in high-resolution functional connectomics: a resting-state functional MRI study.

    Science.gov (United States)

    Du, Hai-Xiao; Liao, Xu-Hong; Lin, Qi-Xiang; Li, Gu-Shu; Chi, Yu-Ze; Liu, Xiang; Yang, Hua-Zhong; Wang, Yu; Xia, Ming-Rui

    2015-10-01

    The combination of resting-state functional MRI (R-fMRI) technique and graph theoretical approaches has emerged as a promising tool for characterizing the topological organization of brain networks, that is, functional connectomics. In particular, the construction and analysis of high-resolution brain connectomics at a voxel scale are important because they do not require prior regional parcellations and provide finer spatial information about brain connectivity. However, the test-retest reliability of voxel-based functional connectomics remains largely unclear. This study tended to investigate both short-term (∼20 min apart) and long-term (6 weeks apart) test-retest (TRT) reliability of graph metrics of voxel-based brain networks. Based on graph theoretical approaches, we analyzed R-fMRI data from 53 young healthy adults who completed two scanning sessions (session 1 included two scans 20 min apart; session 2 included one scan that was performed after an interval of ∼6 weeks). The high-resolution networks exhibited prominent small-world and modular properties and included functional hubs mainly located at the default-mode, salience, and executive control systems. Further analysis revealed that test-retest reliabilities of network metrics were sensitive to the scanning orders and intervals, with fair to excellent long-term reliability between Scan 1 and Scan 3 and lower reliability involving Scan 2. In the long-term case (Scan 1 and Scan 3), most network metrics were generally test-retest reliable, with the highest reliability in global metrics in the clustering coefficient and in the nodal metrics in nodal degree and efficiency. We showed high test-retest reliability for graph properties in the high-resolution functional connectomics, which provides important guidance for choosing reliable network metrics and analysis strategies in future studies. © 2015 John Wiley & Sons Ltd.

  15. 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

  16. Functional MRI study of diencephalic amnesia in Wernicke-Korsakoff syndrome.

    Science.gov (United States)

    Caulo, M; Van Hecke, J; Toma, L; Ferretti, A; Tartaro, A; Colosimo, C; Romani, G L; Uncini, A

    2005-07-01

    Anterograde amnesia in Wernicke-Korsakoff syndrome is associated with diencephalic lesions, mainly in the anterior thalamic nuclei. Whether diencephalic and temporal lobe amnesias are distinct entities is still not clear. We investigated episodic memory for faces using functional MRI (fMRI) in eight controls and in a 34-year-old man with Wernicke-Korsakoff syndrome and diencephalic lesions but without medial temporal lobe (MTL) involvement at MRI. fMRI was performed with a 1.5 tesla unit. Three dual-choice tasks were employed: (i) face encoding (18 faces were randomly presented three times and subjects were asked to memorize the faces); (ii) face perception (subjects indicated which of two faces matched a third face); and (iii) face recognition (subjects indicated which of two faces belonged to the group they had been asked to memorize during encoding). All activation was greater in the right hemisphere. In controls both the encoding and recognition tasks activated two hippocampal regions (anterior and posterior). The anterior hippocampal region was more activated during recognition. Activation in the prefrontal cortex was greater during recognition. In the subject with Wernicke-Korsakoff syndrome, fMRI did not show hippocampal activation during either encoding or recognition. During recognition, although behavioural data showed defective retrieval, the prefrontal regions were activated as in controls, except for the ventrolateral prefrontal cortex. fMRI activation of the visual cortices and the behavioural score on the perception task indicated that the subject with Wernicke-Korsakoff syndrome perceived the faces, paid attention to the task and demonstrated accurate judgement. In the subject with Wernicke-Korsakoff syndrome, although the anatomical damage does not involve the MTL, the hippocampal memory encoding has been lost, possibly as a consequence of the hippocampal-anterior thalamic axis involvement. Anterograde amnesia could therefore be the expression of

  17. Effects of arterial input function selection on kinetic parameters in brain dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Keil, Vera C; Mädler, Burkhard; Gieseke, Jürgen; Fimmers, Rolf; Hattingen, Elke; Schild, Hans H; Hadizadeh, Dariusch R

    2017-07-01

    Kinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) were suggested as a possible instrument for multi-parametric lesion characterization, but have not found their way into clinical practice yet due to inconsistent results. The quantification is heavily influenced by the definition of an appropriate arterial input functions (AIF). Regarding brain tumor DCE-MRI, there are currently several co-existing methods to determine the AIF frequently including different brain vessels as sources. This study quantitatively and qualitatively analyzes the impact of AIF source selection on kinetic parameters derived from commonly selected AIF source vessels compared to a population-based AIF model. 74 patients with brain lesions underwent 3D DCE-MRI. Kinetic parameters [transfer constants of contrast agent efflux and reflux K trans and k ep and, their ratio, v e, that is used to measure extravascular-extracellular volume fraction and plasma volume fraction v p ] were determined using extended Tofts model in 821 ROI from 4 AIF sources [the internal carotid artery (ICA), the closest artery to the lesion, the superior sagittal sinus (SSS), the population-based Parker model]. The effect of AIF source alteration on kinetic parameters was evaluated by tissue type selective intra-class correlation (ICC) and capacity to differentiate gliomas by WHO grade [area under the curve analysis (AUC)]. Arterial AIF more often led to implausible v e >100% values (pkinetic parameters (pkinetic parameters of different AIF sources and tissues were variable (0.08-0.87) and only consistent >0.5 between arterial AIF derived kinetic parameters. Differentiation between WHO III and II glioma was exclusively possible with v p derived from an AIF in the SSS (p=0.03; AUC 0.74). The AIF source has a significant impact on absolute kinetic parameters in DCE-MRI, which limits the comparability of kinetic parameters derived from different AIF sources. The effect is also tissue-dependent. The SSS

  18. Robust preprocessing for stimulus-based functional MRI of the moving fetus.

    Science.gov (United States)

    You, Wonsang; Evangelou, Iordanis E; Zun, Zungho; Andescavage, Nickie; Limperopoulos, Catherine

    2016-04-01

    Fetal motion manifests as signal degradation and image artifact in the acquired time series of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) studies. We present a robust preprocessing pipeline to specifically address fetal and placental motion-induced artifacts in stimulus-based fMRI with slowly cycled block design in the living fetus. In the proposed pipeline, motion correction is optimized to the experimental paradigm, and it is performed separately in each phase as well as in each region of interest (ROI), recognizing that each phase and organ experiences different types of motion. To obtain the averaged BOLD signals for each ROI, both misaligned volumes and noisy voxels are automatically detected and excluded, and the missing data are then imputed by statistical estimation based on local polynomial smoothing. Our experimental results demonstrate that the proposed pipeline was effective in mitigating the motion-induced artifacts in stimulus-based fMRI data of the fetal brain and placenta.

  19. Evaluation of renal function with dynamic MRI-T2-weighted gradient echo technique

    International Nuclear Information System (INIS)

    Kato, Katsuya

    1995-01-01

    To evaluate the usefulness of dynamic MRI of kidneys in healthy volunteers and patients with different 24-hour creatinine clearance (Ccr) levels, a dynamic study that employed the T2 weighted gradient echo technique (FLASH: TR/TE=34/25 msec, flip angle= 20 degrees) with single images during breathhold was performed on 10 healthy volunteers and 35 patients, all examined for the Ccr and suspected of having renal parenchymal disease after a phantom study. T1-weighted and dynamic MR imagings were obtained with a 1.5T imager. I analyzed the time-intensity curve of renal cortex and medulla, and defined a cortex decreased ratio (CDR) and medulla decreased ratio (MDR) in comparison with the Ccr. The cortico-medullary difference ratio (CMDR) of T1WI was also compared with the Ccr. The parameters of the T2 dynamic MRI study (CDR, MDR) better correlated with the Ccr than CMDR. Renal function can be quantitatively evaluated with the T2 dynamic MRI and there is a possibility that we can qualitatively evaluate the renal dysfunction and estimate its cause. (author)

  20. Resting-state, functional MRI on regional homogeneity changes of brain in the heavy smokers

    International Nuclear Information System (INIS)

    Yang Shiqi; Wu Guangyao; Lin Fuchun; Kong Xiangquan; Zhou Guofeng; Pang Haopeng; Zhu Ling; Liu Guobing; Lei Hao

    2012-01-01

    Objective: To explore the mechanism of self-awareness in the heavy smokers (HS) by using regional homogeneity (ReHo) combined with resting-state functional MRI (fMRI). Methods: Thirty HS and 31 healthy non-smokers (NS) matched for age and sex underwent a 3.0 T resting-state fMRI. The data were post-processed by SPM 5 and then the ReHo values were calculated by REST software. The ReHo values between the two groups were compared by two-sample t-test. The brain map with significant difference of ReHo value was obtained. Results: Compared with that in NS group, the regions with decreased ReHo value included the bilateral precuneus, superior frontal gyrus,medial prefrontal cortex, right angular gyrus, inferior frontal gyrus, inferior occipital gyrus, cerebellum, and left middle frontal gyrus in HS group. The regions of increased ReHo value included the bilateral insula, parahippocampal gyrus, white matter of parietal lobe, pons, left inferior parietal lobule, lingual gyrus, thalamus, inferior orbital gyrus, white matter of temporal-frontal lobe, and cerebellum. The difference was more obvious in the left hemisphere. Conclusions: In HS, abnormal ReHo on a resting state which reflects network of smoking addiction. This method may be helpful in understanding the mechanism of self-awareness in HS. (authors)

  1. Cardiac MRI in pulmonary artery hypertension: correlations between morphological and functional parameters and invasive measurements

    Energy Technology Data Exchange (ETDEWEB)

    Alunni, Jean-Philippe; Otal, Philippe; Rousseau, Herve; Chabbert, Valerie [CHU Rangueil, Department of Radiology, Toulouse (France); Degano, Bruno; Tetu, Laurent; Didier, Alain [CHU Larrey, Department of Pneumology, Toulouse (France); Arnaud, Catherine [CHU Rangueil, Department of Methods in Clinical Research, Toulouse (France); Blot-Souletie, Nathalie [CHU Rangueil, Department of Cardiology, Toulouse (France)

    2010-05-15

    To compare cardiac MRI with right heart catheterisation in patients with pulmonary hypertension (PH) and to evaluate its ability to assess PH severity. Forty patients were included. MRI included cine and phase-contrast sequences, study of ventricular function, cardiac cavity areas and ratios, position of the interventricular septum (IVS) in systole and diastole, and flow measurements. We defined four groups according to the severity of PH and three groups according to IVS position: A, normal position; B, abnormal in diastole; C, abnormal in diastole and systole. IVS position was correlated with pulmonary artery pressures and PVR (pulmonary vascular resistance). Median pulmonary artery pressures and resistance were significantly higher in patients with an abnormal septal position compared with those with a normal position. Correlations were good between the right ventricular ejection fraction and PVR, right ventricular end-systolic volume and PAP, percentage of right ventricular area change and PVR, and diastolic and systolic ventricular area ratio and PVR. These parameters were significantly associated with PH severity. Cardiac MRI can help to assess the severity of PH. (orig.)

  2. The approach to developmental dyslexia. The use of functional MRI studies

    International Nuclear Information System (INIS)

    Seki, Ayumi; Koeda, Tatsuya; Okada, Tomohisa; Sadato, Norihiro

    2004-01-01

    Developmental dyslexia is defined as a specific and significant impairment in reading ability that cannot be accounted for by any deficit in general intelligence or sensory acuity. It has been known that dyslexic children exhibit deficits for phonological awareness tasks, which require the ability to manipulate abstract phonological representations. A lower prevalence of dyslexia in Japanese suggests that the Japanese language may be more easily learned and manipulated by people with dyslexia. There are two supposable approaches to studying the mechanism of dyslexia using the functional MRI (fMRI). One is the study in healthy Japanese to investigate advantageous properties of Japanese related to less prevalence of dyslexia and the other is the comparative study in children to investigate the different cortical activity of dyslexia and normal readers. First, fMRI was used to investigate the neural substrates underlying phonological manipulation of the Japanese language. The posterior parts of the superior temporal sulcus (STS) were active during the auditory tasks, suggesting that phonological representations are manipulated in this area. In contrast, the intraparietal sulci (IPS), which have been implicated in visuospatial tasks, were active during the visual tasks, indicating that phonemic manipulation of kana'' letters is visuospatial. We suggest that because of the phonological and orthographical simplicities of the Japanese language, dyslexic children more easily learn the correspondence between letters and sounds. (author)

  3. Morphologic and functional scoring of cystic fibrosis lung disease using MRI

    International Nuclear Information System (INIS)

    Eichinger, Monika; Optazaite, Daiva-Elzbieta; Kopp-Schneider, Annette; Hintze, Christian; Biederer, Jürgen; Niemann, Anne; Mall, Marcus A.; Wielpütz, Mark O.; Kauczor, Hans-Ulrich; Puderbach, Michael

    2012-01-01

    Magnetic resonance imaging (MRI) gains increasing importance in the assessment of cystic fibrosis (CF) lung disease. The aim of this study was to develop a morpho-functional MR-scoring-system and to evaluate its intra- and inter-observer reproducibility and clinical practicability to monitor CF lung disease over a broad severity range from infancy to adulthood. 35 CF patients with broad age range (mean 15.3 years; range 0.5–42) were examined by morphological and functional MRI. Lobe based analysis was performed for parameters bronchiectasis/bronchial-wall-thickening, mucus plugging, abscesses/sacculations, consolidations, special findings and perfusion defects. The maximum global score was 72. Two experienced radiologists scored the images at two time points (interval 10 weeks). Upper and lower limits of agreement, concordance correlation coefficients (CCC), total deviation index and coverage probability were calculated for global, morphology, function, component and lobar scores. Global scores ranged from 6 to 47. Intra- and inter-reader agreement for global scores were good (CCC: 0.98 (R1), 0.94 (R2), 0.97 (R1/R2)) and were comparable between high and low scores. Our results indicate that the proposed morpho-functional MR-scoring-system is reproducible and applicable for semi-quantitative evaluation of a large spectrum of CF lung disease severity. This scoring-system can be applied for the routine assessment of CF lung disease and maybe as endpoint for clinical trials.

  4. Functional MRI for planning in neurosurgery; Funktionelle MR-Bildgebung fuer die neurochirurgische Operationsplanung

    Energy Technology Data Exchange (ETDEWEB)

    Erb, M. [Sektion fuer Experimentelle Kernspinresonanz des ZNS, Abt. Neuroradiologie, Universitaetsklinikum Tuebingen (Germany); Saur, R. [Sektion fuer Experimentelle Kernspinresonanz des ZNS, Abt. Neuroradiologie, Universitaetsklinikum Tuebingen (Germany); Augenklinik des Universitaetsklinikums Tuebingen (Germany); Klinik fuer Psychiatrie und Psychotherapie des Universitaetsklinikums Tuebingen (Germany)

    2007-07-01

    Beside structural images from CT and MR, functional data about localization of brain activations with different tasks becomes more and more important for presurgical planning. With this method, it's possible to depict mainly primary sensory and motoric areas, but also higher functions like speech and memory. To judge this information adequately, one has to be aware of the variability of activation pattern dependent on chosen threshold. Especially, the absence of such activation at a given location does not necessary mean that this area has no function. The reliability of a measurement strongly depends on efficiency of experimental design and cooperation of the patient. Therefore, short and easy tasks which can be performed in a block design should be preferred. Information about localization of functions determined by fMRI can mainly be used for presurgical planning. Intraoperative usage in the navigation system is problematic due to the brain shift. Therefore, intraoperative imaging together with dynamic adaptation using nonlinear deformation algorithms may improve the value of fMRI in the future. (orig.)

  5. Neural Changes following Behavioral Activation for a Depressed Breast Cancer Patient: A Functional MRI Case Study

    Directory of Open Access Journals (Sweden)

    Michael J. Gawrysiak

    2012-01-01

    Full Text Available Functional neuroimaging is an innovative but at this stage underutilized method to assess the efficacy of psychotherapy for depression. Functional magnetic resonance imaging (fMRI was used in this case study to examine changes in brain activity in a depressed breast cancer patient receiving an 8-session Behavioral Activation Treatment for Depression (BATD, based on the work of Hopko and Lejuez (2007. A music listening paradigm was used during fMRI brain scans to assess reward responsiveness at pre- and posttreatment. Following treatment, the patient exhibited attenuated depression and changes in blood oxygenation level dependence (BOLD response in regions of the prefrontal cortex and the subgenual cingulate cortex. These preliminary findings outline a novel means to assess psychotherapy efficacy and suggest that BATD elicits functional brain changes in areas implicated in the pathophysiology of depression. Further research is necessary to explore neurobiological mechanisms of change in BATD, particularly the potential mediating effects of reward responsiveness and associated brain functioning.

  6. Neural plasticity in functional and anatomical MRI studies of children with Tourette syndrome.

    Science.gov (United States)

    Eichele, Heike; Plessen, Kerstin J

    2013-01-01

    Tourette syndrome (TS) is a neuropsychiatric disorder with childhood onset characterized by chronic motor and vocal tics. The typical clinical course of an attenuation of symptoms during adolescence in parallel with the emerging self-regulatory control during development suggests that plastic processes may play an important role in the development of tic symptoms. We conducted a systematic search to identify existing imaging studies (both anatomical and functional magnetic resonance imaging [fMRI]) in young persons under the age of 19 years with TS. The final search resulted in 13 original studies, which were reviewed with a focus on findings suggesting adaptive processes (using fMRI) and plasticity (using anatomical MRI). Differences in brain activation compared to healthy controls during tasks that require overriding of prepotent responses help to understand compensatory pathways in children with TS. Along with alterations in regions putatively representing the origin of tics, deviations in several other regions most likely represent an activity-dependent neural plasticity that help to modulate tic severity, such as the prefrontal cortex, but also in the corpus callosum and the limbic system. Factors that potentially influence the development of adaptive changes in the brain of children with TS are age, comorbidity with other developmental disorders, medication use, IQ along with study-design or MRI techniques for acquisition, and analysis of data. The most prominent limitation of all studies is their cross-sectional design. Longitudinal studies extending to younger age groups and to children at risk for developing TS hopefully will confirm findings of neural plasticity in future investigations.

  7. Noninvasive determination of language dominance using functional MRI and near-infrared spectroscopy

    International Nuclear Information System (INIS)

    Ota, Takahiro; Kamada, Kyousuke; Saito, Nobuhito

    2009-01-01

    Identification of the language dominant hemisphere is important in cases necessary for partial encephalotomy due to epilepsy and tumor. Functional MRI (fMRI) essentially detects oxy-Hb/deoxy-Hb ratio in the brain region resulted from blood flow change and near-infrared spectroscopy (NIRS), the Hb level change in the tissue, in which the image can be detected by light-receiving proves of NIR-light (780-1500 nm wavelength) irradiated and passed through the tissues. This paper describes the comparison of the two methods for determination of language dominance with reference to that identified by Wada test, a gold standard but inconvenient for both operators and patients. Subjects are 11 brain tumor and 11 epilepsy patients (M 10/F 12, av. age of 36.7 y, 19 right-handed), whose dominances are successfully determined previously by Wada test. fMRI is conducted with 3T machine (General Electric, USA) with phased-array coil in patients receiving various language tasks, and data are processed by Dr. View (Asahi Kasei) to calculate the laterality index for the dominance. NIRS is conducted with Hitachi-Medico ETG-4000 with 695 and 830 nm IR in patients receiving other different language tasks, on whose frontotemporal region of head surface 12-channel probes are equipped. Data are processed by the equipped software to calculate the difference of oxy-Hb change rates between the two hemispheres for the dominance determination. Consistency of fMRI in determining the dominance with Wada test is found 86.3% and of NIRS, 72.7%, which suggests the latter can be only supplementary to the former. However, NIRS is noted to be useful in atypical cases like those with right or bilateral dominance. (K.T.)

  8. Clinical fMRI of language function in aphasic patients: Reading paradigm successful, while word generation paradigm fails

    International Nuclear Information System (INIS)

    Engstroem, Maria; Landtblom, Anne-Marie; Ragnehed, Mattias; Lundberg, Peter; Karlsson, Marie; Crone, Marie; Antepohl, Wolfram

    2010-01-01

    Background: In fMRI examinations, it is very important to select appropriate paradigms assessing the brain function of interest. In addition, the patients' ability to perform the required cognitive tasks during fMRI must be taken into account. Purpose: To evaluate two language paradigms, word generation and sentence reading for their usefulness in examinations of aphasic patients and to make suggestions for improvements of clinical fMRI. Material and Methods: Five patients with aphasia after stroke or trauma sequelae were examined by fMRI. The patients' language ability was screened by neurolinguistic tests and elementary pre-fMRI language tests. Results: The sentence-reading paradigm succeeded to elicit adequate language-related activation in perilesional areas whereas the word generation paradigm failed. These findings were consistent with results on the behavioral tests in that all patients showed very poor performance in phonemic fluency, but scored well above mean at a reading comprehension task. Conclusion: The sentence-reading paradigm is appropriate to assess language function in this patient group, while the word-generation paradigm seems to be inadequate. In addition, it is crucial to use elementary pre-fMRI language tests to guide the fMRI paradigm decision.

  9. Clinical fMRI of language function in aphasic patients: Reading paradigm successful, while word generation paradigm fails

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    Engstroem, Maria; Landtblom, Anne-Marie; Ragnehed, Mattias; Lundberg, Peter (Center for Medical Image Science and Visualization (CMIV), Linkoeping Univ., Linkoeping (Sweden)), e-mail: maria.engstrom@liu.se; Karlsson, Marie; Crone, Marie (Dept. of Clinical and Experimental Medicine/Logopedics, Linkoeping Univ., Linkoeping (Sweden)); Antepohl, Wolfram (Dept. of Clinical and Experimental Medicine/Rehabilitation, Linkoeping Univ., Linkoeping (Sweden))

    2010-07-15

    Background: In fMRI examinations, it is very important to select appropriate paradigms assessing the brain function of interest. In addition, the patients' ability to perform the required cognitive tasks during fMRI must be taken into account. Purpose: To evaluate two language paradigms, word generation and sentence reading for their usefulness in examinations of aphasic patients and to make suggestions for improvements of clinical fMRI. Material and Methods: Five patients with aphasia after stroke or trauma sequelae were examined by fMRI. The patients' language ability was screened by neurolinguistic tests and elementary pre-fMRI language tests. Results: The sentence-reading paradigm succeeded to elicit adequate language-related activation in perilesional areas whereas the word generation paradigm failed. These findings were consistent with results on the behavioral tests in that all patients showed very poor performance in phonemic fluency, but scored well above mean at a reading comprehension task. Conclusion: The sentence-reading paradigm is appropriate to assess language function in this patient group, while the word-generation paradigm seems to be inadequate. In addition, it is crucial to use elementary pre-fMRI language tests to guide the fMRI paradigm decision.

  10. Role of New Functional MRI Techniques in the Diagnosis, Staging, and Followup of Gynecological Cancer: Comparison with PET-CT

    International Nuclear Information System (INIS)

    Alvarez Moreno, Elena; Jimenez de la Peña, Mar; Cano Alonso, Raquel

    2012-01-01

    Recent developments in diagnostic imaging techniques have magnified the role and potential of both MRI and PET-CT in female pelvic imaging. This article reviews the techniques and clinical applications of new functional MRI (fMRI) including diffusion-weighted MRI (DWI), dynamic contrast-enhanced (DCE)-MRI, comparing with PET-CT. These new emerging provide not only anatomic but also functional imaging, allowing detection of small volumes of active tumor at diagnosis and early disease relapse, which may not result in detectable morphological changes at conventional imaging. This information is useful in distinguishing between recurrent/residual tumor and post-treatment changes and assessing treatment response, with a clear impact on patient management. Both PET-CT and now fMRI have proved to be very valuable tools for evaluation of gynecologic tumors. Most papers try to compare these techniques, but in our experience both are complementary in management of these patients. Meanwhile PET-CT is superior in diagnosis of ganglionar disease; fMRI presents higher accuracy in local preoperative staging. Both techniques can be used as biomarkers of tumor response and present high accuracy in diagnosis of local recurrence and peritoneal dissemination, with complementary roles depending on histological type, anatomic location and tumoral volume

  11. Role of New Functional MRI Techniques in the Diagnosis, Staging, and Followup of Gynecological Cancer: Comparison with PET-CT

    International Nuclear Information System (INIS)

    Moreno, E.A.; Pena, M.J.; Alonso, R.C.

    2012-01-01

    Recent developments in diagnostic imaging techniques have magnified the role and potential of both MRI and PET-CT in female pelvic imaging. This article reviews the techniques and clinical applications of new functional MRI (fMRI) including diffusion-weighted MRI (DWI), dynamic contrast-enhanced (DCE)-MRI, comparing with PET-CT. These new emerging provide not only anatomic but also functional imaging, allowing detection of small volumes of active tumor at diagnosis and early disease relapse, which may not result in detectable morphological changes at conventional imaging. This information is useful in distinguishing between recurrent/residual tumor and post-treatment changes and assessing treatment response, with a clear impact on patient management. Both PET-CT and now fMRI have proved to be very valuable tools for evaluation of gynecologic tumors. Most papers try to compare these techniques, but in our experience both are complementary in management of these patients. Meanwhile PET-CT is superior in diagnosis of ganglionar disease; fMRI presents higher accuracy in local preoperative staging. Both techniques can be used as bio markers of tumor response and present high accuracy in diagnosis of local recurrence and peritoneal dissemination, with complementary roles depending on histological type, anatomic location and tumoral volume

  12. Cognitive Functioning in Temporal Lobe Epilepsy: A BOLD-fMRI Study.

    Science.gov (United States)

    Guo, Lili; Bai, Genji; Zhang, Hui; Lu, Daoyan; Zheng, Jiyong; Xu, Gang

    2017-12-01

    We aimed to analyze the association between resting-state functional magnetic resonance imaging (re-fMRI) and cognitive function (including language, executive, and memory functions) in temporal lobe epilepsy (TLE) patients, which will help to explore the mechanism of brain function in patients. 15 TLE patients and 15 non-TLE patients were recruited. All subjects underwent neuropsychological testing and memory functional evaluation. Changes in verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), full intelligence quotient (FIQ), and memory quotient (MQ) were compared between two groups. Re-fMRI data were also collected from two groups to evaluate these changes. Each individual score of neuropsychological testing and memory functional evaluation were higher in control group, which was statistically different (all P temporal gyrus back, right superior temporal gyrus, left cerebellum, left angular gyrus, left wedge anterior lobe, and left central back; while the negatively activated brain regions were left prefrontal, right cerebellum, right corner back, and right anterior cingulate gyrus. During the language task, the activated brain regions of the TLE patients were right prefrontal lobe, the lateral temporal gyri, the left cerebellum, left cornu laterale gyrus, left precuneus, and the left postcentral gyrus, whereas the negatively activated brain areas were the left prefrontal cortex, the right cerebellum, right cornu laterale gyrus, and the right anterior cingulate gyrus. During the executive task, epilepsy patients showed activation difference in right prefrontal and right frontal lobe and right brain, left superior temporal gyrus, and right cerebellum anterior lobe compared with the control group; no negatively activated differences in brain areas. During the memory task, the difference lay in bilateral anterior cingulate gyrus and bilateral wedge anterior lobe while the negatively activated brain areas were the left inferior frontal

  13. Effect of bread gluten content on gastrointestinal function: a crossover MRI study on healthy humans.

    Science.gov (United States)

    Coletta, Marina; Gates, Fred K; Marciani, Luca; Shiwani, Henna; Major, Giles; Hoad, Caroline L; Chaddock, Gemma; Gowland, Penny A; Spiller, Robin C

    2016-01-14

    Gluten is a crucial functional component of bread, but the effect of increasing gluten content on gastrointestinal (GI) function remains uncertain. Our aim was to investigate the effect of increasing gluten content on GI function and symptoms in healthy participants using the unique capabilities of MRI. A total of twelve healthy participants completed this randomised, mechanistic, open-label, three-way crossover study. On days 1 and 2 they consumed either gluten-free bread (GFB), or normal gluten content bread (NGCB) or added gluten content bread (AGCB). The same bread was consumed on day 3, and MRI scans were performed every 60 min from fasting baseline up to 360 min after eating. The appearance of the gastric chime in the images was assessed using a visual heterogeneity score. Gastric volumes, the small bowel water content (SBWC), colonic volumes and colonic gas content and GI symptoms were measured. Fasting transverse colonic volume after the 2-d preload was significantly higher after GFB compared with NGCB and AGCB with a dose-dependent response (289 (SEM 96) v. 212 (SEM 74) v. 179 (SEM 87) ml, respectively; P=0·02). The intragastric chyme heterogeneity score was higher for the bread with increased gluten (AGCB 6 (interquartile range (IQR) 0·5) compared with GFB 3 (IQR 0·5); P=0·003). However, gastric half-emptying time was not different between breads nor were study day GI symptoms, postprandial SBWC, colonic volume and gas content. This MRI study showed novel mechanistic insights in the GI responses to different breads, which are poorly understood notwithstanding the importance of this staple food.

  14. Presbycusis Disrupts Spontaneous Activity Revealed by Resting-State Functional MRI

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    Yu-Chen Chen

    2018-03-01

    Full Text Available Purpose: Presbycusis, age-related hearing loss, is believed to involve neural changes in the central nervous system, which is associated with an increased risk of cognitive impairment. The goal of this study was to determine if presbycusis disrupted spontaneous neural activity in specific brain areas involved in auditory processing, attention and cognitive function using resting-state functional magnetic resonance imaging (fMRI approach.Methods: Hearing and resting-state fMRI measurements were obtained from 22 presbycusis patients and 23 age-, sex- and education-matched healthy controls. To identify changes in spontaneous neural activity associated with age-related hearing loss, we compared the amplitude of low-frequency fluctuations (ALFF and regional homogeneity (ReHo of fMRI signals in presbycusis patients vs. controls and then determined if these changes were linked to clinical measures of presbycusis.Results: Compared with healthy controls, presbycusis patients manifested decreased spontaneous activity mainly in the superior temporal gyrus (STG, parahippocampal gyrus (PHG, precuneus and inferior parietal lobule (IPL as well as increased neural activity in the middle frontal gyrus (MFG, cuneus and postcentral gyrus (PoCG. A significant negative correlation was observed between ALFF/ReHo activity in the STG and average hearing thresholds in presbycusis patients. Increased ALFF/ReHo activity in the MFG was positively correlated with impaired Trail-Making Test B (TMT-B scores, indicative of impaired cognitive function involving the frontal lobe.Conclusions: Presbycusis patients have disrupted spontaneous neural activity reflected by ALFF and ReHo measurements in several brain regions; these changes are associated with specific cognitive performance and speech/language processing. These findings mainly emphasize the crucial role of aberrant resting-state ALFF/ReHo patterns in presbycusis patients and will lead to a better understanding of the

  15. Presbycusis Disrupts Spontaneous Activity Revealed by Resting-State Functional MRI.

    Science.gov (United States)

    Chen, Yu-Chen; Chen, Huiyou; Jiang, Liang; Bo, Fan; Xu, Jin-Jing; Mao, Cun-Nan; Salvi, Richard; Yin, Xindao; Lu, Guangming; Gu, Jian-Ping

    2018-01-01

    Purpose : Presbycusis, age-related hearing loss, is believed to involve neural changes in the central nervous system, which is associated with an increased risk of cognitive impairment. The goal of this study was to determine if presbycusis disrupted spontaneous neural activity in specific brain areas involved in auditory processing, attention and cognitive function using resting-state functional magnetic resonance imaging (fMRI) approach. Methods : Hearing and resting-state fMRI measurements were obtained from 22 presbycusis patients and 23 age-, sex- and education-matched healthy controls. To identify changes in spontaneous neural activity associated with age-related hearing loss, we compared the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) of fMRI signals in presbycusis patients vs. controls and then determined if these changes were linked to clinical measures of presbycusis. Results : Compared with healthy controls, presbycusis patients manifested decreased spontaneous activity mainly in the superior temporal gyrus (STG), parahippocampal gyrus (PHG), precuneus and inferior parietal lobule (IPL) as well as increased neural activity in the middle frontal gyrus (MFG), cuneus and postcentral gyrus (PoCG). A significant negative correlation was observed between ALFF/ReHo activity in the STG and average hearing thresholds in presbycusis patients. Increased ALFF/ReHo activity in the MFG was positively correlated with impaired Trail-Making Test B (TMT-B) scores, indicative of impaired cognitive function involving the frontal lobe. Conclusions : Presbycusis patients have disrupted spontaneous neural activity reflected by ALFF and ReHo measurements in several brain regions; these changes are associated with specific cognitive performance and speech/language processing. These findings mainly emphasize the crucial role of aberrant resting-state ALFF/ReHo patterns in presbycusis patients and will lead to a better understanding of the

  16. Convergent Findings of Altered Functional and Structural Brain Connectivity in Individuals with High Functioning Autism: A Multimodal MRI Study.

    Directory of Open Access Journals (Sweden)

    Sophia Mueller

    Full Text Available Brain tissue changes in autism spectrum disorders seem to be rather subtle and widespread than anatomically distinct. Therefore a multimodal, whole brain imaging technique appears to be an appropriate approach to investigate whether alterations in white and gray matter integrity relate to consistent changes in functional resting state connectivity in individuals with high functioning autism (HFA. We applied diffusion tensor imaging (DTI, voxel-based morphometry (VBM and resting state functional connectivity magnetic resonance imaging (fcMRI to assess differences in brain structure and function between 12 individuals with HFA (mean age 35.5, SD 11.4, 9 male and 12 healthy controls (mean age 33.3, SD 9.0, 8 male. Psychological measures of empathy and emotionality were obtained and correlated with the most significant DTI, VBM and fcMRI findings. We found three regions of convergent structural and functional differences between HFA participants and controls. The right temporo-parietal junction area and the left frontal lobe showed decreased fractional anisotropy (FA values along with decreased functional connectivity and a trend towards decreased gray matter volume. The bilateral superior temporal gyrus displayed significantly decreased functional connectivity that was accompanied by the strongest trend of gray matter volume decrease in the temporal lobe of HFA individuals. FA decrease in the right temporo-parietal region was correlated with psychological measurements of decreased emotionality. In conclusion, our results indicate common sites of structural and functional alterations in higher order association cortex areas and may therefore provide multimodal imaging support to the long-standing hypothesis of autism as a disorder of impaired higher-order multisensory integration.

  17. 'What is it?' A functional MRI and SPECT study of ictal speech in a second language

    International Nuclear Information System (INIS)

    Navarro, V.; Chauvire, V.; Baulac, M.; Cohen, L.; Delmaire, Ch.; Lehericy, St.; Habert, M.O.; Footnick, R.; Pallier, Ch.; Baulac, M.; Cohen, L.

    2009-01-01

    Neuronal networks involved in second language (L2) processing vary between normal subjects. Patients with epilepsy may have ictal speech automatisms in their second language. To delineate the brain systems involved in L2 ictal speech, we combined functional MRI during bilingual tasks and ictal - inter-ictal single-photon emission computed tomography in a patient who presented L2 ictal speech productions. These analyses showed that the networks activated by the seizure and those activated by L2 processing intersected in the right hippocampus. These results may provide some insights both into the pathophysiology of ictal speech and into the brain organization for L2. (authors)

  18. A regularized clustering approach to brain parcellation from functional MRI data

    Science.gov (United States)

    Dillon, Keith; Wang, Yu-Ping

    2017-08-01

    We consider a data-driven approach for the subdivision of an individual subject's functional Magnetic Resonance Imaging (fMRI) scan into regions of interest, i.e., brain parcellation. The approach is based on a computational technique for calculating resolution from inverse problem theory, which we apply to neighborhood selection for brain connectivity networks. This can be efficiently calculated even for very large images, and explicitly incorporates regularization in the form of spatial smoothing and a noise cutoff. We demonstrate the reproducibility of the method on multiple scans of the same subjects, as well as the variations between subjects.

  19. Functional hemispherotomy in Rasmussen syndrome in the absence of classic MRI findings

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    Yasunori Nagahama

    2017-01-01

    Full Text Available A 7-year-old previously healthy girl presented with a left-sided focal seizure without impaired consciousness and subsequently developed epilepsia partialis continua. Initial MRI was normal, and the subsequent images only showed a focal T2/FLAIR hyperintense area without cortical atrophy. She was diagnosed with Rasmussen syndrome by pathology and promptly treated with functional hemispherotomy. Rasmussen syndrome is a rare progressive neurological disorder, the only definitive cure for which is hemispheric disconnection. The disease presents a management dilemma, especially early in disease course without characteristic neuroimaging features. A high index of suspicion, multidisciplinary approach, and clear timely communication with the family are critical.

  20. Optimizing functional parameter accuracy for breath-hold DCE-MRI of liver tumours

    International Nuclear Information System (INIS)

    Orton, Matthew R; Miyazaki, Keiko; Koh, Dow-Mu; Collins, David J; Leach, Martin O; Hawkes, David J; Atkinson, David

    2009-01-01

    Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a valuable tool for assessing treatment response to novel cancer therapeutics. With appropriate data acquisition, quantitative functional parameter estimates can be obtained by fitting a model to the data. This research focuses on applying a dual-input single-compartment pharmacokinetic model to breath-hold DCE-MRI imaging of the liver. In this paper, the use of two breath-holds, providing greater temporal information, is compared with a single breath-hold approach. Computer simulations are used to assess the accuracy, precision and sensitivity to input function errors obtained for parameters estimated from the two imaging protocols. Data from ten patients were analysed to assess the noise statistics obtained from the two breath-hold protocols. The noise statistics were used with a pharmacokinetic liver model to simulate data, from which the estimation accuracy, precision and sensitivity for the two protocols were assessed. Data from the ten patients were also analysed, and the estimates were compared with literature values. This work demonstrates the feasibility of obtaining functional liver perfusion estimates over a 3D volume using a sequential breath-hold protocol. The simulation results show that the protocol consisting of two images per breath-hold is to be preferred as it requires identical patient co-operation, but provides parameter estimates that have superior accuracy and precision.

  1. Functional MRI evaluation of supplementary motor area language dominance in right- and left-handed subjects.

    Science.gov (United States)

    Dalacorte, Amauri; Portuguez, Mirna Wetters; Maurer das Neves, Carlos Magno; Anes, Maurício; Dacosta, Jaderson Costa

    2012-01-01

    Functional magnetic resonance imaging (fMRI) is a non-invasive brain imaging technique widely used in the evaluation of the brain function that provides images with high temporal and spatial resolution. Investigation of the supplementary motor area (SMA) function is critical in the pre-surgical evaluation of neurological patients, since marked individual differences and complex overlapping with adjacent cortical areas exist, and it is important to spare the SMA from lesions when adjacent cortical tissue is surgically removed. We used fMRI to assess the activity of SMA in six right-handed and six left-handed healthy volunteers when a task requiring silent repetition of a series of words was given. Brain activation areas in each of the subjects were localized according to the standard Talairach coordinate space, and the individual voxels for each map were compared after 3D sagittal images were created and SMA was delimited. Quantitative analysis of hemispheric and bilateral SMA activation was described as mean ± standard deviation of hot points/total points. The results show that the language task induced bilateral SMA activation. Left SMA activation was significantly higher than right SMA activation in both right-handed and left-handed subjects.

  2. 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.

  3. MRI assessed pancreatic morphology and exocrine function are associated with disease burden in chronic pancreatitis.

    Science.gov (United States)

    Madzak, Adnan; Olesen, Søren Schou; Lykke Poulsen, Jakob; Bolvig Mark, Esben; Mohr Drewes, Asbjørn; Frøkjær, Jens Brøndum

    2017-11-01

    The aim of this study was to explore the association between morphological and functional secretin-stimulated MRI parameters with hospitalization, quality of life (QOL), and pain in patients with chronic pancreatitis (CP). This prospective cohort study included 82 patients with CP. Data were obtained from clinical information, QOL, and pain as assessed by questionnaires (The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and modified Brief Pain Inventory short form). Secretin-stimulated MRI morphological parameters included pancreatic gland volume, main pancreatic duct diameter, the modified Cambridge Classification of Duct Abnormality, apparent diffusion coefficient, fat signal fraction, and the pancreatic secretion volume as a functional parameter. The primary outcomes were time to first hospitalization related to the CP, as well as annual hospitalization frequency and duration. The secondary outcomes were pain severity, QOL, and pain interference scores. A main pancreatic duct diameter below 5 mm was associated with reduced time to first hospitalization (hazard ratio=2.06; 95% confidence interval: 1.02-4.17; P=0.043). Pancreatic secretion volume was correlated with QOL (r=0.31; P=0.0072) and pain interference score (r=-0.27; P=0.032), and fecal elastase was also correlated with QOL (r=0.28; P=0.017). However, functional and morphological findings were not related to pain intensity. Advanced pancreatic imaging techniques may be a highly sensitive tool for prognostication and monitoring of disease activity and its consequences.

  4. Functional resonance magnetic imaging (fMRI) in adolescents with idiopathic musculoskeletal pain: a paradigm of experimental pain

    OpenAIRE

    Molina, Juliana; Amaro, Edson; da Rocha, Liana Guerra Sanches; Jorge, Liliana; Santos, Flavia Heloisa; Len, Claudio A.

    2017-01-01

    Background Studies on functional magnetic resonance imaging (fMRI) have shown that adults with musculoskeletal pain syndromes tolerate smaller amount of pressure (pain) as well as differences in brain activation patterns in areas related to pain.The objective of this study was to evaluate, through fMRI, the brain activation in adolescents with idiopathic musculoskeletal pain (IMP) while performing an experimental paradigm of pain. Methods The study included 10 consecutive adolescents with idi...

  5. TH-CD-202-09: Free-Breathing Proton MRI Functional Lung Avoidance Maps to Guide Radiation Therapy

    International Nuclear Information System (INIS)

    Capaldi, D; Sheikh, K; Parraga, G; Hoover, D; Yaremko, B; Palma, D

    2016-01-01

    Purpose: Pulmonary functional MRI using inhaled gas contrast agents was previously investigated as a way to identify well-functioning lung in patients with NSCLC who are clinical candidates for radiotherapy. Hyperpolarized noble-gas ( 3 He and 129 Xe) MRI has also been optimized to measure functional lung information, but for a number of reasons, the clinical translation of this approach to guide radiotherapy planning has been limited. As an alternative, free-breathing pulmonary 1H MRI using clinically available MRI systems and pulse sequences provides a non-contrast-enhanced method to generate both ventilation and perfusion maps. Free-breathing 1 H MRI exploits non-rigid registration and Fourier decomposition of MRI signal intensity differences (Bauman et al., MRM, 2009) that may be generated during normal tidal breathing. Here, our objective was to generate free-breathing 1 H MRI ventilation and lung function avoidance maps in patients with NSCLC as a way to guide radiation therapy planning. Methods: Stage IIIA/IIIB NSCLC patients (n=8, 68±9yr) provided written informed consent to a randomized controlled clinical trial ( https://clinicaltrials.gov/ct2/show/NCT02002052 ) that aimed to compare outcomes related to image-guided versus conventional radiation therapy planning. Hyperpolarized 3 He/ 129 Xe and dynamic free tidal-breathing 1 H MRI were acquired as previously described (Capaldi et al., Acad Radiol, 2015). Non-rigid registration was performed using the modality-independent-neighbourhood-descriptor (MIND) deformable approach (Heinrich et al., Med Image Anal, 2012). Ventilation-defect-percent ( 3 He:VDP He , 129 Xe:VDP Xe , Free-breathing- 1 H:VDP FB ) and the corresponding ventilation maps were compared using Pearson correlation coefficients (r) and the Dice similarity coefficient (DSC). Results: VDP FB was significantly related to VDP He (r=.71; p=.04) and VDP Xe (r=.80; p=.01) and there were also strong spatial relationships (DSC He /DSC Xe =89±3%/77±11

  6. Multiband multi-echo simultaneous ASL/BOLD for task-induced functional MRI.

    Directory of Open Access Journals (Sweden)

    Alexander D Cohen

    Full Text Available Typical simultaneous blood oxygenation-level dependent (BOLD and arterial spin labeling (ASL sequences acquire two echoes, one perfusion-sensitive and one BOLD-sensitive. However, for ASL, spatial resolution and brain coverage are limited due to the T1 decay of the labeled blood. This study applies a sequence combining a multiband acquisition with four echoes for simultaneous BOLD and pseudo-continuous ASL (pCASL echo planar imaging (MBME ASL/BOLD for block-design task-fMRI. A multiband acceleration of four was employed to increase brain coverage and reduce slice-timing effects on the ASL signal. Multi-echo independent component analysis (MEICA was implemented to automatically denoise the BOLD signal by regressing non-BOLD components. This technique led to increased temporal signal-to-noise ratio (tSNR and BOLD sensitivity. The MEICA technique was also modified to denoise the ASL signal by regressing artifact and BOLD signals from the first echo time-series. The MBME ASL/BOLD sequence was applied to a finger-tapping task functional MRI (fMRI experiment. Signal characteristics and activation were evaluated using single echo BOLD, combined ME BOLD, combined ME BOLD after MEICA denoising, perfusion-weighted (PW, and perfusion-weighted after MEICA denoising time-series. The PW data was extracted using both surround subtraction and high-pass filtering followed by demodulation. In addition, the CBF/BOLD response ratio and CBF/BOLD coupling were analyzed. Results showed that the MEICA denoising procedure significantly improved the BOLD signal, leading to increased BOLD sensitivity, tSNR, and activation statistics compared to conventional single echo BOLD data. At the same time, the denoised PW data showed increased tSNR and activation statistics compared to the non-denoised PW data. CBF/BOLD coupling was also increased using the denoised ASL and BOLD data. Our preliminary data suggest that the MBME ASL/BOLD sequence can be employed to collect whole

  7. Relative sensitivities of DCE-MRI pharmacokinetic parameters to arterial input function (AIF) scaling

    Science.gov (United States)

    Li, Xin; Cai, Yu; Moloney, Brendan; Chen, Yiyi; Huang, Wei; Woods, Mark; Coakley, Fergus V.; Rooney, William D.; Garzotto, Mark G.; Springer, Charles S.

    2016-08-01

    Dynamic-Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) has been used widely for clinical applications. Pharmacokinetic modeling of DCE-MRI data that extracts quantitative contrast reagent/tissue-specific model parameters is the most investigated method. One of the primary challenges in pharmacokinetic analysis of DCE-MRI data is accurate and reliable measurement of the arterial input function (AIF), which is the driving force behind all pharmacokinetics. Because of effects such as inflow and partial volume averaging, AIF measured from individual arteries sometimes require amplitude scaling for better representation of the blood contrast reagent (CR) concentration time-courses. Empirical approaches like blinded AIF estimation or reference tissue AIF derivation can be useful and practical, especially when there is no clearly visible blood vessel within the imaging field-of-view (FOV). Similarly, these approaches generally also require magnitude scaling of the derived AIF time-courses. Since the AIF varies among individuals even with the same CR injection protocol and the perfect scaling factor for reconstructing the ground truth AIF often remains unknown, variations in estimated pharmacokinetic parameters due to varying AIF scaling factors are of special interest. In this work, using simulated and real prostate cancer DCE-MRI data, we examined parameter variations associated with AIF scaling. Our results show that, for both the fast-exchange-limit (FXL) Tofts model and the water exchange sensitized fast-exchange-regime (FXR) model, the commonly fitted CR transfer constant (Ktrans) and the extravascular, extracellular volume fraction (ve) scale nearly proportionally with the AIF, whereas the FXR-specific unidirectional cellular water efflux rate constant, kio, and the CR intravasation rate constant, kep, are both AIF scaling insensitive. This indicates that, for DCE-MRI of prostate cancer and possibly other cancers, kio and kep may be more suitable imaging

  8. A f-MRI study on memory function in normal subjects and patients with partial epilepsies

    International Nuclear Information System (INIS)

    Kamoda, Sachiko

    2004-01-01

    To investigate cerebral regions concerning a memory function and presence of memory lateralization, activated areas and the difference between the right and left hemisphere in functional magnetic resonance imaging (f-MRI) during verbal and visual memory tasks were examined in normal subjects and, as its clinical application, in patients with partial epilepsies. Subjects were 39 normal adult subjects and 10 adult patients. Of the 39 normal subjects, 30 were right-handed and 9 were left-handed. Further, of the 10 patients, 9 were right-handed and one was left-handed, and 7, 2 and 1 had temporal lobe, frontal lobe and undetermined partial epilepsies, respectively. Following the three type of memory task were designed; verbal memory tasks consisting of covert and overt recall tests of 10 words given auditory and visual memory task of covert recall tasks of 6 figures given visually. Activated cerebral areas were imaged with f-MRI using 1.5 tesla Magnetom Vision taken repeatedly during these tasks and neutral condition. Most of the 30 right-handed normal subjects showed activated areas over the left hemisphere specifically on the anterior cingulate, superior, middle and inferior frontal gyri during the verbal memory tasks of covert recall tests. Left hemisphere dominant activated areas in the precentral gyri were added during the verbal memory tasks of overt recall tests. On the other hand, 4 of the 9 left-handed normal subjects showed the left side-dominantly activated areas in the above-mentioned regions during the verbal memory tasks of covert and overt tests, in common with the right-handed subjects. However, 3 of the 9 left-handed normal subjects had right hemisphere dominant activation during the verbal memory tasks, while none of the 30 right-handed normal subjects showed such right side-dominancy. Further, the bilateral occipital lobes were activated during visual memory tasks. The reproducibility in this activation during these verbal and visual memory tasks

  9. Body-centred map in parietal eye fields - functional MRI study

    International Nuclear Information System (INIS)

    Brotchie, P.; Chen, D.Y.; Bradley, W.G.

    2002-01-01

    Full text: In order for us to interact with our environment we need to know where objects are around us, relative to our body. In monkeys, a body-centred map of visual space is known to exist within the parietal eye fields. This map is formed by the modulation of neuronal activity by eye and head position (Brotchie et al, Nature 1995; Synder et al, Nature 1998). In humans no map of body centred space has been demonstrated. By using functional MRI we have localised a region along the intraparietal sulcus which has properties similar to the parietal eye fields of monkeys (Brotchie et al, ISMRM, 2000). The aim of this study was to determine if activity in this region is modulated by head position, consistent with a body centered representation of visual space. Functional MRI was performed on 6 subjects performing simple visually guided saccades using a 1.5 Tesla GE Echospeed scanner. 10 scans were performed on the 6 subjects at left and right body orientations. Regions of interest were selected around the intraparietal sulcus proper (IPSP) of both hemispheres and voxels with BOLD signal which correlated with the paradigm (r>0.35) were selected for further analysis. Comparisons of percentage signal change were made between the left and right IPSP using Student t test. Of the 10 MRI examinations, 6 demonstrated statistically significant differences in the amount of signal change between left and right IPSP. In each of these 6 cases, the signal change was greater within the IPSP contralateral to the direction of head position relative to the body. This indicates a modulation of activity within the IPSP related to head position, most likely reflecting modulation of the underlying neuronal activity and suggests the existence of a body-centred encoding of space within the parietal eye fields of humans. Copyright (2002) Blackwell Science Pty Ltd

  10. Material specific lateralization of medial temporal lobe function: An fMRI investigation.

    Science.gov (United States)

    Dalton, Marshall A; Hornberger, Michael; Piguet, Olivier

    2016-03-01

    The theory of material specific lateralization of memory function posits that left and right MTL regions are asymmetrically involved in mnemonic processing of verbal and nonverbal material respectively. Lesion and functional imaging (fMRI) studies provide robust evidence for a left MTL asymmetry in the verbal memory domain. Evidence for a right MTL/nonverbal asymmetry is not as robust. A handful of fMRI studies have investigated this issue but have generally utilised nonverbal stimuli which are amenable to semantic elaboration. This fMRI study aimed to investigate the neural correlates of recognition memory processing in 20 healthy young adults (mean age = 26 years) for verbal stimuli and nonverbal stimuli that were specifically designed to minimize verbalisation. Analyses revealed that the neural correlates of recognition memory processing for verbal and nonverbal stimuli were differentiable and asymmetrically recruited the left and right MTL respectively. The right perirhinal cortex and hippocampus were preferentially involved in successful recognition memory of items devoid of semantic information. In contrast, the left anterior hippocampus was preferentially involved in successful recognition memory of stimuli which contained semantic meaning. These results suggest that the left MTL is preferentially involved in mnemonic processing of verbal/semantic information. In contrast, the right MTL is preferentially involved in visual/non-semantic mnemonic processing. We propose that during development, the left MTL becomes specialised for verbal mnemonic processing due to its proximity with left lateralised cortical language processing areas while visual/non-semantic mnemonic processing gets 'crowded out' to become predominantly, but not completely, the domain of the right MTL. © 2015 Wiley Periodicals, Inc.

  11. Functional MRI study of the brain with malformations of cortical development

    International Nuclear Information System (INIS)

    Zhang Lei; Zhou Wenjing; Jin Zhen; Li Ke; Zhang Chaoli

    2012-01-01

    Objective: To explore the patterns of motor and linguistic activation in cortical and its correlations with abnormal gray matter in patients with malformations of cortical development (MCD) and epilepsy. Methods: Seven MCD patients with epilepsy (2 patients with focal cortical dysplasia, 2 heterotopia, 2 schizencephaly, and 1 polymicrogyria) underwent blood-oxygen-level-dependent (BOLD) functional MRI (fMRI) in a 3 T MR scanner when practicing bilateral fingers tapping,toes twisting, verb generation, and picture naming.Functional images were post-processed by using SPM 5 software based on a general linear model (GLM) to generate activations above a uniform threshold with the cluster size (≥30 voxels, P<0.001 corrected). The activations were recognized and classified by two experienced neuroradiologists, and then compared with that in abnormal gray matter. Results: The clusters and intensities of motor activations were mainly located in the sensormotor cortex (SMC) and premotor area (PMA). In linguistic tasks, activations produced by verb generation were found in language-associated cortical regions and PMA with higher activation in Wernicke area, picture naming significantly in the visual cortex, and language in Broca area. Combination of the two linguistic tasks produced significant clusters and intensities in language cortex. For MCD patients with abnormal cortical abnormalities, motor and language task could produce neuronal activities within normal as well as abnormal cortex regions. In 6 patients who underwent respective surgery, epileptic seizures decreased significantly, and the follow-up images demonstrated no new neurological dysfunctions and cognitive impairments. Conclusions: fMRI can visualize neuronal activities in patients with MCD and epilepsy and demonstrate the motor and linguistic activations occurring in normal and abnormal gray matter. It should be cautious for surgery in patient with MCD and epilepsy. (authors)

  12. The Nuisance of Nuisance Regression: Spectral Misspecification in a Common Approach to Resting-State fMRI Preprocessing Reintroduces Noise and Obscures Functional Connectivity

    OpenAIRE

    Hallquist, Michael N.; Hwang, Kai; Luna, Beatriz

    2013-01-01

    Recent resting-state functional connectivity fMRI (RS-fcMRI) research has demonstrated that head motion during fMRI acquisition systematically influences connectivity estimates despite bandpass filtering and nuisance regression, which are intended to reduce such nuisance variability. We provide evidence that the effects of head motion and other nuisance signals are poorly controlled when the fMRI time series are bandpass-filtered but the regressors are unfiltered, resulting in the inadvertent...

  13. Functional analysis of third ventriculostomy patency with phase-contrast MRI velocity measurements

    International Nuclear Information System (INIS)

    Lev, S.; Bhadelia, R.A.; Estin, D.; Heilman, C.B.; Wolpert, S.M.

    1997-01-01

    Our purpose was to explore the utility of cine phase-contrast MRI velocity measurements in determining the functional status of third ventriculostomies, and to correlate the quantitative velocity data with clinical follow-up. We examined six patients with third ventriculostomies and 12 normal subjects by phase-contrast MRI. The maximum craniocaudal to maximum caudocranial velocity range was measured at regions of interest near the third ventricular floor, and in cerebrospinal fluid anterior to the upper pons and spinal cord on midline sagittal images. Ratios of the velocities of both the third ventricle and prepontine space to the space anterior to the spinal cord were obtained. The velocities near the third ventricular floor and in the pontine cistern were significantly higher in patients than in normal subjects, but the velocity anterior to the spinal cord was similar between the groups. The velocity ratios, used to normalize individual differences, were also higher in patients than in controls. Two patients had lower velocity ratios than their fellows at the third ventricular floor and in the pontine cistern; one required a shunt 11 months later, while in the other, who had a third ventricular/thalamic tumor, the lower values probably reflect distortion of the third ventricular floor. We conclude that phase-contrast MR velocity measurements, specifically the velocity ratio between the high pontine cistern and the space anterior to the spinal cord, can help determine the functional status of third ventriculostomies. (orig.)

  14. An fMRI Study of Intra-Individual Functional Topography in the Human Cerebellum

    Directory of Open Access Journals (Sweden)

    Catherine J. Stoodley

    2010-01-01

    Full Text Available Neuroimaging studies report cerebellar activation during both motor and non-motor paradigms, and suggest a functional topography within the cerebellum. Sensorimotor tasks activate the anterior lobe, parts of lobule VI, and lobule VIII, whereas higher-level tasks activate lobules VI and VII in the posterior lobe. To determine whether these activation patterns are evident at a single-subject level, we conducted functional magnetic resonance imaging (fMRI during five tasks investigating sensorimotor (finger tapping, language (verb generation, spatial (mental rotation, working memory (N-back, and emotional processing (viewing images from the International Affective Picture System. Finger tapping activated the ipsilateral anterior lobe (lobules IV-V as well as lobules VI and VIII. Activation during verb generation was found in right lobules VII and VIIIA. Mental rotation activated left-lateralized clusters in lobules VII-VIIIA, VI-Crus I, and midline VIIAt. The N-back task showed bilateral activation in right lobules VI-Crus I and left lobules VIIB-VIIIA. Cerebellar activation was evident bilaterally in lobule VI while viewing arousing vs. neutral images. This fMRI study provides the first proof of principle demonstration that there is topographic organization of motor execution vs. cognitive/emotional domains within the cerebellum of a single individual, likely reflecting the anatomical specificity of cerebro-cerebellar circuits underlying different task domains. Inter-subject variability of motor and non-motor topography remains to be determined.

  15. Determination of hemispheric language dominance using functional MRI : comparison of visual and auditory stimuli

    International Nuclear Information System (INIS)

    Yoo, Ic Ryung; Ahn, Kook Jin; Lee, Jae Mun; Kim, Tae

    1999-01-01

    To assess the difference between auditory and visual stimuli when determining hemispheric language dominance by using functional MRI. In ten healthy adult volunteers (8 right-handed, 1 left-handed, 1 ambidextrous), motor language activation in axial slices of frontal lobe was mapped on a Simens 1.5T Vision Plus system using single-shot EPI. Series of 120 consecutive images per section were acquired during three cycles of task activation and rest. During each activation, a series of four syllables was delivered by means of both a visual and auditory method, and the volunteers were asked to mentally generate words starting with each syllable. In both in ferior frontal gyri and whole frontal lobes, lateralization indices were calculated from the activated pixels. We determined the language dominant hemisphere, and compared the results of the visual method and the auditory method. Seven right-handed persons were left-hemisphere dominant, and one left-handed and one ambidex-trous person were right-hemisphere dominant. Five of nine persons demonstrated larger lateralization indices with the auditory method than the visual method, while the remaining four showed larger lateralization indices with the visual method. No statistically significant difference was noted when comparing the results of the two methods(p>0.05). When determining hemispheric language dominance using functional MRI, the two methods are equally appropriate

  16. Determination of hemispheric language dominance using functional MRI : comparison of visual and auditory stimuli

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ic Ryung; Ahn, Kook Jin; Lee, Jae Mun [The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Tae [The Catholic Magnetic Resonance Research Center, Seoul (Korea, Republic of)

    1999-12-01

    To assess the difference between auditory and visual stimuli when determining hemispheric language dominance by using functional MRI. In ten healthy adult volunteers (8 right-handed, 1 left-handed, 1 ambidextrous), motor language activation in axial slices of frontal lobe was mapped on a Simens 1.5T Vision Plus system using single-shot EPI. Series of 120 consecutive images per section were acquired during three cycles of task activation and rest. During each activation, a series of four syllables was delivered by means of both a visual and auditory method, and the volunteers were asked to mentally generate words starting with each syllable. In both in ferior frontal gyri and whole frontal lobes, lateralization indices were calculated from the activated pixels. We determined the language dominant hemisphere, and compared the results of the visual method and the auditory method. Seven right-handed persons were left-hemisphere dominant, and one left-handed and one ambidex-trous person were right-hemisphere dominant. Five of nine persons demonstrated larger lateralization indices with the auditory method than the visual method, while the remaining four showed larger lateralization indices with the visual method. No statistically significant difference was noted when comparing the results of the two methods(p>0.05). When determining hemispheric language dominance using functional MRI, the two methods are equally appropriate.

  17. A theoretical framework for determining cerebral vascular function and heterogeneity from dynamic susceptibility contrast MRI.

    Science.gov (United States)

    Digernes, Ingrid; Bjørnerud, Atle; Vatnehol, Svein Are S; Løvland, Grete; Courivaud, Frédéric; Vik-Mo, Einar; Meling, Torstein R; Emblem, Kyrre E

    2017-06-01

    Mapping the complex heterogeneity of vascular tissue in the brain is important for understanding cerebrovascular disease. In this translational study, we build on previous work using vessel architectural imaging (VAI) and present a theoretical framework for determining cerebral vascular function and heterogeneity from dynamic susceptibility contrast magnetic resonance imaging (MRI). Our tissue model covers realistic structural architectures for vessel branching and orientations, as well as a range of hemodynamic scenarios for blood flow, capillary transit times and oxygenation. In a typical image voxel, our findings show that the apparent MRI relaxation rates are independent of the mean vessel orientation and that the vortex area, a VAI-based parameter, is determined by the relative oxygen saturation level and the vessel branching of the tissue. Finally, in both simulated and patient data, we show that the relative distributions of the vortex area parameter as a function of capillary transit times show unique characteristics in normal-appearing white and gray matter tissue, whereas tumour-voxels in comparison display a heterogeneous distribution. Collectively, our study presents a comprehensive framework that may serve as a roadmap for in vivo and per-voxel determination of vascular status and heterogeneity in cerebral tissue.

  18. Morpho-Functional 1H-MRI of the Lung in COPD: Short-Term Test-Retest Reliability.

    Directory of Open Access Journals (Sweden)

    Bertram J Jobst

    Full Text Available Non-invasive end-points for interventional trials and tailored treatment regimes in chronic obstructive pulmonary disease (COPD for monitoring regionally different manifestations of lung disease instead of global assessment of lung function with spirometry would be valuable. Proton nuclear magnetic resonance imaging (1H-MRI allows for a radiation-free assessment of regional structure and function. The aim of this study was to evaluate the short-term reproducibility of a comprehensive morpho-functional lung MRI protocol in COPD.20 prospectively enrolled COPD patients (GOLD I-IV underwent 1H-MRI of the lung at 1.5T on two consecutive days, including sequences for morphology, 4D contrast-enhanced perfusion, and respiratory mechanics. Image quality and COPD-related morphological and functional changes were evaluated in consensus by three chest radiologists using a dedicated MRI-based visual scoring system. Test-retest reliability was calculated per each individual lung lobe for the extent of large airway (bronchiectasis, wall thickening, mucus plugging and small airway abnormalities (tree in bud, peripheral bronchiectasis, mucus plugging, consolidations, nodules, parenchymal defects and perfusion defects. The presence of tracheal narrowing, dystelectasis, pleural effusion, pulmonary trunk ectasia, right ventricular enlargement and, finally, motion patterns of diaphragma and chest wall were addressed.Median global scores [10(Q1:8.00;Q3:16.00 vs.11(Q1:6.00;Q3:15.00] as well as category subscores were similar between both timepoints, and kappa statistics indicated "almost perfect" global agreement (ĸ = 0.86, 95%CI = 0.81-0.91. Most subscores showed at least "substantial" agreement of MRI1 and MRI2 (ĸ = 0.64-1.00, whereas the agreement for the diagnosis of dystelectasis/effusion (ĸ = 0.42, 95%CI = 0.00-0.93 was "moderate" and of tracheal abnormalities (ĸ = 0.21, 95%CI = 0.00-0.75 "fair". Most MRI acquisitions showed at least diagnostic quality at

  19. 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.

  20. Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Petersen, Claus Leth; Kjaer, Andreas

    2005-01-01

    AIMS: Radionuclide techniques, and recently MRI, have been used for clinical evaluation of right ventricular (RV) volumes function (RVEF) and volumes; but with the introduction of 3D echocardiography, new echocardiographic possibilities for RV evaluation independent of geometrical assumptions have......: Thirty-four subjects with (a) prior inferior ST-elevation myocardial infarction (n=17), (b) a history of pulmonary embolism and persistent dyspnea (n=7) or (c) normal subjects (n=10) had 2D and 3D echocardiography, SPECT and MRI within 24h. End-diastolic volume and peak tricuspid regurgitation velocity...... volume showed significant correlation to RV volumes by MRI. Tricuspid annular plane systolic excursion (TAPSE) had the better correlation to RVEF by MRI, r=0.48, Pechocardiography had a correlation of 0.42, Pechocardiography underestimated RVEF by 5.9%, 95...

  1. Voluntary switching between identities in dissociative identity disorder: A functional MRI case study.

    Science.gov (United States)

    Savoy, R L; Frederick, B B; Keuroghlian, A S; Wolk, P C

    2012-01-01

    Patients who suffer from dissociative identity disorder present unique scientific and clinical challenges for psychology and psychiatry. We have been fortunate in working with a patient who-while undergoing functional MRI-can switch rapidly and voluntarily between her main personality (a middle-aged, high-functioning woman) and an alternate personality (a 4-6-year-old girl). A unique task was designed to isolate the processes occurring during the switches between these personalities. Data are from two imaging sessions, conducted months apart, each showing the same activated areas during switches between these personalities. The activated areas include the following: the primary sensory and motor cortex, likely associated with characteristic facial movements made during switching; the nucleus accumbens bilaterally, possibly associated with aspects of reward connected with switching; and prefrontal sites, presumably associated with the executive control involved in the switching of personalities.

  2. Effects of visual information regarding tactile stimulation on the somatosensory cortical activation: a functional MRI study.

    Science.gov (United States)

    Kwon, Hyeok Gyu; Jang, Sung Ho; Lee, Mi Young

    2017-07-01

    Many studies have investigated the evidence for tactile and visual interactive responses to activation of various brain regions. However, few studies have reported on the effects of visuo-tactile multisensory integration on the amount of brain activation on the somatosensory cortical regions. The aim of this study was to examine whether coincidental information obtained by tactile stimulation can affect the somatosensory cortical activation using functional MRI. Ten right-handed healthy subjects were recruited for this study. Two tasks (tactile stimulation and visuotactile stimulation) were performed using a block paradigm during fMRI scanning. In the tactile stimulation task, in subjects with eyes closed, tactile stimulation was applied on the dorsum of the right hand, corresponding to the proximal to distal directions, using a rubber brush. In the visuotactile stimulation task, tactile stimulation was applied to observe the attached mirror in the MRI chamber reflecting their hands being touched with the brush. In the result of SPM group analysis, we found brain activation on the somatosensory cortical area. Tactile stimulation task induced brain activations in the left primary sensory-motor cortex (SM1) and secondary somatosensory cortex (S2). In the visuo-tactile stimulation task, brain activations were observed in the both SM1, both S2, and right posterior parietal cortex. In all tasks, the peak activation was detected in the contralateral SM1. We examined the effects of visuo-tactile multisensory integration on the SM1 and found that visual information during tactile stimulation could enhance activations on SM1 compared to the tactile unisensory stimulation.

  3. Effects of visual information regarding tactile stimulation on the somatosensory cortical activation: a functional MRI study

    Directory of Open Access Journals (Sweden)

    Hyeok Gyu Kwon

    2017-01-01

    Full Text Available Many studies have investigated the evidence for tactile and visual interactive responses to activation of various brain regions. However, few studies have reported on the effects of visuo-tactile multisensory integration on the amount of brain activation on the somatosensory cortical regions. The aim of this study was to examine whether coincidental information obtained by tactile stimulation can affect the somatosensory cortical activation using functional MRI. Ten right-handed healthy subjects were recruited for this study. Two tasks (tactile stimulation and visuotactile stimulation were performed using a block paradigm during fMRI scanning. In the tactile stimulation task, in subjects with eyes closed, tactile stimulation was applied on the dorsum of the right hand, corresponding to the proximal to distal directions, using a rubber brush. In the visuotactile stimulation task, tactile stimulation was applied to observe the attached mirror in the MRI chamber reflecting their hands being touched with the brush. In the result of SPM group analysis, we found brain activation on the somatosensory cortical area. Tactile stimulation task induced brain activations in the left primary sensory-motor cortex (SM1 and secondary somatosensory cortex (S2. In the visuo-tactile stimulation task, brain activations were observed in the both SM1, both S2, and right posterior parietal cortex. In all tasks, the peak activation was detected in the contralateral SM1. We examined the effects of visuo-tactile multisensory integration on the SM1 and found that visual information during tactile stimulation could enhance activations on SM1 compared to the tactile unisensory stimulation.

  4. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI.

    Science.gov (United States)

    Motaal, Abdallah G; Noorman, Nils; de Graaf, Wolter L; Hoerr, Verena; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously with the heartbeat, resulting in a randomly undersampled kt-space that facilitates compressed sensing reconstruction. The sequence was tested in 4 healthy rats and 4 rats with chronic myocardial infarction, approximately 2 months after surgery. As a control, a non-accelerated self-gated multi-slice FLASH sequence with an echo time (TE) of 2.76 ms, 4.5 signal averages, a matrix of 192 × 192, and an acquisition time of 2 min 34 s per slice was used to obtain Cine MRI with 15 frames per heartbeat. Non-accelerated UTE MRI was performed with TE = 0.29 ms, a reconstruction matrix of 192 × 192, and an acquisition time of 3 min 47 s per slice for 3.5 averages. Accelerated imaging with 2×, 4× and 5× undersampled kt-space data was performed with 1 min, 30 and 15 s acquisitions, respectively. UTE Cine images up to 5× undersampled kt-space data could be successfully reconstructed using a compressed sensing algorithm. In contrast to the FLASH Cine images, flow artifacts in the UTE images were nearly absent due to the short echo time, simplifying segmentation of the left ventricular (LV) lumen. LV functional parameters derived from the control and the accelerated Cine movies were statistically identical.

  5. The impact of "physiological correction" on functional connectivity analysis of pharmacological resting state fMRI

    NARCIS (Netherlands)

    Khalili-Mahani, N.; Chang, C.; Osch, M.J.; Veer, I.M.; van Buchem, M.A.; Dahan, A.; Beckmann, Christian

    2013-01-01

    Growing interest in pharmacological resting state fMRI (RSfMRI) necessitates developing standardized and robust analytical approaches that are insensitive to spurious correlated physiological signals. However, in pharmacological experiments physiological variations constitute an important aspect of

  6. Pharmacologic MRI (phMRI) as a tool to differentiate Parkinson's disease-related from age-related changes in basal ganglia function.

    Science.gov (United States)

    Andersen, Anders H; Hardy, Peter A; Forman, Eric; Gerhardt, Greg A; Gash, Don M; Grondin, Richard C; Zhang, Zhiming

    2015-02-01

    The prevalence of both parkinsonian signs and Parkinson's disease (PD) per se increases with age. Although the pathophysiology of PD has been studied extensively, less is known about the functional changes taking place in the basal ganglia circuitry with age. To specifically address this issue, 3 groups of rhesus macaques were studied: normal middle-aged animals (used as controls), middle-aged animals with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism, and aged animals (>20 years old) with declines in motor function. All animals underwent the same behavioral and pharmacologic magnetic resonance imaging (phMRI) procedures to measure changes in basal ganglia function in response to dopaminergic drug challenges consisting of apomorphine administration followed by either a D1 (SCH23390) or a D2 (raclopride) receptor antagonist. Significant functional changes were predominantly seen in the external segment of the globus pallidus (GPe) in aged animals and in the striatum (caudate nucleus and putamen) in MPTP-lesioned animals. Despite significant differences seen in the putamen and GPe between MPTP-lesioned versus aged animals, a similar response profile to dopaminergic stimulations was found between these 2 groups in the internal segment of the GP. In contrast, the pharmacologic responses seen in the control animals were much milder compared with the other 2 groups in all the examined areas. Our phMRI findings in MPTP-lesioned parkinsonian and aged animals suggest that changes in basal ganglia function in the elderly may differ from those seen in parkinsonian patients and that phMRI could be used to distinguish PD from other age-associated functional alterations in the brain. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Empirical Assessment of Lanius et al.s’ ’Functional MRI of EMDR in Peacekeepers’, a Review of the EMDR Literature and an annotated bibliography

    Science.gov (United States)

    2002-07-01

    8217 "Functional MRI of EMDR in Peacekeepers" a review of the EMDR literature and an annotated bibliography Megan M. Thompson Luigi Pasto DISTRIBUTION...025 July 2002 Canad 20021023 098 "- Empirical assessment of Lanius et al.s’ ’Functional MRI of EMDR in Peacekeepers’, a review of the EMDR ...functional MRI (Magnetic Resonance Imaging), and to determine whether an Eye Movement Desensitization and Reprocessing ( EMDR ) intervention causes

  8. Independent value added by diffusion MRI for prediction of cognitive function in older adults

    Directory of Open Access Journals (Sweden)

    Julia A Scott

    2017-01-01

    Full Text Available The purpose of this study was to determine whether white matter microstructure measured by diffusion magnetic resonance imaging (dMRI provides independent information about baseline level or change in executive function (EF or memory (MEM in older adults with and without cognitive impairment. Longitudinal data was acquired from the Alzheimer's Disease Neuroimaging Initiative (ADNI study from phases GO and 2 (2009–2015. ADNI participants included were diagnosed as cognitively normal (n = 46, early mild cognitive impairment (MCI (n = 48, late MCI (n = 29, and dementia (n = 39 at baseline. We modeled the association between dMRI-based global white matter mean diffusivity (MD and baseline level and change in EF and MEM composite scores, in models controlling for baseline bilateral hippocampal volume, regional cerebral FDG PET metabolism and global cerebral AV45 PET uptake. EF and MEM composite scores were measured at baseline, 6, 12, 24 and 36 months. In the baseline late MCI and dementia groups, greater global MD was associated with lesser baseline EF, but not EF change nor MEM baseline or change. As expected, lesser hippocampal volume and lesser FDG PET metabolism was associated with greater rates of EF and MEM decline. In ADNI-GO/2 participants, white matter integrity provided independent information about current executive function, but was not sensitive to future cognitive change. Since individuals experiencing executive function declines progress to dementia more rapidly than those with only memory impairment, better biomarkers of future executive function decline are needed.

  9. Resting-State fMRI Functional Connectivity Is Associated with Sleepiness, Imagery, and Discontinuity of Mind

    NARCIS (Netherlands)

    Stoffers, D.; Diaz, B Alexander; Chen, Gang; den Braber, Anouk; van 't Ent, Dennis; Boomsma, Dorret I; Mansvelder, Huibert D; de Geus, Eco; Van Someren, Eus J W; Linkenkaer-Hansen, Klaus

    2015-01-01

    Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to investigate the functional architecture of the healthy human brain and how it is affected by learning, lifelong development, brain disorders or pharmacological intervention. Non-sensory experiences are prevalent during

  10. Resting-State fMRI Functional Connectivity Is Associated with Sleepiness, Imagery, and Discontinuity of Mind.

    NARCIS (Netherlands)

    Stoffers, D.; Diaz, B.A.; Cheng, G.; den Braber, A.; van t Ent, D.; Boomsma, D.I.; Mansvelder, H.D.; de Geus, E.J.C.; van Someren, E.J.W.; Linkenkaer-Hansen, K.

    2015-01-01

    Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to investigate the functional architecture of the healthy human brain and how it is affected by learning, lifelong development, brain disorders or pharmacological intervention. Non-sensory experiences are prevalent during

  11. The role of conventional and functional MRI in diagnosis of breast masses

    Directory of Open Access Journals (Sweden)

    Atef Hammad Teama

    2015-12-01

    Conclusion: DCE-MRI of the breast had a higher sensitivity for breast cancer detection and more accurate in delineation of the disease extension. The breast MRI with three parameters (DCE-MRI, DWI, and MRS increased the diagnostic accuracy of the breast cancer.

  12. Evaluating functional MRI procedures for assessing hemispheric language dominance in neurosurgical patients

    Energy Technology Data Exchange (ETDEWEB)

    Baciu, M.V. [Pierre Mendes-France University, Laboratory of Psychology and Neurocognition, Grenoble (France); Watson, J.M.; Maccotta, L.; McDermott, K.B. [Washington University, Department of Psychology, St. Louis (United States); Buckner, R.L. [Washington University, Department of Psychology, St. Louis (United States); Howard Hughes Medical Institute, Washington University, St. Louis (United States); Gilliam, F.G. [Washington University School of Medicine, Department of Neurology, St. Louis (United States); Ojemann, J.G. [Washington University School of Medicine, Department of Neurological Surgery, St. Louis (United States)

    2005-11-01

    Two methods of quantifying hemispheric language dominance (HLD) in neurosurgical patients are compared: (1) an average magnitudes (AM) method, which is a calculation of the average signal intensity variation in regions of interest for each patient that were predefined in a group analysis for each task, and (2) a lateralization indices (LI) method, which is based on the number of activated pixels in regions of interest predefined in each individual patient. Four language tasks [a living/nonliving (LNL) judgment, word stem completion (WSC), semantic associate (SA) and a phonological associate (PA) task] were compared with ''gold standard'' measures such as the Wada test or electrocortical stimulation. Results showed that the LI method was more accurate (73% agreement with gold standard methods) than the AM method (only 40% agreement) across tasks and subjects. Furthermore, by varying the threshold used for determining laterality, the ability of functional magnetic resonance imaging (fMRI) to predict HLD was influenced for the AM method, whereas the LI method was relatively unaffected by changing the threshold. Using the LI method, the SA task was the most accurate for quantifying HLD (100% agreement with gold standard methods) with respect to the other three language tasks (80% accuracy for WSC, 65% for the LNL and 63% for phonological task). Depending on the method and the task, fMRI may be a promising tool for assessing HLD in neurosurgical patients. (orig.)

  13. Different central effects of needle rotation in false and real acupoints on functional MRI

    International Nuclear Information System (INIS)

    Fang Jiliang; Meister, I.

    2004-01-01

    Objective: To observed the cerebral activation patterns under different acupuncture stimuli by using functional magnetic resonance imaging (fMRI). Methods: The cortical activation patterns on fMRI during stimulation of two real (LIV3 and GB40) and one sham acupoints were investigated in 13 healthy subjects, they were punctured in a randomized fashion and for the subjects blinded order employing a) rotating and b) non-rotating methods using a blocked paradigm on a 1.5 T scanner. Results: Only during stimulation of the real acupoints, differential effects were observed, namely on LIV3 an increase of activation within both parietal cortices Brodmann's area (BA) 40, right frontal cortices BA47 and BA10, right thalamus, and left cerebellum; on GB40 an increase of activation within both parietal BA40, right parietal BA2, left frontal BA9, 10, 44, left insula cortices BA13, left temporal cortices BA22, right temporal BA42, right putamen, and left cerebellum. When doing the same contrast in the sham point, there were no suprathreshold voxels. The rotating needle strengthened the effects of acupuncture (the so-called De-Qi) only in real acupoints. Conclusion: Acupuncture seems to result in specific cerebral activation patterns which might explain its therapeutic effects in specific subjects. (author)

  14. Evaluating functional MRI procedures for assessing hemispheric language dominance in neurosurgical patients

    International Nuclear Information System (INIS)

    Baciu, M.V.; Watson, J.M.; Maccotta, L.; McDermott, K.B.; Buckner, R.L.; Gilliam, F.G.; Ojemann, J.G.

    2005-01-01

    Two methods of quantifying hemispheric language dominance (HLD) in neurosurgical patients are compared: (1) an average magnitudes (AM) method, which is a calculation of the average signal intensity variation in regions of interest for each patient that were predefined in a group analysis for each task, and (2) a lateralization indices (LI) method, which is based on the number of activated pixels in regions of interest predefined in each individual patient. Four language tasks [a living/nonliving (LNL) judgment, word stem completion (WSC), semantic associate (SA) and a phonological associate (PA) task] were compared with ''gold standard'' measures such as the Wada test or electrocortical stimulation. Results showed that the LI method was more accurate (73% agreement with gold standard methods) than the AM method (only 40% agreement) across tasks and subjects. Furthermore, by varying the threshold used for determining laterality, the ability of functional magnetic resonance imaging (fMRI) to predict HLD was influenced for the AM method, whereas the LI method was relatively unaffected by changing the threshold. Using the LI method, the SA task was the most accurate for quantifying HLD (100% agreement with gold standard methods) with respect to the other three language tasks (80% accuracy for WSC, 65% for the LNL and 63% for phonological task). Depending on the method and the task, fMRI may be a promising tool for assessing HLD in neurosurgical patients. (orig.)

  15. Hybrid ICA-Seed-Based Methods for fMRI Functional Connectivity Assessment: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Robert E. Kelly

    2010-01-01

    Full Text Available Brain functional connectivity (FC is often assessed from fMRI data using seed-based methods, such as those of detecting temporal correlation between a predefined region (seed and all other regions in the brain; or using multivariate methods, such as independent component analysis (ICA. ICA is a useful data-driven tool, but reproducibility issues complicate group inferences based on FC maps derived with ICA. These reproducibility issues can be circumvented with hybrid methods that use information from ICA-derived spatial maps as seeds to produce seed-based FC maps. We report results from five experiments to demonstrate the potential advantages of hybrid ICA-seed-based FC methods, comparing results from regressing fMRI data against task-related a priori time courses, with “back-reconstruction” from a group ICA, and with five hybrid ICA-seed-based FC methods: ROI-based with (1 single-voxel, (2 few-voxel, and (3 many-voxel seed; and dual-regression-based with (4 single ICA map and (5 multiple ICA map seed.

  16. Altered resting-state brain activity at functional MRI during automatic memory consolidation of fear conditioning.

    Science.gov (United States)

    Feng, Tingyong; Feng, Pan; Chen, Zhencai

    2013-07-26

    Investigations of fear conditioning in rodents and humans have illuminated the neural mechanisms of fear acquisition and extinction. However, the neural mechanism of automatic memory consolidation of fear conditioning is still unclear. To address this question, we measured brain activity following fear acquisition using resting-state functional magnetic resonance imaging (rs-fMRI). In the current study, we used a marker of fMRI, amplitude of low-frequency (0.01-0.08Hz) fluctuation (ALFF) to quantify the spontaneous brain activity. Brain activity correlated to fear memory consolidation was observed in parahippocampus, insula, and thalamus in resting-state. Furthermore, after acquired fear conditioning, compared with control group some brain areas showed ALFF increased in ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) in the experimental group, whereas some brain areas showed decreased ALFF in striatal regions (caudate, putamen). Moreover, the change of ALFF in vmPFC was positively correlated with the subjective fear ratings. These findings suggest that the parahippocampus, insula, and thalamus are the neural substrates of fear memory consolidation. The difference in activity could be attributed to a homeostatic process in which the vmPFC and ACC were involved in the fear recovery process, and change of ALFF in vmPFC predicts subjective fear ratings. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Automatic detection of arterial input function in dynamic contrast enhanced MRI based on affinity propagation clustering.

    Science.gov (United States)

    Shi, Lin; Wang, Defeng; Liu, Wen; Fang, Kui; Wang, Yi-Xiang J; Huang, Wenhua; King, Ann D; Heng, Pheng Ann; Ahuja, Anil T

    2014-05-01

    To automatically and robustly detect the arterial input function (AIF) with high detection accuracy and low computational cost in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In this study, we developed an automatic AIF detection method using an accelerated version (Fast-AP) of affinity propagation (AP) clustering. The validity of this Fast-AP-based method was proved on two DCE-MRI datasets, i.e., rat kidney and human head and neck. The detailed AIF detection performance of this proposed method was assessed in comparison with other clustering-based methods, namely original AP and K-means, as well as the manual AIF detection method. Both the automatic AP- and Fast-AP-based methods achieved satisfactory AIF detection accuracy, but the computational cost of Fast-AP could be reduced by 64.37-92.10% on rat dataset and 73.18-90.18% on human dataset compared with the cost of AP. The K-means yielded the lowest computational cost, but resulted in the lowest AIF detection accuracy. The experimental results demonstrated that both the AP- and Fast-AP-based methods were insensitive to the initialization of cluster centers, and had superior robustness compared with K-means method. The Fast-AP-based method enables automatic AIF detection with high accuracy and efficiency. Copyright © 2013 Wiley Periodicals, Inc.

  18. Determination of arterial input function in dynamic susceptibility contrast MRI using group independent component analysis technique

    International Nuclear Information System (INIS)

    Chen, S.; Liu, H.-L.; Yang Yihong; Hsu, Y.-Y.; Chuang, K.-S.

    2006-01-01

    Quantification of cerebral blood flow (CBF) with dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) requires the determination of the arterial input function (AIF). The segmentation of surrounding tissue by manual selection is error-prone due to the partial volume artifacts. Independent component analysis (ICA) has the advantage in automatically decomposing the signals into interpretable components. Recently group ICA technique has been applied to fMRI study and showed reduced variance caused by motion artifact and noise. In this work, we investigated the feasibility and efficacy of the use of group ICA technique to extract the AIF. Both simulated and in vivo data were analyzed in this study. The simulation data of eight phantoms were generated using randomized lesion locations and time activity curves. The clinical data were obtained from spin-echo EPI MR scans performed in seven normal subjects. Group ICA technique was applied to analyze data through concatenating across seven subjects. The AIFs were calculated from the weighted average of the signals in the region selected by ICA. Preliminary results of this study showed that group ICA technique could not extract accurate AIF information from regions around the vessel. The mismatched location of vessels within the group reduced the benefits of group study

  19. Neural loss aversion differences between depression patients and healthy individuals: A functional MRI investigation.

    Science.gov (United States)

    Chandrasekhar Pammi, V S; Pillai Geethabhavan Rajesh, Purushothaman; Kesavadas, Chandrasekharan; Rappai Mary, Paramban; Seema, Satish; Radhakrishnan, Ashalatha; Sitaram, Ranganatha

    2015-04-01

    Neuroeconomics employs neuroscience techniques to explain decision-making behaviours. Prospect theory, a prominent model of decision-making, features a value function with parameters for risk and loss aversion. Recent work with normal participants identified activation related to loss aversion in brain regions including the amygdala, ventral striatum, and ventromedial prefrontal cortex. However, the brain network for loss aversion in pathologies such as depression has yet to be identified. The aim of the current study is to employ the value function from prospect theory to examine behavioural and neural manifestations of loss aversion in depressed and healthy individuals to identify the neurobiological markers of loss aversion in economic behaviour. We acquired behavioural data and fMRI scans while healthy controls and patients with depression performed an economic decision-making task. Behavioural loss aversion was higher in patients with depression than in healthy controls. fMRI results revealed that the two groups shared a brain network for value function including right ventral striatum, ventromedial prefrontal cortex, and right amygdala. However, the neural loss aversion results revealed greater activations in the right dorsal striatum and the right anterior insula for controls compared with patients with depression, and higher activations in the midbrain region ventral tegmental area for patients with depression compared with controls. These results suggest that while the brain network for loss aversion is shared between depressed and healthy individuals, some differences exist with respect to differential activation of additional areas. Our findings are relevant to identifying neurobiological markers for altered decision-making in the depressed. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  20. Study of the perception of visual motion in amblyopia using functional MRI

    International Nuclear Information System (INIS)

    Lu Guangming; Zhang Zhiqiang; Zhou Wenzhen; Zheng Ling; Yin Jie; Liang Ping

    2006-01-01

    Objective: To research the pathophysiological mechanism of anisometropic and strabismic amblyopia through observation of the cortex activation under the stimulus of visual motion using functional MRI (fMRI). Methods: Seven patients with anisometropic amblyopia and 10 patients with strabismic amblyopia were examined under the stimulus with the paradigm that task and control states were rotating and stationary grating with 1.5 T MR scanners. The data were processed using software of SPM offline, and the result was analyzed with single subject. An index of interocular difference of activation (IDA) was set for Mann-Whitney rank sum test to denote the extension of difference between activation of each eye. Results: There appeared activation on bilaterally occipital lobe in both group of amblyopia patients. There was mild activation on frontal lobe when amblyopic eyes were stimulated, but no activation when sound eyes. The MT area was regarded as region of interesting when analyzed, the activation of all sound eyes was stronger than amblyopic eyes in 7 anisometropic amblyopia patients. There were 5 patients whose level of activation of amblyopic eye's were lower than sound eye, and four were higher than sound eye, among the strabismic amblyopia patients except one patient's activation was none. There was statistical difference between IDA value of two groups (Z=2.382, P=0.017). Conclusion: There are more cortex areas activated of amblyopic eye than sound eye when single eye is stimulated. The function of visual motion maybe has been affected in anisometropic amblyopia. In strabismic amblyopia, the function of visual motion may relate to the underlying mechanism of strabismic, which suggests, as for the impairment of perception of visual motion, there is difference between two types of amblyopia. (authors)

  1. The effect of hippocampal function, volume and connectivity on posterior cingulate cortex functioning during episodic memory fMRI in mild cognitive impairment.

    Science.gov (United States)

    Papma, Janne M; Smits, Marion; de Groot, Marius; Mattace Raso, Francesco U; van der Lugt, Aad; Vrooman, Henri A; Niessen, Wiro J; Koudstaal, Peter J; van Swieten, John C; van der Veen, Frederik M; Prins, Niels D

    2017-09-01

    Diminished function of the posterior cingulate cortex (PCC) is a typical finding in early Alzheimer's disease (AD). It is hypothesized that in early stage AD, PCC functioning relates to or reflects hippocampal dysfunction or atrophy. The aim of this study was to examine the relationship between hippocampus function, volume and structural connectivity, and PCC activation during an episodic memory task-related fMRI study in mild cognitive impairment (MCI). MCI patients (n = 27) underwent episodic memory task-related fMRI, 3D-T1w MRI, 2D T2-FLAIR MRI and diffusion tensor imaging. Stepwise linear regression analysis was performed to examine the relationship between PCC activation and hippocampal activation, hippocampal volume and diffusion measures within the cingulum along the hippocampus. We found a significant relationship between PCC and hippocampus activation during successful episodic memory encoding and correct recognition in MCI patients. We found no relationship between the PCC and structural hippocampal predictors. Our results indicate a relationship between PCC and hippocampus activation during episodic memory engagement in MCI. This may suggest that during episodic memory, functional network deterioration is the most important predictor of PCC functioning in MCI. • PCC functioning during episodic memory relates to hippocampal functioning in MCI. • PCC functioning during episodic memory does not relate to hippocampal structure in MCI. • Functional network changes are an important predictor of PCC functioning in MCI.

  2. Gaze recognition in high-functioning autistic patients. Evidence from functional MRI

    International Nuclear Information System (INIS)

    Takebayashi, Hiroko; Ogai, Masahiro; Matsumoto, Hideo

    2006-01-01

    We examined whether patients with high-functioning autistic disorder (AD) would exhibit abnormal activation in brain regions implicated in the functioning of theory of mind (TOM) during gaze recognition. We investigated brain activity during gaze recognition in 5 patients with high-functioning AD and 9 normal subjects, using functional magnetic resonance imaging. On the gaze task, more activation was found in the left middle frontal gyrus, the right intraparietal sulcus, and the precentral and inferior parietal gyri bilaterally in controls than in AD patients, whereas the patient group showed more powerful signal changes in the left superior temporal gyrus, the right insula, and the right medial frontal gyrus. These results suggest that high-functioning AD patients have functional abnormalities not only in TOM-related brain regions, but also in widely distributed brain regions that are not normally activated upon the processing of information from another person's gaze. (author)

  3. Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study.

    Science.gov (United States)

    Buma, Floor E; Raemaekers, Mathijs; Kwakkel, Gert; Ramsey, Nick F

    2015-01-01

    The nature of changes in brain activation related to good recovery of arm function after stroke is still unclear. While the notion that this is a reflection of neuronal plasticity has gained much support, confounding by compensatory strategies cannot be ruled out. We address this issue by comparing brain activity in recovered patients 6 months after stroke with healthy controls. We included 20 patients with upper limb paresis due to ischemic stroke and 15 controls. We measured brain activation during a finger flexion-extension task with functional MRI, and the relationship between brain activation and hand function. Patients exhibited various levels of recovery, but all were able to perform the task. Comparison between patients and controls with voxel-wise whole-brain analysis failed to reveal significant differences in brain activation. Equally, a region of interest analysis constrained to the motor network to optimize statistical power, failed to yield any differences. Finally, no significant relationship between brain activation and hand function was found in patients. Patients and controls performed scanner task equally well. Brain activation and behavioral performance during finger flexion-extensions in (moderately) well recovered patients seems normal. The absence of significant differences in brain activity even in patients with a residual impairment may suggest that infarcts do not necessarily induce reorganization of motor function. While brain activity could be abnormal with higher task demands, this may also introduce performance confounds. It is thus still uncertain to what extent capacity for true neuronal repair after stroke exists.

  4. Voxel Spread Function (VSF) Method for Correction of Magnetic Field Inhomogeneity Effects in Quantitative Gradient-Echo-Based MRI

    Science.gov (United States)

    Yablonskiy, Dmitriy A; Sukstanskii, Alexander L; Luo, Jie; Wang, Xiaoqi

    2012-01-01

    Purpose Macroscopic magnetic field inhomogeneities adversely affect different aspects of MRI images. In quantitative MRI when the goal is to quantify biological tissue parameters, they bias and often corrupt such measurements. The goal of this paper is to develop a method for correction of macroscopic field inhomogeneities that can be applied to a variety of quantitative gradient-echo-based MRI techniques. Methods We have re-analyzed a basic theory of gradient echo (GE) MRI signal formation in the presence of background field inhomogeneities and derived equations that allow for correction of magnetic field inhomogeneity effects based on the phase and magnitude of GE data. We verified our theory by mapping R2* relaxation rate in computer simulated, phantom, and in vivo human data collected with multi-GE sequences. Results The proposed technique takes into account voxel spread function (VSF) effects and allowed obtaining virtually free from artifacts R2* maps for all simulated, phantom and in vivo data except of the edge areas with very steep field gradients. Conclusion The VSF method, allowing quantification of tissue specific R2*-related tissue properties, has a potential to breed new MRI biomarkers serving as surrogates for tissue biological properties similar to R1 and R2 relaxation rate constants widely used in clinical and research MRI. PMID:23233445

  5. A Functional Iron Oxide Nanoparticles Modified with PLA-PEG-DG as Tumor-Targeted MRI Contrast Agent.

    Science.gov (United States)

    Xiong, Fei; Hu, Ke; Yu, Haoli; Zhou, Lijun; Song, Lina; Zhang, Yu; Shan, Xiuhong; Liu, Jianping; Gu, Ning

    2017-08-01

    Tumor targeting could greatly promote the performance of magnetic nanomaterials as MRI (Magnetic Resonance Imaging) agent for tumor diagnosis. Herein, we reported a novel magnetic nanoparticle modified with PLA (poly lactic acid)-PEG (polyethylene glycol)-DG (D-glucosamine) as Tumor-targeted MRI Contrast Agent. In this work, we took use of the D-glucose passive targeting on tumor cells, combining it on PLA-PEG through amide reaction, and then wrapped the PLA-PEG-DG up to the Fe 3 O 4 @OA NPs. The stability and anti phagocytosis of Fe 3 O 4 @OA@PLA-PEG-DG was tested in vitro; the MRI efficiency and toxicity was also detected in vivo. These functional magnetic nanoparticles demonstrated good biocompatibility and stability both in vitro and in vivo. Cell experiments showed that Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles exist good anti phagocytosis and high targetability. In vivo MRI images showed that the contrast effect of Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles prevailed over the commercial non tumor-targeting magnetic nanomaterials MRI agent at a relatively low dose. The DG can validly enhance the tumor-targetting effect of Fe 3 O 4 @OA@PLA-PEG nanoparticle. Maybe MRI agents with DG can hold promise as tumor-targetting development in the future.

  6. New coil positioning method for interleaved transcranial magnetic stimulation (TMS)/functional MRI (fMRI) and its validation in a motor cortex study.

    Science.gov (United States)

    Moisa, Marius; Pohmann, Rolf; Ewald, Lars; Thielscher, Axel

    2009-01-01

    To develop and test a novel method for coil placement in interleaved transcranial magnetic stimulation (TMS)/functional MRI (fMRI) studies. Initially, a desired TMS coil position at the subject's head is recorded using a neuronavigation system. Subsequently, a custom-made holding device is used for coil placement inside the MR scanner. The parameters of the device corresponding to the prerecorded position are automatically determined from a fast structural image acquired directly before the experiment. The spatial accuracy of our method was verified on a phantom. Finally, in a study on five subjects, the coil was placed above the cortical representation of a hand muscle in M1 and the blood oxygenation level-dependent (BOLD) responses to short repetitive TMS (rTMS) trains were assessed using echo-planar imaging (EPI) recordings. The spatial accuracy of our method is in the range of 2.9 +/- 1.3 (SD) mm. Motor cortex stimulation resulted in robust BOLD activations in motor- and auditory related brain areas, with the activation in M1 being localized in the hand knob. We present a user-friendly method for TMS coil positioning in the MR scanner that exhibits good spatial accuracy and speeds up the setup of the experiment. The motor-cortex study proves the viability of the approach and validates our interleaved TMS/fMRI setup.

  7. Neural plasticity in functional and anatomical MRI studies of children with Tourette syndrome

    DEFF Research Database (Denmark)

    Eichele, Heike; Plessen, Kerstin J

    2012-01-01

    Background: Tourette syndrome (TS) is a neuropsychiatric disorder with childhood onset characterized by chronic motor and vocal tics. The typical clinical course of an attenuation of symptoms during adolescence in parallel with the emerging self-regulatory control during development suggests...... that plastic processes may play an important role in the development of tic symptoms. Methods: We conducted a systematic search to identify existing imaging studies (both anatomical and functional magnetic resonance imaging [fMRI]) in young persons under the age of 19 years with TS. Results: The final search...... compensatory pathways in children with TS. Along with alterations in regions putatively representing the origin of tics, deviations in several other regions most likely represent an activity-dependent neural plasticity that help to modulate tic severity, such as the prefrontal cortex, but also in the corpus...

  8. The neural correlates of coloured music: a functional MRI investigation of auditory-visual synaesthesia.

    Science.gov (United States)

    Neufeld, J; Sinke, C; Dillo, W; Emrich, H M; Szycik, G R; Dima, D; Bleich, S; Zedler, M

    2012-01-01

    In auditory-visual synaesthesia, all kinds of sound can induce additional visual experiences. To identify the brain regions mainly involved in this form of synaesthesia, functional magnetic resonance imaging (fMRI) has been used during non-linguistic sound perception (chords and pure tones) in synaesthetes and non-synaesthetes. Synaesthetes showed increased activation in the left inferior parietal cortex (IPC), an area involved in multimodal integration, feature binding and attention guidance. No significant group-differences could be detected in area V4, which is known to be related to colour vision and form processing. The results support the idea of the parietal cortex acting as sensory nexus area in auditory-visual synaesthesia, and as a common neural correlate for different types of synaesthesia. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Functional mapping of the human visual cortex with intravoxel incoherent motion MRI.

    Directory of Open Access Journals (Sweden)

    Christian Federau

    Full Text Available Functional imaging with intravoxel incoherent motion (IVIM magnetic resonance imaging (MRI is demonstrated. Images were acquired at 3 Tesla using a standard Stejskal-Tanner diffusion-weighted echo-planar imaging sequence with multiple b-values. Cerebro-spinal fluid signal, which is highly incoherent, was suppressed with an inversion recovery preparation pulse. IVIM microvascular perfusion parameters were calculated according to a two-compartment (vascular and non-vascular diffusion model. The results obtained in 8 healthy human volunteers during visual stimulation are presented. The IVIM blood flow related parameter fD* increased 170% during stimulation in the visual cortex, and 70% in the underlying white matter.

  10. Age-related functional changes in gustatory and reward processing regions: An fMRI study.

    Science.gov (United States)

    Jacobson, Aaron; Green, Erin; Murphy, Claire

    2010-11-01

    Changes in appetite in older adults may result in unhealthy weight change and negatively affect overall nutrition. Research examining gustatory processing in young adults has linked changes in patterns of the hemodynamic response of gustatory and motivation related brain regions to the physiological states of hunger and satiety. Whether the same brain regions are involved in taste processing in older adults is unknown. The current study used functional magnetic resonance imaging (fMRI) to examine age-related changes in gustatory processing during hedonic assessment. Caffeine, citric acid, sucrose, and NaCl were administered orally during two event-related fMRI sessions, one during hunger and one after a pre-load. Participants assessed the pleasantness of the solutions in each session. Increased activity of the insula was seen in both age groups during hunger. Activity of secondary and higher order taste processing and reward regions such as the orbitofrontal cortex, amygdala, hippocampus, thalamus, and caudate nucleus was also observed. Hunger and satiety differentially affected the hemodynamic response, resulting in positive global activation during hunger and negative during satiety in both age groups. While in a state of hunger, the frequency and consistency of positive activation in gustatory and reward processing regions was greater in older adults. Additional regions not commonly associated with taste processing were also activated in older adults. Investigating the neurological response of older adults to taste stimuli under conditions of hunger and satiety may aid in understanding appetite, health, and functional changes in this population. Copyright 2010 Elsevier Inc. All rights reserved.

  11. Comparison of two fMRI tasks for the evaluation of the expressive language function

    Energy Technology Data Exchange (ETDEWEB)

    Sanjuan, Ana; Avila, Cesar [Universitat Jaume I, Departamento de Psicologia Basica, Clinica y Psicobiologia, Castellon de la Plana (Spain); Hospital La Fe, Unidad de Epilepsia, Servicio de Neurologia, Valencia (Spain); Bustamante, Juan-Carlos; Forn, Cristina; Ventura-Campos, Noelia; Barros-Loscertales, Alfonso [Universitat Jaume I, Departamento de Psicologia Basica, Clinica y Psicobiologia, Castellon de la Plana (Spain); Martinez, Juan-Carlos [Hospital La Fe, Eresa, Valencia (Spain); Hospital La Fe, Unidad de Epilepsia, Servicio de Neurologia, Valencia (Spain); Villanueva, Vicente [Hospital La Fe, Unidad de Epilepsia, Servicio de Neurologia, Valencia (Spain)

    2010-05-15

    Presurgical evaluation of language is important in patients who are candidates for neurosurgery since language decline is a frequent complication after an operation. Different functional magnetic resonance imaging (fMRI) tasks, such as the verb generation task (VGT) and the verbal fluency task (VFT) have been employed. Our objective was to compare how effective these tasks are at evaluating language functioning in controls (study 1) and patients (study 2). Eighteen controls and 58 patient candidates for neurosurgery (16 patients with temporal lobe epilepsy and 42 patients with brain lesions: 11 astrocytomas, six cavernomas, 14 gliomas, four AVM and seven meningiomas) were recruited in order to compare the activation patterns of language areas as determined by the VGT and VFT. In both samples, the VGT produced a more specific activation of left Broca's area. In contrast, the VFT yielded a wider and more intense activation of the left Broca's area in controls, as well as other activations in the dorsolateral prefrontal cortex and the striatum. Additionally, both studies showed good agreement on language dominance derived from the tasks, although there was some variability in laterality index scores. Both language tasks are useful in evaluation of expressive language. The VGT is a more specific task, while the VFT is more unspecific but activates language-related areas that are not found with the VGT owing to its phonological component. Therefore, each task contributes to the lateralisation and localisation of expressive language areas with complementary information. The advisability of combining tasks to improve fMRI presurgical evaluation is confirmed. (orig.)

  12. Comparison of two fMRI tasks for the evaluation of the expressive language function

    International Nuclear Information System (INIS)

    Sanjuan, Ana; Avila, Cesar; Bustamante, Juan-Carlos; Forn, Cristina; Ventura-Campos, Noelia; Barros-Loscertales, Alfonso; Martinez, Juan-Carlos; Villanueva, Vicente

    2010-01-01

    Presurgical evaluation of language is important in patients who are candidates for neurosurgery since language decline is a frequent complication after an operation. Different functional magnetic resonance imaging (fMRI) tasks, such as the verb generation task (VGT) and the verbal fluency task (VFT) have been employed. Our objective was to compare how effective these tasks are at evaluating language functioning in controls (study 1) and patients (study 2). Eighteen controls and 58 patient candidates for neurosurgery (16 patients with temporal lobe epilepsy and 42 patients with brain lesions: 11 astrocytomas, six cavernomas, 14 gliomas, four AVM and seven meningiomas) were recruited in order to compare the activation patterns of language areas as determined by the VGT and VFT. In both samples, the VGT produced a more specific activation of left Broca's area. In contrast, the VFT yielded a wider and more intense activation of the left Broca's area in controls, as well as other activations in the dorsolateral prefrontal cortex and the striatum. Additionally, both studies showed good agreement on language dominance derived from the tasks, although there was some variability in laterality index scores. Both language tasks are useful in evaluation of expressive language. The VGT is a more specific task, while the VFT is more unspecific but activates language-related areas that are not found with the VGT owing to its phonological component. Therefore, each task contributes to the lateralisation and localisation of expressive language areas with complementary information. The advisability of combining tasks to improve fMRI presurgical evaluation is confirmed. (orig.)

  13. Mutual connectivity analysis (MCA) using generalized radial basis function neural networks for nonlinear functional connectivity network recovery in resting-state functional MRI

    Science.gov (United States)

    D'Souza, Adora M.; Abidin, Anas Zainul; Nagarajan, Mahesh B.; Wismüller, Axel

    2016-03-01

    We investigate the applicability of a computational framework, called mutual connectivity analysis (MCA), for directed functional connectivity analysis in both synthetic and resting-state functional MRI data. This framework comprises of first evaluating non-linear cross-predictability between every pair of time series prior to recovering the underlying network structure using community detection algorithms. We obtain the non-linear cross-prediction score between time series using Generalized Radial Basis Functions (GRBF) neural networks. These cross-prediction scores characterize the underlying functionally connected networks within the resting brain, which can be extracted using non-metric clustering approaches, such as the Louvain method. We first test our approach on synthetic models with known directional influence and network structure. Our method is able to capture the directional relationships between time series (with an area under the ROC curve = 0.92 +/- 0.037) as well as the underlying network structure (Rand index = 0.87 +/- 0.063) with high accuracy. Furthermore, we test this method for network recovery on resting-state fMRI data, where results are compared to the motor cortex network recovered from a motor stimulation sequence, resulting in a strong agreement between the two (Dice coefficient = 0.45). We conclude that our MCA approach is effective in analyzing non-linear directed functional connectivity and in revealing underlying functional network structure in complex systems.

  14. Analyzing functional, structural, and anatomical correlation of hemispheric language lateralization in healthy subjects using functional MRI, diffusion tensor imaging, and voxel-based morphometry.

    Science.gov (United States)

    James, Jija S; Kumari, Sheela R; Sreedharan, Ruma Madhu; Thomas, Bejoy; Radhkrishnan, Ashalatha; Kesavadas, Chandrasekharan

    2015-01-01

    To evaluate the efficacy of diffusion fiber tractography (DFT) and voxel-based morphometry (VBM) for lateralizing language in comparison with functional magnetic resonance imaging (fMRI) to noninvasively assess hemispheric language lateralization in normal healthy volunteers. The aim of the present study is to evaluate the concordance of language lateralization obtained by diffusion tensor imaging (DTI) and VBM to fMRI, and thus to see whether there exists an anatomical correlate for language lateralization result obtained using fMRI. This is an advanced neuroimaging study conducted in normal healthy volunteers. Fifty-seven normal healthy subjects (39 males and 18 females; age range: 15-40 years) underwent language fMRI and 30 underwent direction DTI. fMRI language laterality index (LI), fiber tract asymmetry index (AI), and tract-based statistics of dorsal and ventral language pathways were calculated. The combined results were correlated with VBM-based volumetry of Heschl's gyrus (HG), planum temporale (PT), and insula for lateralization of language function. A linear regression analysis was done to study the correlation between fMRI, DTI, and VBM measurements. A good agreement was found between language fMRI LI and fiber tract AI, more specifically for arcuate fasciculus (ArcF) and inferior longitudinal fasciculus (ILF). The study demonstrated significant correlations (P based statistics, and PT and HG volumetry for determining language lateralization. A strong one-to-one correlation between fMRI, laterality index, DTI tractography measures, and VBM-based volumetry measures for determining language lateralization exists.

  15. Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

    International Nuclear Information System (INIS)

    Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T.

    2005-01-01

    The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

  16. Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

    Energy Technology Data Exchange (ETDEWEB)

    Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T. [ULB-Hopital Erasme, Radiology, Brussels (Belgium)

    2005-09-01

    The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

  17. Insulin Resistance-Associated Interhemispheric Functional Connectivity Alterations in T2DM: A Resting-State fMRI Study

    Directory of Open Access Journals (Sweden)

    Wenqing Xia

    2015-01-01

    Full Text Available We aim to investigate whether decreased interhemispheric functional connectivity exists in patients with type 2 diabetes mellitus (T2DM by using resting-state functional magnetic resonance imaging (rs-fMRI. In addition, we sought to determine whether interhemispheric functional connectivity deficits associated with cognition and insulin resistance (IR among T2DM patients. We compared the interhemispheric resting state functional connectivity of 32 T2DM patients and 30 healthy controls using rs-fMRI. Partial correlation coefficients were used to detect the relationship between rs-fMRI information and cognitive or clinical data. Compared with healthy controls, T2DM patients showed bidirectional alteration of functional connectivity in several brain regions. Functional connectivity values in the middle temporal gyrus (MTG and in the superior frontal gyrus were inversely correlated with Trail Making Test-B score of patients. Notably, insulin resistance (log homeostasis model assessment-IR negatively correlated with functional connectivity in the MTG of patients. In conclusion, T2DM patients exhibit abnormal interhemispheric functional connectivity in several default mode network regions, particularly in the MTG, and such alteration is associated with IR. Alterations in interhemispheric functional connectivity might contribute to cognitive dysfunction in T2DM patients.

  18. Motor Imagery as a Function of Disease Severity in Multiple Sclerosis: An fMRI Study

    Directory of Open Access Journals (Sweden)

    Andrea Tacchino

    2018-01-01

    Full Text Available Motor imagery (MI is defined as mental execution without any actual movement. While healthy adults usually show temporal equivalence, i.e., isochrony, between the mental simulation of an action and its actual performance, neurological disorders are associated with anisochrony. Unlike in patients with stroke and Parkinson disease, only a few studies have investigated differences of MI ability in multiple sclerosis (MS. However, the relationship among disease severity, anisochrony and brain activation patterns during MI has not been investigated yet. Here, we propose to investigate MI in MS patients using fMRI during a behavioral task executed with dominant/non-dominant hand and to evaluate whether anisochrony is associated with disease severity. Thirty-seven right-handed MS patients, 17 with clinically isolated syndrome (CIS suggestive of MS and 20 with relapsing-remitting MS (RR-MS and 20 right-handed healthy controls (HC underwent fMRI during a motor task consisting in the actual or imaged movement of squeezing a foam ball with the dominant and non-dominant hand. The same tasks were performed outside the MRI room to record the number of actual and imagined ball squeezes, and calculate an Index of performance (IP based on the ratio between actual and imagined movements. IP showed that a progressive loss of ability in simulating actions (i.e., anisochrony more pronounced for non-dominant hand, was found as function of the disease course. Moreover, anisochrony was associated with activation of occipito-parieto-frontal areas that were more extensive at the early stages of the disease, probably in order to counteract the changes due to MS. However, the neural engagement of compensatory brain areas becomes more difficult with more challenging tasks, i.e., dominant vs. non-dominant hand, with a consequent deficit in behavioral performance. These results show a strict association between MI performance and disease severity, suggesting that, at early

  19. Resting State fMRI Functional Connectivity-Based Classification Using a Convolutional Neural Network Architecture

    Directory of Open Access Journals (Sweden)

    Regina J. Meszlényi

    2017-10-01

    Full Text Available Machine learning techniques have become increasingly popular in the field of resting state fMRI (functional magnetic resonance imaging network based classification. However, the application of convolutional networks has been proposed only very recently and has remained largely unexplored. In this paper we describe a convolutional neural network architecture for functional connectome classification called connectome-convolutional neural network (CCNN. Our results on simulated datasets and a publicly available dataset for amnestic mild cognitive impairment classification demonstrate that our CCNN model can efficiently distinguish between subject groups. We also show that the connectome-convolutional network is capable to combine information from diverse functional connectivity metrics and that models using a combination of different connectivity descriptors are able to outperform classifiers using only one metric. From this flexibility follows that our proposed CCNN model can be easily adapted to a wide range of connectome based classification or regression tasks, by varying which connectivity descriptor combinations are used to train the network.

  20. Resting State fMRI Functional Connectivity-Based Classification Using a Convolutional Neural Network Architecture

    Science.gov (United States)

    Meszlényi, Regina J.; Buza, Krisztian; Vidnyánszky, Zoltán

    2017-01-01

    Machine learning techniques have become increasingly popular in the field of resting state fMRI (functional magnetic resonance imaging) network based classification. However, the application of convolutional networks has been proposed only very recently and has remained largely unexplored. In this paper we describe a convolutional neural network architecture for functional connectome classification called connectome-convolutional neural network (CCNN). Our results on simulated datasets and a publicly available dataset for amnestic mild cognitive impairment classification demonstrate that our CCNN model can efficiently distinguish between subject groups. We also show that the connectome-convolutional network is capable to combine information from diverse functional connectivity metrics and that models using a combination of different connectivity descriptors are able to outperform classifiers using only one metric. From this flexibility follows that our proposed CCNN model can be easily adapted to a wide range of connectome based classification or regression tasks, by varying which connectivity descriptor combinations are used to train the network. PMID:29089883

  1. Neural Basis of Enhanced Executive Function in Older Video Game Players: An fMRI Study.

    Science.gov (United States)

    Wang, Ping; Zhu, Xing-Ting; Qi, Zhigang; Huang, Silin; Li, Hui-Jie

    2017-01-01

    Video games have been found to have positive influences on executive function in older adults; however, the underlying neural basis of the benefits from video games has been unclear. Adopting a task-based functional magnetic resonance imaging (fMRI) study targeted at the flanker task, the present study aims to explore the neural basis of the improved executive function in older adults with video game experiences. Twenty video game players (VGPs) and twenty non-video game players (NVGPs) of 60 years of age or older participated in the present study, and there are no significant differences in age ( t = 0.62, p = 0.536), gender ratio ( t = 1.29, p = 0.206) and years of education ( t = 1.92, p = 0.062) between VGPs and NVGPs. The results show that older VGPs present significantly better behavioral performance than NVGPs. Older VGPs activate greater than NVGPs in brain regions, mainly in frontal-parietal areas, including the right dorsolateral prefrontal cortex, the left supramarginal gyrus, the right angular gyrus, the right precuneus and the left paracentral lobule. The present study reveals that video game experiences may have positive influences on older adults in behavioral performance and the underlying brain activation. These results imply the potential role that video games can play as an effective tool to improve cognitive ability in older adults.

  2. Structural and Functional MRI Differences in Master Sommeliers: A pilot study on expertise in the brain

    Directory of Open Access Journals (Sweden)

    Sarah Jane Banks

    2016-08-01

    Full Text Available Our experiences, even as adults, shape our brains. Regional differences have been found in experts, with the regions associated with their particular skill-set. Functional differences have also been noted in brain activation patterns in some experts. This study uses multimodal techniques to assess structural and functional patterns that differ between experts and nonexperts. Sommeliers are experts in wine and thus in olfaction. We assessed differences in Master Sommeliers’ brains, compared with controls, in structure and also in functional response to olfactory and visual judgment tasks. MRI data were analyzed using voxel-based morphometry as well as automated parcellation to assess structural properties, and group differences between tasks were calculated. Results indicate enhanced volume in the right insula and entorhinal cortex, with the cortical thickness of the entorhinal correlating with experience. There were regional activation differences in a large area involving the right olfactory and memory regions, with heightened activation specifically for sommeliers during an olfactory task. Our results indicate that sommeliers’ brains show specialization in the expected regions of the olfactory and memory networks, and also in regions important in integration of internal sensory stimuli and external cues. Overall, these differences suggest that specialized expertise and training might result in enhancements in the brain well into adulthood. This is particularly important given the regions involved, which are the first to be impacted by many neurodegenerative diseases.

  3. Tailored functionalization of iron oxide nanoparticles for MRI, drug delivery, magnetic separation and immobilization of biosubstances.

    Science.gov (United States)

    Hola, Katerina; Markova, Zdenka; Zoppellaro, Giorgio; Tucek, Jiri; Zboril, Radek

    2015-11-01

    In this critical review, we outline various covalent and non-covalent approaches for the functionalization of iron oxide nanoparticles (IONPs). Tuning the surface chemistry and design of magnetic nanoparticles are described in relation to their applicability in advanced medical technologies and biotechnologies including magnetic resonance imaging (MRI) contrast agents, targeted drug delivery, magnetic separations and immobilizations of proteins, enzymes, antibodies, targeting agents and other biosubstances. We review synthetic strategies for the controlled preparation of IONPs modified with frequently used functional groups including amine, carboxyl and hydroxyl groups as well as the preparation of IONPs functionalized with other species, e.g., epoxy, thiol, alkane, azide, and alkyne groups. Three main coupling strategies for linking IONPs with active agents are presented: (i) chemical modification of amine groups on the surface of IONPs, (ii) chemical modification of bioactive substances (e.g. with fluorescent dyes), and (iii) the activation of carboxyl groups mainly for enzyme immobilization. Applications for drug delivery using click chemistry linking or biodegradable bonds are compared to non-covalent methods based on polymer modified condensed magnetic nanoclusters. Among many challenges, we highlight the specific surface engineering allowing both therapeutic and diagnostic applications (theranostics) of IONPs and magnetic/metallic hybrid nanostructures possessing a huge potential in biocatalysis, green chemistry, magnetic bioseparations and bioimaging. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Prenatal marijuana exposure impacts executive functioning into young adulthood: An fMRI study.

    Science.gov (United States)

    Smith, Andra M; Mioduszewski, Ola; Hatchard, Taylor; Byron-Alhassan, Aziza; Fall, Carley; Fried, Peter A

    Understanding the potentially harmful long term consequences of prenatal marijuana exposure is important given the increase in number of pregnant women smoking marijuana to relieve morning sickness. Altered executive functioning is one area of research that has suggested negative consequences of prenatal marijuana exposure into adolescence. Investigating if these findings continue into young adulthood and exploring the neural basis of these effects was the purpose of this research. Thirty one young adults (ages 18-22years) from the longitudinal Ottawa Prenatal Prospective Study (OPPS) underwent functional magnetic resonance imaging (fMRI) during four tasks; 1) Visuospatial 2-Back, 2) Go/NoGo, 3) Letter 2-Back and 4) Counting Stroop task. Sixteen participants were prenatally exposed to marijuana while 15 had no prenatal marijuana exposure. Task performance was similar for both groups but blood flow was significantly different between the groups. This paper presents the results for all 4 tasks, highlighting the consistently increased left posterior brain activity in the prenatally exposed group compared with the control group. These alterations in neurophysiological functioning of young adults prenatally exposed to marijuana emphasizes the importance of education for women in child bearing years, as well as for policy makers and physicians interested in the welfare of both the pregnant women and their offspring's future success. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Functional MRI analysis of body and body part representations in the extrastriate and fusiform body areas.

    Science.gov (United States)

    Taylor, John C; Wiggett, Alison J; Downing, Paul E

    2007-09-01

    This study examined the contributions of two previously identified brain regions-the extrastriate and fusiform body areas (EBA and FBA)-to the visual representation of the human form. Specifically we measured in these two areas the magnitude of fMRI response as a function of the amount of the human figure that is visible in the image, in the range from a single finger to the entire body. A second experiment determined the selectivity of these regions for body and body part stimuli relative to closely matched control images. We found a gradual increase in the selectivity of the EBA as a function of the amount of body shown. In contrast, the FBA shows a steplike function, with no significant selectivity for individual fingers or hands. In a third experiment we demonstrate that the response pattern seen in EBA does not extend to adjacent motion-selective human midtemporal area. We propose an interpretation of these results by analogy to nearby face-selective regions occipital face area (OFA) and fusiform face area (FFA). Specifically, we hypothesize that the EBA analyzes bodies at the level of parts (as has been proposed for faces in the OFA), whereas FBA (by analogy to FFA) may have a role in processing the configuration of body parts into wholes.

  6. Neural Basis of Enhanced Executive Function in Older Video Game Players: An fMRI Study

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2017-11-01

    Full Text Available Video games have been found to have positive influences on executive function in older adults; however, the underlying neural basis of the benefits from video games has been unclear. Adopting a task-based functional magnetic resonance imaging (fMRI study targeted at the flanker task, the present study aims to explore the neural basis of the improved executive function in older adults with video game experiences. Twenty video game players (VGPs and twenty non-video game players (NVGPs of 60 years of age or older participated in the present study, and there are no significant differences in age (t = 0.62, p = 0.536, gender ratio (t = 1.29, p = 0.206 and years of education (t = 1.92, p = 0.062 between VGPs and NVGPs. The results show that older VGPs present significantly better behavioral performance than NVGPs. Older VGPs activate greater than NVGPs in brain regions, mainly in frontal-parietal areas, including the right dorsolateral prefrontal cortex, the left supramarginal gyrus, the right angular gyrus, the right precuneus and the left paracentral lobule. The present study reveals that video game experiences may have positive influences on older adults in behavioral performance and the underlying brain activation. These results imply the potential role that video games can play as an effective tool to improve cognitive ability in older adults.

  7. The Functional Architecture of Noise Correlation in fMRI Responses from Human Visual Cortex

    Directory of Open Access Journals (Sweden)

    Jungwon Ryu

    2011-05-01

    Full Text Available When an identical stimulus is presented repeatedly, the activity of sensory cortical neurons varies from trial to trial, dubbed ‘neuronal noise’. Recent electrophysiological and imaging studies reported that the ‘noise’ is not just a random and independent deviation from signal and reflects correlated activity among local cortical sites. Here we investigated the structure of correlated ‘noises’ in early human visual areas by monitoring moment-to-moment fluctuations in fMRI responses to visual stimuli. By defining receptive fields and stimulus preferences of individual voxels, we could reveal a reliable functional architecture of noise correlation: noise correlation was high in pairs of voxels whose stimulus preferences are similar and whose receptive fields are close to each other. The analysis of residual correlation confirmed that this functionally defined structure of noise correlation could not be explained by trivial correlations due to anatomical proximity. The spectral analysis of time series revealed that the stimulus-preference-dependent correlation was maximal at a low (<0.035Hz band of temporal frequency whereas the receptive field-dependent correlation was maximal at a medium (0.035∼0.082Hz band. Furthermore, the functional structure of noise correlation was held true for voxel pairs within and between different visual areas, regardless of the presence or types of visual stimulation.

  8. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2008-01-01

    PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twent...

  9. The potential of half a million neurons. Studies with electrocorticography and functional MRI in motor and language areas

    NARCIS (Netherlands)

    Hermes, D.|info:eu-repo/dai/nl/31410917X

    2012-01-01

    This thesis describes studies on the electric potential of a neuronal population of about half a million neurons. It is essential to understand neurophysiology at the millimeter scale since ECoG and fMRI studies have shown that some functional units are specifically defined at this scale. While ECoG

  10. Frequency-dependent changes in the regional amplitude and synchronization of resting-state functional MRI in stroke.

    Directory of Open Access Journals (Sweden)

    Jianfang Zhu

    Full Text Available Resting-state functional magnetic resonance imaging (R-fMRI has been intensively used to assess alterations of inter-regional functional connectivity in patients with stroke, but the regional properties of brain activity in stroke have not yet been fully investigated. Additionally, no study has examined a frequency effect on such regional properties in stroke patients, although this effect has been shown to play important roles in both normal brain functioning and functional abnormalities. Here we utilized R-fMRI to measure the amplitude of low-frequency fluctuations (ALFF and regional homogeneity (ReHo, two major methods for characterizing the regional properties of R-fMRI, in three different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.73 Hz; and typical band: 0.01-0.1 Hz in 19 stroke patients and 15 healthy controls. Both the ALFF and ReHo analyses revealed changes in brain activity in a number of brain regions, particularly the parietal cortex, in stroke patients compared with healthy controls. Remarkably, the regions with changed activity as detected by the slow-5 band data were more extensive, and this finding was true for both the ALFF and ReHo analyses. These results not only confirm previous studies showing abnormality in the parietal cortex in patients with stroke, but also suggest that R-fMRI studies of stroke should take frequency effects into account when measuring intrinsic brain activity.

  11. Single-Channel Blind Estimation of Arterial Input Function and Tissue Impulse Response in DCE-MRI

    Czech Academy of Sciences Publication Activity Database

    Taxt, T.; Jiřík, Radovan; Rygh, C. B.; Grüner, R.; Bartoš, M.; Andersen, E.; Curry, F. R.; Reed, R. K.

    2012-01-01

    Roč. 59, č. 4 (2012), s. 1012-1021 ISSN 0018-9294 Institutional support: RVO:68081731 Keywords : arterial input function (AIF) * blind deconvolution * dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) * multichannel * perfusion * single channel Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.348, year: 2012

  12. Presurgical brain mapping in epilepsy using simultaneous EEG and functional MRI at ultra-high field : feasibility and first results

    NARCIS (Netherlands)

    Grouiller, Frédéric; Jorge, João; Pittau, Francesca; Van der Zwaag, W.; Iannotti, Giannina Rita; Michel, Christoph Martin; Vulliémoz, Serge; Vargas, Maria Isabel; Lazeyras, François

    OBJECTIVES: The aim of this study was to demonstrate that eloquent cortex and epileptic-related hemodynamic changes can be safely and reliably detected using simultaneous electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) recordings at ultra-high field (UHF) for clinical

  13. High resolution data analysis strategies for mesoscale human functional MRI at 7 and 9.4T

    NARCIS (Netherlands)

    Kemper, Valentin G; De Martino, Federico; Emmerling, Thomas C; Yacoub, Essa; Goebel, R.

    2018-01-01

    The advent of ultra-high field functional magnetic resonance imaging (fMRI) has greatly facilitated submillimeter resolution acquisitions (voxel volume below (1mm³)), allowing the investigation of cortical columns and cortical depth dependent (i.e. laminar) structures in the human brain. Advanced

  14. Discriminative Analysis of Migraine without Aura: Using Functional and Structural MRI with a Multi-Feature Classification Approach.

    Directory of Open Access Journals (Sweden)

    Qiongmin Zhang

    Full Text Available Magnetic resonance imaging (MRI is by nature a multi-modality technique that provides complementary information about different aspects of diseases. So far no attempts have been reported to assess the potential of multi-modal MRI in discriminating individuals with and without migraine, so in this study, we proposed a classification approach to examine whether or not the integration of multiple MRI features could improve the classification performance between migraine patients without aura (MWoA and healthy controls. Twenty-one MWoA patients and 28 healthy controls participated in this study. Resting-state functional MRI data was acquired to derive three functional measures: the amplitude of low-frequency fluctuations, regional homogeneity and regional functional correlation strength; and structural MRI data was obtained to measure the regional gray matter volume. For each measure, the values of 116 pre-defined regions of interest were extracted as classification features. Features were first selected and combined by a multi-kernel strategy; then a support vector machine classifier was trained to distinguish the subjects at individual level. The performance of the classifier was evaluated using a leave-one-out cross-validation method, and the final classification accuracy obtained was 83.67% (with a sensitivity of 92.86% and a specificity of 71.43%. The anterior cingulate cortex, prefrontal cortex, orbitofrontal cortex and the insula contributed the most discriminative features. In general, our proposed framework shows a promising classification capability for MWoA by integrating information from multiple MRI features.

  15. 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)

  16. Unique functional abnormalities in youth with combined marijuana use and depression: an fMRI study

    Directory of Open Access Journals (Sweden)

    Kristen A Ford

    2014-09-01

    Full Text Available Prior research has shown a relationship between early onset marijuana (MJ use and depression, however this relationship is complex and poorly understood. Here, we utilized passive music listening and fMRI to examine functional brain activation to a rewarding stimulus in 75 participants (healthy controls (HC, patients with Major Depressive Disorder (MDD, frequent MJ users (MJ, and the combination of MDD and MJ (MDD+MJ. For each participant a preferred and neutral piece of instrumental music was determined (utilizing ratings on a standardized scale, and each completed two 6-minute fMRI scans of a passive music listening task. Data underwent preprocessing and 61 participants were carried forward for analysis (17 HC, 15 MDD, 15 MJ, 14 MDD+MJ. Two statistical analyses were performed using SPM8, an ANCOVA with two factors (group x music-type and a whole brain, multiple regression analysis incorporating two predictors of interest (MJ use in past 28 days; and Beck Depression Inventory (BDI score. We identified a significant group x music-type interaction. Post hoc comparisons showed the preferred music had significantly greater activation in the MDD+MJ group in areas including the right middle and inferior frontal gyri extending into the claustrum and putamen and the anterior cingulate. No significant differences were identified in MDD, MJ or HC groups. Multiple regression analysis showed that activation in medial frontal cortex was positively correlated with amount of MJ use, and activation in areas including the insula was negatively correlated with BDI score. Results showed modulation in brain activation during passive music listening specific to MDD, frequent MJ users. This supports the suggestion that frequent MJ use, when combined with MDD, is associated with changes in neurocircuitry involved in reward-processing in ways that are absent with either frequent marijuana use or MDD alone. This could help inform clinical recommendations for youth with

  17. Effect of hyoscine butylbromide on prostate multiparametric MRI anatomical and functional image quality.

    Science.gov (United States)

    Slough, R A; Caglic, I; Hansen, N L; Patterson, A J; Barrett, T

    2018-02-01

    To evaluate the effect of the spasmolytic agent hyoscine butylbromide (HBB) on the quality of anatomical and functional imaging of the prostate. One hundred and seventy-three patients were included in this retrospective study. Eighty-seven patients received intravenous HBB prior to scanning (HBB group) and 86 patients did not (non-HBB group). Multiparametric (mp) 3 T magnetic resonance imaging (MRI) was performed using a 32-channel body coil. Two radiologists independently evaluated the image quality of T2-weighted imaging (WI), diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps, using a five-point Likert scale. DWI was further assessed for distortion and artefact (four-point Likert scale), and T2WI for the presence of motion artefact or blurring. Dynamic contrast-enhanced (DCE) image quality was assessed by recording the number of corrupt contrast curve data points. T2W image quality in the HBB group was significantly higher than in the non-HBB group (3.63±1.11 versus 2.84±0.899); ppoints from the contrast curve (2.47±2.44 versus 3.68±2.64), but this did not reach significance (p=0.052). Administration of HBB significantly improves the image quality of T2WI images. These results provide evidence for the use of HBB in routine patient preparation prior to prostate mpMRI. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  18. The representation of social interaction in episodic memory: a functional MRI study.

    Science.gov (United States)

    Mano, Yoko; Sugiura, Motoaki; Tsukiura, Takashi; Chiao, Joan Y; Yomogida, Yukihito; Jeong, Hyeonjeong; Sekiguchi, Atsushi; Kawashima, Ryuta

    2011-08-01

    The representation of social interaction in episodic memory is a critical factor for the successful navigation of social relationships. In general, it is important to separate episodic memory during social interaction from episodic memory during the self-generation of action events. Different cortical representations have been associated with social interaction vs. self-generated episodic memory. Here we clarified the cortical representation of the effect of context (social vs. solitary) on episodic memory by comparing it with the generation effect (self vs. other) on episodic memory. Each participant learned words while engaged in a sentence generation and a reading task, and subsequently each participant was scanned with functional magnetic resonance imaging (fMRI) while they performed a recognition task using the words that had been learned. The experiment was comprised of four conditions and we looked at two situations that involved a social context and non-social (solitary) context task. In the learning session before entering the MRI, two participants collaborated in a social context either generating (social-contextual self-generation condition: SS) or reading (social-contextual other-generation condition: SO) a sequence of sentences alternately to construct a meaningful story narrative. In the non-social context, the participants generated (non-social-contextual self-generation condition: NS) or read (non-social-contextual other-generation condition: NO) a sequence of sentences individually. The stimuli for the recognition session consisted of learned words and novel words. Activation for social context retrieval was identified in the right medial prefrontal cortex (mPFC), and activation for self-generated retrieval was identified in the left mPFC and the left middle cingulate cortex. These results indicate that dissociable regions within the medial prefrontal cortices contribute to the processes involved in the representation of social interaction

  19. Increase in MST activity correlates with visual motion learning: A functional MRI study of perceptual learning.

    Science.gov (United States)

    Larcombe, Stephanie J; Kennard, Chris; Bridge, Holly

    2018-01-01

    Repeated practice of a specific task can improve visual performance, but the neural mechanisms underlying this improvement in performance are not yet well understood. Here we trained healthy participants on a visual motion task daily for 5 days in one visual hemifield. Before and after training, we used functional magnetic resonance imaging (fMRI) to measure the change in neural activity. We also imaged a control group of participants on two occasions who did not receive any task training. While in the MRI scanner, all participants completed the motion task in the trained and untrained visual hemifields separately. Following training, participants improved their ability to discriminate motion direction in the trained hemifield and, to a lesser extent, in the untrained hemifield. The amount of task learning correlated positively with the change in activity in the medial superior temporal (MST) area. MST is the anterior portion of the human motion complex (hMT+). MST changes were localized to the hemisphere contralateral to the region of the visual field, where perceptual training was delivered. Visual areas V2 and V3a showed an increase in activity between the first and second scan in the training group, but this was not correlated with performance. The contralateral anterior hippocampus and bilateral dorsolateral prefrontal cortex (DLPFC) and frontal pole showed changes in neural activity that also correlated with the amount of task learning. These findings emphasize the importance of MST in perceptual learning of a visual motion task. Hum Brain Mapp 39:145-156, 2018. © 2017 Wiley Periodicals, Inc. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  20. Timed function tests, motor function measure, and quantitative thigh muscle MRI in ambulant children with Duchenne muscular dystrophy: A cross-sectional analysis.

    Science.gov (United States)

    Schmidt, Simone; Hafner, Patricia; Klein, Andrea; Rubino-Nacht, Daniela; Gocheva, Vanya; Schroeder, Jonas; Naduvilekoot Devasia, Arjith; Zuesli, Stephanie; Bernert, Guenther; Laugel, Vincent; Bloetzer, Clemens; Steinlin, Maja; Capone, Andrea; Gloor, Monika; Tobler, Patrick; Haas, Tanja; Bieri, Oliver; Zumbrunn, Thomas; Fischer, Dirk; Bonati, Ulrike

    2018-01-01

    The development of new therapeutic agents for the treatment of Duchenne muscular dystrophy has put a focus on defining outcome measures most sensitive to capture treatment effects. This cross-sectional analysis investigates the relation between validated clinical assessments such as the 6-minute walk test, motor function measure and quantitative muscle MRI of thigh muscles in ambulant Duchenne muscular dystrophy patients, aged 6.5 to 10.8 years (mean 8.2, SD 1.1). Quantitative muscle MRI included the mean fat fraction using a 2-point Dixon technique, and transverse relaxation time (T2) measurements. All clinical assessments were highly significantly inter-correlated with p quantitative muscle MRI values significantly correlated with all clinical assessments with the extensors showing the strongest correlation. In contrast to the clinical assessments, quantitative muscle MRI values were highly significantly correlated with age. In conclusion, the motor function measure and timed function tests measure disease severity in a highly comparable fashion and all tests correlated with quantitative muscle MRI values quantifying fatty muscle degeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2008-01-01

    -seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP (3)He-MRI and MSCT. Mean age was 55 (+/-12) years, 18 female and 9 male. Mean ADC from (3)He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values......PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twenty...... from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0...

  2. The Mirror Neurons Network in Aging, Mild Cognitive Impairment, and Alzheimer Disease: A functional MRI Study.

    Science.gov (United States)

    Farina, Elisabetta; Baglio, Francesca; Pomati, Simone; D'Amico, Alessandra; Campini, Isabella C; Di Tella, Sonia; Belloni, Giulia; Pozzo, Thierry

    2017-01-01

    The aim of the current study is to investigate the integrity of the Mirror Neurons (MN) network in normal aging, Mild Cognitive Impairment (MCI), and Alzheimer disease (AD). Although AD and MCI are considered "cognitive" diseases, there has been increasing recognition of a link between motor function and AD. More recently the embodied cognition hypothesis has also been developed: it postulates that a part of cognition results from the coupling between action and perception representations. MN represent a neuronal population which links perception, action, and cognition, therefore we decided to characterize MN functioning in neurodegenerative cognitive decline. Three matched groups of 16 subjects (normal elderly-NE, amnesic MCI with hippocampal atrophy and AD) were evaluated with a focused neuropsychological battery and an fMRI task specifically created to test MN: that comprised of an observation run, where subjects were shown movies of a right hand grasping different objects, and of a motor run, where subjects observed visual pictures of objects oriented to be grasped with the right hand. In NE subjects, the conjunction analysis (comparing fMRI activation during observation and execution), showed the activation of a bilateral fronto-parietal network in "classical" MN areas, and of the superior temporal gyrus (STG). The MCI group showed the activation of areas belonging to the same network, however, parietal areas were activated to a lesser extent and the STG was not activated, while the opposite was true for the right Broca's area. We did not observe any activation of the fronto-parietal network in AD participants. They did not perform as well as the NE subjects in all the neuropsychological tests (including tests of functions attributed to MN) whereas the MCI subjects were significantly different from the NE subjects only in episodic memory and semantic fluency. Here we show that the MN network is largely preserved in aging, while it appears involved following an

  3. The Mirror Neurons Network in Aging, Mild Cognitive Impairment, and Alzheimer Disease: A functional MRI Study

    Directory of Open Access Journals (Sweden)

    Elisabetta Farina

    2017-11-01

    Full Text Available The aim of the current study is to investigate the integrity of the Mirror Neurons (MN network in normal aging, Mild Cognitive Impairment (MCI, and Alzheimer disease (AD. Although AD and MCI are considered “cognitive” diseases, there has been increasing recognition of a link between motor function and AD. More recently the embodied cognition hypothesis has also been developed: it postulates that a part of cognition results from the coupling between action and perception representations. MN represent a neuronal population which links perception, action, and cognition, therefore we decided to characterize MN functioning in neurodegenerative cognitive decline. Three matched groups of 16 subjects (normal elderly-NE, amnesic MCI with hippocampal atrophy and AD were evaluated with a focused neuropsychological battery and an fMRI task specifically created to test MN: that comprised of an observation run, where subjects were shown movies of a right hand grasping different objects, and of a motor run, where subjects observed visual pictures of objects oriented to be grasped with the right hand. In NE subjects, the conjunction analysis (comparing fMRI activation during observation and execution, showed the activation of a bilateral fronto-parietal network in “classical” MN areas, and of the superior temporal gyrus (STG. The MCI group showed the activation of areas belonging to the same network, however, parietal areas were activated to a lesser extent and the STG was not activated, while the opposite was true for the right Broca's area. We did not observe any activation of the fronto-parietal network in AD participants. They did not perform as well as the NE subjects in all the neuropsychological tests (including tests of functions attributed to MN whereas the MCI subjects were significantly different from the NE subjects only in episodic memory and semantic fluency. Here we show that the MN network is largely preserved in aging, while it appears

  4. Activation of Visuomotor Systems during Visually Guided Movements: A Functional MRI Study

    Science.gov (United States)

    Ellermann, Jutta M.; Siegal, Joel D.; Strupp, John P.; Ebner, Timothy J.; Ugurbil, Kâmil

    1998-04-01

    The dorsal stream is a dominant visuomotor pathway that connects the striate and extrastriate cortices to posterior parietal areas. In turn, the posterior parietal areas send projections to the frontal primary motor and premotor areas. This cortical pathway is hypothesized to be involved in the transformation of a visual input into the appropriate motor output. In this study we used functional magnetic resonance imaging (fMRI) of the entire brain to determine the patterns of activation that occurred while subjects performed a visually guided motor task. In nine human subjects, fMRI data were acquired on a 4-T whole-body MR system equipped with a head gradient coil and a birdcage RF coil using aT*2-weighted EPI sequence. Functional activation was determined for three different tasks: (1) a visuomotor task consisting of moving a cursor on a screen with a joystick in relation to various targets, (2) a hand movement task consisting of moving the joystick without visual input, and (3) a eye movement task consisting of moving the eyes alone without visual input. Blood oxygenation level-dependent (BOLD) contrast-based activation maps of each subject were generated using period cross-correlation statistics. Subsequently, each subject's brain was normalized to Talairach coordinates, and the individual maps were compared on a pixel by pixel basis. Significantly activated pixels common to at least four out of six subjects were retained to construct the final functional image. The pattern of activation during visually guided movements was consistent with the flow of information from striate and extrastriate visual areas, to the posterior parietal complex, and then to frontal motor areas. The extensive activation of this network and the reproducibility among subjects is consistent with a role for the dorsal stream in transforming visual information into motor behavior. Also extensively activated were the medial and lateral cerebellar structures, implicating the cortico

  5. Robust deep brain stimulation functional MRI procedures in rats and mice using an MR-compatible tungsten microwire electrode.

    Science.gov (United States)

    Lai, Hsin-Yi; Albaugh, Daniel L; Kao, Yu-Chieh Jill; Younce, John R; Shih, Yen-Yu Ian

    2015-03-01

    To develop a series of robust and readily adoptable protocols for the application of deep brain stimulation (DBS)-functional MRI (fMRI) in rodents. DBS-fMRI procedures were conducted in rat and mouse under varying anesthetic conditions (isoflurane in rat and mouse, α-chloralose in rat). A homemade two-channel tungsten microwire electrode was used to minimize magnetic susceptibility artifacts, and was targeted to the ventral posteromedial (VPM) thalamus for DBS-fMRI scanning procedures. Compared with a commercially available MR-compatible electrode, the tungsten microwire generated greatly reduced magnetic-susceptibility artifacts. In the rat, VPM-DBS using the microwire electrode resulted in robust positive blood-oxygen-level-dependent signal changes in somatosensory cortex that were relatively independent of anesthetic type. In the mouse, VPM-DBS similarly generated large, positive neurovascular responses in somatosensory cortex that were detected using cerebral blood volume measurements. Collectively, this work describes reasonable and easily adoptable procedures for conducting DBS-fMRI studies in rodent models. The protocols developed herein may be extended to study DBS effects under numerous experimental conditions and at varying stimulation targets. © 2014 Wiley Periodicals, Inc.

  6. Lateralization effects on functional connectivity of the auditory network in patients with unilateral pulsatile tinnitus as detected by functional MRI.

    Science.gov (United States)

    Lv, Han; Zhao, Pengfei; Liu, Zhaohui; Liu, Xuehuan; Ding, Heyu; Liu, Liheng; Wang, Guopeng; Xie, Jing; Zeng, Rong; Chen, Yuchen; Yang, Zhenghan; Gong, Shusheng; Wang, Zhenchang

    2018-02-02

    Unilateral pulsatile tinnitus (PT) was proved to be a kind of disease with brain functional abnormalities within and beyond the auditory network (AN). However, changes in patterns of the lateralization effects of PT are yet to be established. Relationship between the AN and other brain networks in PT patients is also a scientific question need to be answered. In this study, we recruited 23 left-sided, 23 right-sided PT (LSPT, RSPT) patients and 23 normal controls (NC). We combined applied independent component analysis and seed-based functional connectivity (FC) analysis to investigate alteration feature of the FC of the AN by using resting-state functional magnetic resonance imaging (rs-fMRI). Compared with NC, LSPT patients demonstrated disconnected FC within the AN on both sides. Disrupted network integrity between AN and several brain functional networks, including executive control network, self-perceptual network and the limbic network, was also demonstrated in LSPT patient group bilaterally. In contrast, compared with NC, RSPT demonstrated decreased FC within the AN on the left side, but significant increased FC within the AN on the right side (symptomatic side). Enhanced FC between AN and executive control network, self-perceptual network and limbic network was also found mainly on the right side in patients with RSPT. Positive FC between the auditory network and the limbic network may be a reason to explain why RSPT patients are willing to be in the clinic. Briefly, LSPT exhibit disrupted network integrity in brain functional networks. But RSPT is featured by enhanced FC within AN and between networks, especially on the right (symptomatic) side. Corroboration of featured FC helps to reveal the pathophysiological changing process of the brain in patients with PT, providing imaging-based biomarker to distinguish PT from other kind of tinnitus. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Enhancing insight in scientific problem solving by highlighting the functional features of prototypes: an fMRI study.

    Science.gov (United States)

    Hao, Xin; Cui, Shuai; Li, Wenfu; Yang, Wenjing; Qiu, Jiang; Zhang, Qinglin

    2013-10-09

    Insight can be the first step toward creating a groundbreaking product. As evident in anecdotes and major inventions in history, heuristic events (heuristic prototypes) prompted inventors to acquire insight when solving problems. Bionic imitation in scientific innovation is an example of this kind of problem solving. In particular, heuristic prototypes (e.g., the lotus effect; the very high water repellence exhibited by lotus leaves) help solve insight problems (e.g., non-stick surfaces). We speculated that the biological functional feature of prototypes is a critical factor in inducing insightful scientific problem solving. In this functional magnetic resonance imaging (fMRI) study, we selected scientific innovation problems and utilized "learning prototypes-solving problems" two-phase paradigm to test the supposition. We also explored its neural mechanisms. Functional MRI data showed that the activation of the middle temporal gyrus (MTG, BA 37) and the middle occipital gyrus (MOG, BA 19) were associated with the highlighted functional feature condition. fMRI data also indicated that the MTG (BA 37) could be responsible for the semantic processing of functional features and for the formation of novel associations based on related functions. In addition, the MOG (BA 19) could be involved in the visual imagery of formation and application of function association between the heuristic prototype and problem. Our findings suggest that both semantic processing and visual imagery could be crucial components underlying scientific problem solving. © 2013 Elsevier B.V. All rights reserved.

  8. Comparison of language cortex reorganization patterns between cerebral arteriovenous malformations and gliomas: a functional MRI study.

    Science.gov (United States)

    Deng, Xiaofeng; Zhang, Yan; Xu, Long; Wang, Bo; Wang, Shuo; Wu, Jun; Zhang, Dong; Wang, Rong; Wang, Jia; Zhao, Jizong

    2015-05-01

    OBJECT Cerebral arteriovenous malformations (AVMs) are congenital malformations that may grow in the language cortex but usually do not lead to aphasia. In contrast, language dysfunction is a common presentation for patients with a glioma that involves language areas. The authors attempted to demonstrate the difference in patterns of language cortex reorganization between cerebral AVMs and gliomas by blood oxygen level-dependent (BOLD) functional MRI (fMRI) evaluation. METHODS The authors retrospectively reviewed clinical and imaging data of 63 patients with an unruptured cerebral AVM (AVM group) and 38 patients with a glioma (glioma group) who underwent fMRI. All the patients were right handed, and all their lesions were located in the left cerebral hemisphere. Patients were further categorized into 1 of the 2 following subgroups according to their lesion location: the BA subgroup (overlying or adjacent to the inferior frontal or the middle frontal gyri [the Broca area]) and the WA subgroup (overlying or adjacent to the supramarginal, angular, or superior temporal gyri [the Wernicke area]). Lateralization indices of BOLD signal activations were calculated separately for the Broca and Wernicke areas. Statistical analysis was performed to identify the difference in patterns of language cortex reorganization between the 2 groups. RESULTS In the AVM group, right-sided lateralization of BOLD signal activations was observed in 23 patients (36.5%), including 6 with right-sided lateralization in the Broca area alone, 12 in the Wernicke area alone, and 5 in both areas. More specifically, in the 34 patients in the AVM-BA subgroup, right-sided lateralization of the Broca area was detected in 9 patients (26.5%), and right-sided lateralization of the Wernicke area was detected in 4 (11.8%); in the 29 patients in the AVM-WA subgroup, 2 (6.9%) had right-sided lateralization of the Broca area, and 13 (44.8%) had right-sided lateralization of the Wernicke area. In the glioma group

  9. A new operational method of functional neurosurgery combining micro-recording and MRI stereotaxy for the treatment of Parkinson's disease

    International Nuclear Information System (INIS)

    Nishimura, Hiroyuki; Hirai, Tatsuo.

    1993-01-01

    We have developed a new operational method for stereotactic functional neurosurgery using MRI stereotaxy combined with microelectrode recording. MRI stereotaxy shows us the individual variations of thalamic configurations. The tentative target points were determined using the MRI stereotaxy assisted software system which revised the distortion of MRI images. Consequently, the accuracy and safety of the microelectrode recording were increased. This, in turn, increased the accuracy and stereotactic thalamotomy while producing encouraging operational outcomes. The effectiveness of stereotactic thalamotomy for Parkinson's disease was confirmed by these excellent operative results. The symptoms improved and the dosage of medications, including L-DOPA, decreased. Furthermore, our results indicate that the distributing area of deep sensory neurons in the thalamus extended more posteriorly and upward than previously expected. Therefore, the functional and anatomical similarity between the human and monkey thalamus was reaffirmed. In this report, based on the above data, we reevaluated the neural mechanism of tremor and the role of stereotactic functional neurosurgery for Parkinson's disease. (author)

  10. Dimensionality reduction impedes the extraction of dynamic functional connectivity states from fMRI recordings of resting wakefulness.

    Science.gov (United States)

    Kafashan, MohammadMehdi; Palanca, Ben Julian A; Ching, ShiNung

    2018-01-01

    Resting wakefulness is not a unitary state, with evidence accumulating that spontaneous reorganization of brain activity can be assayed through functional magnetic resonance imaging (fMRI). The dynamics of correlated fMRI signals among functionally-related brain regions, termed dynamic functional connectivity (dFC), may represent nonstationarity arising from underlying neural processes. However, given the dimensionality and noise inherent in such recordings, seeming fluctuations in dFC could be due to sampling variability or artifacts. Here, we highlight key methodological considerations when evaluating dFC in resting-state fMRI data. In particular, we demonstrate how dimensionality reduction of fMRI data, a common practice often involving principal component analysis, may give rise to spurious dFC phenomenology due to its effect of decorrelating the underlying time-series. We formalize a dFC assessment that avoids dimensionality reduction and use it to show the existence of at least two FC states in the resting-state. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Effective connectivity of brain regions underlying third-party punishment: Functional MRI and Granger causality evidence.

    Science.gov (United States)

    Bellucci, Gabriele; Chernyak, Sergey; Hoffman, Morris; Deshpande, Gopikrishna; Dal Monte, Olga; Knutson, Kristine M; Grafman, Jordan; Krueger, Frank

    2017-04-01

    Third-party punishment (TPP) for norm violations is an essential deterrent in large-scale human societies, and builds on two essential cognitive functions: evaluating legal responsibility and determining appropriate punishment. Despite converging evidence that TPP is mediated by a specific set of brain regions, little is known about their effective connectivity (direction and strength of connections). Applying parametric event-related functional MRI in conjunction with multivariate Granger causality analysis, we asked healthy participants to estimate how much punishment a hypothetical perpetrator deserves for intentionally committing criminal offenses varying in levels of harm. Our results confirmed that TPP legal decisions are based on two domain-general networks: the mentalizing network for evaluating legal responsibility and the central-executive network for determining appropriate punishment. Further, temporal pole (TP) and dorsomedial prefrontal cortex (PFC) emerged as hubs of the mentalizing network, uniquely generating converging output connections to ventromedial PFC, temporo-parietal junction, and posterior cingulate. In particular, dorsomedial PFC received inputs only from TP and both its activation and its connectivity to dorsolateral PFC correlated with degree of punishment. This supports the hypothesis that dorsomedial PFC acts as the driver of the TPP activation pattern, leading to the decision on the appropriate punishment. In conclusion, these results advance our understanding of the organizational elements of the TPP brain networks and provide better insights into the mental states of judges and jurors tasked with blaming and punishing legal wrongs.

  12. Dynamic network participation of functional connectivity hubs assessed by resting-state fMRI.

    Science.gov (United States)

    Schaefer, Alexander; Margulies, Daniel S; Lohmann, Gabriele; Gorgolewski, Krzysztof J; Smallwood, Jonathan; Kiebel, Stefan J; Villringer, Arno

    2014-01-01

    Network studies of large-scale brain connectivity have demonstrated that highly connected areas, or "hubs," are a key feature of human functional and structural brain organization. We use resting-state functional MRI data and connectivity clustering to identify multi-network hubs and show that while hubs can belong to multiple networks their degree of integration into these different networks varies dynamically over time. The extent of the network variation was related to the connectedness of the hub. In addition, we found that these network dynamics were inversely related to positive self-generated thoughts reported by individuals and were further decreased with older age. Moreover, the left caudate varied its degree of participation between a default mode subnetwork and a limbic network. This variation was predictive of individual differences in the reports of past-related thoughts. These results support an association between ongoing thought processes and network dynamics and offer a new approach to investigate the brain dynamics underlying mental experience.

  13. An fMRI study of the functional mechanisms of Stroop/reverse-Stroop effects.

    Science.gov (United States)

    Song, Yongning; Hakoda, Yuji

    2015-09-01

    Many previous behavioral inhibition studies have employed the classic Stroop and reverse-Stroop paradigm. Although an experimental dissociation has been demonstrated between Stroop interference (SI) and reverse-Stroop interference (RI), the mechanisms that underlie these phenomena remain unclear. In this study, we used functional magnetic resonance imaging (fMRI) to compare the functional mechanisms of SI and RI. We identified the brain regions activated by the Stroop word-color matching task using four tests: the Stroop control test (Test 1), Stroop test (Test 2), reverse-Stroop control test (Test 3), and reverse-Stroop test (Test 4). Neuroimaging results revealed that SI elicited activation in the bilateral middle frontal gyrus (BA9). In contrast, a number of other regions, including the bilateral middle frontal gyrus (BA 9 and BA10), medial frontal gyrus (BA 8), and cingulate gyrus (BA6 and BA 32) exhibited significant activation during RI. Our results indicate that there is a dissociation between the types of interference and brain activation. These findings suggest that SI and RI interference can be attributable to different neural mechanisms. It also suggests that the prefrontal cortex and the cingulate cortex are differentially sensitive to various types of interference, and that the reverse-Stroop task may be more useful than the Stroop task for evaluating interference control in psychiatric patients with frontal dysfunction. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Functional MRI study of verbal working memory in children with attention deficit hyperactivity disorder

    International Nuclear Information System (INIS)

    Lu Youran; Geng Daoying; Feng Xiaoyuan; Du Yasong; Zhao Zhimin

    2006-01-01

    Objective: To study the verbal working memory of children with attention deficit hyperactivity disorder (ADHD) as well as to explore the characteristics of functional areas of verbal working memory with blood oxygenation level dependent functional magnetic resonance imaging (fMRI). Method: Eighteen children were selected in the study. There were 9 ADHD children with inattention subtype and 9 healthy subjects. All patients and healthy subjects completed the cognitive examination and the block- designed N-block verbal working memory task using a GE 3.0 T MR. Data were analyzed by AFNI software. Result: The neural activations of ADHD's children are lower than that of control under verbal working memory. Especially in the areas of bilateral middle frontal gyri and inferior frontal gyri, bilateral superior parietal lobules and inferior parietal lobules, right basal ganglia in the 1-BACK task. And bilateral middle frontal gyri and inferior frontal gyri, bilateral superior parietal lobules, left cortex inferior parietallobule, right basal ganglia, anterior cingulatecortex in the 2-BACK task. Conclusion: The hypofunctional areas of verbal working memory (including bilateral dorsolateral prefrontal cortex and parietal cortex) can be seen in the ADHD children especially who also has lower activation of anterior cingulate cortex under 2-BACK task. (authors)

  15. Neuroticism related differences in the functional neuroanatomical correlates of multitasking. An fMRI study.

    Science.gov (United States)

    Szameitat, Andre J; Saylik, Rahmi; Parton, Andrew

    2016-12-02

    It is known that neuroticism impairs cognitive performance mostly in difficult tasks, but not so much in easier tasks. One pervasive situation of this type is multitasking, in which the combination of two simple tasks creates a highly demanding dual-task, and consequently high neurotics show higher dual-task costs than low neurotics. However, the functional neuroanatomical correlates of these additional performance impairments in high neurotics are unknown. To test for this, we assessed brain activity by means of functional magnetic resonance imaging (fMRI) in 17 low and 15 high neurotics while they were performing a demanding dual-task and the less demanding component tasks as single-tasks. Behavioural results showed that performance (response times and error rates) was lower in the dual-task than in the single-tasks (dual-task costs), and that these dual-task costs were significantly higher in high neurotics. Imaging data showed that high neurotics showed less dual-task specific activation in lateral (mainly middle frontal gyrus) and medial prefrontal cortices. We conclude that high levels of neuroticism impair behavioural performance in demanding tasks, and that this impairment is accompanied by reduced activation of the task-associated brain areas. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  16. The effect of hippocampal function, volume and connectivity on posterior cingulate cortex functioning during episodic memory fMRI in mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Papma, Janne M.; Koudstaal, Peter J.; Swieten, John C. van [Erasmus MC - University Medical Center Rotterdam, Department of Neurology, Rotterdam (Netherlands); Smits, Marion; Lugt, Aad van der [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, Rotterdam (Netherlands); Groot, Marius de; Vrooman, Henri A. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, Rotterdam (Netherlands); Erasmus MC - University Medical Center Rotterdam, Department of Medical Informatics, Rotterdam (Netherlands); Mattace Raso, Francesco U. [Erasmus MC - University Medical Center Rotterdam, Department of Geriatrics, Rotterdam (Netherlands); Niessen, Wiro J. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, Rotterdam (Netherlands); Erasmus MC - University Medical Center Rotterdam, Department of Medical Informatics, Rotterdam (Netherlands); Delft University of Technology, Faculty of Applied Sciences, Delft (Netherlands); Veen, Frederik M. van der [Erasmus University Rotterdam, Institute of Psychology, Rotterdam (Netherlands); Prins, Niels D. [VU University Medical Center, Alzheimer Center, Department of Neurology, Amsterdam (Netherlands)

    2017-09-15

    Diminished function of the posterior cingulate cortex (PCC) is a typical finding in early Alzheimer's disease (AD). It is hypothesized that in early stage AD, PCC functioning relates to or reflects hippocampal dysfunction or atrophy. The aim of this study was to examine the relationship between hippocampus function, volume and structural connectivity, and PCC activation during an episodic memory task-related fMRI study in mild cognitive impairment (MCI). MCI patients (n = 27) underwent episodic memory task-related fMRI, 3D-T1w MRI, 2D T2-FLAIR MRI and diffusion tensor imaging. Stepwise linear regression analysis was performed to examine the relationship between PCC activation and hippocampal activation, hippocampal volume and diffusion measures within the cingulum along the hippocampus. We found a significant relationship between PCC and hippocampus activation during successful episodic memory encoding and correct recognition in MCI patients. We found no relationship between the PCC and structural hippocampal predictors. Our results indicate a relationship between PCC and hippocampus activation during episodic memory engagement in MCI. This may suggest that during episodic memory, functional network deterioration is the most important predictor of PCC functioning in MCI. (orig.)

  17. The effect of hippocampal function, volume and connectivity on posterior cingulate cortex functioning during episodic memory fMRI in mild cognitive impairment

    International Nuclear Information System (INIS)

    Papma, Janne M.; Koudstaal, Peter J.; Swieten, John C. van; Smits, Marion; Lugt, Aad van der; Groot, Marius de; Vrooman, Henri A.; Mattace Raso, Francesco U.; Niessen, Wiro J.; Veen, Frederik M. van der; Prins, Niels D.

    2017-01-01

    Diminished function of the posterior cingulate cortex (PCC) is a typical finding in early Alzheimer's disease (AD). It is hypothesized that in early stage AD, PCC functioning relates to or reflects hippocampal dysfunction or atrophy. The aim of this study was to examine the relationship between hippocampus function, volume and structural connectivity, and PCC activation during an episodic memory task-related fMRI study in mild cognitive impairment (MCI). MCI patients (n = 27) underwent episodic memory task-related fMRI, 3D-T1w MRI, 2D T2-FLAIR MRI and diffusion tensor imaging. Stepwise linear regression analysis was performed to examine the relationship between PCC activation and hippocampal activation, hippocampal volume and diffusion measures within the cingulum along the hippocampus. We found a significant relationship between PCC and hippocampus activation during successful episodic memory encoding and correct recognition in MCI patients. We found no relationship between the PCC and structural hippocampal predictors. Our results indicate a relationship between PCC and hippocampus activation during episodic memory engagement in MCI. This may suggest that during episodic memory, functional network deterioration is the most important predictor of PCC functioning in MCI. (orig.)

  18. Markov models for fMRI correlation structure: is brain functional connectivity small world, or decomposable into networks?

    OpenAIRE

    Varoquaux, Gaël; Gramfort, Alexandre; Poline, Jean Baptiste; Thirion, Bertrand

    2012-01-01

    International audience; Correlations in the signal observed via functional Magnetic Resonance Imaging (fMRI), are expected to reveal the interactions in the underlying neural populations through hemodynamic response. In particular, they highlight distributed set of mutually correlated regions that correspond to brain networks related to different cognitive functions. Yet graph-theoretical studies of neural connections give a different picture: that of a highly integrated system with small-wor...

  19. Network analysis of functional brain connectivity in borderline personality disorder using resting-state fMRI

    OpenAIRE

    Tingting Xu; Kathryn R. Cullen; Bryon Mueller; Mindy W. Schreiner; Kelvin O. Lim; S. Charles Schulz; Keshab K. Parhi

    2016-01-01

    Borderline personality disorder (BPD) is associated with symptoms such as affect dysregulation, impaired sense of self, and self-harm behaviors. Neuroimaging research on BPD has revealed structural and functional abnormalities in specific brain regions and connections. However, little is known about the topological organizations of brain networks in BPD. We collected resting-state functional magnetic resonance imaging (fMRI) data from 20 patients with BPD and 10 healthy controls, and construc...

  20. Multi-Site Diagnostic Classification of Schizophrenia Using Discriminant Deep Learning with Functional Connectivity MRI.

    Science.gov (United States)

    Zeng, Ling-Li; Wang, Huaning; Hu, Panpan; Yang, Bo; Pu, Weidan; Shen, Hui; Chen, Xingui; Liu, Zhening; Yin, Hong; Tan, Qingrong; Wang, Kai; Hu, Dewen

    2018-03-23

    A lack of a sufficiently large sample at single sites causes poor generalizability in automatic diagnosis classification of heterogeneous psychiatric disorders such as schizophrenia based on brain imaging scans. Advanced deep learning methods may be capable of learning subtle hidden patterns from high dimensional imaging data, overcome potential site-related variation, and achieve reproducible cross-site classification. However, deep learning-based cross-site transfer classification, despite less imaging site-specificity and more generalizability of diagnostic models, has not been investigated in schizophrenia. A large multi-site functional MRI sample (n = 734, including 357 schizophrenic patients from seven imaging resources) was collected, and a deep discriminant autoencoder network, aimed at learning imaging site-shared functional connectivity features, was developed to discriminate schizophrenic individuals from healthy controls. Accuracies of approximately 85·0% and 81·0% were obtained in multi-site pooling classification and leave-site-out transfer classification, respectively. The learned functional connectivity features revealed dysregulation of the cortical-striatal-cerebellar circuit in schizophrenia, and the most discriminating functional connections were primarily located within and across the default, salience, and control networks. The findings imply that dysfunctional integration of the cortical-striatal-cerebellar circuit across the default, salience, and control networks may play an important role in the "disconnectivity" model underlying the pathophysiology of schizophrenia. The proposed discriminant deep learning method may be capable of learning reliable connectome patterns and help in understanding the pathophysiology and achieving accurate prediction of schizophrenia across multiple independent imaging sites. Copyright © 2018. Published by Elsevier B.V.

  1. Language lateralization by functional MRI : a comparison with wada test-preliminary results

    International Nuclear Information System (INIS)

    Ryoo, Jae Wook; Na, Dong Gyu; Byun, Hong Sik

    1999-01-01

    To evaluate the usefulness of functional MR imaging (fMRI) for the determination of language dominance and to assess differences in language lateralization according to activation task or activated area. Functional maps of the language area were obtained during word generation tasks(noun and verb) and a reading task in ten patients (9 right handed, 1 left handed) who had undergone the Wada test. MR examinations were performed using a 1.5T scanner and the EPI BOLD technique. The SPM program was employed for the postprocessing of images and the threshold for significance was set at p<0.001 or p<0.01. A lateralization index was calculated from the number of activated pixels in three hemispheric regions (whole hemisphere, frontal lobe, and temporoparietal lobe), and the results were compared with those of Wada tests. The results for lateralization of language area were compared among stimulation tasks and regions and used for calculation of lateralization indices. During the Wada test, nine patients were left dominant and one patient was right dominant for language. Language dominance based on activated signals in each hemisphere was consistent with the results of the Wada test in 87.5% (verb and noun generation tasks) and 90% (reading task) of patients. Language dominance determined by activated signals in the frontal lobe was consistent in 87.5%, 75%, and 80% of patients in each stimulation task (verb generation, noun generation, and reading), respectively. The consistency rate of activated signals in the temporoparietal lobe was 87.5%, 87.5% and 80% of patients in each task. the mean value of the lateralization index, calculated on the basis of activated signals in the temporoparietal lobe was higher than that in the hemisphere or frontal lobe. The verb generation task showed a higher lateralization index than the noun generation or reading task. The lateralization index was higher in the verb generation task and in the region of the temporoparietal lobe than in

  2. Development of visual cortical function in infant macaques: A BOLD fMRI study.

    Directory of Open Access Journals (Sweden)

    Tom J Van Grootel

    Full Text Available Functional brain development is not well understood. In the visual system, neurophysiological studies in nonhuman primates show quite mature neuronal properties near birth although visual function is itself quite immature and continues to develop over many months or years after birth. Our goal was to assess the relative development of two main visual processing streams, dorsal and ventral, using BOLD fMRI in an attempt to understand the global mechanisms that support the maturation of visual behavior. Seven infant macaque monkeys (Macaca mulatta were repeatedly scanned, while anesthetized, over an age range of 102 to 1431 days. Large rotating checkerboard stimuli induced BOLD activation in visual cortices at early ages. Additionally we used static and dynamic Glass pattern stimuli to probe BOLD responses in primary visual cortex and two extrastriate areas: V4 and MT-V5. The resulting activations were analyzed with standard GLM and multivoxel pattern analysis (MVPA approaches. We analyzed three contrasts: Glass pattern present/absent, static/dynamic Glass pattern presentation, and structured/random Glass pattern form. For both GLM and MVPA approaches, robust coherent BOLD activation appeared relatively late in comparison to the maturation of known neuronal properties and the development of behavioral sensitivity to Glass patterns. Robust differential activity to Glass pattern present/absent and dynamic/static stimulus presentation appeared first in V1, followed by V4 and MT-V5 at older ages; there was no reliable distinction between the two extrastriate areas. A similar pattern of results was obtained with the two analysis methods, although MVPA analysis showed reliable differential responses emerging at later ages than GLM. Although BOLD responses to large visual stimuli are detectable, our results with more refined stimuli indicate that global BOLD activity changes as behavioral performance matures. This reflects an hierarchical development of

  3. Identifying individuals at high risk of psychosis: predictive utility of Support Vector Machine using structural and functional MRI data

    Directory of Open Access Journals (Sweden)

    Isabel eValli

    2016-04-01

    Full Text Available The identification of individuals at high risk of developing psychosis is entirely based on clinical assessment, associated with limited predictive potential. There is therefore increasing interest in the development of biological markers that could be used in clinical practice for this purpose. We studied 25 individuals with an At Risk Mental State for psychosis and 25 healthy controls using structural MRI, and functional MRI in conjunction with a verbal memory task. Data were analysed using a standard univariate analysis, and with Support Vector Machine (SVM, a multivariate pattern recognition technique that enables statistical inferences to be made at the level of the individual, yielding results with high translational potential. The application of SVM to structural MRI data permitted the identification of individuals at high risk of psychosis with a sensitivity of 68% and a specificity of 76%, resulting in an accuracy of 72% (p<0.001. Univariate volumetric between-group differences did not reach statistical significance. In contrast, the univariate fMRI analysis identified between-group differences (p<0.05 corrected while the application of SVM to the same data did not. Since SVM is well suited at identifying the pattern of abnormality that distinguishes two groups, whereas univariate methods are more likely to identify regions that individually are most different between two groups, our results suggest the presence of focal functional abnormalities in the context of a diffuse pattern of structural abnormalities in individuals at high clinical risk of psychosis.

  4. Fluorodopa is a Promising Fluorine-19 MRI Probe for Evaluating Striatal Dopaminergic Function in a Rat Model of Parkinson's Disease.

    Science.gov (United States)

    Yanagisawa, Daijiro; Oda, Keisuke; Inden, Masatoshi; Morikawa, Shigehiro; Inubushi, Toshiro; Taniguchi, Takashi; Hijioka, Masanori; Kitamura, Yoshihisa; Tooyama, Ikuo

    2017-07-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra projecting to the striatum. It has been estimated that approximately 80% of the striatal dopamine and 50% of nigral dopaminergic neurons are lost before the onset of typical motor symptoms, indicating that early diagnosis of PD using noninvasive imaging is feasible. Fluorine-19 ( 19 F) magnetic resonance imaging (MRI) represents a highly sensitive, easily available, low-background, and cost-effective approach to evaluate dopaminergic function using non-radioactive fluorine-containing dopaminergic agents. The aim of this study was to find a potent 19 F MRI probe to evaluate dopaminergic presynaptic function in the striatum. To select candidates for 19 F MRI probes, we investigated the following eight non-radioactive fluorine-containing dopaminergic agents: fluorodopa (F-DOPA), F-tyrosine, haloperidol, GBR13069 duhydrochloride, GBR12909 duhydrochloride, 3-bis-(4-fluorophenyl) methoxytropane hydrochloride, flupenthixol, and fenfluramine. In 19 F nuclear magnetic resonance measurements, F-tyrosine and F-DOPA displayed a relatively higher signal-to-noise ratio value in brain homogenates than in others. F-DOPA, but not F-tyrosine, induced the rotational behavior in a 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rat model. In addition, a significantly high amount of F-DOPA accumulated in the ipsilateral striatum of hemiparkinsonian rats after the injection. We performed 19 F MRI in PC12 cells and isolated rat brain using a 7T MR scanner. Our findings suggest that F-DOPA is a promising 19 F MRI probe for evaluating dopaminergic presynaptic function in the striatum of hemiparkinsonian rats. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Surface-Based fMRI-Driven Diffusion Tractography in the Presence of Significant Brain Pathology: A Study Linking Structure and Function in Cerebral Palsy

    Science.gov (United States)

    Cunnington, Ross; Boyd, Roslyn N.; Rose, Stephen E.

    2016-01-01

    Diffusion MRI (dMRI) tractography analyses are difficult to perform in the presence of brain pathology. Automated methods that rely on cortical parcellation for structural connectivity studies often fail, while manually defining regions is extremely time consuming and can introduce human error. Both methods also make assumptions about structure-function relationships that may not hold after cortical reorganisation. Seeding tractography with functional-MRI (fMRI) activation is an emerging method that reduces these confounds, but inherent smoothing of fMRI signal may result in the inclusion of irrelevant pathways. This paper describes a novel fMRI-seeded dMRI-analysis pipeline based on surface-meshes that reduces these issues and utilises machine-learning to generate task specific white matter pathways, minimising the requirement for manually-drawn ROIs. We directly compared this new strategy to a standard voxelwise fMRI-dMRI approach, by investigating correlations between clinical scores and dMRI metrics of thalamocortical and corticomotor tracts in 31 children with unilateral cerebral palsy. The surface-based approach successfully processed more participants (87%) than the voxel-based approach (65%), and provided significantly more-coherent tractography. Significant correlations between dMRI metrics and five clinical scores of function were found for the more superior regions of these tracts. These significant correlations were stronger and more frequently found with the surface-based method (15/20 investigated were significant; R2 = 0.43–0.73) than the voxelwise analysis (2 sig. correlations; 0.38 & 0.49). More restricted fMRI signal, better-constrained tractography, and the novel track-classification method all appeared to contribute toward these differences. PMID:27487011

  6. Surface-Based fMRI-Driven Diffusion Tractography in the Presence of Significant Brain Pathology: A Study Linking Structure and Function in Cerebral Palsy.

    Science.gov (United States)

    Reid, Lee B; Cunnington, Ross; Boyd, Roslyn N; Rose, Stephen E

    2016-01-01

    Diffusion MRI (dMRI) tractography analyses are difficult to perform in the presence of brain pathology. Automated methods that rely on cortical parcellation for structural connectivity studies often fail, while manually defining regions is extremely time consuming and can introduce human error. Both methods also make assumptions about structure-function relationships that may not hold after cortical reorganisation. Seeding tractography with functional-MRI (fMRI) activation is an emerging method that reduces these confounds, but inherent smoothing of fMRI signal may result in the inclusion of irrelevant pathways. This paper describes a novel fMRI-seeded dMRI-analysis pipeline based on surface-meshes that reduces these issues and utilises machine-learning to generate task specific white matter pathways, minimising the requirement for manually-drawn ROIs. We directly compared this new strategy to a standard voxelwise fMRI-dMRI approach, by investigating correlations between clinical scores and dMRI metrics of thalamocortical and corticomotor tracts in 31 children with unilateral cerebral palsy. The surface-based approach successfully processed more participants (87%) than the voxel-based approach (65%), and provided significantly more-coherent tractography. Significant correlations between dMRI metrics and five clinical scores of function were found for the more superior regions of these tracts. These significant correlations were stronger and more frequently found with the surface-based method (15/20 investigated were significant; R2 = 0.43-0.73) than the voxelwise analysis (2 sig. correlations; 0.38 & 0.49). More restricted fMRI signal, better-constrained tractography, and the novel track-classification method all appeared to contribute toward these differences.

  7. Impact of alcohol-related video sequences on functional MRI in abstinent alcoholics.

    Science.gov (United States)

    Krienke, Ute J; Nikesch, Florian; Spiegelhalder, Kai; Hennig, Jürgen; Olbrich, Hans M; Langosch, Jens M

    2014-01-01

    The object of this study was the identification of brain areas that were significantly more connected than other regions with a previously identified reference region, the posterior cingulate cortex, during the presentation of visual cues in alcoholics. Alcohol-related and neutral video sequences were presented to 30 alcoholics who had been abstinent for at least 4 days. Participants underwent a psychometric assessment before and after the presentation of the video sequences. Functional MRI data were acquired. Psychophysiological interaction analyses were carried out. Participants reported a significant increase in craving and arousal after the presentation of alcohol-related video sequences. The simple contrast alcohol versus neutral was found not to be significantly different in the present study. The brain regions that were found to correlate significantly more with the posterior cingulate cortex under the alcohol-related condition were the inferior parietal lobe, the medial temporal lobe, the inferior frontal gyrus, the postcentral gyrus, and the precuneus. The involvement of these regions in processes of memory, self-control, and self-reflection with a particular focus on alcohol dependence and craving will be discussed. Copyright © 2013 S. Karger AG, Basel.

  8. Impaired sense of agency in functional movement disorders: An fMRI study.

    Directory of Open Access Journals (Sweden)

    Fatta B Nahab

    Full Text Available The sense of agency (SA is an established framework that refers to our ability to exert and perceive control over our own actions. Having an intact SA provides the basis for the human perception of voluntariness, while impairments in SA are hypothesized to lead to the perception of movements being involuntary that may be seen many neurological or psychiatric disorders. Individuals with functional movement disorders (FMD experience a lack of control over their movements, yet these movements appear voluntary by physiology. We used fMRI to explore whether alterations in SA in an FMD population could explain why these patients feel their movements are involuntary. We compared the FMD group to a control group that was previously collected using an ecologically valid, virtual-reality movement paradigm that could modulate SA. We found selective dysfunction of the SA neural network, whereby the dorsolateral prefrontal cortex and pre-supplementary motor area on the right did not respond differentially to the loss of movement control. These findings provide some of the strongest evidence to date for a physiological basis underlying these disabling disorders.

  9. Multivariate pattern classification of pediatric Tourette syndrome using functional connectivity MRI.

    Science.gov (United States)

    Greene, Deanna J; Church, Jessica A; Dosenbach, Nico U F; Nielsen, Ashley N; Adeyemo, Babatunde; Nardos, Binyam; Petersen, Steven E; Black, Kevin J; Schlaggar, Bradley L

    2016-07-01

    Tourette syndrome (TS) is a developmental neuropsychiatric disorder characterized by motor and vocal tics. Individuals with TS would benefit greatly from advances in prediction of symptom timecourse and treatment effectiveness. As a first step, we applied a multivariate method - support vector machine (SVM) classification - to test whether patterns in brain network activity, measured with resting state functional connectivity (RSFC) MRI, could predict diagnostic group membership for individuals. RSFC data from 42 children with TS (8-15 yrs) and 42 unaffected controls (age, IQ, in-scanner movement matched) were included. While univariate tests identified no significant group differences, SVM classified group membership with ~70% accuracy (p classification that, in addition to an overall accuracy rate for the SVM, provides a confidence measure for the accurate classification of each individual. Our results support the contention that multivariate methods can better capture the complexity of some brain disorders, and hold promise for predicting prognosis and treatment outcome for individuals with TS. © 2016 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

  10. Functional MRI in peripheral arterial disease: arterial peak flow versus ankle-brachial index.

    Directory of Open Access Journals (Sweden)

    Bas Versluis

    Full Text Available OBJECTIVES: The purpose of this study was to compare the success rate of successful arterial peak flow (APF and ankle-brachial index (ABI measurements in patients with suspected or known peripheral arterial disease (PAD. MATERIALS AND METHODS: 183 patients with varying degrees of PAD were included. All subjects underwent ABI measurements and MR imaging of the popliteal artery to determine APF. Proportions of patients with successful APF and ABI measurements were compared and the discriminative capability was evaluated. RESULTS: APF was successfully measured in 91% of the patients, whereas the ABI could be determined in 71% of the patients (p<0.01. Success rates of APF and ABI were significantly higher in patients with intermittent claudication (95% and 80%, respectively than in patients with critical ischemia (87% and 62%, respectively. CONCLUSIONS: Compared to the assessment of PAD severity with ABI, the success rate of MRI-based APF measurements in patients with a clinical indication for MRA is 20% higher, with similar discriminatory capacity for disease severity. Therefore, APF is an especially convenient and valuable measure to assess severity in PAD patients scheduled to undergo MR angiography to obtain additional functional information concerning the vascular status.

  11. Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

    Science.gov (United States)

    Fernandez-Gonzalo, R; Tesch, P A; Linnehan, R M; Kreider, R B; Di Salvo, V; Suarez-Arrones, L; Alomar, X; Mendez-Villanueva, A; Rodas, G

    2016-06-01

    This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (Phamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (Phamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Studying Brain Circuit Function with Dynamic Causal Modeling for Optogenetic fMRI.

    Science.gov (United States)

    Bernal-Casas, David; Lee, Hyun Joo; Weitz, Andrew J; Lee, Jin Hyung

    2017-02-08

    Defining the large-scale behavior of brain circuits with cell type specificity is a major goal of neuroscience. However, neuronal circuit diagrams typically draw upon anatomical and electrophysiological measurements acquired in isolation. Consequently, a dynamic and cell-type-specific connectivity map has never been constructed from simultaneous measurements across the brain. Here, we introduce dynamic causal modeling (DCM) for optogenetic fMRI experiments-which uniquely allow cell-type-specific, brain-wide functional measurements-to parameterize the causal relationships among regions of a distributed brain network with cell type specificity. Strikingly, when applied to the brain-wide basal ganglia-thalamocortical network, DCM accurately reproduced the empirically observed time series, and the strongest connections were key connections of optogenetically stimulated pathways. We predict that quantitative and cell-type-specific descriptions of dynamic connectivity, as illustrated here, will empower novel systems-level understanding of neuronal circuit dynamics and facilitate the design of more effective neuromodulation therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. [Functional MRI of human brain in musicians and non-musicians].

    Science.gov (United States)

    Cui, Heng-wu; Zhang, Shi-zheng; Di, Hai-bo; Liu, Hai; Zhu, Yi-hong; Zhang, Qiao-wei; Weng, Xu-chu; Chen, Yi-zhang

    2005-07-01

    To explore the differences in brain activation between musicians and non-musicians by use of functional MRI. Twelve right-handed musicians and twelve right-handed non-musicians were recruited in the study. During a listening task, they were scanned on the Sigma 1.5T scanner (GE) while they were passively listening to several segments of music of "the Butterfly Love" and the white noise with same physical energy. Both musicians and non-musicians demonstrated bilateral transverse gyrus weak activated while listening to the white noise. But when listening to music, they showed bilateral temporal areas strongly activated including superior temporal gyrus, transverse gyrus and some middle temporal areas. Moreover, musicians showed relative left dominance (10/12), whereas non-musicians demonstrated right dominance(11/12). Furthermore,besides bilateral temporal areas, more and stronger activated areas were found in musicians such as cuneus, precuneus,medial frontal and left middle occipital gyrus. There are different neuro-patterns between musicians and non-musicians.

  14. PreSurgMapp: a MATLAB Toolbox for Presurgical Mapping of Eloquent Functional Areas Based on Task-Related and Resting-State Functional MRI.

    Science.gov (United States)

    Huang, Huiyuan; Ding, Zhongxiang; Mao, Dewang; Yuan, Jianhua; Zhu, Fangmei; Chen, Shuda; Xu, Yan; Lou, Lin; Feng, Xiaoyan; Qi, Le; Qiu, Wusi; Zhang, Han; Zang, Yu-Feng

    2016-10-01

    The main goal of brain tumor surgery is to maximize tumor resection while minimizing the risk of irreversible postoperative functional sequelae. Eloquent functional areas should be delineated preoperatively, particularly for patients with tumors near eloquent areas. Functional magnetic resonance imaging (fMRI) is a noninvasive technique that demonstrates great promise for presurgical planning. However, specialized data processing toolkits for presurgical planning remain lacking. Based on several functions in open-source software such as Statistical Parametric Mapping (SPM), Resting-State fMRI Data Analysis Toolkit (REST), Data Processing Assistant for Resting-State fMRI (DPARSF) and Multiple Independent Component Analysis (MICA), here, we introduce an open-source MATLAB toolbox named PreSurgMapp. This toolbox can reveal eloquent areas using comprehensive methods and various complementary fMRI modalities. For example, PreSurgMapp supports both model-based (general linear model, GLM, and seed correlation) and data-driven (independent component analysis, ICA) methods and processes both task-based and resting-state fMRI data. PreSurgMapp is designed for highly automatic and individualized functional mapping with a user-friendly graphical user interface (GUI) for time-saving pipeline processing. For example, sensorimotor and language-related components can be automatically identified without human input interference using an effective, accurate component identification algorithm using discriminability index. All the results generated can be further evaluated and compared by neuro-radiologists or neurosurgeons. This software has substantial value for clinical neuro-radiology and neuro-oncology, including application to patients with low- and high-grade brain tumors and those with epilepsy foci in the dominant language hemisphere who are planning to undergo a temporal lobectomy.

  15. Pathological changes of the chemosensory function in multiple sclerosis. An MRI study

    International Nuclear Information System (INIS)

    Schmidt, F.A.; Harms, L.; Fleiner, F.; Dahlslett, B.; Goektas, Oe.; Bohner, G.; Erb, K.; Luedemann, L.

    2011-01-01

    Purpose: To examine possible causes for olfactory and gustatory dysfunction in MS patients in a prospective study with MRI. Materials and Methods: 30 MS patients (21 women, 11 men, 22 - 65 years, diameter 42 years) were examined by MRI. The olfactory bulb (OB) and olfactory brain volume was correlated with the number and volume of MS lesions in the olfactory brain and the non-olfactory brain. Olfactory testing was performed using the Threshold-Discrimination-Identification Test (TDI), and gustatory function was tested using the Taste-Strips-Test (TST). Results: 33 % of the MS patients displayed olfactory dysfunction (8 % of the control group), and 17 % displayed gustatory dysfunction (5 % of the control group). There was a correlation between the olfactory brain volume and the number (r = -0.38, p < 0.05) and volume (r = -0.38, p < 0.05) of MS lesions in the olfactory brain. The olfactory brain volume correlated with the number of MS lesions in the non-olfactory brain (r = -0.48, p < 0.05). The volume of the left OB correlated with the volume of MS lesions in the olfactory brain (r = -0.42, p < 0.05), the number (r = 0.37, p < 0.05) and volume (r = 0.4, p < 0.05) of lesions in the left part of the olfactory brain and with the TST score (r = -0.45, p < 0.05). The TST score correlated with the volume of lesions in the left (r = -0.45, p < 0.05) and right part (r = -0.53, p < 0.05) of the olfactory brain. The TST score correlated with the number of lesions in the non-olfactory brain (r = -0.48, p < 0.05). Conclusion: The correlation between a higher number and volume of MS lesions in the olfactory brain with a decreased OB and olfactory brain volume could help to explain olfactory and gustatory dysfunction in MS patients. Just the left OB correlated with the number and volume of lesions in the olfactory brain. Manual segmentation was a suitable method for measuring OB and olfactory brain volume. (orig.)

  16. Resting state functional MRI in Parkinson's disease: the impact of deep brain stimulation on 'effective' connectivity.

    Science.gov (United States)

    Kahan, Joshua; Urner, Maren; Moran, Rosalyn; Flandin, Guillaume; Marreiros, Andre; Mancini, Laura; White, Mark; Thornton, John; Yousry, Tarek; Zrinzo, Ludvic; Hariz, Marwan; Limousin, Patricia; Friston, Karl; Foltynie, Tom

    2014-04-01

    Depleted of dopamine, the dynamics of the parkinsonian brain impact on both 'action' and 'resting' motor behaviour. Deep brain stimulation has become an established means of managing these symptoms, although its mechanisms of action remain unclear. Non-invasive characterizations of induced brain responses, and the effective connectivity underlying them, generally appeals to dynamic causal modelling of neuroimaging data. When the brain is at rest, however, this sort of characterization has been limited to correlations (functional connectivity). In this work, we model the 'effective' connectivity underlying low frequency blood oxygen level-dependent fluctuations in the resting Parkinsonian motor network-disclosing the distributed effects of deep brain stimulation on cortico-subcortical connections. Specifically, we show that subthalamic nucleus deep brain stimulation modulates all the major components of the motor cortico-striato-thalamo-cortical loop, including the cortico-striatal, thalamo-cortical, direct and indirect basal ganglia pathways, and the hyperdirect subthalamic nucleus projections. The strength of effective subthalamic nucleus afferents and efferents were reduced by stimulation, whereas cortico-striatal, thalamo-cortical and direct pathways were strengthened. Remarkably, regression analysis revealed that the hyperdirect, direct, and basal ganglia afferents to the subthalamic nucleus predicted clinical status and therapeutic response to deep brain stimulation; however, suppression of the sensitivity of the subthalamic nucleus to its hyperdirect afferents by deep brain stimulation may subvert the clinical efficacy of deep brain stimulation. Our findings highlight the distributed effects of stimulation on the resting motor network and provide a framework for analysing effective connectivity in resting state functional MRI with strong a priori hypotheses.

  17. Neural Activations of Guided Imagery and Music in Negative Emotional Processing: A Functional MRI Study.

    Science.gov (United States)

    Lee, Sang Eun; Han, Yeji; Park, HyunWook

    2016-01-01

    The Bonny Method of Guided Imagery and Music uses music and imagery to access and explore personal emotions associated with episodic memories. Understanding the neural mechanism of guided imagery and music (GIM) as combined stimuli for emotional processing informs clinical application. We performed functional magnetic resonance imaging (fMRI) to demonstrate neural mechanisms of GIM for negative emotional processing when personal episodic memory is recalled and re-experienced through GIM processes. Twenty-four healthy volunteers participated in the study, which used classical music and verbal instruction stimuli to evoke negative emotions. To analyze the neural mechanism, activated regions associated with negative emotional and episodic memory processing were extracted by conducting volume analyses for the contrast between GIM and guided imagery (GI) or music (M). The GIM stimuli showed increased activation over the M-only stimuli in five neural regions associated with negative emotional and episodic memory processing, including the left amygdala, left anterior cingulate gyrus, left insula, bilateral culmen, and left angular gyrus (AG). Compared with GI alone, GIM showed increased activation in three regions associated with episodic memory processing in the emotional context, including the right posterior cingulate gyrus, bilateral parahippocampal gyrus, and AG. No neural regions related to negative emotional and episodic memory processing showed more activation for M and GI than for GIM. As a combined multimodal stimulus, GIM may increase neural activations related to negative emotions and episodic memory processing. Findings suggest a neural basis for GIM with personal episodic memories affecting cortical and subcortical structures and functions. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. A functional MRI study of happy and sad affective states induced by classical music.

    Science.gov (United States)

    Mitterschiffthaler, Martina T; Fu, Cynthia H Y; Dalton, Jeffrey A; Andrew, Christopher M; Williams, Steven C R

    2007-11-01

    The present study investigated the functional neuroanatomy of transient mood changes in response to Western classical music. In a pilot experiment, 53 healthy volunteers (mean age: 32.0; SD = 9.6) evaluated their emotional responses to 60 classical musical pieces using a visual analogue scale (VAS) ranging from 0 (sad) through 50 (neutral) to 100 (happy). Twenty pieces were found to accurately induce the intended emotional states with good reliability, consisting of 5 happy, 5 sad, and 10 emotionally unevocative, neutral musical pieces. In a subsequent functional magnetic resonance imaging (fMRI) study, the blood oxygenation level dependent (BOLD) signal contrast was measured in response to the mood state induced by each musical stimulus in a separate group of 16 healthy participants (mean age: 29.5; SD = 5.5). Mood state ratings during scanning were made by a VAS, which confirmed the emotional valence of the selected stimuli. Increased BOLD signal contrast during presentation of happy music was found in the ventral and dorsal striatum, anterior cingulate, parahippocampal gyrus, and auditory association areas. With sad music, increased BOLD signal responses were noted in the hippocampus/amygdala and auditory association areas. Presentation of neutral music was associated with increased BOLD signal responses in the insula and auditory association areas. Our findings suggest that an emotion processing network in response to music integrates the ventral and dorsal striatum, areas involved in reward experience and movement; the anterior cingulate, which is important for targeting attention; and medial temporal areas, traditionally found in the appraisal and processing of emotions. Copyright 2006 Wiley-Liss, Inc.

  19. Cerebral Correlates of Abnormal Emotion Conflict Processing in Euthymic Bipolar Patients: A Functional MRI Study.

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    Pauline Favre

    Full Text Available Patients with bipolar disorder experience cognitive and emotional impairment that may persist even during the euthymic state of the disease. These persistent symptoms in bipolar patients (BP may be characterized by disturbances of emotion regulation and related fronto-limbic brain circuitry. The present study aims to investigate the modulation of fronto-limbic activity and connectivity in BP by the processing of emotional conflict.Fourteen euthymic BP and 13 matched healthy subjects (HS underwent functional magnetic resonance imaging (fMRI while performing a word-face emotional Stroop task designed to dissociate the monitoring/generation of emotional conflict from its resolution. Functional connectivity was determined by means of psychophysiological interaction (PPI approach.Relative to HS, BP were slower to process incongruent stimuli, reflecting higher amount of behavioral interference during emotional Stroop. Furthermore, BP showed decreased activation of the right dorsolateral prefrontal cortex (DLPFC during the monitoring and a lack of bilateral amygdala deactivation during the resolution of the emotional conflict. In addition, during conflict monitoring, BP showed abnormal positive connectivity between the right DLPFC and several regions of the default mode network.Overall, our results highlighted dysfunctional processing of the emotion conflict in euthymic BP that may be subtended by abnormal activity and connectivity of the DLPFC during the conflict monitoring, which, in turn, leads to failure of amygdala deactivation during the resolution of the conflict. Emotional dysregulation in BP may be underpinned by a lack of top-down cognitive control and a difficulty to focus on the task due to persistent self-oriented attention.

  20. Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy: a pilot study

    International Nuclear Information System (INIS)

    Deblaere, K.; Vandemaele, P.; Achten, E.; Backes, W.H.; Hofman, P.; Wilmink, J.; Boon, P.A.; Vonck, K.; Boon, P.; Troost, J.; Vermeulen, J.; Aldenkamp, A.

    2002-01-01

    Our aim was to put together and test a comprehensive functional MRI (fMRI) protocol which could compete with the intracarotid amytal (IAT) or Wada test for the localisation of language and memory function in patients with intractable temporal lobe epilepsy. The protocol was designed to be performed in under 1 h on a standard 1.5 tesla imager. We used five paradigms to test nine healthy right-handed subjects: complex scene-encoding, picture-naming, reading, word-generation and semantic-decision tasks. The combination of these tasks generated two activation maps related to memory in the mesial temporal lobes, and three language-related maps of activation in a major part of the known language network. The functional maps from the encoding and naming tasks showed typical and symmetrical posterior mesial temporal lobe activation related to memory in all subjects. Only four of nine subjects also showed symmetrical anterior hippocampal activation. Language lateralisation was best with the word generation and reading paradigms and proved possible in all subjects. The reading paradigm enables localisation of language function in the left anterior temporal pole and middle temporal gyrus, areas typically resected during epilepsy surgery. The combined results of this comprehensive f MRI protocol are adequate for a comparative study with the IAT in patients with epilepsy being assessed for surgery. (orig.)

  1. Sleep duration and resting fMRI functional connectivity: examination of short sleepers with and without perceived daytime dysfunction.

    Science.gov (United States)

    Curtis, Brian J; Williams, Paula G; Jones, Christopher R; Anderson, Jeffrey S

    2016-12-01

    Approximately 30% of the U.S. population reports recurrent short sleep; however, perceived sleep need varies widely among individuals. Some "habitual short sleepers" routinely sleep 4-6 hr/night without self-reported adverse consequences. Identifying neural mechanisms underlying individual differences in perceived sleep-related dysfunction has important implications for understanding associations between sleep duration and health. This study utilized data from 839 subjects of the Human Connectome Project to examine resting functional connectivity associations with self-reported short sleep duration, as well as differences between short sleepers with versus without reported dysfunction. Functional connectivity was analyzed using a parcellation covering the cortical, subcortical, and cerebellar gray matter at 5 mm resolution. Self-reported sleep duration predicts one of the primary patterns of intersubject variance in resting functional connectivity. Compared to conventional sleepers, both short sleeper subtypes exhibited resting fMRI (R-fMRI) signatures consistent with diminished wakefulness, potentially indicating inaccurate perception of functionality among those denying dysfunction. Short sleepers denying dysfunction exhibited increased connectivity between sensory cortices and bilateral amygdala and hippocampus, suggesting that efficient sleep-related memory consolidation may partly explain individual differences in perceived daytime dysfunction. Overall, current findings indicate that R-fMRI investigations should include assessment of average sleep duration during the prior month. Furthermore, short sleeper subtype findings provide a candidate neural mechanism underlying differences in perceived daytime impairment associated with short sleep duration.

  2. Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Deblaere, K.; Vandemaele, P.; Achten, E. [MRI Department -1 K12, Department of Radiology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Backes, W.H.; Hofman, P.; Wilmink, J. [Department of Neuroradiology, University Hospital Maastricht, Postbus 5800, 6202 AZ Maastricht (Netherlands); Boon, P.A.; Vonck, K. [Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Boon, P. [Department of Medical Psychology, University Hospital Maastricht (Netherlands); Troost, J. [Department of Neurology, University Hospital Maastricht (Netherlands); Vermeulen, J. [S.E.I.N Heemstede, Psychological Laboratory, Achterweg 5, 2103 SW Heemstede (Netherlands); Aldenkamp, A. [Epilepsy Center ' Kempenhaeghe' , Postbus 61, 5900 AB Heeze (Netherlands)

    2002-08-01

    Our aim was to put together and test a comprehensive functional MRI (fMRI) protocol which could compete with the intracarotid amytal (IAT) or Wada test for the localisation of language and memory function in patients with intractable temporal lobe epilepsy. The protocol was designed to be performed in under 1 h on a standard 1.5 tesla imager. We used five paradigms to test nine healthy right-handed subjects: complex scene-encoding, picture-naming, reading, word-generation and semantic-decision tasks. The combination of these tasks generated two activation maps related to memory in the mesial temporal lobes, and three language-related maps of activation in a major part of the known language network. The functional maps from the encoding and naming tasks showed typical and symmetrical posterior mesial temporal lobe activation related to memory in all subjects. Only four of nine subjects also showed symmetrical anterior hippocampal activation. Language lateralisation was best with the word generation and reading paradigms and proved possible in all subjects. The reading paradigm enables localisation of language function in the left anterior temporal pole and middle temporal gyrus, areas typically resected during epilepsy surgery. The combined results of this comprehensive f MRI protocol are adequate for a comparative study with the IAT in patients with epilepsy being assessed for surgery. (orig.)

  3. Presurgical mapping with functional MRI. Comparative study with transcranial magnetic stimulation and intraoperative mapping

    Energy Technology Data Exchange (ETDEWEB)

    Kaminogo, Makio; Morikawa, Minoru; Ishimaru, Hideki; Ochi, Makoto; Onizuka, Masanori; Shirakawa, Yasushi; Takahashi, Haruki; Shibata, Shobu [Nagasaki Univ. (Japan). School of Medicine

    1999-05-01

    The thumb movement was evoked by transcranical magnetic stimulation (TCS) for the mapping of the motor cortex. After the placement of the marker determined by TCS on the scalp, fMRI under motor tasks consisting of repetitive grasping was performed. For motor cortex activation, an axial oblique plane to maximize gray matter sampling in the rolandic cortex was employed in order to compare these different mapping techniques more precisely. Sixteen patients with brain tumors were included in this study. In nine patients, fMRI disclosed activation in one restricted gyrus or in the localized area around one restricted sulcus. Of these nine patients, preoperative TCS mapping corresponded closely with fMRI in six, while in the remaining three, the TCS marker fell between 1 and 2 cm apart from the fMRI-activated area. However, in these three patients, intraoperative electrocortical stimulation corresponded with the preoperative mapping with fMRI. In six patients, contiguous two gyri were activated by motor tasks. The TCS marker was disclosed on one of the two activated gyri. Of these six patients, the position of the TCS marker and fMRI-activated site corresponded with each other in four cases. They were found on the same gyrus but there was 1.0-2.0 cm distance between them in two cases. Intraoperative somatosensory evoked potential was monitored in two of these six cases. They corresponded well with the mapping by fMRI and TCS together. In only one patient, no significant activation area was obtained by fMRI because of excessive head motion during motor tasks. The TCS maker in this patients was identical with intraoperative electro-cortical stimulation mapping. (K.H.)

  4. Structural and functional abnormalities of default mode network in minimal hepatic encephalopathy: a study combining DTI and fMRI.

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    Rongfeng Qi

    Full Text Available BACKGROUND AND PURPOSE: Live failure can cause brain edema and aberrant brain function in cirrhotic patients. In particular, decreased functional connectivity within the brain default-mode network (DMN has been recently reported in overt hepatic encephalopathy (HE patients. However, so far, little is known about the connectivity among the DMN in the minimal HE (MHE, the mildest form of HE. Here, we combined diffusion tensor imaging (DTI and resting-state functional MRI (rs-fMRI to test our hypothesis that both structural and functional connectivity within the DMN were disturbed in MHE. MATERIALS AND METHODS: Twenty MHE patients and 20 healthy controls participated in the study. We explored the changes of structural (path length, tracts count, fractional anisotropy [FA] and mean diffusivity [MD] derived from DTI tractography and functional (temporal correlation coefficient derived from rs-fMRI connectivity of the DMN in MHE patients. Pearson correlation analysis was performed between the structural/functional indices and venous blood ammonia levels/neuropsychological tests scores of patients. All thresholds were set at P<0.05, Bonferroni corrected. RESULTS: Compared to the healthy controls, MHE patients showed both decreased FA and increased MD in the tract connecting the posterior cingulate cortex/precuneus (PCC/PCUN to left parahippocampal gyrus (PHG, and decreased functional connectivity between the PCC/PCUN and left PHG, and medial prefrontal cortex (MPFC. MD values of the tract connecting PCC/PCUN to the left PHG positively correlated to the ammonia levels, the temporal correlation coefficients between the PCC/PCUN and the MPFC showed positive correlation to the digital symbol tests scores of patients. CONCLUSION: MHE patients have both disturbed structural and functional connectivity within the DMN. The decreased functional connectivity was also detected between some regions without abnormal structural connectivity, suggesting that the

  5. Predictive value of different conventional and non-conventional MRI-parameters for specific domains of cognitive function in multiple sclerosis

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    Daniela Pinter

    2015-01-01

    Conclusions: The predictive value of distinct MRI-parameters differs for specific domains of cognitive function, with a greater impact of cortical volume, focal and diffuse white matter abnormalities on overall cognitive function, an additional role of basal ganglia iron deposition on cognitive efficiency, and thalamic and hippocampal volume on memory function. This suggests the usefulness of using multiparametric MRI to assess (microstructural correlates of different cognitive constructs.

  6. Modulation of functionally localized right insular cortex activity using real-time fMRI-based neurofeedback

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    Brian D Berman

    2013-10-01

    Full Text Available The capacity for subjects to learn to volitionally control localized brain activity using neurofeedback is actively being investigated. We aimed to investigate the ability of healthy volunteers to quickly learn to use visual feedback during real-time functional MRI (rtfMRI to modulate brain activity within their anterior right insular cortex (RIC localized during a blink suppression task, an approach of possible interest in the use of rtfMRI to reduce urges. The RIC region of interest (RIC-ROI was functionally localized using a blink suppression task, and BOLD signal changes within RIC-ROI used to create a constantly updating display fed back to the subject in the scanner. Subjects were instructed to use emotional imagery to try and increase activity within RIC-ROI during four feedback training runs (FB1–FB4. A ‘control’ run (CNTRL before training and a ‘transfer’ run (XSFR after training were performed without feedback to assess for baseline abilities and learning effects. Fourteen participants completed all neurofeedback training runs. At the group level, increased BOLD activity was seen in the anterior RIC during all the FB runs, but a significant increase in the functionally defined RIC-ROI was only attained during FB2. In atlas-defined insular cortex ROIs, significant increases were seen bilaterally during the CNTRL, FB1, FB2, and FB4 runs. Increased activity within the insular cortices did not show lateralization. Training did, however, result in a significant increase in functional connectivity between the RIC-ROI and the medial frontal gyrus when comparing FB4 to FB1. Since neurofeedback training did not lead to an increase in BOLD signal across all feedback runs, we suggest that learning to control one’s brain activity in this fashion may require longer or repeated rtfMRI training sessions.

  7. Total Cerebral Small Vessel Disease MRI Score Is Associated With Cognitive Decline In Executive Function In Patients With Hypertension

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    Renske Uiterwijk

    2016-12-01

    Full Text Available Objectives: Hypertension is a major risk factor for white matter hyperintensities, lacunes, cerebral microbleeds and perivascular spaces, which are MRI markers of cerebral small vessel disease (SVD. Studies have shown associations between these individual MRI markers and cognitive functioning and decline. Recently, a total SVD score was proposed in which the different MRI markers were combined into one measure of SVD, to capture total SVD-related brain damage. We investigated if this SVD score was associated with cognitive decline over 4 years in patients with hypertension. Methods: In this longitudinal cohort study, 130 hypertensive patients (91 patients with uncomplicated hypertension and 39 hypertensive patients with a lacunar stroke were included. They underwent a neuropsychological assessment at baseline and after 4 years. The presence of white matter hyperintensities, lacunes, cerebral microbleeds, and perivascular spaces were rated on baseline MRI. Presence of each individual marker was added to calculate the total SVD score (range 0-4 in each patient. Results: Uncorrected linear regression analyses showed associations between SVD score and decline in overall cognition (p=0.017, executive functioning (p<0.001 and information processing speed (p=0.037, but not with memory (p=0.911. The association between SVD score and decline in overall cognition and executive function remained significant after adjustment for age, sex, education, anxiety and depression score, potential vascular risk factors, patient group and baseline cognitive performance.Conclusions: Our study shows that a total SVD score can predict cognitive decline, specifically in executive function, over 4 years in hypertensive patients. This emphasizes the importance of considering total brain damage due to SVD.

  8. Automatic denoising of functional MRI data: combining independent component analysis and hierarchical fusion of classifiers.

    Science.gov (United States)

    Salimi-Khorshidi, Gholamreza; Douaud, Gwenaëlle; Beckmann, Christian F; Glasser, Matthew F; Griffanti, Ludovica; Smith, Stephen M

    2014-04-15

    Many sources of fluctuation contribute to the fMRI signal, and this makes identifying the effects that are truly related to the underlying neuronal activity difficult. Independent component analysis (ICA) - one of the most widely used techniques for the exploratory analysis of fMRI data - has shown to be a powerful technique in identifying various sources of neuronally-related and artefactual fluctuation in fMRI data (both with the application of external stimuli and with the subject "at rest"). ICA decomposes fMRI data into patterns of activity (a set of spatial maps and their corresponding time series) that are statistically independent and add linearly to explain voxel-wise time series. Given the set of ICA components, if the components representing "signal" (brain activity) can be distinguished form the "noise" components (effects of motion, non-neuronal physiology, scanner artefacts and other nuisance sources), the latter can then be removed from the data, providing an effective cleanup of structured noise. Manual classification of components is labour intensive and requires expertise; hence, a fully automatic noise detection algorithm that can reliably detect various types of noise sources (in both task and resting fMRI) is desirable. In this paper, we introduce FIX ("FMRIB's ICA-based X-noiseifier"), which provides an automatic solution for denoising fMRI data via accurate classification of ICA components. For each ICA component FIX generates a large number of distinct spatial and temporal features, each describing a different aspect of the data (e.g., what proportion of temporal fluctuations are at high frequencies). The set of features is then fed into a multi-level classifier (built around several different classifiers). Once trained through the hand-classification of a sufficient number of training datasets, the classifier can then automatically classify new datasets. The noise components can then be subtracted from (or regressed out of) the original

  9. Altered brain functions in HIV positive patients free of HIV- associated neurocognitive disorders: A MRI study during unilateral hand movements

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    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.

  10. Real-time correction by optical tracking with integrated geometric distortion correction for reducing motion artifacts in functional MRI.

    Science.gov (United States)

    Rotenberg, David; Chiew, Mark; Ranieri, Shawn; Tam, Fred; Chopra, Rajiv; Graham, Simon J

    2013-03-01

    Head motion artifacts are a major problem in functional MRI that limit its use in neuroscience research and clinical settings. Real-time scan-plane correction by optical tracking has been shown to correct slice misalignment and nonlinear spin-history artifacts; however, residual artifacts due to dynamic magnetic field nonuniformity may remain in the data. A recently developed correction technique, Phase Labeling for Additional Coordinate Encoding, can correct for absolute geometric distortion using only the complex image data from two echo planar images with slightly shifted k-space trajectories. An approach is presented that integrates Phase Labeling for Additional Coordinate Encoding into a real-time scan-plane update system by optical tracking, applied to a tissue-equivalent phantom undergoing complex motion and an functional MRI finger tapping experiment with overt head motion to induce dynamic field nonuniformity. Experiments suggest that such integrated volume-by-volume corrections are very effective at artifact suppression, with potential to expand functional MRI applications. Copyright © 2012 Wiley Periodicals, Inc.

  11. Dynamic Contrast-Enhanced Perfusion MRI of High Grade Brain Gliomas Obtained with Arterial or Venous Waveform Input Function.

    Science.gov (United States)

    Filice, Silvano; Crisi, Girolamo

    2016-01-01

    The aim of this study was to evaluate the differences in dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) perfusion estimates of high-grade brain gliomas (HGG) due to the use of an input function (IF) obtained respectively from arterial (AIF) and venous (VIF) approaches by two different commercially available software applications. This prospective study includes 20 patients with pathologically confirmed diagnosis of high-grade gliomas. The data source was processed by using two DCE dedicated commercial packages, both based on the extended Toft model, but the first customized to obtain input function from arterial measurement and the second from sagittal sinus sampling. The quantitative parametric perfusion maps estimated from the two software packages were compared by means of a region of interest (ROI) analysis. The resulting input functions from venous and arterial data were also compared. No significant difference has been found between the perfusion parameters obtained with the two different software packages (P-value < .05). The comparison of the VIFs and AIFs obtained by the two packages showed no statistical differences. Direct comparison of DCE-MRI measurements with IF generated by means of arterial or venous waveform led to no statistical difference in quantitative metrics for evaluating HGG. However, additional research involving DCE-MRI acquisition protocols and post-processing would be beneficial to further substantiate the effectiveness of venous approach as the IF method compared with arterial-based IF measurement. Copyright © 2015 by the American Society of Neuroimaging.

  12. Functional MRI of motor speech area combined with motor stimulation during resting period

    International Nuclear Information System (INIS)

    Lim, Yeong Su; Park, Hark Hoon; Chung, Gyung Ho; Lee, Sang Yong; Chon, Su Bin; Kang, Shin Hwa

    1999-01-01

    To evaluate functional MR imaging of the motor speech area with and without motor stimulation during the rest period. Nine healthy, right-handed volunteers(M:F=7:2, age:21-40years) were included in this study. Brain activity was mapped using a multislice, gradient echo single shot EPI on a 1.5T MR scanner. The paradigm consisted on a series of alternating rest and activation tasks, performed six times. Each volunteer in the first study(group A) was given examples of motor stimulation during the rest period, while each in the second study(group B) was not given examples of a rest period. Motor stimulation in group A was achieved by continuously flexing five fingers of the right hand. In both groups, maximum internal word generation was achieved during the activation period. Using fMRI analysis software(Stimulate 5.0) and a cross-correlation method(backgroud threshold, 200; correlation threshold, 0.3; ceiling, 1.0; floor, 0.3; minimal count, 3), functional images were analysed. After correlating the activated foci and a time-signal intensity curve, the activated brain cortex and number of pixels were analysed and compared between the two tasks. The t-test was used for statistical analysis. In all nine subjects in group A and B, activation was observed in and adjacent to the left Broca's area. The mean number of activated pixels was 31.6 in group A and 27.8 in group B, a difference which was not statistically significant(P>0.1). Activities in and adjacent to the right Broca's area were seen in seven of group A and four of group B. The mean number of activated pixels was 14.9 in group A and 18 in group B. Eight of nine volunteers in group A showed activity in the left primary motor area with negative correlation to the time-signal intensity curve. The mean number of activated pixels for this group was 17.5. In three volonteers, activation in the right primary motor area was also observed, the mean number of activated pixels in these cases was 10.0. During the rest

  13. Functional MRI preprocessing in lesioned brains: manual versus automated region of interest analysis

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    Kathleen A Garrison

    2015-09-01

    Full Text Available Functional magnetic resonance imaging has significant potential in the study and treatment of neurological disorders and stroke. Region of interest (ROI analysis in such studies allows for testing of strong a priori clinical hypotheses with improved statistical power. A commonly used automated approach to ROI analysis is to spatially normalize each participant’s structural brain image to a template brain image and define ROIs using an atlas. However, in studies of individuals with structural brain lesions such as stroke, the gold standard approach may be to manually hand-draw ROIs on each participant’s non-normalized structural brain image. Automated approaches to ROI analysis are faster and more standardized, yet are susceptible to preprocessing error (e.g., normalization error that can be greater in lesioned brains. The manual approach to ROI analysis has high demand for time and expertise but may provide a more accurate estimate of brain response. In this study, we directly compare commonly used automated and manual approaches to ROI analysis by reanalyzing data from a previously published hypothesis-driven cognitive fMRI study involving individuals with stroke. The ROI evaluated is the pars opercularis of the inferior frontal gyrus. We found a significant difference in task-related effect size and percent activated voxels in this ROI between the automated and manual approaches to ROI analysis. Task interactions, however, were consistent across ROI analysis approaches. These findings support the use of automated approaches to ROI analysis in studies of lesioned brains, provided they employ a task interaction design.

  14. The human likeness dimension of the "uncanny valley hypothesis": behavioural and functional MRI findings.

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    Marcus eCheetham

    2011-11-01

    Full Text Available The uncanny valley hypothesis (Mori, 1970 predicts differential experience of negative and positive affect as a function of human likeness. Affective experience of realistic humanlike robots and computer-generated characters (avatars dominates uncanny research, but findings are inconsistent. How objects are actually perceived along the hypothesis’ dimension of human likeness (DOH, defined only in terms of human physical similarity, is unknown. To examine whether the DOH can be defined also in terms of effects of categorical perception (CP, stimuli from morph continua with controlled differences in physical human likeness between avatar and human faces as endpoints were presented. Two behavioural studies found a sharp category boundary along the DOH and enhanced visual discrimination (i.e. CP of fine-grained differences between face pairs at the category boundary. Discrimination was better for face pairs that presented category change in the human-to-avatar than avatar-to-human direction along DOH. To investigate brain representation of physical and category change within the uncanny valley hypothesis’ framework, an event-related fMRI study used the same stimuli in a paired repetition-priming paradigm. Bilateral mid-fusiform areas and a different right mid-fusiform area were sensitive to physical change within the human and avatar categories, respectively, whereas entirely different regions were sensitive to the human-to-avatar (caudate head, putamen, thalamus, red nucleus and avatar-to-human (hippocampus, amygdala, mid-insula direction of category change. Our findings show that Mori's DOH definition does not reflect subjective perception of human likeness and suggest that future uncanny studies consider CP and the DOH category structure in guiding experience of nonhuman objects.

  15. A functional MRI study of happy and sad emotions in music with and without lyrics

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    Elvira eBrattico

    2011-12-01

    Full Text Available Musical emotions, such as happiness and sadness, have been investigated using instrumental music devoid of linguistic content. However, pop and rock, the most common musical genres, utilize lyrics for conveying emotions. Using participants’ self-selected musical excerpts, we studied their behavior and brain responses to elucidate how lyrics interact with musical emotion processing, as reflected by emotion recognition and activation of limbic areas involved in affective experience. We extracted samples from subjects’ selections of sad and happy pieces and sorted them according to the presence of lyrics. Acoustic feature analysis showed that music with lyrics differed from music without lyrics in spectral centroid, a feature related to perceptual brightness, whereas sad music with lyrics did not diverge from happy music without lyrics, indicating the role of other factors in emotion classification. Behavioral ratings revealed that happy music without lyrics induced stronger positive emotions than happy music with lyrics. We also acquired functional magnetic resonance imaging (fMRI data while subjects performed affective tasks regarding the music. First, using ecological and acoustically variable stimuli, we broadened previous findings about the brain processing of musical emotions and of songs versus instrumental music. Additionally, contrasts between sad music with versus without lyrics recruited the parahippocampal gyrus, the amygdala, the claustrum, the putamen, the precentral gyrus, the medial and inferior frontal gyri (including Broca’s area, and the auditory cortex, while the reverse contrast produced no activations. Happy music without lyrics activated structures of the limbic system and the right pars opercularis of the inferior frontal gyrus, whereas auditory regions alone responded to happy music with lyrics. These findings point to the role of acoustic cues for the experience of happiness in music and to the importance of lyrics

  16. Identification of Voxels Confounded by Venous Signals Using Resting-State fMRI Functional Connectivity Graph Clustering

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    Klaudius eKalcher

    2015-12-01

    Full Text Available Identifying venous voxels in fMRI datasets is important to increase the specificity of fMRI analyses to microvasculature in the vicinity of the neural processes triggering the BOLD response. This is, however, difficult to achieve in particular in typical studies where magnitude images of BOLD EPI are the only data available. In this study, voxelwise functional connectivity graphs were computed on minimally preprocessed low TR (333 ms multiband resting-state fMRI data, using both high positive and negative correlations to define edges between nodes (voxels. A high correlation threshold for binarization ensures that most edges in the resulting sparse graph reflect the high coherence of signals in medium to large veins. Graph clustering based on the optimization of modularity was then employed to identify clusters of coherent voxels in this graph, and all clusters of 50 or more voxels were then interpreted as corresponding to medium to large veins. Indeed, a comparison with SWI reveals that 75.6 ± 5.9% of voxels within these large clusters overlap with veins visible in the SWI image or lie outside the brain parenchyma. Some of the remainingdifferences between the two modalities can be explained by imperfect alignment or geometric distortions between the two images. Overall, the graph clustering based method for identifying venous voxels has a high specificity as well as the additional advantages of being computed in the same voxel grid as the fMRI dataset itself and not needingany additional data beyond what is usually acquired (and exported in standard fMRI experiments.

  17. Functional MRI of the cervical spinal cord on 1.5 T with fingertapping: to what extent is it feasible?

    International Nuclear Information System (INIS)

    Govers, N.; Beghin, J.; Goethem, J.W.M. van; Hauwe, L. van den; Vandervliet, E.; Parizel, P.M.; Michiels, J.

    2007-01-01

    Until recently, functional magnetic resonance imaging (fMRI) with blood oxygen level-dependent (BOLD) contrast, was mainly used to study brain physiology. The activation signal measured with fMRI is based upon the changes in the concentration of deoxyhaemoglobin that arise from an increase in blood flow in the vicinity of neuronal firing. Technical limitations have impeded such research in the human cervical spinal cord. The purpose of this investigation was to determine whether a reliable fMRI signal can be elicited from the cervical spinal cord during fingertapping, a complex motor activity. Furthermore, we wanted to determine whether the fMRI signal could be spatially localized to the particular neuroanatomical location specific for this task. A group of 12 right-handed healthy volunteers performed the complex motor task of fingertapping with their right hand. T2*-weighted gradient-echo echo-planar imaging on a 1.5-T clinical unit was used to image the cervical spinal cord. Motion correction was applied. Cord activation was measured in the transverse imaging plane, between the spinal cord levels C5 and T1. In all subjects spinal cord responses were found, and in most of them on the left and the right side. The distribution of the activation response showed important variations between the subjects. While regions of activation were distributed throughout the spinal cord, concentrated activity was found at the anatomical location of expected motor innervation, namely nerve root C8, in 6 of the 12 subjects. fMRI of the human cervical spinal cord on an 1.5-T unit detects neuronal activity related to a complex motor task. The location of the neuronal activation (spinal cord segment C5 through T1 with a peak on C8) corresponds to the craniocaudal anatomical location of the neurons that activate the muscles in use. (orig.)

  18. Evaluating the impact of fast-fMRI on dynamic functional connectivity in an event-based paradigm.

    Directory of Open Access Journals (Sweden)

    Ashish Kaul Sahib

    Full Text Available The human brain is known to contain several functional networks that interact dynamically. Therefore, it is desirable to analyze the temporal features of these networks by dynamic functional connectivity (dFC. A sliding window approach was used in an event-related fMRI (visual stimulation using checkerboards to assess the impact of repetition time (TR and window size on the temporal features of BOLD dFC. In addition, we also examined the spatial distribution of dFC and tested the feasibility of this approach for the analysis of interictal epileptiforme discharges. 15 healthy controls (visual stimulation paradigm and three patients with epilepsy (EEG-fMRI were measured with EPI-fMRI. We calculated the functional connectivity degree (FCD by determining the total number of connections of a given voxel above a predefined threshold based on Pearson correlation. FCD could capture hemodynamic changes relative to stimulus onset in controls. A significant effect of TR and window size was observed on FCD estimates. At a conventional TR of 2.6 s, FCD values were marginal compared to FCD values using sub-seconds TRs achievable with multiband (MB fMRI. Concerning window sizes, a specific maximum of FCD values (inverted u-shape behavior was found for each TR, indicating a limit to the possible gain in FCD for increasing window size. In patients, a dynamic FCD change was found relative to the onset of epileptiform EEG patterns, which was compatible with their clinical semiology. Our findings indicate that dynamic FCD transients are better detectable with sub-second TR than conventional TR. This approach was capable of capturing neuronal connectivity across various regions of the brain, indicating a potential to study the temporal characteristics of interictal epileptiform discharges and seizures in epilepsy patients or other brain diseases with brief events.

  19. Validity of semi-quantitative scale for brain MRI in unilateral cerebral palsy due to periventricular white matter lesions: Relationship with hand sensorimotor function and structural connectivity.

    Science.gov (United States)

    Fiori, Simona; Guzzetta, Andrea; Pannek, Kerstin; Ware, Robert S; Rossi, Giuseppe; Klingels, Katrijn; Feys, Hilde; Coulthard, Alan; Cioni, Giovanni; Rose, Stephen; Boyd, Roslyn N

    2015-01-01

    To provide first evidence of construct validity of a semi-quantitative scale for brain structural MRI (sqMRI scale) in children with unilateral cerebral palsy (UCP) secondary to periventricular white matter (PWM) lesions, by examining the relationship with hand sensorimotor function and whole brain structural connectivity. Cross-sectional study of 50 children with UCP due to PWM lesions using 3 T (MRI), diffusion MRI and assessment of hand sensorimotor function. We explored the relationship of lobar, hemispheric and global scores on the sqMRI scale, with fractional anisotropy (FA), as a measure of brain white matter microstructure, and with hand sensorimotor measures (Assisting Hand Assessment, AHA; Jebsen-Taylor Test for Hand Function, JTTHF; Melbourne Assessment of Unilateral Upper Limb Function, MUUL; stereognosis; 2-point discrimination). Lobar and hemispheric scores on the sqMRI scale contralateral to the clinical side of hemiplegia correlated with sensorimotor paretic hand function measures and FA of a number of brain structural connections, including connections of brain areas involved in motor control (postcentral, precentral and paracentral gyri in the parietal lobe). More severe lesions correlated with lower sensorimotor performance, with the posterior limb of internal capsule score being the strongest contributor to impaired hand function. The sqMRI scale demonstrates first evidence of construct validity against impaired motor and sensory function measures and brain structural connectivity in a cohort of children with UCP due to PWM lesions. More severe lesions correlated with poorer paretic hand sensorimotor function and impaired structural connectivity in the hemisphere contralateral to the clinical side of hemiplegia. The quantitative structural MRI scoring may be a useful clinical tool for studying brain structure-function relationships but requires further validation in other populations of CP.

  20. WE-E-BRA-02: Optimization of Functional MRI Techniques for Assessment of Tumor and Normal Tissue Response to RT.

    Science.gov (United States)

    Cao, Y

    2012-06-01

    The advantages of physiological and functional MRI for radiation treatment assessment of tumor response and normal tissue damage for adaptive RT as well as for boost target definition are well recognized. However, several limitations of functional MRI have hindered its wide application in radiation therapy, including concerns about optimal pulse sequence parameters, high resolution volumetric acquisition, acquisition speed, motion-sensitivity, reproducibility, and image processing. Many of these shortcomings have been overcome or will be overcome by standardization of image acquisition and quantification. It is also important to understand sensitivity and specificity of these imaging techniques for particular clinical questions. This lecture will provide an overview on these techniques and issues. Examples of applying these techniques to liver and prostate will be given. 1. Understand new MRI technologies that are relevant to radiation treatment assessment; 2. Understand the influence of imaging parameters on image quality and contrast; 3. Understand image processing techniques for derived quantitative parameters; 4. Understand clinical applications and limitations. Author's work is supported in part by NIH P01 CA59827, NCI RO1 CA132834, and RO1 NS064973. 3959. © 2012 American Association of Physicists in Medicine.

  1. Quantitative estimation of renal function with dynamic contrast-enhanced MRI using a modified two-compartment model.

    Directory of Open Access Journals (Sweden)

    Bin Chen

    Full Text Available To establish a simple two-compartment model for glomerular filtration rate (GFR and renal plasma flow (RPF estimations by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI.A total of eight New Zealand white rabbits were included in DCE-MRI. The two-compartment model was modified with the impulse residue function in this study. First, the reliability of GFR measurement of the proposed model was compared with other published models in Monte Carlo simulation at different noise levels. Then, functional parameters were estimated in six healthy rabbits to test the feasibility of the new model. Moreover, in order to investigate its validity of GFR estimation, two rabbits underwent acute ischemia surgical procedure in unilateral kidney before DCE-MRI, and pixel-wise measurements were implemented to detect the cortical GFR alterations between normal and abnormal kidneys.The lowest variability of GFR and RPF measurements were found in the proposed model in the comparison. Mean GFR was 3.03±1.1 ml/min and mean RPF was 2.64±0.5 ml/g/min in normal animals, which were in good agreement with the published values. Moreover, large GFR decline was found in dysfunction kidneys comparing to the contralateral control group.Results in our study demonstrate that measurement of renal kinetic parameters based on the proposed model is feasible and it has the ability to discriminate GFR changes in healthy and diseased kidneys.

  2. Baseline brain activity changes in patients with clinically isolated syndrome revealed by resting-state functional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yaou; Duan, Yunyun; Liang, Peipeng; Jia, Xiuqin; Yu, Chunshui [Dept. of Radiology, Xuanwu Hospital, Capital Medical Univ., Beijing (China); Ye, Jing [Dept. of Neurology, Xuanwu Hospital, Capital Medical Univ., Beijing (China); Butzkueven, Helmut [Dept. of Medicine, Univ. of Melbourne, Melbourne (Australia); Dong, Huiqing [Dept. of Neurology, Xuanwu Hospital, Capital Medical Univ., Beijing (China); Li, Kuncheng [Dept. of Radiology, Xuanwu Hospital, Capital Medical Univ., Beijing (China); Beijing Key Laboratory of MRI and Brain Informatics, Beijing (China)], E-mail: likuncheng1955@yahoo.com.cn

    2012-11-15

    Background A clinically isolated syndrome (CIS) is the first manifestation of multiple sclerosis (MS). Previous task-related functional MRI studies demonstrate functional reorganization in patients with CIS. Purpose To assess baseline brain activity changes in patients with CIS by using the technique of regional amplitude of low frequency fluctuation (ALFF) as an index in resting-state fMRI. Material and Methods Resting-state fMRIs data acquired from 37 patients with CIS and 37 age- and sex-matched normal controls were compared to investigate ALFF differences. The relationships between ALFF in regions with significant group differences and the EDSS (Expanded Disability Status Scale), disease duration, and T2 lesion volume (T2LV) were further explored. Results Patients with CIS had significantly decreased ALFF in the right anterior cingulate cortex, right caudate, right lingual gyrus, and right cuneus (P < 0.05 corrected for multiple comparisons using Monte Carlo simulation) compared to normal controls, while no significantly increased ALFF were observed in CIS. No significant correlation was found between the EDSS, disease duration, T2LV, and ALFF in regions with significant group differences. Conclusion In patients with CIS, resting-state fMRI demonstrates decreased activity in several brain regions. These results are in contrast to patients with established MS, in whom ALFF demonstrates several regions of increased activity. It is possible that this shift from decreased activity in CIS to increased activity in MS could reflect the dynamics of cortical reorganization.

  3. Assessing motor, visual and language function using a single 5-minute fMRI paradigm: three birds with one stone.

    Science.gov (United States)

    Fiori, Simona; Zendler, Carolin; Hauser, Till-Karsten; Lidzba, Karen; Wilke, Marko

    2018-02-26

    Clinical functional Magnetic Resonance Imaging (fMRI) requires inferences on localization of major brain functions at the individual subject level. We hypothesized that a single "triple use" task would satisfy sensitivity and reliability requirements for successfully assessing the motor, visual and language domain in this context. This was tested here by the application in a group of healthy adults, assessing sensitivity and reliability at the individual subject level, separately for each domain.Our "triple use" task consisted of 2 conditions (condition 1, assessing motor and visual domain, and condition 2, assessing the language domain), serving mutually as active/control. We included 20 healthy adult subjects. Random effect analyses showed activation in primary motor, visual and language regions, as expected. Less expected regions were activated both for the motor and visual domains. Further, reliability of primary activation patterns was very high across individual subjects, with activation seen in 70-100% of subjects in primary motor, visual, and left-lateralized language regions.These findings suggest the "triple use" task to be reliable at the individual subject's level to assess motor, visual and language domains in the clinical fMRI context. Benefits of such an approach include shortening of acquisition time, simplicity of the task for each domain, and using a visual stimulus. Following establishment of reliability in adults, the task may also be a valuable addition in the pediatric clinical fMRI context, where each of these factors is of high relevance.

  4. Working memory capacity and the functional connectome - insights from resting-state fMRI and voxelwise centrality mapping.

    Science.gov (United States)

    Markett, Sebastian; Reuter, Martin; Heeren, Behrend; Lachmann, Bernd; Weber, Bernd; Montag, Christian

    2018-02-01

    The functional connectome represents a comprehensive network map of functional connectivity throughout the human brain. To date, the relationship between the organization of functional connectivity and cognitive performance measures is still poorly understood. In the present study we use resting-state functional magnetic resonance imaging (fMRI) data to explore the link between the functional connectome and working memory capacity in an individual differences design. Working memory capacity, which refers to the maximum amount of context information that an individual can retain in the absence of external stimulation, was assessed outside the MRI scanner and estimated based on behavioral data from a change detection task. Resting-state time series were analyzed by means of voxelwise degree and eigenvector centrality mapping, which are data-driven network analytic approaches for the characterization of functional connectivity. We found working memory capacity to be inversely correlated with both centrality in the right intraparietal sulcus. Exploratory analyses revealed that this relationship was putatively driven by an increase in negative connectivity strength of the structure. This resting-state connectivity finding fits previous task based activation studies that have shown that this area responds to manipulations of working memory load.

  5. Pre-surgical evaluation of the cerebral tumor in the left language related areas by functional MRI

    International Nuclear Information System (INIS)

    Zou Zhitong; Ma Lin; Weng Xuchu

    2010-01-01

    Objective: To evaluate the application of combination of BOLD-fMRI and diffusion tensor tractography (DTT) in pre-operative evaluation of cerebral tumors located at the left language related areas. Methods: A non-vocal button pressing semantic judging paradigm was developed and validated in 10 right-handed volunteers at 3 T. After validation, this protocol combined with DTI were applied to 15 patients with left cerebral tumor prior to surgical resection, and 3 of them had aphasia. fMRI data analysis was on subject-specific basis by one-sampled t-test. The distance from the tumor to Broca area and pre-central 'hand-knot' area were measured separately. Functional language laterality index (LI) was calculated by taking out Broca area and Wernicke area. Three dimensional architecture of frontal lobe white matter fibers, especially arcuate fasciculus, were visualized using diffusion tensor tractography on Volume-one software. The images demonstrating relationship among tumor, language activation areas and white matter fibers were reviewed by neurosurgeons as part of pre-operative planning. One year after the operation, patients were followed up with MRI and language function test. Results: The non-vocal semantic judging paradigm successfully detect Broca area, Wernicke area and pre-central 'hand-knot' area. In 12 of 15 patients, the relationship of Broca area and pre-central motor area to the left brain tumor in language related areas was identified, which make the pre-operative neurosurgical plan applicable to minimize the disruption of language and motor. 8 patients had the left language dominant hemisphere, 3 patients with the right language dominant hemisphere and 1 patient with bilateral dominance. The other 3 patients' fMRI data were corrupted by patients' motion. Diffusion tensor images were corrupted by motion in 1 patient but demonstrated the impact of tumor on left accouter fasciculus in 14 patients. Diffusion tensor tractography showed disruption of left

  6. Brain activation areas of sexual arousal with olfactory stimulation in men: a preliminary study using functional MRI.

    Science.gov (United States)

    Huh, Joon; Park, Kwangsung; Hwang, In Sang; Jung, Seung Il; Kim, Hyeong-Jung; Chung, Tae-Woong; Jeong, Gwang-Woo

    2008-03-01

    There have been extensive studies evaluating the functional neuroanatomy of the brain during visual sexual stimulation. However, little data exist concerning the role of olfactory stimulation in human sexuality. This preliminary study intended to elucidate the brain areas responding to an olfactory sexual stimulus using functional magnetic resonance imaging (fMRI). Eight healthy right-handed heterosexual male volunteers (20-35 years of age), having normal olfaction and no brain diseases, were recruited. During fMRI, a women's perfume was given as an olfactory sexual stimulant in an alternating block design with a 30-second stimulation period followed by a 30-second rest. After the fMRI sessions, the participants provided ratings for both the odorant's intensity and perceived arousal. The study subjects rated the odorant stimulation and perceived sexual arousal response by Likert-type rating scales. Brain activation maps were made by blood oxygenation level-dependent (BOLD)-based fMRI with an echo-planar imaging pulse sequence. Two out of eight subjects experienced "strong" sexual arousal, and three subjects experienced "moderate" arousal during olfactory stimulation, resulting in a mean score of 2.25 on a 4-point scale. The common brain areas activated in response to the odor stimulus in all eight subjects included the insula, the inferior and middle frontal gyrus, and the hypothalamus. The median cingulate gyrus, thalamus, angular gyrus, lingual gyrus, and cerebellar cortex were activated in subjects who had moderate or strong sexual arousal response. Olfactory stimulation with women's perfume produces the activation of specific brain areas in men. The brain areas activated differed according to the degree of perceived sexual arousal response. Further studies are needed to elucidate brain activation response according to the different kinds and intensities of olfactory stimulation.

  7. Mild cognitive impairment and fMRI studies of brain functional connectivity: the state of the art

    Science.gov (United States)

    Farràs-Permanyer, Laia; Guàrdia-Olmos, Joan; Peró-Cebollero, Maribel

    2015-01-01

    In the last 15 years, many articles have studied brain connectivity in Mild Cognitive Impairment patients with fMRI techniques, seemingly using different connectivity statistical models in each investigation to identify complex connectivity structures so as to recognize typical behavior in this type of patient. This diversity in statistical approaches may cause problems in results comparison. This paper seeks to describe how researchers approached the study of brain connectivity in MCI patients using fMRI techniques from 2002 to 2014. The focus is on the statistical analysis proposed by each research group in reference to the limitations and possibilities of those techniques to identify some recommendations to improve the study of functional connectivity. The included articles came from a search of Web of Science and PsycINFO using the following keywords: f MRI, MCI, and functional connectivity. Eighty-one papers were found, but two of them were discarded because of the lack of statistical analysis. Accordingly, 79 articles were included in this review. We summarized some parts of the articles, including the goal of every investigation, the cognitive paradigm and methods used, brain regions involved, use of ROI analysis and statistical analysis, emphasizing on the connectivity estimation model used in each investigation. The present analysis allowed us to confirm the remarkable variability of the statistical analysis methods found. Additionally, the study of brain connectivity in this type of population is not providing, at the moment, any significant information or results related to clinical aspects relevant for prediction and treatment. We propose to follow guidelines for publishing fMRI data that would be a good solution to the problem of study replication. The latter aspect could be important for future publications because a higher homogeneity would benefit the comparison between publications and the generalization of results. PMID:26300802

  8. Functional MRI for characterization of renal perfusion impairment and edema formation due to acute kidney injury in different mouse strains.

    Science.gov (United States)

    Tewes, Susanne; Gueler, Faikah; Chen, Rongjun; Gutberlet, Marcel; Jang, Mi-Sun; Meier, Martin; Mengel, Michael; Hartung, Dagmar; Wacker, Frank; Rong, Song; Hueper, Katja

    2017-01-01

    The purpose was to characterize acute kidney injury (AKI) in C57BL/6 (B6)- and 129/Sv (Sv)-mice by noninvasive measurement of renal perfusion and tissue edema using functional MRI. Different severities of AKI were induced in B6- and Sv-mice by renal ischemia reperfusion injury (IRI). Unilateral clamping of the renal pedicle for 35 min (moderate AKI) or 45 min (severe AKI) was done. MRI (7-Tesla) was performed 1, 7 and 28 days after surgery using a flow alternating inversion recovery (FAIR) arterial spin labeling (ASL) sequence. Maps of perfusion and T1-relaxation time were calculated. Relative MRI-parameters of the IRI kidney compared to the contralateral not-clipped kidney were compared between AKI severities and between mouse strains using unpaired t-tests. In addition, fibrosis was assessed by Masson Trichrome and collagen IV staining. After moderate AKI relative perfusion impairment was significantly higher in B6- than in Sv-mice at d7 (55±7% vs. 82±8%, prenal cortex and outer stripe of outer medulla. Kidney volume loss (compared to the contralateral kidney) occurred already after 7 days but proceeded markedly towards 4 weeks in severe AKI. Early renal perfusion impairment was predictive for later kidney volume loss. The progression to chronic kidney disease (CKD) in the severe AKI model was similar in both mouse strains as revealed by histology. Quantification of renal perfusion and tissue edema by functional MRI allows characterization of strain differences upon AKI. Renal perfusion impairment was stronger in B6- compared to Sv-animals following moderate AKI. Prolonged ischemia times were associated with more severe perfusion impairment and edema formation in the early phase and progression to CKD within 4 weeks of observation.

  9. Portable MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  10. Portable MRI

    International Nuclear Information System (INIS)

    Espy, Michelle A.

    2012-01-01

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  11. Assessment of left ventricular function with single breath-hold highly accelerated cine MRI combined with guide-point modeling

    International Nuclear Information System (INIS)

    Heilmaier, Christina; Nassenstein, Kai; Nielles-Vallespin, Sonia; Zuehlsdorff, Sven; Hunold, Peter; Barkhausen, Joerg

    2010-01-01

    Purpose: To prospectively assess the performance of highly accelerated cine MRI in multi-orientations combined with a new guide-point modeling post-processing technique (GPM approach) for assessment of left ventricular (LV) function compared to the standard summation of slices method based on a stack of short axis views (SoS approach). Materials and methods: 33 consecutive patients were examined on a 1.5 T scanner with a standard steady state free precession (SSFP) sequence (TR, 3.0 ms; TE, 1.5 m; flip angle (FA), 60 o ; acceleration factor (AF), 2) analyzed with the SoS method and a highly accelerated, single breath-hold temporal parallel acquisition SSFP sequence (TR, 4.6 ms; TE, 1.1 ms; AF, 3) post-processed with the GPM method. LV function values were measured by two independent readers with different experience in cardiac MRI and compared by using the paired t-test and F-test. Inter- and intraobserver agreements were calculated using Bland-Altman-Plots. Results: Mean acquisition and post-processing time was significantly shorter with the GPM approach (15 s/3 min versus 360 s/6 min). For all LV function parameters interobserver agreement between the experienced and non-experienced reader was significantly improved when the GPM approach was used. However, end-diastolic and end-systolic volumes were larger for the GPM technique when compared to the SoS method (P 0.121). In both readers and for all parameters variances did not differ significantly (P ≥ 0.409) and the two approaches showed an excellent linear correlation (r > 0.951). Conclusion: Due to its accurate, fast and reproducible assessment of LV function parameters highly accelerated MRI combined with the GPM technique may become the technique of first choice for assessment of LV function in clinical routine.

  12. Local vascular CO2 reactivity in the infant brain assessed by functional MRI

    DEFF Research Database (Denmark)

    Toft, P.B.; Leth, H; Lou, H.C.

    1995-01-01

    The local cerebral vascular response to hyperventilation was investigated in five distressed, intubated infants by means of a T2 sensitive gradient-echo MRI technique at 1.5 T. In one preterm infant, the MR signal change during hyperventilation was sparse. In four term infants, the mean MR signal...

  13. Detection of Brain Reorganization in Pediatric Multiple Sclerosis Using Functional MRI

    Science.gov (United States)

    2014-10-01

    data by the implementation of custom software and novel techniques Funding Support: No change Name: John Hussey Project Role: Research Assistant...Neumann,K.,Euler,H.A.,vonGudenberg,A.W.,Gall, V., et al. (2003). Event related fMRI for the suppression of speech-associated artifacts in stuttering

  14. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI

    NARCIS (Netherlands)

    Motaal, Abdallah G.; Noorman, Nils; de Graaf, Wolter L.; Hoerr, Verena; Florack, Luc M. J.; Nicolay, Klaas; Strijkers, Gustav J.

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously

  15. Phase-based vascular input function: Improved quantitative DCE-MRI of atherosclerotic plaques

    NARCIS (Netherlands)

    van Hoof, R. H. M.; Hermeling, E.; Truijman, M. T. B.; van Oostenbrugge, R. J.; Daemen, J. W. H.; van der Geest, R. J.; van Orshoven, N. P.; Schreuder, A. H.; Backes, W. H.; Daemen, M. J. A. P.; Wildberger, J. E.; Kooi, M. E.

    2015-01-01

    Purpose: Quantitative pharmacokinetic modeling of dynamic contrast-enhanced (DCE)-MRI can be used to assess atherosclerotic plaque microvasculature, which is an important marker of plaque vulnerability. Purpose of the present study was (1) to compare magnitude-versus phase-based vascular input

  16. Review of functional MRI in HIV : effects of aging and medication

    NARCIS (Netherlands)

    Hakkers, C. S.; Arends, J. E.; Barth, R. E.; du Plessis, S.; Hoepelman, A. I M; Vink, M.

    HIV-associated neurocognitive disorder (HAND) is a frequently occurring comorbidity of HIV infection. Evidence suggests this condition starts subclinical before a progression to a symptomatic stage. Blood oxygenated level dependent (BOLD) fMRI has shown to be a sensitive tool to detect abnormal

  17. Association of Coffee Consumption with MRI Markers and Cognitive Function: A Population-Based Study

    NARCIS (Netherlands)

    L.F. Araújo (Larissa Fortunato); S.S. Mirza (Saira); D. Bos (Daniel); W.J. Niessen (Wiro); S.M. Barreto (Sandhi Maria); A. van der Lugt (Aad); M.W. Vernooij (Meike); A. Hofman (Albert); H.W. Tiemeier (Henning); M.A. Ikram (Arfan); Polidori, M.C. (M. Cristina)

    2016-01-01

    textabstractBackground: Coffee is one of the most widely consumed beverages worldwide and has been of considerable interest in research on cognition and dementia. Objective: To investigate the effect of coffee on preclinical brain MRI markers of dementia and cognitive performance. Methods: In 2,914

  18. Global Functional Connectivity Differences between Sleep-Like States in Urethane Anesthetized Rats Measured by fMRI.

    Directory of Open Access Journals (Sweden)

    Ekaterina Zhurakovskaya

    Full Text Available Sleep is essential for nervous system functioning and sleep disorders are associated with several neurodegenerative diseases. However, the macroscale connectivity changes in brain networking during different sleep states are poorly understood. One of the hindering factors is the difficulty to combine functional connectivity investigation methods with spontaneously sleeping animals, which prevents the use of numerous preclinical animal models. Recent studies, however, have implicated that urethane anesthesia can uniquely induce different sleep-like brain states, resembling rapid eye movement (REM and non-REM (NREM sleep, in rodents. Therefore, the aim of this study was to assess changes in global connectivity and topology between sleep-like states in urethane anesthetized rats, using blood oxygenation level dependent (BOLD functional magnetic resonance imaging. We detected significant changes in corticocortical (increased in NREM-like state and corticothalamic connectivity (increased in REM-like state. Additionally, in graph analysis the modularity, the measure of functional integration in the brain, was higher in NREM-like state than in REM-like state, indicating a decrease in arousal level, as in normal sleep. The fMRI findings were supported by the supplementary electrophysiological measurements. Taken together, our results show that macroscale functional connectivity changes between sleep states can be detected robustly with resting-state fMRI in urethane anesthetized rats. Our findings pave the way for studies in animal models of neurodegenerative diseases where sleep abnormalities are often one of the first markers for the disorder development.

  19. Functional connectivity associated with social networks in older adults: A resting-state fMRI study.

    Science.gov (United States)

    Pillemer, Sarah; Holtzer, Roee; Blumen, Helena M

    2017-06-01

    Poor social networks and decreased levels of social support are associated with worse mood, health, and cognition in younger and older adults. Yet, we know very little about the brain substrates associated with social networks and social support, particularly in older adults. This study examined functional brain substrates associated with social networks using the Social Network Index (SNI) and resting-state functional magnetic resonance imaging (fMRI). Resting-state fMRI data from 28 non-demented older adults were analyzed with independent components analyses. As expected, four established resting-state networks-previously linked to motor, vision, speech, and other language functions-correlated with the quality (SNI-1: total number of high-contact roles of a respondent) and quantity (SNI-2: total number of individuals in a respondent's social network) of social networks: a sensorimotor, a visual, a vestibular/insular, and a left frontoparietal network. Moreover, SNI-1 was associated with greater functional connectivity in the lateral prefrontal regions of the left frontoparietal network, while SNI-2 was associated with greater functional connectivity in the medial prefrontal regions of this network. Thus, lateral prefrontal regions may be particularly linked to the quality of social networks while medial prefrontal regions may be particularly linked to the quantity of social networks.

  20. Fully automated calculation of image-derived input function in simultaneous PET/MRI in a sheep model

    Energy Technology Data Exchange (ETDEWEB)

    Jochimsen, Thies H.; Zeisig, Vilia [Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig (Germany); Schulz, Jessica [Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, Leipzig, D-04103 (Germany); Werner, Peter; Patt, Marianne; Patt, Jörg [Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig (Germany); Dreyer, Antje Y. [Fraunhofer Institute of Cell Therapy and Immunology, Perlickstr. 1, Leipzig, D-04103 (Germany); Translational Centre for Regenerative Medicine, University Leipzig, Philipp-Rosenthal-Str. 55, Leipzig, D-04103 (Germany); Boltze, Johannes [Fraunhofer Institute of Cell Therapy and Immunology, Perlickstr. 1, Leipzig, D-04103 (Germany); Translational Centre for Regenerative Medicine, University Leipzig, Philipp-Rosenthal-Str. 55, Leipzig, D-04103 (Germany); Fraunhofer Research Institution of Marine Biotechnology and Institute for Medical and Marine Biotechnology, University of Lübeck, Lübeck (Germany); Barthel, Henryk; Sabri, Osama; Sattler, Bernhard [Department of Nuclear Medicine, Leipzig University Hospital, Liebigstr. 18, Leipzig (Germany)

    2016-02-13

    Obtaining the arterial input function (AIF) from image data in dynamic positron emission tomography (PET) examinations is a non-invasive alternative to arterial blood sampling. In simultaneous PET/magnetic resonance imaging (PET/MRI), high-resolution MRI angiographies can be used to define major arteries for correction of partial-volume effects (PVE) and point spread function (PSF) response in the PET data. The present study describes a fully automated method to obtain the image-derived input function (IDIF) in PET/MRI. Results are compared to those obtained by arterial blood sampling. To segment the trunk of the major arteries in the neck, a high-resolution time-of-flight MRI angiography was postprocessed by a vessel-enhancement filter based on the inertia tensor. Together with the measured PSF of the PET subsystem, the arterial mask was used for geometrical deconvolution, yielding the time-resolved activity concentration averaged over a major artery. The method was compared to manual arterial blood sampling at the hind leg of 21 sheep (animal stroke model) during measurement of blood flow with O15-water. Absolute quantification of activity concentration was compared after bolus passage during steady state, i.e., between 2.5- and 5-min post injection. Cerebral blood flow (CBF) values from blood sampling and IDIF were also compared. The cross-calibration factor obtained by comparing activity concentrations in blood samples and IDIF during steady state is 0.98 ± 0.10. In all examinations, the IDIF provided a much earlier and sharper bolus peak than in the time course of activity concentration obtained by arterial blood sampling. CBF using the IDIF was 22 % higher than CBF obtained by using the AIF yielded by blood sampling. The small deviation between arterial blood sampling and IDIF during steady state indicates that correction of PVE and PSF is possible with the method presented. The differences in bolus dynamics and, hence, CBF values can be explained by the

  1. A semiquantitative MRI-Score can predict loss of lung function in patients with cystic fibrosis: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Juergen F.; Schmidt, Katharina; Teufel, Matthias; Fleischer, Sabrina; Gatidis, Sergios; Schaefer, Susanne; Nikolaou, Konstantin; Tsiflikas, Ilias [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Hector, Andreas; Graepler-Mainka, Ute; Riethmueller, Joachim; Hartl, Dominik [University Children' s Hospital of Tuebingen, Department of Paediatrics I, Tuebingen (Germany)

    2018-01-15

    To evaluate the applicability of a semiquantitative MRI scoring system (MR-CF-S) as a prognostic marker for clinical course of cystic fibrosis (CF) lung disease. This observational study of a single-centre CF cohort included a group of 61 patients (mean age 12.9 ± 4.7 years) receiving morphological and functional pulmonary MRI, pulmonary function testing (PFT) and follow-up of 2 years. MRI was analysed by three raters using MR-CF-S. The inter-rater agreement, correlation of score categories with forced expiratory volume in 1 s (FEV{sub 1}) at baseline, and the predictive value of clinical parameters, and score categories was assessed for the whole cohort and a subgroup of 40 patients with moderately impaired lung function. The inter-rater agreement of MR-CF-S was sufficient (mean intraclass correlation coefficient 0.92). MR-CF-S (-0.62; p < 0.05) and most of the categories significantly correlated with FEV{sub 1}. Differences between patients with relevant loss of FEV{sub 1}