WorldWideScience

Sample records for volumetric neuroimage analysis

  1. Quantitative Techniques in Volumetric Analysis

    Science.gov (United States)

    Zimmerman, John; Jacobsen, Jerrold J.

    1996-12-01

    Quantitative Techniques in Volumetric Analysis is a visual library of techniques used in making volumetric measurements. This 40-minute VHS videotape is designed as a resource for introducing students to proper volumetric methods and procedures. The entire tape, or relevant segments of the tape, can also be used to review procedures used in subsequent experiments that rely on the traditional art of quantitative analysis laboratory practice. The techniques included are: Quantitative transfer of a solid with a weighing spoon Quantitative transfer of a solid with a finger held weighing bottle Quantitative transfer of a solid with a paper strap held bottle Quantitative transfer of a solid with a spatula Examples of common quantitative weighing errors Quantitative transfer of a solid from dish to beaker to volumetric flask Quantitative transfer of a solid from dish to volumetric flask Volumetric transfer pipet A complete acid-base titration Hand technique variations The conventional view of contemporary quantitative chemical measurement tends to focus on instrumental systems, computers, and robotics. In this view, the analyst is relegated to placing standards and samples on a tray. A robotic arm delivers a sample to the analysis center, while a computer controls the analysis conditions and records the results. In spite of this, it is rare to find an analysis process that does not rely on some aspect of more traditional quantitative analysis techniques, such as careful dilution to the mark of a volumetric flask. Figure 2. Transfer of a solid with a spatula. Clearly, errors in a classical step will affect the quality of the final analysis. Because of this, it is still important for students to master the key elements of the traditional art of quantitative chemical analysis laboratory practice. Some aspects of chemical analysis, like careful rinsing to insure quantitative transfer, are often an automated part of an instrumental process that must be understood by the

  2. Workflow-based approaches to neuroimaging analysis.

    Science.gov (United States)

    Fissell, Kate

    2007-01-01

    Analysis of functional and structural magnetic resonance imaging (MRI) brain images requires a complex sequence of data processing steps to proceed from raw image data to the final statistical tests. Neuroimaging researchers have begun to apply workflow-based computing techniques to automate data analysis tasks. This chapter discusses eight major components of workflow management systems (WFMSs): the workflow description language, editor, task modules, data access, verification, client, engine, and provenance, and their implementation in the Fiswidgets neuroimaging workflow system. Neuroinformatics challenges involved in applying workflow techniques in the domain of neuroimaging are discussed.

  3. Online open neuroimaging mass meta-analysis

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Kempton, Matthew J.; Williams, Steven C. R.

    We describe a system for meta-analysis where a wiki stores numerical data in a simple format and a web service performs the numerical computation. We initially apply the system on multiple meta-analyses of structural neuroimaging data results. The described system allows for mass meta-analysis, e...

  4. Energy landscape analysis of neuroimaging data

    CERN Document Server

    Ezaki, Takahiro; Ohzeki, Masayuki; Masuda, Naoki

    2016-01-01

    Computational neuroscience models have been used for understanding neural dynamics in the brain and how they may be altered when physiological or other conditions change. We review and develop a data-driven approach to neuroimaging data called the energy landscape analysis. The methods are rooted in statistical physics theory, in particular, the Ising model, also known as the (pairwise) maximum entropy model and Boltzmann machine. The methods have been applied to fitting electrophysiological data in neuroscience for a decade, but its use in neuroimaging data is still in its infancy. We first review the methods and discuss some algorithms and technical aspects. Then, we apply the methods to functional magnetic resonance imaging data recorded from healthy individuals to inspect the relationship between the accuracy of fitting, the size of the brain system to be analyzed, and the data length.

  5. Energy landscape analysis of neuroimaging data

    Science.gov (United States)

    Ezaki, Takahiro; Watanabe, Takamitsu; Ohzeki, Masayuki; Masuda, Naoki

    2017-05-01

    Computational neuroscience models have been used for understanding neural dynamics in the brain and how they may be altered when physiological or other conditions change. We review and develop a data-driven approach to neuroimaging data called the energy landscape analysis. The methods are rooted in statistical physics theory, in particular the Ising model, also known as the (pairwise) maximum entropy model and Boltzmann machine. The methods have been applied to fitting electrophysiological data in neuroscience for a decade, but their use in neuroimaging data is still in its infancy. We first review the methods and discuss some algorithms and technical aspects. Then, we apply the methods to functional magnetic resonance imaging data recorded from healthy individuals to inspect the relationship between the accuracy of fitting, the size of the brain system to be analysed and the data length. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

  6. [Neuroimaging in psychiatry: multivariate analysis techniques for diagnosis and prognosis].

    Science.gov (United States)

    Kambeitz, J; Koutsouleris, N

    2014-06-01

    Multiple studies successfully applied multivariate analysis to neuroimaging data demonstrating the potential utility of neuroimaging for clinical diagnostic and prognostic purposes. Summary of the current state of research regarding the application of neuroimaging in the field of psychiatry. Literature review of current studies. Results of current studies indicate the potential application of neuroimaging data across various diagnoses, such as depression, schizophrenia, bipolar disorder and dementia. Potential applications include disease classification, differential diagnosis and prediction of disease course. The results of the studies are heterogeneous although some studies report promising findings. Further multicentre studies are needed with clearly specified patient populations to systematically investigate the potential utility of neuroimaging for the clinical routine.

  7. LSTGEE: longitudinal analysis of neuroimaging data

    Science.gov (United States)

    Li, Yimei; Zhu, Hongtu; Chen, Yasheng; An, Hongyu; Gilmore, John; Lin, Weili; Shen, Dinggang

    2009-02-01

    Longitudinal imaging studies are essential to understanding the neural development of neuropsychiatric disorders, substance use disorders, and normal brain. Using appropriate image processing and statistical tools to analyze the imaging, behavioral, and clinical data is critical for optimally exploring and interpreting the findings from those imaging studies. However, the existing imaging processing and statistical methods for analyzing imaging longitudinal measures are primarily developed for cross-sectional neuroimaging studies. The simple use of these cross-sectional tools to longitudinal imaging studies will significantly decrease the statistical power of longitudinal studies in detecting subtle changes of imaging measures and the causal role of time-dependent covariate in disease process. The main objective of this paper is to develop longitudinal statistics toolbox, called LSTGEE, for the analysis of neuroimaging data from longitudinal studies. We develop generalized estimating equations for jointly modeling imaging measures with behavioral and clinical variables from longitudinal studies. We develop a test procedure based on a score test statistic and a resampling method to test linear hypotheses of unknown parameters, such as associations between brain structure and function and covariates of interest, such as IQ, age, gene, diagnostic groups, and severity of disease. We demonstrate the application of our statistical methods to the detection of the changes of the fractional anisotropy across time in a longitudinal neonate study. Particularly, our results demonstrate that the use of longitudinal statistics can dramatically increase the statistical power in detecting the changes of neuroimaging measures. The proposed approach can be applied to longitudinal data with multiple outcomes and accommodate incomplete and unbalanced data, i.e., subjects with different number of measurements.

  8. Basics of Multivariate Analysis in Neuroimaging Data

    Science.gov (United States)

    Habeck, Christian Georg

    2010-01-01

    Multivariate analysis techniques for neuroimaging data have recently received increasing attention as they have many attractive features that cannot be easily realized by the more commonly used univariate, voxel-wise, techniques1,5,6,7,8,9. Multivariate approaches evaluate correlation/covariance of activation across brain regions, rather than proceeding on a voxel-by-voxel basis. Thus, their results can be more easily interpreted as a signature of neural networks. Univariate approaches, on the other hand, cannot directly address interregional correlation in the brain. Multivariate approaches can also result in greater statistical power when compared with univariate techniques, which are forced to employ very stringent corrections for voxel-wise multiple comparisons. Further, multivariate techniques also lend themselves much better to prospective application of results from the analysis of one dataset to entirely new datasets. Multivariate techniques are thus well placed to provide information about mean differences and correlations with behavior, similarly to univariate approaches, with potentially greater statistical power and better reproducibility checks. In contrast to these advantages is the high barrier of entry to the use of multivariate approaches, preventing more widespread application in the community. To the neuroscientist becoming familiar with multivariate analysis techniques, an initial survey of the field might present a bewildering variety of approaches that, although algorithmically similar, are presented with different emphases, typically by people with mathematics backgrounds. We believe that multivariate analysis techniques have sufficient potential to warrant better dissemination. Researchers should be able to employ them in an informed and accessible manner. The current article is an attempt at a didactic introduction of multivariate techniques for the novice. A conceptual introduction is followed with a very simple application to a diagnostic

  9. Volumetric Parcellation Methodology of the Human Hypothalamus in Neuroimaging: Normative Data and Sex Differences

    Science.gov (United States)

    Makris, Nikos; Swaab, Dick F.; van der Kouwe, Andre; Abbs, Brandon; Boriel, Denise; Handa, Robert; Tobet, Stuart; Goldstein, Jill M.

    2013-01-01

    There is increasing evidence regarding the importance of the hypothalamus for understanding sex differences in relation to neurological, psychiatric, endocrine and sleep disorders. Although different in histology, physiology, connections and function, multiple hypothalamic nuclei subserve non-voluntary functions and are nodal points for the purpose of maintaining homeostasis of the organism. Thus, given the critical importance of hypothalamic nuclei and their key multiple roles in regulating basic functions, it is important to develop the ability to conduct in vivo human studies of anatomic structure, volume, connectivity, and function of hypothalamic regions represented at the level of its nuclei. The goals of the present study were to develop a novel method of semi-automated volumetric parcellation for the human hypothalamus that could be used to investigate clinical conditions using MRI and to demonstrate its applicability. The proposed new method subdivides the hypothalamus into five parcels based on visible anatomic landmarks associated with specific nuclear groupings and was confirmed using two ex vivo hypothalami that were imaged in a 7 Tesla (7T) scanner and processed histologically. Imaging results were compared with histology from the same brain. Further, the method was applied to 44 healthy adults (26 men; 18 women, comparable on age, handedness, ethnicity, SES) to derive normative volumes and assess sex differences in hypothalamic regions using 1.5 Tesla MRI. Men compared to women had a significantly larger total hypothalamus, relative to cerebrum size, similar for both hemispheres, a difference that was primarily driven by the tuberal region, with the sex effect size being largest in the superior tuberal region and, to a lesser extent, inferior tuberal region. Given the critical role of hypothalamic nuclei in multiple chronic diseases and the importance of sex differences, we argue that the use of the novel methodology presented here will allow for

  10. Cortical thickness and brain volumetric analysis in body dysmorphic disorder.

    Science.gov (United States)

    Madsen, Sarah K; Zai, Alex; Pirnia, Tara; Arienzo, Donatello; Zhan, Liang; Moody, Teena D; Thompson, Paul M; Feusner, Jamie D

    2015-04-30

    Individuals with body dysmorphic disorder (BDD) suffer from preoccupations with perceived defects in physical appearance, causing severe distress and disability. Although BDD affects 1-2% of the population, the neurobiology is not understood. Discrepant results in previous volumetric studies may be due to small sample sizes, and no study has investigated cortical thickness in BDD. The current study is the largest neuroimaging analysis of BDD. Participants included 49 medication-free, right-handed individuals with DSM-IV BDD and 44 healthy controls matched by age, sex, and education. Using high-resolution T1-weighted magnetic resonance imaging, we computed vertex-wise gray matter (GM) thickness on the cortical surface and GM volume using voxel-based morphometry. We also computed volumes in cortical and subcortical regions of interest. In addition to group comparisons, we investigated associations with symptom severity, insight, and anxiety within the BDD group. In BDD, greater anxiety was significantly associated with thinner GM in the left superior temporal cortex and greater GM volume in the right caudate nucleus. There were no significant differences in cortical thickness, GM volume, or volumes in regions of interest between BDD and control subjects. Subtle associations with clinical symptoms may characterize brain morphometric patterns in BDD, rather than large group differences in brain structure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Online Open Neuroimaging Mass Meta-Analysis with a Wiki

    DEFF Research Database (Denmark)

    Nielsen, Finn Arup; Kempton, Matthew J.; Williams, Steven C. R.

    2015-01-01

    We describe a system for meta-analysis where a wiki stores numerical data in a simple comma-separated values format and a web service performs the numerical statistical computation. We initially apply the system on multiple meta-analyses of structural neuroimaging data results. The described system...

  12. Detecting Neuroimaging Biomarkers for Depression: A Meta-analysis of Multivariate Pattern Recognition Studies.

    Science.gov (United States)

    Kambeitz, Joseph; Cabral, Carlos; Sacchet, Matthew D; Gotlib, Ian H; Zahn, Roland; Serpa, Mauricio H; Walter, Martin; Falkai, Peter; Koutsouleris, Nikolaos

    2017-09-01

    Multiple studies have examined functional and structural brain alteration in patients diagnosed with major depressive disorder (MDD). The introduction of multivariate statistical methods allows investigators to utilize data concerning these brain alterations to generate diagnostic models that accurately differentiate patients with MDD from healthy control subjects (HCs). However, there is substantial heterogeneity in the reported results, the methodological approaches, and the clinical characteristics of participants in these studies. We conducted a meta-analysis of all studies using neuroimaging (volumetric measures derived from T1-weighted images, task-based functional magnetic resonance imaging [MRI], resting-state MRI, or diffusion tensor imaging) in combination with multivariate statistical methods to differentiate patients diagnosed with MDD from HCs. Thirty-three (k = 33) samples including 912 patients with MDD and 894 HCs were included in the meta-analysis. Across all studies, patients with MDD were separated from HCs with 77% sensitivity and 78% specificity. Classification based on resting-state MRI (85% sensitivity, 83% specificity) and on diffusion tensor imaging data (88% sensitivity, 92% specificity) outperformed classifications based on structural MRI (70% sensitivity, 71% specificity) and task-based functional MRI (74% sensitivity, 77% specificity). Our results demonstrate the high representational capacity of multivariate statistical methods to identify neuroimaging-based biomarkers of depression. Future studies are needed to elucidate whether multivariate neuroimaging analysis has the potential to generate clinically useful tools for the differential diagnosis of affective disorders and the prediction of both treatment response and functional outcome. Copyright © 2016 Society of Biological Psychiatry. All rights reserved.

  13. The RUMBA software: tools for neuroimaging data analysis.

    Science.gov (United States)

    Bly, Benjamin Martin; Rebbechi, Donovan; Hanson, Stephen Jose; Grasso, Giorgio

    2004-01-01

    The enormous scale and complexity of data sets in functional neuroimaging makes it crucial to have well-designed and flexible software for image processing, modeling, and statistical analysis. At present, researchers must choose between general purpose scientific computing environments (e.g., Splus and Matlab), and specialized human brain mapping packages that implement particular analysis strategies (e.g., AFNI, SPM, VoxBo, FSL or FIASCO). For the vast majority of users in Human Brain Mapping and Cognitive Neuroscience, general purpose computing environments provide an insufficient framework for a complex data-analysis regime. On the other hand, the operational particulars of more specialized neuroimaging analysis packages are difficult or impossible to modify and provide little transparency or flexibility to the user for approaches other than massively multiple comparisons based on inferential statistics derived from linear models. In order to address these problems, we have developed open-source software that allows a wide array of data analysis procedures. The RUMBA software includes programming tools that simplify the development of novel methods, and accommodates data in several standard image formats. A scripting interface, along with programming libraries, defines a number of useful analytic procedures, and provides an interface to data analysis procedures. The software also supports a graphical functional programming environment for implementing data analysis streams based on modular functional components. With these features, the RUMBA software provides researchers programmability, reusability, modular analysis tools, novel data analysis streams, and an analysis environment in which multiple approaches can be contrasted and compared. The RUMBA software retains the flexibility of general scientific computing environments while adding a framework in which both experts and novices can develop and adapt neuroimaging-specific analyses.

  14. Cross-View Neuroimage Pattern Analysis for Alzheimer's Disease Staging

    Directory of Open Access Journals (Sweden)

    Sidong eLiu

    2016-02-01

    Full Text Available The research on staging of pre-symptomatic and prodromal phase of neurological disorders, e.g., Alzheimer's disease (AD, is essential for prevention of dementia. New strategies for AD staging with a focus on early detection, are demanded to optimize potential efficacy of disease-modifying therapies that can halt or slow the disease progression. Recently, neuroimaging are increasingly used as additional research-based markers to detect AD onset and predict conversion of MCI and normal control (NC to AD. Researchers have proposed a variety of neuroimaging biomarkers to characterize the patterns of the pathology of AD and MCI, and suggested that multi-view neuroimaging biomarkers could lead to better performance than single-view biomarkers in AD staging. However, it is still unclear what leads to such synergy and how to preserve or maximize. In an attempt to answer these questions, we proposed a cross-view pattern analysis framework for investigating the synergy between different neuroimaging biomarkers. We quantitatively analyzed 9 types of biomarkers derived from FDG-PET and T1-MRI, and evaluated their performance in a task of classifying AD, MCI and NC subjects obtained from the ADNI baseline cohort. The experiment results showed that these biomarkers could depict the pathology of AD from different perspectives, and output distinct patterns that are significantly associated with the disease progression. Most importantly, we found that these features could be separated into clusters, each depicting a particular aspect; and the inter-cluster features could always achieve better performance than the intra-cluster features in AD staging.

  15. Neuroimaging diagnosis for cerebral infarction An 8-year bibliometric analysis

    Institute of Scientific and Technical Information of China (English)

    Yan Du; Xiaoxia Yang; Hong Song; Bo Chen; Lin Li; Yue Pan; Qiong Wu; Jia Li

    2012-01-01

    OBJECTIVE:To identify global research trends in neuroimaging diagnosis for cerebral infarction using a bibliometric analysis of the Web of Science.DATA RETRIEVAL:We performed a bibliometric analysis of data retrieval for neuroimaging diagnosis for cerebral infarction containing the key words "CT,magnetic resonance imaging,MRI,transcranial Doppler,transvaginal color Doppler,digital subtraction angiography,and cerebral infarction" using the Web of Science.SELECTION CRITERIA:Inclusion criteria were:(a) peer-reviewed articles on neuroimaging diagnosis for cerebral infarction which were published and indexed in the Web of Science; (b) original research articles and reviews; and (c) publication between 2004-2011.Exclusion criteria were:(a) articles that required manual searching or telephone access; and (b) corrected papers or book chapters.MAIN OUTCOME MEASURES:(1)Annual publication output; (2) distribution according to country;(3) distribution according to institution; (4) top cited publications; (5) distribution according to journals; and (6) comparison of study results on neuroimaging diagnosis for cerebral infarction.RESULTS:Imaging has become the predominant method used in diagnosing cerebral infarction.The most frequently used clinical imaging methods were digital subtraction angiography,CT,MRI,and transcranial color Doppler examination.Digital subtraction angiography is used as the gold standard.However,it is a costly and time-consuming invasive diagnosis that requires some radiation exposure,and is poorly accepted by patients.As such,it is mostly adopted in interventional therapy in the clinic.CT is now accepted as a rapid,simple,and reliable non-invasive method for use in diagnosis of cerebrovascular disease and preoperative appraisal.Ultrasonic Doppler can be used to reflect the hardness of the vascular wall and the nature of the plaque more clearly than CT and MRI.CONCLUSION:At present,there is no unified standard of classification of cerebral infarction

  16. Brain volumetric and metabolic correlates of electroconvulsive therapy for treatment-resistant depression: a longitudinal neuroimaging study

    Science.gov (United States)

    Cano, M; Martínez-Zalacaín, I; Bernabéu-Sanz, Á; Contreras-Rodríguez, O; Hernández-Ribas, R; Via, E; de Arriba-Arnau, A; Gálvez, V; Urretavizcaya, M; Pujol, J; Menchón, J M; Cardoner, N; Soriano-Mas, C

    2017-01-01

    Recent research suggests that neuroplastic and neuroinflammatory changes may account for the mode of action of electroconvulsive therapy (ECT), although extant data do not allow for a clear disambiguation between these two hypotheses. Multimodal neuroimaging approaches (for example, combining structural and metabolic information) may help in clarifying this issue. Here we aimed to assess longitudinal changes in (i) regional gray matter (GM) volumes and (ii) hippocampal metabolite concentrations throughout an acute course of bitemporal ECT, as well as (iii) to determine the association between imaging changes and clinical improvement. We assessed 12 patients with treatment-resistant depression (TRD) at four time points (pre-treatment, after the first ECT session, after the ninth ECT session and 15 days after ECT course completion) and 10 healthy participants at two time points, 5 weeks apart. Patients with TRD showed bilateral medial temporal lobe (MTL) and perigenual anterior cingulate cortex volume increases. Left MTL volume increase was associated with (i) a hippocampal N-acetylaspartate concentration decrease, (ii) a hippocampal Glutamate+Glutamine concentration increase and (iii) significant clinical improvement. The observed findings are, in part, compatible with both neuroplastic and neuroinflammatory changes induced by ECT. We postulate that such phenomena may be interrelated, therefore reconciling the neuroplasticity and neuroinflammatory hypotheses of ECT action. PMID:28170003

  17. Volumetric measurements of pulmonary nodules: variability in automated analysis tools

    Science.gov (United States)

    Juluru, Krishna; Kim, Woojin; Boonn, William; King, Tara; Siddiqui, Khan; Siegel, Eliot

    2007-03-01

    Over the past decade, several computerized tools have been developed for detection of lung nodules and for providing volumetric analysis. Incidentally detected lung nodules have traditionally been followed over time by measurements of their axial dimensions on CT scans to ensure stability or document progression. A recently published article by the Fleischner Society offers guidelines on the management of incidentally detected nodules based on size criteria. For this reason, differences in measurements obtained by automated tools from various vendors may have significant implications on management, yet the degree of variability in these measurements is not well understood. The goal of this study is to quantify the differences in nodule maximum diameter and volume among different automated analysis software. Using a dataset of lung scans obtained with both "ultra-low" and conventional doses, we identified a subset of nodules in each of five size-based categories. Using automated analysis tools provided by three different vendors, we obtained size and volumetric measurements on these nodules, and compared these data using descriptive as well as ANOVA and t-test analysis. Results showed significant differences in nodule maximum diameter measurements among the various automated lung nodule analysis tools but no significant differences in nodule volume measurements. These data suggest that when using automated commercial software, volume measurements may be a more reliable marker of tumor progression than maximum diameter. The data also suggest that volumetric nodule measurements may be relatively reproducible among various commercial workstations, in contrast to the variability documented when performing human mark-ups, as is seen in the LIDC (lung imaging database consortium) study.

  18. CoSMoMVPA: multi-modal multivariate pattern analysis of neuroimaging datain Matlab / GNU Octave

    Directory of Open Access Journals (Sweden)

    Nikolaas N Oosterhof

    2016-07-01

    Full Text Available Recent years have seen an increase in the popularity of multivariate pattern (MVP analysis of functional magnetic resonance (fMRI data, and, to a much lesser extent, magneto- and electro-encephalography (M/EEG data. We present CoSMoMVPA, a lightweight MVPA (MVP analysis toolbox implemented in the intersection of the Matlab and GNU Octave languages, that treats both fMRI and M/EEG data as first-class citizens.CoSMoMVPA supports all state-of-the-art MVP analysis techniques, including searchlight analyses, classification, correlations, representational similarity analysis, and the time generalization method. These can be used to address both data-driven and hypothesis-driven questions about neural organization and representations, both within and across: space, time, frequency bands, neuroimaging modalities, individuals, and species.It uses a uniform data representation of fMRI data in the volume or on the surface, and of M/EEG data at the sensor and source level. Through various external toolboxes, it directly supports reading and writing a variety of fMRI and M/EEG neuroimaging formats, and, where applicable, can convert between them. As a result, it can be integrated readily in existing pipelines and used with existing preprocessed datasets. CoSMoMVPA overloads the traditional volumetric searchlight concept to support neighborhoods for M/EEG and surface-based fMRI data, which supports localization of multivariate effects of interest across space, time, and frequency dimensions. CoSMoMVPA also provides a generalized approach to multiple comparison correction across these dimensions using Threshold-Free Cluster Enhancement with state-of-the-art clustering and permutation techniques.CoSMoMVPA is highly modular and uses abstractions to provide a uniform interface for a variety of MVP measures. Typical analyses require a few lines of code, making it accessible to beginner users. At the same time, expert programmers can easily extend its functionality

  19. On Statistical Analysis of Neuroimages with Imperfect Registration

    Science.gov (United States)

    Kim, Won Hwa; Ravi, Sathya N.; Johnson, Sterling C.; Okonkwo, Ozioma C.; Singh, Vikas

    2016-01-01

    A variety of studies in neuroscience/neuroimaging seek to perform statistical inference on the acquired brain image scans for diagnosis as well as understanding the pathological manifestation of diseases. To do so, an important first step is to register (or co-register) all of the image data into a common coordinate system. This permits meaningful comparison of the intensities at each voxel across groups (e.g., diseased versus healthy) to evaluate the effects of the disease and/or use machine learning algorithms in a subsequent step. But errors in the underlying registration make this problematic, they either decrease the statistical power or make the follow-up inference tasks less effective/accurate. In this paper, we derive a novel algorithm which offers immunity to local errors in the underlying deformation field obtained from registration procedures. By deriving a deformation invariant representation of the image, the downstream analysis can be made more robust as if one had access to a (hypothetical) far superior registration procedure. Our algorithm is based on recent work on scattering transform. Using this as a starting point, we show how results from harmonic analysis (especially, non-Euclidean wavelets) yields strategies for designing deformation and additive noise invariant representations of large 3-D brain image volumes. We present a set of results on synthetic and real brain images where we achieve robust statistical analysis even in the presence of substantial deformation errors; here, standard analysis procedures significantly under-perform and fail to identify the true signal. PMID:27042168

  20. Volumetric analysis of corticocancellous bones using CT data

    Energy Technology Data Exchange (ETDEWEB)

    Krappinger, Dietmar; Linde, Astrid von; Rosenberger, Ralf; Blauth, Michael [Medical University Innsbruck, Department of Trauma Surgery and Sports Medicine, Innsbruck (Austria); Glodny, Bernhard; Niederwanger, Christian [Medical University Innsbruck, Department of Radiology I, Innsbruck (Austria)

    2012-05-15

    To present a method for an automated volumetric analysis of corticocancellous bones such as the superior pubic ramus using CT data and to assess the reliability of this method. Computed tomography scans of a consecutive series of 250 patients were analyzed. A Hounsfield unit (HU) thresholding-based reconstruction technique (''Vessel Tracking,'' GE Healthcare) was used. A contiguous space of cancellous bone with similar HU values between the starting and end points was automatically identified as the region of interest. The identification was based upon the density gradient to the adjacent cortical bone. The starting point was defined as the middle of the parasymphyseal corticocancellous transition zone on the axial slice showing the parasymphyseal superior pubic ramus in its maximum anteroposterior width. The end point was defined as the middle of the periarticular corticocancellous transition zone on the axial slice showing the quadrilateral plate as a thin cortical plate. The following parameters were automatically obtained on both sides: length of the center line, volume of the superior pubic ramus between the starting point and end point, minimum, maximum and mean diameter perpendicular to the center line, and mean cross-sectional area perpendicular to the center line. An automated analysis without manual adjustments was successful in 207 patients (82.8%). The center line showed a significantly greater length in female patients (67.6 mm vs 65.0 mm). The volume was greater in male patients (21.8 cm{sup 3} vs 19.4 cm{sup 3}). The intersite reliability was high with a mean difference between the left and right sides of between 0.1% (cross-sectional area) and 2.3% (volume). The method presented allows for an automated volumetric analysis of a corticocancellous bone using CT data. The method is intended to provide preoperative information for the use of intramedullary devices in fracture fixation and percutaneous cement augmentation techniques

  1. Volumetric and MGMT parameters in glioblastoma patients: Survival analysis

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    Iliadis Georgios

    2012-01-01

    Full Text Available Abstract Background In this study several tumor-related volumes were assessed by means of a computer-based application and a survival analysis was conducted to evaluate the prognostic significance of pre- and postoperative volumetric data in patients harboring glioblastomas. In addition, MGMT (O6-methylguanine methyltransferase related parameters were compared with those of volumetry in order to observe possible relevance of this molecule in tumor development. Methods We prospectively analyzed 65 patients suffering from glioblastoma (GBM who underwent radiotherapy with concomitant adjuvant temozolomide. For the purpose of volumetry T1 and T2-weighted magnetic resonance (MR sequences were used, acquired both pre- and postoperatively (pre-radiochemotherapy. The volumes measured on preoperative MR images were necrosis, enhancing tumor and edema (including the tumor and on postoperative ones, net-enhancing tumor. Age, sex, performance status (PS and type of operation were also included in the multivariate analysis. MGMT was assessed for promoter methylation with Multiplex Ligation-dependent Probe Amplification (MLPA, for RNA expression with real time PCR, and for protein expression with immunohistochemistry in a total of 44 cases with available histologic material. Results In the multivariate analysis a negative impact was shown for pre-radiochemotherapy net-enhancing tumor on the overall survival (OS (p = 0.023 and for preoperative necrosis on progression-free survival (PFS (p = 0.030. Furthermore, the multivariate analysis confirmed the importance of PS in PFS and OS of patients. MGMT promoter methylation was observed in 13/23 (43.5% evaluable tumors; complete methylation was observed in 3/13 methylated tumors only. High rate of MGMT protein positivity (> 20% positive neoplastic nuclei was inversely associated with pre-operative tumor necrosis (p = 0.021. Conclusions Our findings implicate that volumetric parameters may have a significant role in

  2. An Analysis Methodology for Stochastic Characteristic of Volumetric Error in Multiaxis CNC Machine Tool

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    Qiang Cheng

    2013-01-01

    Full Text Available Traditional approaches about error modeling and analysis of machine tool few consider the probability characteristics of the geometric error and volumetric error systematically. However, the individual geometric error measured at different points is variational and stochastic, and therefore the resultant volumetric error is aslo stochastic and uncertain. In order to address the stochastic characteristic of the volumetric error for multiaxis machine tool, a new probability analysis mathematical model of volumetric error is proposed in this paper. According to multibody system theory, a mean value analysis model for volumetric error is established with consideration of geometric errors. The probability characteristics of geometric errors are obtained by statistical analysis to the measured sample data. Based on probability statistics and stochastic process theory, the variance analysis model of volumetric error is established in matrix, which can avoid the complex mathematics operations during the direct differential. A four-axis horizontal machining center is selected as an illustration example. The analysis results can reveal the stochastic characteristic of volumetric error and are also helpful to make full use of the best workspace to reduce the random uncertainty of the volumetric error and improve the machining accuracy.

  3. Nonlinear Denoising and Analysis of Neuroimages With Kernel Principal Component Analysis and Pre-Image Estimation

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Abrahamsen, Trine Julie; Madsen, Kristoffer Hougaard

    2012-01-01

    We investigate the use of kernel principal component analysis (PCA) and the inverse problem known as pre-image estimation in neuroimaging: i) We explore kernel PCA and pre-image estimation as a means for image denoising as part of the image preprocessing pipeline. Evaluation of the denoising...... base these illustrations on two fMRI BOLD data sets — one from a simple finger tapping experiment and the other from an experiment on object recognition in the ventral temporal lobe....

  4. The 100 most-cited articles in neuroimaging: A bibliometric analysis.

    Science.gov (United States)

    Kim, Hye Jeong; Yoon, Dae Young; Kim, Eun Soo; Lee, Kwanseop; Bae, Jong Seok; Lee, Ju-Hun

    2016-06-18

    The purpose of our study was to identify and characterize the 100 most-cited articles in neuroimaging. Based on the database of Journal Citation Reports, we selected 669 journals that were considered as potential outlets for neuroimaging articles. The Web of Science search tools were used to identify the 100 most-cited articles relevant to neuroimaging within the selected journals. The following information was recorded for each article: publication year, journal, category and impact factor of journal, number of citations, number of annual citations, authorship, department, institution, country, article type, imaging technique used, and topic. The 100 most-cited articles in neuroimaging were published between 1980 and 2012, with 1995-2004 producing 69 articles. Citations ranged from 4384 to 673 and annual citations ranged from 313.1 to 24.9. The majority of articles were published in radiology/imaging journals (n=75), originated in the United States (n=58), were original articles (n=63), used MRI as imaging modality (n=85), and dealt with imaging technique (n=45). The Oxford Centre for Functional Magnetic Resonance Imaging of the Brain at John Radcliffe Hospital (n=10) was the leading institutions and Karl J. Friston (n=11) was the most prolific author. Our study presents a detailed list and an analysis of the 100 most-cited articles in the field of neuroimaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

  5. Analysis of Changing Swarm Rate using Volumetric Strain

    Science.gov (United States)

    Kumazawa, T.; Ogata, Y.; Kimura, K.; Maeda, K.; Kobayashi, A.

    2015-12-01

    Near the eastern coast of Izu peninsula is an active submarine volcanic region in Japan, where magma intrusions have been observed many times. The forecast of earthquake swarm activities and eruptions are serious concern particularly in nearby hot spring resort areas. It is well known that temporal durations of the swarm activities have been correlated with early volumetric strain changes at a certain observation station of about 20 km distance apart. Therefore the Earthquake Research Committee (2010) investigated some empirical statistical relations to predict sizes of the swarm activity. Here we looked at the background seismicity rate changes during these swarm periods using the non-stationary ETAS model (Kumazawa and Ogata, 2013, 2014), and have found the followings. The modified volumetric strain data, by removing the effect of earth tides, precipitation and coseismic jumps, have significantly higher cross-correlations to the estimated background rates of the ETAS model than to the swarm rate-changes. Specifically, the background seismicity rate synchronizes clearer to the strain change by the lags around a half day. These relations suggest an enhanced prediction of earthquakes in this region using volumetric strain measurements. Hence we propose an extended ETAS model where the background rate is modulated by the volumetric strain data. We have also found that the response function to the strain data can be well approximated by an exponential functions with the same decay rate, but that their intersects are inversely proportional to the distances between the volumetric strain-meter and the onset location of the swarm. Our numerical results by the same proposed model show consistent outcomes for the various major swarms in this region.

  6. Understanding the minds of others: A neuroimaging meta-analysis.

    Science.gov (United States)

    Molenberghs, Pascal; Johnson, Halle; Henry, Julie D; Mattingley, Jason B

    2016-06-01

    Theory of mind (ToM) is an important skill that refers broadly to the capacity to understand the mental states of others. A large number of neuroimaging studies have focused on identifying the functional brain regions involved in ToM, but many important questions remain with respect to the neural networks implicated in specific types of ToM tasks. In the present study, we conducted a series of activation likelihood estimation (ALE) meta-analyses on 144 datasets (involving 3150 participants) to address these questions. The ALE results revealed common regions shared across all ToM tasks and broader task parameters, but also some important dissociations. In terms of commonalities, consistent activation was identified in the medial prefrontal cortex and bilateral temporoparietal junction. On the other hand, ALE contrast analyses on our dataset, as well as meta-analytic connectivity modelling (MACM) analyses on the BrainMap database, indicated that different types of ToM tasks reliably elicit activity in unique brain areas. Our findings provide the most accurate picture to date of the neural networks that underpin ToM function.

  7. DIFFERENTIAL ANALYSIS OF VOLUMETRIC STRAINS IN POROUS MATERIALS IN TERMS OF WATER FREEZING

    Directory of Open Access Journals (Sweden)

    Rusin Z.

    2013-06-01

    Full Text Available The paper presents the differential analysis of volumetric strain (DAVS. The method allows measurements of volumetric deformations of capillary-porous materials caused by water-ice phase change. The VSE indicator (volumetric strain effect, which under certain conditions can be interpreted as the minimum degree of phase change of water contained in the material pores, is proposed. The test results (DAVS for three materials with diversified microstructure: clinker brick, calcium-silicate brick and Portland cement mortar were compared with the test results for pore characteristics obtained with the mercury intrusion porosimetry.

  8. Semi-automated volumetric analysis of artificial lymph nodes in a phantom study.

    Science.gov (United States)

    Fabel, M; Biederer, J; Jochens, A; Bornemann, L; Soza, G; Heller, M; Bolte, H

    2011-12-01

    Quantification of tumour burden in oncology requires accurate and reproducible image evaluation. The current standard is one-dimensional measurement (e.g. RECIST) with inherent disadvantages. Volumetric analysis is discussed as an alternative for therapy monitoring of lung and liver metastases. The aim of this study was to investigate the accuracy of semi-automated volumetric analysis of artificial lymph node metastases in a phantom study. Fifty artificial lymph nodes were produced in a size range from 10 to 55mm; some of them enhanced using iodine contrast media. All nodules were placed in an artificial chest phantom (artiCHEST®) within different surrounding tissues. MDCT was performed using different collimations (1-5 mm) at varying reconstruction kernels (B20f, B40f, B60f). Volume and RECIST measurements were performed using Oncology Software (Siemens Healthcare, Forchheim, Germany) and were compared to reference volume and diameter by calculating absolute percentage errors. The software performance allowed a robust volumetric analysis in a phantom setting. Unsatisfying segmentation results were frequently found for native nodules within surrounding muscle. The absolute percentage error (APE) for volumetric analysis varied between 0.01 and 225%. No significant differences were seen between different reconstruction kernels. The most unsatisfactory segmentation results occurred in higher slice thickness (4 and 5 mm). Contrast enhanced lymph nodes showed better segmentation results by trend. The semi-automated 3D-volumetric analysis software tool allows a reliable and convenient segmentation of artificial lymph nodes in a phantom setting. Lymph nodes adjacent to tissue of similar density cause segmentation problems. For volumetric analysis of lymph node metastases in clinical routine a slice thickness of ≤3mm and a medium soft reconstruction kernel (e.g. B40f for Siemens scan systems) may be a suitable compromise for semi-automated volumetric analysis. Copyright

  9. Semi-automated volumetric analysis of lymph node metastases during follow-up--initial results.

    Science.gov (United States)

    Fabel, Michael; Bolte, H; von Tengg-Kobligk, H; Bornemann, L; Dicken, V; Delorme, S; Kauczor, H-U; Heller, M; Biederer, J

    2011-04-01

    Quantification of tumour burden in oncology requires accurate and reproducible evaluation. The current standard is RECIST measurement with its inherent disadvantages. Volumetric analysis is an alternative for therapy monitoring. The aim of this study was to evaluate the feasibility of volumetric analysis of lymph node metastases using a software prototype in a follow-up setting. MSCT was performed in 50 patients covering the chest, abdomen and pelvis. A total of 174 suspicious lymph nodes were evaluated by two radiologists regarding short axis diameters and volumetric analysis using semi-automated software. Quality of segmentation, time, maximum diameter and volume were documented. Variability of the derived change rates was computed as the standard deviation of the difference of the obtained respective change rates. The software performance provides robust volumetric analysis. Quality of segmentation was rated acceptable to excellent in 76-79% by each reader. Mean time spent per lesion was 38 s. The variability of change in effective diameters was 10.6%; for change rates of RECIST maximum diameter variability was 27.5%. Semi-automated volumetric analysis allows fast and convenient segmentation of most lymph node metastases. Compared with RECIST the inter-observer-variability in baseline and follow-up is reduced. This should principally allow subtle changes to be subclassified within the RECIST stable range as minor response [-15% to +10%].

  10. CoSMoMVPA: Multi-Modal Multivariate Pattern Analysis of Neuroimaging Data in Matlab/GNU Octave.

    Science.gov (United States)

    Oosterhof, Nikolaas N; Connolly, Andrew C; Haxby, James V

    2016-01-01

    Recent years have seen an increase in the popularity of multivariate pattern (MVP) analysis of functional magnetic resonance (fMRI) data, and, to a much lesser extent, magneto- and electro-encephalography (M/EEG) data. We present CoSMoMVPA, a lightweight MVPA (MVP analysis) toolbox implemented in the intersection of the Matlab and GNU Octave languages, that treats both fMRI and M/EEG data as first-class citizens. CoSMoMVPA supports all state-of-the-art MVP analysis techniques, including searchlight analyses, classification, correlations, representational similarity analysis, and the time generalization method. These can be used to address both data-driven and hypothesis-driven questions about neural organization and representations, both within and across: space, time, frequency bands, neuroimaging modalities, individuals, and species. It uses a uniform data representation of fMRI data in the volume or on the surface, and of M/EEG data at the sensor and source level. Through various external toolboxes, it directly supports reading and writing a variety of fMRI and M/EEG neuroimaging formats, and, where applicable, can convert between them. As a result, it can be integrated readily in existing pipelines and used with existing preprocessed datasets. CoSMoMVPA overloads the traditional volumetric searchlight concept to support neighborhoods for M/EEG and surface-based fMRI data, which supports localization of multivariate effects of interest across space, time, and frequency dimensions. CoSMoMVPA also provides a generalized approach to multiple comparison correction across these dimensions using Threshold-Free Cluster Enhancement with state-of-the-art clustering and permutation techniques. CoSMoMVPA is highly modular and uses abstractions to provide a uniform interface for a variety of MVP measures. Typical analyses require a few lines of code, making it accessible to beginner users. At the same time, expert programmers can easily extend its functionality. Co

  11. Position Paper: Provenance Data Visualisation for Neuroimaging Analysis

    OpenAIRE

    Arshad, B.; Munir, K.; McClatchey, R.; Liaquat Kiani, S.

    2015-01-01

    Visualisation facilitates the understanding of scientific data both through exploration and explanation of visualised data. Provenance contributes to the understanding of data by containing the contributing factors behind a result. With the significant increase in data volumes and algorithm complexity, clinical researchers are struggling with information tracking, analysis reproducibility and the verification of scientific output. Data coming from various heterogeneous sources (multiple sourc...

  12. Volumetric Analysis of Regional Cerebral Development in Preterm Children

    Science.gov (United States)

    Kesler, Shelli R.; Ment, Laura R.; Vohr, Betty; Pajot, Sarah K.; Schneider, Karen C.; Katz, Karol H.; Ebbitt, Timothy B.; Duncan, Charles C.; Makuch, Robert W.; Reiss, Allan L.

    2011-01-01

    Preterm birth is frequently associated with both neuropathologic and cognitive sequelae. This study examined cortical lobe, subcortical, and lateral ventricle development in association with perinatal variables and cognitive outcome. High-resolution volumetric magnetic resonance imaging scans were acquired and quantified using advanced image processing techniques. Seventy-three preterm and 33 term control children ages 7.3-11.4 years were included in the study. Results indicated disproportionately enlarged parietal and frontal gray matter, occipital horn, and ventricular body, as well as reduced temporal and subcortical gray volumes in preterm children compared with control subjects. Birth weight was negatively correlated with parietal and frontal gray, as well as occipital horn volumes. Intraventricular hemorrhage was associated with reduced subcortical gray matter. Ventricular cerebrospinal fluid was negatively correlated with subcortical gray matter volumes but not with white matter volumes. Maternal education was the strongest predictor of cognitive function in the preterm group. Preterm birth appears to be associated with disorganized cortical development, possibly involving disrupted synaptic pruning and neural migration. Lower birth weight and the presence of intraventricular hemorrhage may increase the risk for neuroanatomic abnormality. PMID:15519112

  13. A BAYESIAN HIERARCHICAL SPATIAL POINT PROCESS MODEL FOR MULTI-TYPE NEUROIMAGING META-ANALYSIS.

    Science.gov (United States)

    Kang, Jian; Nichols, Thomas E; Wager, Tor D; Johnson, Timothy D

    2014-09-01

    Neuroimaging meta-analysis is an important tool for finding consistent effects over studies that each usually have 20 or fewer subjects. Interest in meta-analysis in brain mapping is also driven by a recent focus on so-called "reverse inference": where as traditional "forward inference" identifies the regions of the brain involved in a task, a reverse inference identifies the cognitive processes that a task engages. Such reverse inferences, however, requires a set of meta-analysis, one for each possible cognitive domain. However, existing methods for neuroimaging meta-analysis have significant limitations. Commonly used methods for neuroimaging meta-analysis are not model based, do not provide interpretable parameter estimates, and only produce null hypothesis inferences; further, they are generally designed for a single group of studies and cannot produce reverse inferences. In this work we address these limitations by adopting a non-parametric Bayesian approach for meta analysis data from multiple classes or types of studies. In particular, foci from each type of study are modeled as a cluster process driven by a random intensity function that is modeled as a kernel convolution of a gamma random field. The type-specific gamma random fields are linked and modeled as a realization of a common gamma random field, shared by all types, that induces correlation between study types and mimics the behavior of a univariate mixed effects model. We illustrate our model on simulation studies and a meta analysis of five emotions from 219 studies and check model fit by a posterior predictive assessment. In addition, we implement reverse inference by using the model to predict study type from a newly presented study. We evaluate this predictive performance via leave-one-out cross validation that is efficiently implemented using importance sampling techniques.

  14. Automatic analysis (aa): efficient neuroimaging workflows and parallel processing using Matlab and XML.

    Science.gov (United States)

    Cusack, Rhodri; Vicente-Grabovetsky, Alejandro; Mitchell, Daniel J; Wild, Conor J; Auer, Tibor; Linke, Annika C; Peelle, Jonathan E

    2014-01-01

    Recent years have seen neuroimaging data sets becoming richer, with larger cohorts of participants, a greater variety of acquisition techniques, and increasingly complex analyses. These advances have made data analysis pipelines complicated to set up and run (increasing the risk of human error) and time consuming to execute (restricting what analyses are attempted). Here we present an open-source framework, automatic analysis (aa), to address these concerns. Human efficiency is increased by making code modular and reusable, and managing its execution with a processing engine that tracks what has been completed and what needs to be (re)done. Analysis is accelerated by optional parallel processing of independent tasks on cluster or cloud computing resources. A pipeline comprises a series of modules that each perform a specific task. The processing engine keeps track of the data, calculating a map of upstream and downstream dependencies for each module. Existing modules are available for many analysis tasks, such as SPM-based fMRI preprocessing, individual and group level statistics, voxel-based morphometry, tractography, and multi-voxel pattern analyses (MVPA). However, aa also allows for full customization, and encourages efficient management of code: new modules may be written with only a small code overhead. aa has been used by more than 50 researchers in hundreds of neuroimaging studies comprising thousands of subjects. It has been found to be robust, fast, and efficient, for simple-single subject studies up to multimodal pipelines on hundreds of subjects. It is attractive to both novice and experienced users. aa can reduce the amount of time neuroimaging laboratories spend performing analyses and reduce errors, expanding the range of scientific questions it is practical to address.

  15. Automatic analysis (aa: efficient neuroimaging workflows and parallel processing using Matlab and XML

    Directory of Open Access Journals (Sweden)

    Rhodri eCusack

    2015-01-01

    Full Text Available Recent years have seen neuroimaging data becoming richer, with larger cohorts of participants, a greater variety of acquisition techniques, and increasingly complex analyses. These advances have made data analysis pipelines complex to set up and run (increasing the risk of human error and time consuming to execute (restricting what analyses are attempted. Here we present an open-source framework, automatic analysis (aa, to address these concerns. Human efficiency is increased by making code modular and reusable, and managing its execution with a processing engine that tracks what has been completed and what needs to be (redone. Analysis is accelerated by optional parallel processing of independent tasks on cluster or cloud computing resources. A pipeline comprises a series of modules that each perform a specific task. The processing engine keeps track of the data, calculating a map of upstream and downstream dependencies for each module. Existing modules are available for many analysis tasks, such as SPM-based fMRI preprocessing, individual and group level statistics, voxel-based morphometry, tractography, and multi-voxel pattern analyses (MVPA. However, aa also allows for full customization, and encourages efficient management of code: new modules may be written with only a small code overhead. aa has been used by more than 50 researchers in hundreds of neuroimaging studies comprising thousands of subjects. It has been found to be robust, fast and efficient, for simple single subject studies up to multimodal pipelines on hundreds of subjects. It is attractive to both novice and experienced users. aa can reduce the amount of time neuroimaging laboratories spend performing analyses and reduce errors, expanding the range of scientific questions it is practical to address.

  16. Design of a novel biomedical signal processing and analysis tool for functional neuroimaging.

    Science.gov (United States)

    Kaçar, Sezgin; Sakoğlu, Ünal

    2016-03-01

    In this paper, a MATLAB-based graphical user interface (GUI) software tool for general biomedical signal processing and analysis of functional neuroimaging data is introduced. Specifically, electroencephalography (EEG) and electrocardiography (ECG) signals can be processed and analyzed by the developed tool, which incorporates commonly used temporal and frequency analysis methods. In addition to common methods, the tool also provides non-linear chaos analysis with Lyapunov exponents and entropies; multivariate analysis with principal and independent component analyses; and pattern classification with discriminant analysis. This tool can also be utilized for training in biomedical engineering education. This easy-to-use and easy-to-learn, intuitive tool is described in detail in this paper.

  17. The importance of accurate anatomic assessment for the volumetric analysis of the amygdala

    Directory of Open Access Journals (Sweden)

    L. Bonilha

    2005-03-01

    Full Text Available There is a wide range of values reported in volumetric studies of the amygdala. The use of single plane thick magnetic resonance imaging (MRI may prevent the correct visualization of anatomic landmarks and yield imprecise results. To assess whether there is a difference between volumetric analysis of the amygdala performed with single plane MRI 3-mm slices and with multiplanar analysis of MRI 1-mm slices, we studied healthy subjects and patients with temporal lobe epilepsy. We performed manual delineation of the amygdala on T1-weighted inversion recovery, 3-mm coronal slices and manual delineation of the amygdala on three-dimensional volumetric T1-weighted images with 1-mm slice thickness. The data were compared using a dependent t-test. There was a significant difference between the volumes obtained by the coronal plane-based measurements and the volumes obtained by three-dimensional analysis (P < 0.001. An incorrect estimate of the amygdala volume may preclude a correct analysis of the biological effects of alterations in amygdala volume. Three-dimensional analysis is preferred because it is based on more extensive anatomical assessment and the results are similar to those obtained in post-mortem studies.

  18. Improving the analysis, storage and sharing of neuroimaging data using relational databases and distributed computing.

    Science.gov (United States)

    Hasson, Uri; Skipper, Jeremy I; Wilde, Michael J; Nusbaum, Howard C; Small, Steven L

    2008-01-15

    The increasingly complex research questions addressed by neuroimaging research impose substantial demands on computational infrastructures. These infrastructures need to support management of massive amounts of data in a way that affords rapid and precise data analysis, to allow collaborative research, and to achieve these aims securely and with minimum management overhead. Here we present an approach that overcomes many current limitations in data analysis and data sharing. This approach is based on open source database management systems that support complex data queries as an integral part of data analysis, flexible data sharing, and parallel and distributed data processing using cluster computing and Grid computing resources. We assess the strengths of these approaches as compared to current frameworks based on storage of binary or text files. We then describe in detail the implementation of such a system and provide a concrete description of how it was used to enable a complex analysis of fMRI time series data.

  19. Volumetric analysis of the African elephant ventricular system.

    Science.gov (United States)

    Maskeo, Busisiwe C; Spocter, Muhammed A; Haagensen, Mark; Manger, Paul R

    2011-08-01

    This study used magnetic resonance imaging (MRI) to determine the volume of the ventricular system in the brain of three adult male African elephants (Loxodonta africana). The ventricular system of the elephant has a volume of ∼240 mL, an order of magnitude larger than that seen in the adult human. Despite this large size, allometric analysis indicates that the volume of the ventricles in the elephant is what one would expect for a mammal with an ∼5 kg brain. Interestingly, our comparison with other mammals revealed that primates appear to have small relative ventricular volumes, and that megachiropterans and microchiropterans follow different scaling rules when comparing ventricular volume to brain mass indicating separate phylogenetic histories. The current study provides context for one aspect of the elephant brain in the broader picture of mammalian brain evolution. Copyright © 2011 Wiley-Liss, Inc.

  20. BIDS apps: Improving ease of use, accessibility, and reproducibility of neuroimaging data analysis methods

    Science.gov (United States)

    Auer, Tibor; Churchill, Nathan W.; Flandin, Guillaume; Guntupalli, J. Swaroop; Raffelt, David; Quirion, Pierre-Olivier; Smith, Robert E.; Strother, Stephen C.; Varoquaux, Gaël

    2017-01-01

    The rate of progress in human neurosciences is limited by the inability to easily apply a wide range of analysis methods to the plethora of different datasets acquired in labs around the world. In this work, we introduce a framework for creating, testing, versioning and archiving portable applications for analyzing neuroimaging data organized and described in compliance with the Brain Imaging Data Structure (BIDS). The portability of these applications (BIDS Apps) is achieved by using container technologies that encapsulate all binary and other dependencies in one convenient package. BIDS Apps run on all three major operating systems with no need for complex setup and configuration and thanks to the comprehensiveness of the BIDS standard they require little manual user input. Previous containerized data processing solutions were limited to single user environments and not compatible with most multi-tenant High Performance Computing systems. BIDS Apps overcome this limitation by taking advantage of the Singularity container technology. As a proof of concept, this work is accompanied by 22 ready to use BIDS Apps, packaging a diverse set of commonly used neuroimaging algorithms. PMID:28278228

  1. Estimating multivariate similarity between neuroimaging datasets with sparse canonical correlation analysis: an application to perfusion imaging.

    Science.gov (United States)

    Rosa, Maria J; Mehta, Mitul A; Pich, Emilio M; Risterucci, Celine; Zelaya, Fernando; Reinders, Antje A T S; Williams, Steve C R; Dazzan, Paola; Doyle, Orla M; Marquand, Andre F

    2015-01-01

    An increasing number of neuroimaging studies are based on either combining more than one data modality (inter-modal) or combining more than one measurement from the same modality (intra-modal). To date, most intra-modal studies using multivariate statistics have focused on differences between datasets, for instance relying on classifiers to differentiate between effects in the data. However, to fully characterize these effects, multivariate methods able to measure similarities between datasets are needed. One classical technique for estimating the relationship between two datasets is canonical correlation analysis (CCA). However, in the context of high-dimensional data the application of CCA is extremely challenging. A recent extension of CCA, sparse CCA (SCCA), overcomes this limitation, by regularizing the model parameters while yielding a sparse solution. In this work, we modify SCCA with the aim of facilitating its application to high-dimensional neuroimaging data and finding meaningful multivariate image-to-image correspondences in intra-modal studies. In particular, we show how the optimal subset of variables can be estimated independently and we look at the information encoded in more than one set of SCCA transformations. We illustrate our framework using Arterial Spin Labeling data to investigate multivariate similarities between the effects of two antipsychotic drugs on cerebral blood flow.

  2. Volumetric analysis of syringomyelia following hindbrain decompression for Chiari malformation Type I: syringomyelia resolution follows exponential kinetics

    Science.gov (United States)

    Coumans, Jean-Valery; Walcott, Brian P.; Butler, William E.; Nahed, Brian V.; Kahle, Kristopher T.

    2013-01-01

    Object Resolution of syringomyelia is common following hindbrain decompression for Chiari malformation, yet little is known about the kinetics governing this process. The authors sought to establish the volumetric rate of syringomyelia resolution. Methods A retrospective cohort of patients undergoing hindbrain decompression for a Chiari malformation Type I with preoperative cervical or thoracic syringomyelia was identified. Patients were included in the study if they had at least 3 neuroimaging studies that detailed the entirety of their preoperative syringomyelia over a minimum of 6 months postoperatively. The authors reconstructed the MR images in 3 dimensions and calculated the volume of the syringomyelia. They plotted the syringomyelia volume over time and constructed regression models using the method of least squares. The Akaike information criterion and Bayesian information criterion were used to calculate the relative goodness of fit. The coefficients of determination R2 (unadjusted and adjusted) were calculated to describe the proportion of variability in each individual data set accounted for by the statistical model. Results Two patients were identified as meeting inclusion criteria. Plots of the least-squares best fit were identified as 4.01459e−0.0180804x and 13.2556e−0.00615859x. Decay of the syringomyelia followed an exponential model in both patients (R2 = 0.989582 and 0.948864). Conclusions Three-dimensional analysis of syringomyelia resolution over time enables the kinetics to be estimated. This technique is yet to be validated in a large cohort. Because syringomyelia is the final common pathway for a number of different pathological processes, it is possible that this exponential only applies to syringomyelia related to treatment of Chiari malformation Type I. PMID:21882909

  3. Two pitfalls of BOLD fMRI magnitude-based neuroimage analysis: non-negativity and edge effect.

    Science.gov (United States)

    Chen, Zikuan; Calhoun, Vince D

    2011-08-15

    BOLD fMRI is accepted as a noninvasive imaging modality for neuroimaging and brain mapping. A BOLD fMRI dataset consists of magnitude and phase components. Currently, only the magnitude is used for neuroimage analysis. In this paper, we show that the fMRI-magnitude-based neuroimage analysis may suffer two pitfalls: one is that the magnitude is non-negative and cannot differentiate positive from negative BOLD activity; the other is an edge effect that may manifest as an edge enhancement or a spatial interior dip artifact at a local uniform BOLD region. We demonstrate these pitfalls via numeric simulations using a BOLD fMRI model and also via a phantom experiment. We also propose a solution by making use of the fMRI phase image, the counterpart of the fMRI magnitude.

  4. Neuroimaging after mild traumatic brain injury: Review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Cyrus Eierud

    2014-01-01

    Full Text Available This paper broadly reviews the study of mild traumatic brain injury (mTBI, across the spectrum of neuroimaging modalities. Among the range of imaging methods, however, magnetic resonance imaging (MRI is unique in its applicability to studying both structure and function. Thus we additionally performed meta-analyses of MRI results to examine 1 the issue of anatomical variability and consistency for functional MRI (fMRI findings, 2 the analogous issue of anatomical consistency for white-matter findings, and 3 the importance of accounting for the time post injury in diffusion weighted imaging reports. As we discuss, the human neuroimaging literature consists of both small and large studies spanning acute to chronic time points that have examined both structural and functional changes with mTBI, using virtually every available medical imaging modality. Two key commonalities have been used across the majority of imaging studies. The first is the comparison between mTBI and control populations. The second is the attempt to link imaging results with neuropsychological assessments. Our fMRI meta-analysis demonstrates a frontal vulnerability to mTBI, demonstrated by decreased signal in prefrontal cortex compared to controls. This vulnerability is further highlighted by examining the frequency of reported mTBI white matter anisotropy, in which we show a strong anterior-to-posterior gradient (with anterior regions being more frequently reported in mTBI. Our final DTI meta-analysis examines a debated topic arising from inconsistent anisotropy findings across studies. Our results support the hypothesis that acute mTBI is associated with elevated anisotropy values and chronic mTBI complaints are correlated with depressed anisotropy. Thus, this review and set of meta-analyses demonstrate several important points about the ongoing use of neuroimaging to understand the functional and structural changes that occur throughout the time course of mTBI recovery

  5. Brain stem and cerebellum volumetric analysis of Machado Joseph disease patients

    Directory of Open Access Journals (Sweden)

    S T Camargos

    2011-01-01

    Full Text Available Machado-Joseph disease, or spinocerebellar ataxia type 3(MJD/SCA3, is the most frequent late onset spinocerebellar ataxia and results from a CAG repeat expansion in the ataxin-3 gene. Previous studies have found correlation between atrophy of cerebellum and brainstem with age and CAG repeats, although no such correlation has been found with disease duration and clinical manifestations. In this study we test the hypothesis that atrophy of cerebellum and brainstem in MJD/SCA3 is related to clinical severity, disease duration and CAG repeat length as well as to other variables such as age and ICARS (International Cooperative Ataxia Rating Scale. Whole brain high resolution MRI and volumetric measurement with cranial volume normalization were obtained from 15 MJD/SCA3 patients and 15 normal, age and sex-matchedcontrols. We applied ICARS and compared the score with volumes and CAG number, disease duration and age. We found significant correlation of both brain stem and cerebellar atrophy with CAG repeat length, age, disease duration and degree of disability. The Spearman rank correlation was stronger with volumetric reduction of the cerebellum than with brain stem. Our data allow us to conclude that volumetric analysis might reveal progressive degeneration after disease onset, which in turn is linked to both age and number of CAG repeat expansions in SCA 3.

  6. Three-dimensional linear and volumetric analysis of maxillary sinus pneumatization

    Directory of Open Access Journals (Sweden)

    Reham M. Hamdy

    2014-05-01

    Full Text Available Considering the anatomical variability related to the maxillary sinus, its intimate relation to the maxillary posterior teeth and because of all the implications that pneumatization may possess, three-dimensional assessment of maxillary sinus pneumatization is of most usefulness. The aim of this study is to analyze the maxillary sinus dimensions both linearly and volumetrically using cone beam computed tomography (CBCT to assess the maxillary sinus pneumatization. Retrospective analysis of 30 maxillary sinuses belonging to 15 patients’ CBCT scans was performed. Linear and volumetric measurements were conducted and statistically analyzed. The maximum craniocaudal extension of the maxillary sinus was located around the 2nd molar in 93% of the sinuses, while the maximum mediolateral and antroposterior extensions of the maxillary sinus were located at the level of root of zygomatic complex in 90% of sinuses. There was a high correlation between the linear measurements of the right and left sides, where the antroposterior extension of the sinus at level of the nasal floor had the largest correlation (0.89. There was also a high correlation between the Simplant and geometric derived maxillary sinus volumes for both right and left sides (0.98 and 0.96, respectively. The relations of the sinus floor can be accurately assessed on the different orthogonal images obtained through 3D CBCT scan. The geometric method offered a much cheaper, easier, and less sophisticated substitute; therefore, with the availability of software, 3D volumetric measurements are more facilitated.

  7. The social evaluation of faces: a meta-analysis of functional neuroimaging studies.

    Science.gov (United States)

    Mende-Siedlecki, Peter; Said, Christopher P; Todorov, Alexander

    2013-03-01

    Neuroscience research on the social evaluation of faces has accumulated over the last decade, yielding divergent results. We used a meta-analytic technique, multi-level kernel density analysis (MKDA), to analyze 29 neuroimaging studies on face evaluation. Across negative face evaluations, we observed the most consistent activations in bilateral amygdala. Across positive face evaluations, we observed the most consistent activations in medial prefrontal cortex, pregenual anterior cingulate cortex (pgACC), medial orbitofrontal cortex (mOFC), left caudate and nucleus accumbens (NAcc). Based on additional analyses comparing linear and non-linear responses, we propose a ventral/dorsal dissociation within the amygdala, wherein separate populations of neurons code for face valence and intensity, respectively. Finally, we argue that some of the differences between studies are attributable to differences in the typicality of face stimuli. Specifically, extremely attractive faces are more likely to elicit responses in NAcc/caudate and mOFC.

  8. Enhancing Volumetric Bouligand-Minkowski Fractal Descriptors by using Functional Data Analysis

    CERN Document Server

    Florindo, João Batista; Bruno, Odemir Martinez; 10.1142/S0129183111016701

    2012-01-01

    This work proposes and study the concept of Functional Data Analysis transform, applying it to the performance improving of volumetric Bouligand-Minkowski fractal descriptors. The proposed transform consists essentially in changing the descriptors originally defined in the space of the calculus of fractal dimension into the space of coefficients used in the functional data representation of these descriptors. The transformed decriptors are used here in texture classification problems. The enhancement provided by the FDA transform is measured by comparing the transformed to the original descriptors in terms of the correctness rate in the classification of well known datasets.

  9. Preliminary performance analysis of a transverse flow spectrally selective two-slab packed bed volumetric receiver

    CSIR Research Space (South Africa)

    Roos, TH

    2016-05-01

    Full Text Available stream_source_info Roos_2016_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 2694 Content-Encoding UTF-8 stream_name Roos_2016_ABSTRACT.pdf.txt Content-Type text/plain; charset=UTF-8 21st SolarPACES... International Conference (SolarPACES 2015), 13-16 October 2015 Preliminary Performance Analysis of a Transverse Flow Spectrally Selective Two-slab Packed Bed Volumetric Receiver Thomas H. Roos1, a) and Thomas M. Harms2, b) 1Aeronautical Systems...

  10. Volumetric texture analysis of breast lesions on contrast-enhanced magnetic resonance images.

    Science.gov (United States)

    Chen, Weijie; Giger, Maryellen L; Li, Hui; Bick, Ulrich; Newstead, Gillian M

    2007-09-01

    Automated image analysis aims to extract relevant information from contrast-enhanced magnetic resonance images (CE-MRI) of the breast and improve the accuracy and consistency of image interpretation. In this work, we extend the traditional 2D gray-level co-occurrence matrix (GLCM) method to investigate a volumetric texture analysis approach and apply it for the characterization of breast MR lesions. Our database of breast MR images was obtained using a T1-weighted 3D spoiled gradient echo sequence and consists of 121 biopsy-proven lesions (77 malignant and 44 benign). A fuzzy c-means clustering (FCM) based method is employed to automatically segment 3D breast lesions on CE-MR images. For each 3D lesion, a nondirectional GLCM is then computed on the first postcontrast frame by summing 13 directional GLCMs. Texture features are extracted from the nondirectional GLCMs and the performance of each texture feature in the task of distinguishing between malignant and benign breast lesions is assessed by receiver operating characteristics (ROC) analysis. Our results show that the classification performance of volumetric texture features is significantly better than that based on 2D analysis. Our investigations of the effects of various of parameters on the diagnostic accuracy provided means for the optimal use of the approach.

  11. Stuttering as a trait or state - an ALE meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Belyk, Michel; Kraft, Shelly Jo; Brown, Steven

    2015-01-01

    Stuttering is a speech disorder characterised by repetitions, prolongations and blocks that disrupt the forward movement of speech. An earlier meta-analysis of brain imaging studies of stuttering (Brown et al., 2005) revealed a general trend towards rightward lateralization of brain activations and hyperactivity in the larynx motor cortex bilaterally. The present study sought not only to update that meta-analysis with recent work but to introduce an important distinction not present in the first study, namely the difference between 'trait' and 'state' stuttering. The analysis of trait stuttering compares people who stutter (PWS) with people who do not stutter when behaviour is controlled for, i.e., when speech is fluent in both groups. In contrast, the analysis of state stuttering examines PWS during episodes of stuttered speech compared with episodes of fluent speech. Seventeen studies were analysed using activation likelihood estimation. Trait stuttering was characterised by the well-known rightward shift in lateralization for language and speech areas. State stuttering revealed a more diverse pattern. Abnormal activation of larynx and lip motor cortex was common to the two analyses. State stuttering was associated with overactivation in the right hemisphere larynx and lip motor cortex. Trait stuttering was associated with overactivation of lip motor cortex in the right hemisphere but underactivation of larynx motor cortex in the left hemisphere. These results support a large literature highlighting laryngeal and lip involvement in the symptomatology of stuttering, and disambiguate two possible sources of activation in neuroimaging studies of persistent developmental stuttering.

  12. Biomarkers of Eating Disorders Using Support Vector Machine Analysis of Structural Neuroimaging Data: Preliminary Results.

    Science.gov (United States)

    Cerasa, Antonio; Castiglioni, Isabella; Salvatore, Christian; Funaro, Angela; Martino, Iolanda; Alfano, Stefania; Donzuso, Giulia; Perrotta, Paolo; Gioia, Maria Cecilia; Gilardi, Maria Carla; Quattrone, Aldo

    2015-01-01

    Presently, there are no valid biomarkers to identify individuals with eating disorders (ED). The aim of this work was to assess the feasibility of a machine learning method for extracting reliable neuroimaging features allowing individual categorization of patients with ED. Support Vector Machine (SVM) technique, combined with a pattern recognition method, was employed utilizing structural magnetic resonance images. Seventeen females with ED (six with diagnosis of anorexia nervosa and 11 with bulimia nervosa) were compared against 17 body mass index-matched healthy controls (HC). Machine learning allowed individual diagnosis of ED versus HC with an Accuracy ≥ 0.80. Voxel-based pattern recognition analysis demonstrated that voxels influencing the classification Accuracy involved the occipital cortex, the posterior cerebellar lobule, precuneus, sensorimotor/premotor cortices, and the medial prefrontal cortex, all critical regions known to be strongly involved in the pathophysiological mechanisms of ED. Although these findings should be considered preliminary given the small size investigated, SVM analysis highlights the role of well-known brain regions as possible biomarkers to distinguish ED from HC at an individual level, thus encouraging the translational implementation of this new multivariate approach in the clinical practice.

  13. Biomarkers of Eating Disorders Using Support Vector Machine Analysis of Structural Neuroimaging Data: Preliminary Results

    Directory of Open Access Journals (Sweden)

    Antonio Cerasa

    2015-01-01

    Full Text Available Presently, there are no valid biomarkers to identify individuals with eating disorders (ED. The aim of this work was to assess the feasibility of a machine learning method for extracting reliable neuroimaging features allowing individual categorization of patients with ED. Support Vector Machine (SVM technique, combined with a pattern recognition method, was employed utilizing structural magnetic resonance images. Seventeen females with ED (six with diagnosis of anorexia nervosa and 11 with bulimia nervosa were compared against 17 body mass index-matched healthy controls (HC. Machine learning allowed individual diagnosis of ED versus HC with an Accuracy ≥ 0.80. Voxel-based pattern recognition analysis demonstrated that voxels influencing the classification Accuracy involved the occipital cortex, the posterior cerebellar lobule, precuneus, sensorimotor/premotor cortices, and the medial prefrontal cortex, all critical regions known to be strongly involved in the pathophysiological mechanisms of ED. Although these findings should be considered preliminary given the small size investigated, SVM analysis highlights the role of well-known brain regions as possible biomarkers to distinguish ED from HC at an individual level, thus encouraging the translational implementation of this new multivariate approach in the clinical practice.

  14. Neuroticism and the brain: a quantitative meta-analysis of neuroimaging studies investigating emotion processing.

    Science.gov (United States)

    Servaas, Michelle N; van der Velde, Jorien; Costafreda, Sergi G; Horton, Paul; Ormel, Johan; Riese, Harriëtte; Aleman, André

    2013-09-01

    Neuroticism is a robust personality trait that constitutes a risk factor for mood disorders. Neuroimaging findings related to neuroticism have been inconsistent across studies and hardly integrated in order to construct a model of the underlying neural correlates of neuroticism. The aim of the current meta-analysis was to provide a quantitative summary of the literature, using a parametric coordinate-based meta-analysis (PCM) approach. Data were pooled for emotion processing tasks investigating the contrasts (negative>neutral) and (positive>neutral) to identify brain regions that are consistently associated with neuroticism across studies. Significant negative and positive correlations with neuroticism were found only for the contrast (negative>neutral) after multiple comparisons correction. Differences in brain activation were found to be associated with neuroticism during fear learning, anticipation of aversive stimuli and the processing and regulation of emotion. The relationship between neuroticism and these three psychological processes and their corresponding neural correlates is discussed. Furthermore, the meta-analytic findings are incorporated into a general model of emotion processing in neuroticism.

  15. Multivariate Data Analysis for Neuroimaging Data: Overview and Application to Alzheimer’s Disease

    Science.gov (United States)

    Stern, Yaakov

    2010-01-01

    As clinical and cognitive neuroscience mature, the need for sophisticated neuroimaging analysis becomes more apparent. Multivariate analysis techniques have recently received increasing attention as they have many attractive features that cannot be easily realized by the more commonly used univariate, voxel-wise, techniques. Multivariate approaches evaluate correlation/covariance of activation across brain regions, rather than proceeding on a voxel-by-voxel basis. Thus, their results can be more easily interpreted as a signature of neural networks. Univariate approaches, on the other hand, cannot directly address functional connectivity in the brain. The covariance approach can also result in greater statistical power when compared with univariate techniques, which are forced to employ very stringent, and often overly conservative, corrections for voxel-wise multiple comparisons. Multivariate techniques also lend themselves much better to prospective application of results from the analysis of one dataset to entirely new datasets. Multivariate techniques are thus well placed to provide information about mean differences and correlations with behavior, similarly to univariate approaches, with potentially greater statistical power and better reproducibility checks. In contrast to these advantages is the high barrier of entry to the use of multivariate approaches, preventing more widespread application in the community. To the neuroscientist becoming familiar with multivariate analysis techniques, an initial survey of the field might present a bewildering variety of approaches that, although algorithmically similar, are presented with different emphases, typically by people with mathematics backgrounds. We believe that multivariate analysis techniques have sufficient potential to warrant better dissemination. Researchers should be able to employ them in an informed and accessible manner. The following article attempts to provide a basic introduction with sample

  16. Numerical analysis of radiation propagation in innovative volumetric receivers based on selective laser melting techniques

    Science.gov (United States)

    Alberti, Fabrizio; Santiago, Sergio; Roccabruna, Mattia; Luque, Salvador; Gonzalez-Aguilar, Jose; Crema, Luigi; Romero, Manuel

    2016-05-01

    Volumetric absorbers constitute one of the key elements in order to achieve high thermal conversion efficiencies in concentrating solar power plants. Regardless of the working fluid or thermodynamic cycle employed, design trends towards higher absorber output temperatures are widespread, which lead to the general need of components of high solar absorptance, high conduction within the receiver material, high internal convection, low radiative and convective heat losses and high mechanical durability. In this context, the use of advanced manufacturing techniques, such as selective laser melting, has allowed for the fabrication of intricate geometries that are capable of fulfilling the previous requirements. This paper presents a parametric design and analysis of the optical performance of volumetric absorbers of variable porosity conducted by means of detailed numerical ray tracing simulations. Sections of variable macroscopic porosity along the absorber depth were constructed by the fractal growth of single-cell structures. Measures of performance analyzed include optical reflection losses from the absorber front and rear faces, penetration of radiation inside the absorber volume, and radiation absorption as a function of absorber depth. The effects of engineering design parameters such as absorber length and wall thickness, material reflectance and porosity distribution on the optical performance of absorbers are discussed, and general design guidelines are given.

  17. Brain activation in response to bladder filling in healthy adults: An activation likelihood estimation meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Arya, Nisha G; Weissbart, Steven J; Xu, Sihua; Rao, Hengyi

    2017-04-01

    Recent studies have used different neuroimaging techniques and identified various brain regions that are activated during bladder filling. However, there is a lack of consensus regarding which of these brain regions regulate the process of urine storage. The aim of this meta-analysis is to identify brain regions that are commonly activated during bladder filling in healthy adults across different studies. PubMed was searched for neuroimaging studies investigating the effects of bladder filling on regional brain activation. Studies were excluded if they did not report brain activation differences from whole-brain group analysis by comparing the state of bladder filling with the state of bladder rest. The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. We identified 14 neuroimaging studies examining brain activation in response to experimental bladder filling in 181 healthy subjects, which reported 89 foci for ALE analysis. The meta-analysis revealed significant activation in multiple brain regions including thalamus (bilaterally), right insula, cerebellum, and brainstem (bilaterally). Several key brain regions involved in sensory processing are commonly activated during bladder filling in healthy adults across different studies. Neurourol. Urodynam. 36:960-965, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Emotion recognition and theory of mind in schizophrenia: A meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Jáni, Martin; Kašpárek, Tomáš

    2017-05-30

    Patients with schizophrenia have difficulties processing the emotional and cognitive states of others. Neuroimaging studies show inconsistent findings. We used a Seed-based d Mapping meta-analytic method to explore brain activation during facial emotion recognition and theory of mind tasks in schizophrenia patients. The patients showed lesser recruitment of the facial emotion processing network; behavioural performance was associated with the activation of the precentral gyrus. We found abnormal activation of the mentalising network in schizophrenia patients during reasoning about other people's mental states; patients with worse performances showed lesser activation in the right insula and superior temporal gyrus. Multimodal meta-analysis showed overlaps of brain-related abnormalities for both modalities in schizophrenia, with reduced recruitment of the right insula, anterior cingulate and medial prefrontal cortex and increased activation in the bilateral parietal cortex. Meta-regression results indicate that illness duration, medication and symptomatology might influence social-cognitive network disruptions in schizophrenia. These findings suggest the complex impairment of social cognition, as demonstrated by neural-related circuit disruptions during facial emotion processing and theory of mind tasks in schizophrenia.

  19. Graph Theoretical Analysis of Structural Neuroimaging in Temporal Lobe Epilepsy with and without Psychosis.

    Directory of Open Access Journals (Sweden)

    Daichi Sone

    Full Text Available Psychosis is one of the most important psychiatric comorbidities in temporal lobe epilepsy (TLE, and its pathophysiology still remains unsolved. We aimed to explore the connectivity differences of structural neuroimaging between TLE with and without psychosis using a graph theoretical analysis, which is an emerging mathematical method to investigate network connections in the brain as a small-world system.We recruited 11 TLE patients with unilateral hippocampal sclerosis (HS presenting psychosis or having a history of psychosis (TLE-P group. As controls, 15 TLE patients with unilateral HS without any history of psychotic episodes were also recruited (TLE-N group. For graph theoretical analysis, the normalized gray matter images of both groups were subjected to Graph Analysis Toolbox (GAT. As secondary analyses, each group was compared to 14 age- and gender-matched healthy subjects.The hub node locations were found predominantly in the ipsilateral hemisphere in the TLE-N group, and mainly on the contralateral side in the TLE-P group. The TLE-P group showed significantly higher characteristic path length, transitivity, lower global efficiency, and resilience to random or targeted attack than those of the TLE-N group. The regional comparison in betweenness centrality revealed significantly decreased connectivity in the contralateral temporal lobe, ipsilateral middle frontal gyrus, and bilateral postcentral gyri in the TLE-P group. The healthy subjects showed well-balanced nodes/edges distributions, similar metrics to TLE-N group except for higher small-worldness/modularity/assortativity, and various differences of regional betweenness/clustering.In TLE with psychosis, graph theoretical analysis of structural imaging revealed disrupted connectivity in the contralateral hemisphere. The network metrics suggested that the existence of psychosis can bring vulnerability and decreased efficiency of the whole-brain network. The sharp differences in

  20. Volumetric MRI analysis of hippocampal subregions in Cushing's disease: a model for glucocorticoid neural modulation.

    Science.gov (United States)

    Toffanin, T; Nifosì, F; Follador, H; Passamani, A; Zonta, F; Ferri, G; Scanarini, M; Amistà, P; Pigato, G; Scaroni, C; Mantero, F; Carollo, C; Perini, G I

    2011-01-01

    Several preclinical studies have demonstrated neuronal effects of glucocorticoids on the hippocampus (HC), a limbic structure with anterior-posterior anatomical and functional segmentation. We propose a volumetric magnetic resonance imaging analysis of hippocampus head (HH), body (HB) and tail (HT) using Cushing's disease (CD) as model, to investigate whether there is a differential sensitivity to glucocorticoid neuronal damage in these segments. We found a significant difference in the HH bilaterally after 12 months from trans-sphenoidal surgical selective resection of the adrenocorticotropic hormone (ACTH)-secreting pituitary micro-adenomas. This pre-post surgery difference could contribute to better understand the pathopysiology of CD as an in vivo model for stress-related hypercortisolemic neuropsychiatric disorders.

  1. Multi-physics analysis of permanent magnet tubular linear motors under severe volumetric and thermal constraints

    Institute of Scientific and Technical Information of China (English)

    李方; 叶佩青; 张辉

    2016-01-01

    Permanent magnet tubular linear motors (TLMs) arranged in multiple rows and multiple columns used for a radiotherapy machine were studied. Due to severe volumetric and thermal constraints, the TLMs were at high risk of overheating. To predict the performance of the TLMs accurately, a multi-physics analysis approach was proposed. Specifically, it considered the coupling effects amongst the electromagnetic and the thermal models of the TLMs, as well as the fluid model of the surrounding air. To reduce computation cost, both the electromagnetic and the thermal models were based on lumped-parameter methods. Only a minimum set of numerical computation (computational fluid dynamics, CFD) was performed to model the complex fluid behavior. With the proposed approach, both steady state and transient state temperature distributions, thermal rating and permissible load can be predicted. The validity of this approach is verified through the experiment.

  2. Meta-analysis of structural brain abnormalities associated with stimulant drug dependence and neuroimaging of addiction vulnerability and resilience.

    Science.gov (United States)

    Ersche, Karen D; Williams, Guy B; Robbins, Trevor W; Bullmore, Edward T

    2013-08-01

    Since the first study in stimulant-dependent individuals using structural MRI was published fifteen years ago, much evidence has accumulated on brain abnormalities associated with stimulant drug dependence. Here we conducted a voxel-based morphometry meta-analysis of published MRI data in stimulant-dependent individuals to clarify the most robust abnormalities underlying the disorder. We found that neuroimaging studies in stimulant-dependent individuals consistently report a gray matter decline in the prefrontal cortex regions associated with self-regulation and self-awareness. One of the next key questions that neuroimaging research today needs to address is the question of causality, namely to what extent these brain abnormalities are caused by the toxic effects of drug exposure, or the possibility that these may have predated drug-taking and even predisposed individuals for the development of drug dependence. Although the question of causality has not yet been answered completely, there has been significant progress made to date.

  3. Looking for Neuroimaging Markers in Frontotemporal Lobar Degeneration Clinical Trials: A Multi-Voxel Pattern Analysis Study in Granulin Disease.

    Science.gov (United States)

    Premi, Enrico; Cauda, Franco; Costa, Tommaso; Diano, Matteo; Gazzina, Stefano; Gualeni, Vera; Alberici, Antonella; Archetti, Silvana; Magoni, Mauro; Gasparotti, Roberto; Padovani, Alessandro; Borroni, Barbara

    2016-01-01

    In light of future pharmacological interventions, neuroimaging markers able to assess the response to treatment would be crucial. In Granulin (GRN) disease, preclinical data will prompt pharmacological trials in the future. Two main points need to be assessed: (1) to identify target regions in different disease stages and (2) to determine the most accurate functional and structural neuroimaging index to be used. To this aim, we have taken advantage of the multivariate approach of multi-voxel pattern analysis (MVPA) to explore the information of brain activity patterns in a cohort of GRN Thr272fs carriers at different disease stages (14 frontotemporal dementia (FTD) patients and 17 asymptomatic carriers) and a group of 33 healthy controls. We studied structural changes by voxel-based morphometry (VBM), functional connectivity by assessing salience, default mode, fronto-parietal, dorsal attentional, executive networks, and local connectivity by regional homogeneity, amplitude of low frequency fluctuations (ALFF), fractional ALFF (fALFF), degree centrality, and voxel-mirrored homotopic connectivity. In FTD patients with GRN mutation, the most predictive measure was VBM structural analysis, while in asymptomatic carriers the best predictor marker was the local connectivity measure (fALFF). Altogether, all indexes demonstrated fronto-temporo-parietal damage in GRN pathology, with widespread structural damage of fronto-parietal and temporal regions when disease is overt. MVPA could be of aid in identifying the most accurate neuroimaging marker for clinical trials. This approach was able to identify both the target region and the best neuroimaging approach, which would be specific in the different disease stages. Further studies are needed to simultaneously integrate multimodal indexes in a classifier able to trace the disease progression moving from preclinical to clinical stage of the disease.

  4. A meta-analysis of neuroimaging studies on divergent thinking using activation likelihood estimation.

    Science.gov (United States)

    Wu, Xin; Yang, Wenjing; Tong, Dandan; Sun, Jiangzhou; Chen, Qunlin; Wei, Dongtao; Zhang, Qinglin; Zhang, Meng; Qiu, Jiang

    2015-07-01

    In this study, an activation likelihood estimation (ALE) meta-analysis was used to conduct a quantitative investigation of neuroimaging studies on divergent thinking. Based on the ALE results, the functional magnetic resonance imaging (fMRI) studies showed that distributed brain regions were more active under divergent thinking tasks (DTTs) than those under control tasks, but a large portion of the brain regions were deactivated. The ALE results indicated that the brain networks of the creative idea generation in DTTs may be composed of the lateral prefrontal cortex, posterior parietal cortex [such as the inferior parietal lobule (BA 40) and precuneus (BA 7)], anterior cingulate cortex (ACC) (BA 32), and several regions in the temporal cortex [such as the left middle temporal gyrus (BA 39), and left fusiform gyrus (BA 37)]. The left dorsolateral prefrontal cortex (BA 46) was related to selecting the loosely and remotely associated concepts and organizing them into creative ideas, whereas the ACC (BA 32) was related to observing and forming distant semantic associations in performing DTTs. The posterior parietal cortex may be involved in the semantic information related to the retrieval and buffering of the formed creative ideas, and several regions in the temporal cortex may be related to the stored long-term memory. In addition, the ALE results of the structural studies showed that divergent thinking was related to the dopaminergic system (e.g., left caudate and claustrum). Based on the ALE results, both fMRI and structural MRI studies could uncover the neural basis of divergent thinking from different aspects (e.g., specific cognitive processing and stable individual difference of cognitive capability). © 2015 Wiley Periodicals, Inc.

  5. Computational analysis in epilepsy neuroimaging: A survey of features and methods

    Directory of Open Access Journals (Sweden)

    Lohith G. Kini

    2016-01-01

    Advances in neuroimaging and machine learning allow semi-automated detection of malformations of cortical development (MCDs, a common cause of drug resistant epilepsy. A frequently asked question in the field is what techniques currently exist to assist radiologists in identifying these lesions, especially subtle forms of MCDs such as focal cortical dysplasia (FCD Type I and low grade glial tumors. Below we introduce some of the common lesions encountered in patients with epilepsy and the common imaging findings that radiologists look for in these patients. We then review and discuss the computational techniques introduced over the past 10 years for quantifying and automatically detecting these imaging findings. Due to large variations in the accuracy and implementation of these studies, specific techniques are traditionally used at individual centers, often guided by local expertise, as well as selection bias introduced by the varying prevalence of specific patient populations in different epilepsy centers. We discuss the need for a multi-institutional study that combines features from different imaging modalities as well as computational techniques to definitively assess the utility of specific automated approaches to epilepsy imaging. We conclude that sharing and comparing these different computational techniques through a common data platform provides an opportunity to rigorously test and compare the accuracy of these tools across different patient populations and geographical locations. We propose that these kinds of tools, quantitative imaging analysis methods and open data platforms for aggregating and sharing data and algorithms, can play a vital role in reducing the cost of care, the risks of invasive treatments, and improve overall outcomes for patients with epilepsy.

  6. Intrinsic functional component analysis via sparse representation on Alzheimer's disease neuroimaging initiative database.

    Science.gov (United States)

    Jiang, Xi; Zhang, Xin; Zhu, Dajiang

    2014-10-01

    Alzheimer's disease (AD) is the most common type of dementia (accounting for 60% to 80%) and is the fifth leading cause of death for those people who are 65 or older. By 2050, one new case of AD in United States is expected to develop every 33 sec. Unfortunately, there is no available effective treatment that can stop or slow the death of neurons that causes AD symptoms. On the other hand, it is widely believed that AD starts before development of the associated symptoms, so its prestages, including mild cognitive impairment (MCI) or even significant memory concern (SMC), have received increasing attention, not only because of their potential as a precursor of AD, but also as a possible predictor of conversion to other neurodegenerative diseases. Although these prestages have been defined clinically, accurate/efficient diagnosis is still challenging. Moreover, brain functional abnormalities behind those alterations and conversions are still unclear. In this article, by developing novel sparse representations of whole-brain resting-state functional magnetic resonance imaging signals and by using the most updated Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset, we successfully identified multiple functional components simultaneously, and which potentially represent those intrinsic functional networks involved in the resting-state activities. Interestingly, these identified functional components contain all the resting-state networks obtained from traditional independent-component analysis. Moreover, by using the features derived from those functional components, it yields high classification accuracy for both AD (94%) and MCI (92%) versus normal controls. Even for SMC we can still have 92% accuracy.

  7. Multi-source feature learning for joint analysis of incomplete multiple heterogeneous neuroimaging data.

    Science.gov (United States)

    Yuan, Lei; Wang, Yalin; Thompson, Paul M; Narayan, Vaibhav A; Ye, Jieping

    2012-07-02

    Analysis of incomplete data is a big challenge when integrating large-scale brain imaging datasets from different imaging modalities. In the Alzheimer's Disease Neuroimaging Initiative (ADNI), for example, over half of the subjects lack cerebrospinal fluid (CSF) measurements; an independent half of the subjects do not have fluorodeoxyglucose positron emission tomography (FDG-PET) scans; many lack proteomics measurements. Traditionally, subjects with missing measures are discarded, resulting in a severe loss of available information. In this paper, we address this problem by proposing an incomplete Multi-Source Feature (iMSF) learning method where all the samples (with at least one available data source) can be used. To illustrate the proposed approach, we classify patients from the ADNI study into groups with Alzheimer's disease (AD), mild cognitive impairment (MCI) and normal controls, based on the multi-modality data. At baseline, ADNI's 780 participants (172AD, 397 MCI, 211 NC), have at least one of four data types: magnetic resonance imaging (MRI), FDG-PET, CSF and proteomics. These data are used to test our algorithm. Depending on the problem being solved, we divide our samples according to the availability of data sources, and we learn shared sets of features with state-of-the-art sparse learning methods. To build a practical and robust system, we construct a classifier ensemble by combining our method with four other methods for missing value estimation. Comprehensive experiments with various parameters show that our proposed iMSF method and the ensemble model yield stable and promising results.

  8. Investigating socio-cognitive processes in deception: a quantitative meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Lisofsky, Nina; Kazzer, Philipp; Heekeren, Hauke R; Prehn, Kristin

    2014-08-01

    Recent neuroimaging studies have found a broad network of brain regions involved in deception, including the prefrontal cortex, insula, anterior cingulate cortex (ACC), and inferior parietal lobule (IPL). Although deception can be conceptualized as the attempt to deliberately cause another person to accept a false belief, research to date has mainly focused on executive control processes when participants are instructed to lie under certain conditions. Recently, more ecologically valid and interactive experimental paradigms have been used in which subjects were also requested to take the perspective of another person, read his or her intentions, and make a self-determined decision to deceive that person and break a moral rule. To investigate the influence of these socio-cognitive processes on the neural network of deception, we performed a quantitative meta-analysis combining the data from 416 participants across 22 fMRI and two PET studies. Based on the description of the experimental paradigm, studies were divided in social interactive and non-interactive deception studies. Increased activation in the dorsal ACC, the right temporo-parietal junction (TPJ)/angular gyrus, and the bilateral temporal pole (TP) was found to be greater in social interactive than in non-interactive deception. These results demonstrate the important role of perspective taking, theory of mind, and moral reasoning processes in deception as well as conflict processing. In addition to the role of executive control processes determined by previous meta-analyses, our findings show the importance of these socio-cognitive processes in deception and give new insight into the function and interpretation of the brain regions involved.

  9. Neuroticism and the brain : A quantitative meta-analysis of neuroimaging studies investigating emotion processing

    NARCIS (Netherlands)

    Servaas, Michelle N.; van der Velde, Jorien; Costafreda, Sergi G.; Horton, Paul; Ormel, Johan; Riese, Harriette; Aleman, Andre

    2013-01-01

    Neuroticism is a robust personality trait that constitutes a risk factor for mood disorders. Neuroimaging findings related to neuroticism have been inconsistent across studies and hardly integrated in order to construct a model of the underlying neural correlates of neuroticism. The aim of the curre

  10. Functional neuroimaging of visual creativity: a systematic review and meta‐analysis

    OpenAIRE

    2016-01-01

    Abstract Introduction The generation of creative visual imagery contributes to technological and scientific innovation and production of visual art. The underlying cognitive and neural processes are, however, poorly understood. Methods This review synthesizes functional neuroimaging studies of visual creativity. Seven functional magnetic resonance imaging (fMRI) and 19 electroencephalography (EEG) studies were included, comprising 27 experiments and around 800 participants. Results Activation...

  11. Global segmentation and curvature analysis of volumetric data sets using trivariate B-spline functions.

    Science.gov (United States)

    Soldea, Octavian; Elber, Gershon; Rivlin, Ehud

    2006-02-01

    This paper presents a method to globally segment volumetric images into regions that contain convex or concave (elliptic) iso-surfaces, planar or cylindrical (parabolic) iso-surfaces, and volumetric regions with saddle-like (hyperbolic) iso-surfaces, regardless of the value of the iso-surface level. The proposed scheme relies on a novel approach to globally compute, bound, and analyze the Gaussian and mean curvatures of an entire volumetric data set, using a trivariate B-spline volumetric representation. This scheme derives a new differential scalar field for a given volumetric scalar field, which could easily be adapted to other differential properties. Moreover, this scheme can set the basis for more precise and accurate segmentation of data sets targeting the identification of primitive parts. Since the proposed scheme employs piecewise continuous functions, it is precise and insensitive to aliasing.

  12. Data sharing in neuroimaging research

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste ePoline

    2012-04-01

    Full Text Available Significant resources around the world have been invested in neuroimaging studies of brain function and disease. Easier access to this large body of work should have profound impact on research in cognitive neuroscience and psychiatry, leading to advances in the diagnosis and treatment of psychiatric and neurological disease. A trend toward increased sharing of neuroimaging data has emerged in recent years. Nevertheless, a number of barriers continue to impede momentum. Many researchers and institutions remain uncertain about how to share data or lack the tools and expertise to participate in data sharing. The use of electronic data capture methods for neuroimaging greatly simplifies the task of data collection and has the potential to help standardize many aspects of data sharing. We review here the motivations for sharing neuroimaging data, the current data sharing landscape, and the sociological or technical barriers that still need to be addressed. The INCF Task Force on Neuroimaging Datasharing, in conjunction with several collaborative groups around the world, has started work on several tools to ease and eventually automate the practice of data sharing. It is hoped that such tools will allow researchers to easily share raw, processed, and derived neuroimaging data, with appropriate metadata and provenance records, and will improve the reproducibility of neuroimaging studies. By providing seamless integration of data sharing and analysis tools within a commodity research environment, the Task Force seeks to identify and minimize barriers to data sharing in the field of neuroimaging.

  13. Neuroimaging in dementia

    Energy Technology Data Exchange (ETDEWEB)

    Barkhof, Frederik [VU Univ. Medical Center, Amsterdam (NL). Dept. of Radiology and Image Analysis Center (IAC); Fox, Nick C. [UCL Institute of Neurology, London (United Kingdom). Dementia Research Centre; VU Univ. Medical Center, Amsterdam (Netherlands); Bastos-Leite, Antonio J. [Porto Univ. (Portugal). Dept. of Medical Imaging; Scheltens, Philip [VU Univ. Medical Center, Amsterdam (Netherlands). Dept. of Neurology and Alzheimer Center

    2011-07-01

    Against a background of an ever-increasing number of patients, new management options, and novel imaging modalities, neuroimaging is playing an increasingly important role in the diagnosis of dementia. This up-to-date, superbly illustrated book aims to provide a practical guide to the effective use of neuroimaging in the patient with cognitive decline. It sets out the key clinical and imaging features of the wide range of causes of dementia and directs the reader from clinical presentation to neuroimaging and on to an accurate diagnosis whenever possible. After an introductory chapter on the clinical background, the available ''toolbox'' of structural and functional neuroimaging techniques is reviewed in detail, including CT, MRI and advanced MR techniques, SPECT and PET, and image analysis methods. The imaging findings in normal ageing are then discussed, followed by a series of chapters that carefully present and analyze the key imaging findings in patients with dementias. A structured path of analysis follows the main presenting feature: disorders associated with primary gray matter loss, with white matter changes, with brain swelling, etc. Throughout, a practical approach is adopted, geared specifically to the needs of clinicians (neurologists, radiologists, psychiatrists, geriatricians) working in the field of dementia, for whom this book should prove an invaluable resource. (orig.)

  14. MR volumetric analysis of the course of nephroblastomatosis under chemotherapy in childhood

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Patrick; Waag, Karl Ludwig [Department of Paediatric Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Troeger, Jochen; Schenk, Jens-Peter [Department of Paediatric Radiology, University of Heidelberg (Germany); Graf, Norbert [Department of Paediatric Oncology, Children' s Hospital, University of Homburg/Saar (Germany)

    2004-08-01

    Nephroblastomatosis is a paediatric renal disease that may undergo malignant transformation. When neoadjuvant chemotherapy is indicated for nephroblastomatosis or bilateral Wilms' tumours, exact volumetric analysis using high-speed data processing and visualization may aid in determining tumour response. Using 3D-volume-rendering software, the 0.5-T MRI data of a 2-year-old girl with bilateral nephroblastomatosis was analysed. Exact volume determination of foci of nephroblastomatosis was performed by automatic and manual segmentation, and the relation to normal renal parenchyma was determined over a 12-month period. At the first visit, 80% (460/547 ml) of the extremely enlarged right kidney was due to nephroblastomatosis. Total tumour volume within the right kidney decreased to 74 ml under chemotherapy. Volume analysis of the two emerging right-sided masses after treatment correctly suggested Wilms' tumour. Three-dimensional rendering of the growing masses aided the surgeon in nephron-sparing surgery during tumour resection. (orig.)

  15. ConnectomeExplorer: Query-guided visual analysis of large volumetric neuroscience data

    KAUST Repository

    Beyer, Johanna

    2013-12-01

    This paper presents ConnectomeExplorer, an application for the interactive exploration and query-guided visual analysis of large volumetric electron microscopy (EM) data sets in connectomics research. Our system incorporates a knowledge-based query algebra that supports the interactive specification of dynamically evaluated queries, which enable neuroscientists to pose and answer domain-specific questions in an intuitive manner. Queries are built step by step in a visual query builder, building more complex queries from combinations of simpler queries. Our application is based on a scalable volume visualization framework that scales to multiple volumes of several teravoxels each, enabling the concurrent visualization and querying of the original EM volume, additional segmentation volumes, neuronal connectivity, and additional meta data comprising a variety of neuronal data attributes. We evaluate our application on a data set of roughly one terabyte of EM data and 750 GB of segmentation data, containing over 4,000 segmented structures and 1,000 synapses. We demonstrate typical use-case scenarios of our collaborators in neuroscience, where our system has enabled them to answer specific scientific questions using interactive querying and analysis on the full-size data for the first time. © 1995-2012 IEEE.

  16. Volumetric analysis of the mandibular condyle using cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bayram, Mehmet, E-mail: dtmehmetbayram@yahoo.com [Karadeniz Technical University, Faculty of Dentistry, Department of Orthodontics, 61080 Trabzon (Turkey); Kayipmaz, Saadettin; Sezgin, Oemer Said [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Radiology, Trabzon (Turkey); Kuecuek, Murat [Karadeniz Technical University, Faculty of Arts and Sciences, Department of Chemistry, Trabzon (Turkey)

    2012-08-15

    Objective: The aim was to determine the accuracy of volumetric analysis of the mandibular condyle using cone-beam computed tomography (CBCT). Materials and methods: Five dry mandibles containing 9 condyles were used. CBCT scans of the mandibles and an impression of each condylar area were taken. The physical volumes of the condyles were calculated as the gold standard using the water displacement technique. After isolating, the condylar volume was sectioned in the sagittal plane, and 0.3 mm thick sections with 0.9 mm intervals were obtained from 3D reconstructions. Using the Cavalieri principle, the volume of each condyle was estimated from the CBCT images by three observers. The accuracy of the CBCT volume measurements and the relation agreements between the results of the three observers were assessed using the Wilcoxon Signed Rank test and Pearson correlation test. The level of statistical significance was set at 0.05. Results: The results of the Pearson correlation showed that there were highly significant positive correlations between the observers' measurements. According to the results of the Wilcoxon Signed Rank test comparing the physical and observers' measurements, there were no statistically significant differences (p > 0.05). Conclusion: The Cavalieri principle, used in conjunction with a planimetry method, is a valid and effective method for volume estimation of the mandibular condyle on CBCT images.

  17. Cognitive strategies used by chemistry students to solve volumetric analysis problems

    Science.gov (United States)

    Anamuah-Mensah, J.

    The study investigated the strategies used by 47 high school students to solve volumetric analysis problems in chemistry. Using the talking-aloud technique, the students were required to calculate the concentration of hydrochloric acid used in a titration with NaOH after having performed the titration themselves. Students were met individually and their verbalization audiotaped. After making this calculation, each student was asked to use the same data to predict the concentration of acid in three situations involving different mole ratios. It was found that two main strategies, Formula Approach and Proportional Approach with their variants, were employed by the students during the problem solving process. The Formula Approach was found to be used mainly by the students in the high ability group while students in the low ability group used the Proportional Approach. It was also found that problems involving 2:1 stoichiometric ratios presented a number of conceptual problems to the students. These conceptual problems were found to be related to their inability to write balanced equations or write correct formulas, focusing on only the strength of acid, inability to use the mole ratios in the calulations and deriving the mole ratios from the formulas of reactants.

  18. A retrospective analysis for patient-specific quality assurance of volumetric-modulated arc therapy plans

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guangjun [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Wu, Kui [Department of Radiotherapy, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province (China); Peng, Guang; Zhang, Yingjie [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Bai, Sen, E-mail: baisen@scu.edu.cn [Radiation Physics Center, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China)

    2014-01-01

    Volumetric-modulated arc therapy (VMAT) is now widely used clinically, as it is capable of delivering a highly conformal dose distribution in a short time interval. We retrospectively analyzed patient-specific quality assurance (QA) of VMAT and examined the relationships between the planning parameters and the QA results. A total of 118 clinical VMAT cases underwent pretreatment QA. All plans had 3-dimensional diode array measurements, and 69 also had ion chamber measurements. Dose distribution and isocenter point dose were evaluated by comparing the measurements and the treatment planning system (TPS) calculations. In addition, the relationship between QA results and several planning parameters, such as dose level, control points (CPs), monitor units (MUs), average field width, and average leaf travel, were also analyzed. For delivered dose distribution, a gamma analysis passing rate greater than 90% was obtained for all plans and greater than 95% for 100 of 118 plans with the 3%/3-mm criteria. The difference (mean ± standard deviation) between the point doses measured by the ion chamber and those calculated by TPS was 0.9% ± 2.0% for all plans. For all cancer sites, nasopharyngeal carcinoma and gastric cancer have the lowest and highest average passing rates, respectively. From multivariate linear regression analysis, the dose level (p = 0.001) and the average leaf travel (p < 0.001) showed negative correlations with the passing rate, and the average field width (p = 0.003) showed a positive correlation with the passing rate, all indicating a correlation between the passing rate and the plan complexity. No statistically significant correlation was found between MU or CP and the passing rate. Analysis of the results of dosimetric pretreatment measurements as a function of VMAT plan parameters can provide important information to guide the plan parameter setting and optimization in TPS.

  19. Predicting deliverability of volumetric-modulated arc therapy (VMAT) plans using aperture complexity analysis.

    Science.gov (United States)

    Younge, Kelly C; Roberts, Don; Janes, Lindsay A; Anderson, Carlos; Moran, Jean M; Matuszak, Martha M

    2016-07-08

    The purpose of this study was to evaluate the ability of an aperture complexity metric for volumetric-modulated arc therapy (VMAT) plans to predict plan delivery accuracy. We developed a complexity analysis tool as a plug-in script to Varian's Eclipse treatment planning system. This script reports the modulation of plans, arcs, and individual control points for VMAT plans using a previously developed complexity metric. The calculated complexities are compared to that of 649 VMAT plans previously treated at our institution from 2013 to mid-2015. We used the VMAT quality assurance (QA) results from the 649 treated plans, plus 62 plans that failed pretreatment QA, to validate the ability of the complexity metric to predict plan deliverability. We used a receiver operating characteristic (ROC) analysis to determine an appropriate complexity threshold value above which a plan should be considered for reoptimization before it moves further through our planning workflow. The average complexity metric for the 649 treated plans analyzed with the script was 0.132 mm-1 with a standard deviation of 0.036 mm-1. We found that when using a threshold complexity value of 0.180 mm-1, the true positive rate for correctly identifying plans that failed QA was 44%, and the false-positive rate was 7%. Used clinically with this threshold, the script can identify overly modulated plans and thus prevent a significant portion of QA failures. Reducing VMAT plan complexity has a number of important clinical benefits, including improving plan deliverability and reducing treatment time. Use of the complexity metric during both the planning and QA processes can reduce the number of QA failures and improve the quality of VMAT plans used for treatment.

  20. A Functional Neuroimaging Analysis of the Trail Making Test-B: Implications for Clinical Application

    Directory of Open Access Journals (Sweden)

    Mark D. Allen

    2011-01-01

    Full Text Available Recent progress has been made using fMRI as a clinical assessment tool, often employing analogues of traditional “paper and pencil” tests. The Trail Making Test (TMT, popular for years as a neuropsychological exam, has been largely ignored in the realm of neuroimaging, most likely because its physical format and administration does not lend itself to straightforward adaptation as an fMRI paradigm. Likewise, there is relatively more ambiguity about the neural systems associated with this test than many other tests of comparable clinical use. In this study, we describe an fMRI version of Trail Making Test-B (TMTB that maintains the core functionality of the TMT while optimizing its use for both research and clinical settings. Subjects (N = 32 were administered the Functional Trail Making Test-B (f-TMTB. Brain region activations elicited by the f-TMTB were consistent with expectations given by prior TMT neurophysiological studies, including significant activations in the ventral and dorsal visual pathways and the medial pre-supplementary motor area. The f-TMTB was further evaluated for concurrent validity with the traditional TMTB using an additional sample of control subjects (N = 100. Together, these results support the f-TMTB as a viable neuroimaging adaptation of the TMT that is optimized to evoke maximally robust fMRI activation with minimal time and equipment requirements.

  1. Interpreting support vector machine models for multivariate group wise analysis in neuroimaging.

    Science.gov (United States)

    Gaonkar, Bilwaj; T Shinohara, Russell; Davatzikos, Christos

    2015-08-01

    Machine learning based classification algorithms like support vector machines (SVMs) have shown great promise for turning a high dimensional neuroimaging data into clinically useful decision criteria. However, tracing imaging based patterns that contribute significantly to classifier decisions remains an open problem. This is an issue of critical importance in imaging studies seeking to determine which anatomical or physiological imaging features contribute to the classifier's decision, thereby allowing users to critically evaluate the findings of such machine learning methods and to understand disease mechanisms. The majority of published work addresses the question of statistical inference for support vector classification using permutation tests based on SVM weight vectors. Such permutation testing ignores the SVM margin, which is critical in SVM theory. In this work we emphasize the use of a statistic that explicitly accounts for the SVM margin and show that the null distributions associated with this statistic are asymptotically normal. Further, our experiments show that this statistic is a lot less conservative as compared to weight based permutation tests and yet specific enough to tease out multivariate patterns in the data. Thus, we can better understand the multivariate patterns that the SVM uses for neuroimaging based classification.

  2. Multi-atlas multi-shape segmentation of fetal brain MRI for volumetric and morphometric analysis of ventriculomegaly.

    Science.gov (United States)

    Gholipour, Ali; Akhondi-Asl, Alireza; Estroff, Judy A; Warfield, Simon K

    2012-04-15

    The recent development of motion robust super-resolution fetal brain MRI holds out the potential for dramatic new advances in volumetric and morphometric analysis. Volumetric analysis based on volumetric and morphometric biomarkers of the developing fetal brain must include segmentation. Automatic segmentation of fetal brain MRI is challenging, however, due to the highly variable size and shape of the developing brain; possible structural abnormalities; and the relatively poor resolution of fetal MRI scans. To overcome these limitations, we present a novel, constrained, multi-atlas, multi-shape automatic segmentation method that specifically addresses the challenge of segmenting multiple structures with similar intensity values in subjects with strong anatomic variability. Accordingly, we have applied this method to shape segmentation of normal, dilated, or fused lateral ventricles for quantitative analysis of ventriculomegaly (VM), which is a pivotal finding in the earliest stages of fetal brain development, and warrants further investigation. Utilizing these innovative techniques, we introduce novel volumetric and morphometric biomarkers of VM comparing these values to those that are generated by standard methods of VM analysis, i.e., by measuring the ventricular atrial diameter (AD) on manually selected sections of 2D ultrasound or 2D MRI. To this end, we studied 25 normal and abnormal fetuses in the gestation age (GA) range of 19 to 39 weeks (mean=28.26, stdev=6.56). This heterogeneous dataset was essentially used to 1) validate our segmentation method for normal and abnormal ventricles; and 2) show that the proposed biomarkers may provide improved detection of VM as compared to the AD measurement.

  3. Virtual brain mapping: Meta-analysis and visualization in functional neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup

    Results from functional neuroimaging such as positron emission tomography and functional magnetic resonance are often reported as sets of 3-dimensional coordinates in Talairach stereotactic space. By utilizing data collected in the BrainMap database and from our own small XML database we can...... automatically model and visualize several studies at once. We model a set of 3-dimensional coordinates by a voxelization step where flexible probability density models such as kernel density estimators produce a voxel-volume representation of a study, allowing us to represent all coordinate data in one single...... lists. Image-based indices can be created by singular value decomposition and by matching individual volumes against eigenimages. Individual experiments, sets of experiments as well as results from meta-analyses can be rendered as glyphs, cut-planes or isosurfaces in 3-dimensional Corner Cube...

  4. Perception of affective and linguistic prosody: an ALE meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Belyk, Michel; Brown, Steven

    2014-09-01

    Prosody refers to the melodic and rhythmic aspects of speech. Two forms of prosody are typically distinguished: 'affective prosody' refers to the expression of emotion in speech, whereas 'linguistic prosody' relates to the intonation of sentences, including the specification of focus within sentences and stress within polysyllabic words. While these two processes are united by their use of vocal pitch modulation, they are functionally distinct. In order to examine the localization and lateralization of speech prosody in the brain, we performed two voxel-based meta-analyses of neuroimaging studies of the perception of affective and linguistic prosody. There was substantial sharing of brain activations between analyses, particularly in right-hemisphere auditory areas. However, a major point of divergence was observed in the inferior frontal gyrus: affective prosody was more likely to activate Brodmann area 47, while linguistic prosody was more likely to activate the ventral part of area 44.

  5. Recent advances in the data analysis method of functional magnetic resonance imaging and its applications in neuroimaging

    Institute of Scientific and Technical Information of China (English)

    TIAN Jie; YANG Lei; HU Jin

    2006-01-01

    Functional magnetic resonance imaging (fMRI) has opened a new area to explore the human brain. The fMRI can reveal the deep insights of spatial and temporal changes underlying a broad range of brain function, such as motor, vision, memory and emotion, all of which are helpful in the clinical investigation. In this paper, we introduce some recent-developed algorithms for fMRI signal detection such as model-driven method (general linear model, deconvolution model, non-linear model, etc. ) and data-driven method (principle component analysis, independent component analysis, self-organization mapping, clustered constrained non-negative matrix factorization, etc. ). We also propose several important applications of neuroimaging and point out their shortcomings and future perspectives.

  6. The ethics of secondary data analysis: considering the application of Belmont principles to the sharing of neuroimaging data.

    Science.gov (United States)

    Brakewood, Beth; Poldrack, Russell A

    2013-11-15

    The sharing of data is essential to increasing the speed of scientific discovery and maximizing the value of public investment in scientific research. However, the sharing of human neuroimaging data poses unique ethical concerns. We outline how data sharing relates to the Belmont principles of respect-for-persons, justice, and beneficence. Whereas regulators of human subjects research often view data sharing solely in terms of potential risks to subjects, we argue that the principles of human subject research require an analysis of both risks and benefits, and that such an analysis suggests that researchers may have a positive duty to share data in order to maximize the contribution that individual participants have made.

  7. Radiology resident MR and CT image analysis skill assessment using an interactive volumetric simulation tool - the RadioLOG project.

    Science.gov (United States)

    Gondim Teixeira, Pedro Augusto; Cendre, Romain; Hossu, Gabriela; Leplat, Christophe; Felblinger, Jacques; Blum, Alain; Braun, Marc

    2017-02-01

    Assess the use of a volumetric simulation tool for the evaluation of radiology resident MR and CT interpretation skills. Forty-three participants were evaluated with a software allowing the visualisation of multiple volumetric image series. There were 7 medical students, 28 residents and 8 senior radiologists among the participants. Residents were divided into two sub-groups (novice and advanced). The test was composed of 15 exercises on general radiology and lasted 45 min. Participants answered a questionnaire on their experience with the test using a 5-point Likert scale. This study was approved by the dean of the medical school and did not require ethics committee approval. The reliability of the test was good with a Cronbach alpha value of 0.9. Test scores were significantly different in all sub-groups studies (p radiological practice (3.9 ± 0.9 on a 5-point scale) and was better than the conventional evaluation methods (4.6 ± 0.5 on a 5-point scale). This software provides a high quality evaluation tool for the assessment of the interpretation skills in radiology residents. • This tool allows volumetric image analysis of MR and CT studies. • A high reliability test could be created with this tool. • Test scores were strongly associated with the examinee expertise level. • Examinees positively evaluated the authenticity and usability of this tool.

  8. Volumetric analysis of complex lunar craters - Implications for basin ring formation

    Science.gov (United States)

    Hale, W. S.; Grieve, R. A. F.

    1982-01-01

    The crater to basin transition in complex lunar craters is characterized by combining morphological and volumetric analyses of their central peaks with subsurface data from terrestrial complex impact structures which suggest that the amount of uplifted material, as judged from its depth of origin, continues to increase with increasing rim diameter. This latter phenomenon implies that a redistribution of uplifted material away from a centralized peak may occur in the larger craters. The morphological and volumetric changes described occur over a rim diameter range of 51-80 km, which is considerably lower than the previously proposed range for the crater to basin transition of 140-175 km. Evidence is given in support of a crater to basin transition which begins at 51-80 km, and is characterized by a relative reduction in central peak volume and a development of rings of floor roughening which may be precursors of peak ring development.

  9. Recommendations for sex/gender neuroimaging research: key principles and implications for research design, analysis, and interpretation

    Science.gov (United States)

    Rippon, Gina; Jordan-Young, Rebecca; Kaiser, Anelis; Fine, Cordelia

    2014-01-01

    Neuroimaging (NI) technologies are having increasing impact in the study of complex cognitive and social processes. In this emerging field of social cognitive neuroscience, a central goal should be to increase the understanding of the interaction between the neurobiology of the individual and the environment in which humans develop and function. The study of sex/gender is often a focus for NI research, and may be motivated by a desire to better understand general developmental principles, mental health problems that show female-male disparities, and gendered differences in society. In order to ensure the maximum possible contribution of NI research to these goals, we draw attention to four key principles—overlap, mosaicism, contingency and entanglement—that have emerged from sex/gender research and that should inform NI research design, analysis and interpretation. We discuss the implications of these principles in the form of constructive guidelines and suggestions for researchers, editors, reviewers and science communicators. PMID:25221493

  10. Comparative analysis of volumetric flow meters used for mass flow estimation in multiphase and multidensity environments

    Science.gov (United States)

    Pedone, Richard; Korman, Valentin; Wiley, John T.

    2006-05-01

    Accurate and reliable multiphase flow measurements are needed for liquid propulsion systems. Existing volumetric flow meters are adequate for flow measurements with well-characterized, clean liquids and gases. However, these technologies are inadequate for multiphase environments, such as cryogenic fluids. Although, properly calibrated turbine flow meters can provide highly accurate and repeatable data, problems are still prevalent with multiphase flows. Limitations are thus placed on the applicability of intrusive turbine flow meters.

  11. Neuroimaging in Epilepsy

    Directory of Open Access Journals (Sweden)

    Mahmoud Motamedi

    2009-01-01

    scanning protocol for a patient with refractory epilepsy may include T1-weighted imaging, T2-weighted imaging, FLAIR imaging, and 3D volume acquisition sequences. Imaging must be in hippocampal axis and good signal -to -noise ratio is as important as thin slices. The application of contrast agents is indicated if there is suspicion of a primary or metastatic tumor, infection, or inflammatory lesion. In epilepsy centers, it must be possible to diagnose hippocampal sclerosis with high sensitivity and specificity with visual analysis."nOne should think good "epilepsy MRI" not "MRI." To achieve this, knowledge of MRI is needed not only by the radiologist, but also by the neurologist and epileptologist. It is this continuing interaction that enables optimized imaging to be obtained."nQuantification of Volumes and T2 Relaxometry in Epilepsy"nHigh-resolution T1-weighted 3D volume sequences can be used quantitatively to measure the volume of any particular regions of interest. In the case of epilepsy this is usually the hippocampus. Volumetric measurements require a significant investment in learning the hippocampal boundaries and depend on a large number of variables that need to be understood and controlled for in image analysis and acquisition. Volumetric assessment makes it possible to assess the progression of volumetric changes and may begin to help unravel the effects of the primary disease from the secondary effects of seizures. It can be performed manually or with half- or fully-automated software."nT2 relaxometry is the quantitative determination of the T2 relaxation time. To achieve this, several T2-weighted images are acquired at different echo times, and in each voxel the resultant values are fit with an exponential decay curve to estimate the T2 decay rate of the imaged tissue. T2 relaxometry has been established as a reliable tool that is stable over time. In contrast to elaborate volumetric assessment, the T2 relaxometry is a quick technique with small variance and

  12. Multi-Source Learning for Joint Analysis of Incomplete Multi-Modality Neuroimaging Data.

    Science.gov (United States)

    Yuan, Lei; Wang, Yalin; Thompson, Paul M; Narayan, Vaibhav A; Ye, Jieping

    2012-01-01

    Incomplete data present serious problems when integrating largescale brain imaging data sets from different imaging modalities. In the Alzheimer's Disease Neuroimaging Initiative (ADNI), for example, over half of the subjects lack cerebrospinal fluid (CSF) measurements; an independent half of the subjects do not have fluorodeoxyglucose positron emission tomography (FDG-PET) scans; many lack proteomics measurements. Traditionally, subjects with missing measures are discarded, resulting in a severe loss of available information. We address this problem by proposing two novel learning methods where all the samples (with at least one available data source) can be used. In the first method, we divide our samples according to the availability of data sources, and we learn shared sets of features with state-of-the-art sparse learning methods. Our second method learns a base classifier for each data source independently, based on which we represent each source using a single column of prediction scores; we then estimate the missing prediction scores, which, combined with the existing prediction scores, are used to build a multi-source fusion model. To illustrate the proposed approaches, we classify patients from the ADNI study into groups with Alzheimer's disease (AD), mild cognitive impairment (MCI) and normal controls, based on the multi-modality data. At baseline, ADNI's 780 participants (172 AD, 397 MCI, 211 Normal), have at least one of four data types: magnetic resonance imaging (MRI), FDG-PET, CSF and proteomics. These data are used to test our algorithms. Comprehensive experiments show that our proposed methods yield stable and promising results.

  13. Neuroimaging in Iran: A Review

    Directory of Open Access Journals (Sweden)

    G. Ali Hossein-Zadeh

    2010-11-01

    Full Text Available ABSTRACTNeuroimaging allows noninvasive evaluation of the anatomy, physiology, and function of the brain. It is widely used for diagnosis, treatment planning, and treatment evaluation of neurological disorders as well as understanding functions of the brain in health and disease. Neuroimaging modalities include X-ray computed tomography (CT, magnetic resonance imaging (MRI, single photon emission computed tomography (SPECT, positron emission tomography (PET, electroencephalography (EEG, and magnetoencephalography (MEG. This paper presents an overview of the neuroimaging research in Iran in recent years, partitioned into three categories: anatomical imaging; anatomical image analysis; and functional imaging and analysis. Published papers reflect considerable progress in development of neuroimaging infrastructure, hardware installation and software development. However, group work and research collaborations among engineers, scientists, and clinicians need significant enhancement to optimize utility of the resources and maximize productivity. This is a challenge that cannot be solved without specific plans, policies, and funding.

  14. MTF analysis of a prototype table-top inverse-geometry volumetric CT system

    Science.gov (United States)

    Schmidt, Taly G.; Bennett, N. Robert; Mazin, Samuel R.; Star-Lack, Josh; Solomon, Edward G.; Pelc, Norbert J.

    2005-04-01

    This work investigates the modulation transfer function (MTF) of a prototype table-top inverse-geometry volumetric CT (IGCT) system. The IGCT system has been proposed to acquire sufficient volumetric data in one circular rotation using a large-area scanned source and a narrower array of fast detectors. The source and detector arrays have the same axial, or slice, extent, thus providing sufficient volumetric coverage. A prototype system has been built using a NexRay Scanning-Beam Digital X-ray system (NexRay, Inc., Los Gatos, CA) with the C-arm gantry in the horizontal position and a stage placed between the source and detector to rotate the scanned object. The resulting system has a 16-cm in-plane field of view (FOV) and 5-cm axial FOV. Two phantoms were constructed for measuring the MTF. A 76 micron tungsten wire placed axially in a plastic frame was used to measure the in-plane MTF, and the same wire slanted at 45 degrees was used to test the isotropy of the MTF. The data were calibrated for flat-field intensity and geometric misalignment and reconstructed using a modified 3D PET algorithm. For both phantoms, slices perpendicular to the wires were reconstructed. Simulations which model the IGCT system were used to verify the MTF measurement, along with analytical predictions. The measured MTF curve was similar in shape to the predicted curve with a 10% point at 20 lp/cm compared to a predicted 18 lp/cm. Future work will also study the uniformity of the MTF across the FOV and further characterize the IGCT system.

  15. Finite element analysis of volumetrically heated fluids in an axisymmetric enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Gartling, D.K.

    1979-01-01

    A general purpose finite element computer code has been used to analyze the steady state and transient response of a confined fluid that is heated volumetrically. The numerical procedure is demonstrated to be capable of resolving flow fields of considerable complexity without undue computational expense. Results are discussed for a Grashof number range (4.0 x 10/sup 4/ to 4.0 x 10/sup 6/) in which the flow varies from a steady, single cell configuration to a multiple cell configuration that includes a periodic interaction.

  16. Structural MRI volumetric analysis in patients with organic amnesia, 1: methods and comparative findings across diagnostic groups

    National Research Council Canada - National Science Library

    Colchester, A; Kingsley, D; Lasserson, D; Kendall, B; Bello, F; Rush, C; Stevens, T G; Goodman, G; Heilpern, G; Stanhope, N; Kopelman, M D

    2001-01-01

    .... Previous neuroimaging reports in patients with Korsakoff syndrome have generally found widespread or non-specific change, whereas in patients with herpes encephalitis the extent of pathological...

  17. Measurement of anterior and posterior circulation flow contributions to cerebral blood flow. An ultrasound-derived volumetric flow analysis.

    Science.gov (United States)

    Boyajian, R A; Schwend, R B; Wolfe, M M; Bickerton, R E; Otis, S M

    1995-01-01

    Ultrasound-derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the anterior (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (internal carotid arteries bilaterally) carried 82% of the brain's blood supply and comprised 67% of the total vascular cross-sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen-Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound-derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.

  18. Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Won; Lee, Woo Jin; Choi, Soon Chul; Lee, Sam Sun; Heo, Min Suk; Huh, Kyung Hoe; Kim, Tae Il; Yi, Won Ji [Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2015-03-15

    We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05). It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

  19. Is meditation associated with altered brain structure? A systematic review and meta-analysis of morphometric neuroimaging in meditation practitioners.

    Science.gov (United States)

    Fox, Kieran C R; Nijeboer, Savannah; Dixon, Matthew L; Floman, James L; Ellamil, Melissa; Rumak, Samuel P; Sedlmeier, Peter; Christoff, Kalina

    2014-06-01

    Numerous studies have begun to address how the brain's gray and white matter may be shaped by meditation. This research is yet to be integrated, however, and two fundamental questions remain: Is meditation associated with altered brain structure? If so, what is the magnitude of these differences? To address these questions, we reviewed and meta-analyzed 123 brain morphology differences from 21 neuroimaging studies examining ∼300 meditation practitioners. Anatomical likelihood estimation (ALE) meta-analysis found eight brain regions consistently altered in meditators, including areas key to meta-awareness (frontopolar cortex/BA 10), exteroceptive and interoceptive body awareness (sensory cortices and insula), memory consolidation and reconsolidation (hippocampus), self and emotion regulation (anterior and mid cingulate; orbitofrontal cortex), and intra- and interhemispheric communication (superior longitudinal fasciculus; corpus callosum). Effect size meta-analysis (calculating 132 effect sizes from 16 studies) suggests a global 'medium' effect size (Cohen's d¯=0.46; r¯=.19). Publication bias and methodological limitations are strong concerns, however. Further research using rigorous methods is required to definitively link meditation practice to altered brain morphology.

  20. Neural correlates of conversion disorder: overview and meta-analysis of neuroimaging studies on motor conversion disorder.

    Science.gov (United States)

    Boeckle, Markus; Liegl, Gregor; Jank, Robert; Pieh, Christoph

    2016-06-10

    Conversion Disorders (CD) are prevalent functional disorders. Although the pathogenesis is still not completely understood, an interaction of genetic, neurobiological, and psychosocial factors is quite likely. The aim of this study is to provide a systematic overview on imaging studies on CDs and investigate neuronal areas involved in Motor Conversion Disorders (MCD). A systematic literature search was conducted on CD. Subsequently a meta-analysis of functional neuroimaging studies on MCD was implemented using an Activation Likelihood Estimation (ALE). We calculated differences between patients and healthy controls as well as between affected versus unaffected sides in addition to an overall analysis in order to identify neuronal areas related to MCD. Patients with MCD differ from healthy controls in the amygdala, superior temporal lobe, retrosplenial area, primary motor cortex, insula, red nucleus, thalamus, anterior as well as dorsolateral prefrontal and frontal cortex. When comparing affected versus unaffected sides, temporal cortex, dorsal anterior cingulate cortex, supramarginal gyrus, dorsal temporal lobe, anterior insula, primary somatosensory cortex, superior frontal gyrus and anterior prefrontal as well as frontal cortex show significant differences. Neuronal areas seem to be involved in the pathogenesis, maintenance or as a result of MCD. Areas that are important for motor-planning, motor-selection or autonomic response seem to be especially relevant. Our results support the emotional unawareness theory but also underline the need of more support by conduction imaging studies on both CD and MCD.

  1. Volumetric analysis of day of injury computed tomography is associated with rehabilitation outcomes after traumatic brain injury.

    Science.gov (United States)

    Majercik, Sarah; Bledsoe, Joseph; Ryser, David; Hopkins, Ramona O; Fair, Joseph E; Brock Frost, R; MacDonald, Joel; Barrett, Ryan; Horn, Susan; Pisani, David; Bigler, Erin D; Gardner, Scott; Stevens, Mark; Larson, Michael J

    2017-01-01

    Day-of-injury (DOI) brain lesion volumes in traumatic brain injury (TBI) patients are rarely used to predict long-term outcomes in the acute setting. The purpose of this study was to investigate the relationship between acute brain injury lesion volume and rehabilitation outcomes in patients with TBI at a level one trauma center. Patients with TBI who were admitted to our rehabilitation unit after the acute care trauma service from February 2009-July 2011 were eligible for the study. Demographic data and outcome variables including cognitive and motor Functional Independence Measure (FIM) scores, length of stay (LOS) in the rehabilitation unit, and ability to return to home were obtained. The DOI quantitative injury lesion volumes and degree of midline shift were obtained from DOI brain computed tomography scans. A multiple stepwise regression model including 13 independent variables was created. This model was used to predict postrehabilitation outcomes, including FIM scores and ability to return to home. A p value less than 0.05 was considered significant. Ninety-six patients were enrolled in the study. Mean age was 43 ± 21 years, admission Glasgow Coma Score was 8.4 ± 4.8, Injury Severity Score was 24.7 ± 9.9, and head Abbreviated Injury Scale score was 3.73 ± 0.97. Acute hospital LOS was 12.3 ± 8.9 days, and rehabilitation LOS was 15.9 ± 9.3 days. Day-of-injury TBI lesion volumes were inversely associated with cognitive FIM scores at rehabilitation admission (p = 0.004) and discharge (p = 0.004) and inversely associated with ability to be discharged to home after rehabilitation (p = 0.006). In a cohort of patients with moderate to severe TBI requiring a rehabilitation unit stay after the acute care hospital stay, DOI brain injury lesion volumes are associated with worse cognitive FIM scores at the time of rehabilitation admission and discharge. Smaller-injury volumes were associated with eventual discharge to home. Volumetric neuroimaging in the acute

  2. Volumetric composition of nanocomposites

    DEFF Research Database (Denmark)

    Madsen, Bo; Lilholt, Hans; Mannila, Juha

    2015-01-01

    Detailed characterisation of the properties of composite materials with nanoscale fibres is central for the further progress in optimization of their manufacturing and properties. In the present study, a methodology for the determination and analysis of the volumetric composition of nanocomposites...... is presented, using cellulose/epoxy and aluminosilicate/polylactate nanocomposites as case materials. The buoyancy method is used for the accurate measurements of materials density. The accuracy of the method is determined to be high, allowing the measured nanocomposite densities to be reported with 5...... significant figures. The plotting of the measured nanocomposite density as a function of the nanofibre weight content is shown to be a first good approach of assessing the porosity content of the materials. The known gravimetric composition of the nanocomposites is converted into a volumetric composition...

  3. Neuroimaging in tuberculous meningitis

    Directory of Open Access Journals (Sweden)

    Ravindra Kumar Garg

    2016-01-01

    Full Text Available Tuberculous meningitis is a serious infection caused by Mycobacterium tuberculosis. Early diagnosis is the key to success of treatment. Neuroimaging plays a crucial role in the early and accurate diagnosis of tuberculous meningitis and its disabling complications. Magnetic resonance imaging is considered superior to computed tomography. Neuroimaging characteristics include leptomeningeal and basal cisternal enhancement, hydrocephalus, periventricular infarcts, and tuberculoma. Partially treated pyogenic meningitis, cryptococcal meningitis, viral encephalitis, carcinomatous, and lymphomatous meningitis may have many similar neuroimaging characteristics, and differentiation from tuberculous meningitis at times on the basis of neuroimaging characteristics becomes difficult.

  4. Dopamine Transporter Neuroimaging as an Enrichment Biomarker in Early Parkinson's Disease Clinical Trials: A Disease Progression Modeling Analysis.

    Science.gov (United States)

    Conrado, Daniela J; Nicholas, Timothy; Tsai, Kuenhi; Macha, Sreeraj; Sinha, Vikram; Stone, Julie; Corrigan, Brian; Bani, Massimo; Muglia, Pierandrea; Watson, Ian A; Kern, Volker D; Sheveleva, Elena; Marek, Kenneth; Stephenson, Diane T; Romero, Klaus

    2017-07-27

    Given the recognition that disease-modifying therapies should focus on earlier Parkinson's disease stages, trial enrollment based purely on clinical criteria poses significant challenges. The goal herein was to determine the utility of dopamine transporter neuroimaging as an enrichment biomarker in early motor Parkinson's disease clinical trials. Patient-level longitudinal data of 672 subjects with early-stage Parkinson's disease in the Parkinson's Progression Markers Initiative (PPMI) observational study and the Parkinson Research Examination of CEP-1347 Trial (PRECEPT) clinical trial were utilized in a linear mixed-effects model analysis. The rate of worsening in the motor scores between subjects with or without a scan without evidence of dopamine transporter deficit was different both statistically and clinically. The average difference in the change from baseline of motor scores at 24 months between biomarker statuses was -3.16 (90% confidence interval [CI] = -0.96 to -5.42) points. Dopamine transporter imaging could identify subjects with a steeper worsening of the motor scores, allowing trial enrichment and 24% reduction of sample size. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  5. Correlation between gamma analysis for midline and lateralized tumors by using volumetric modulated arc therapy

    Directory of Open Access Journals (Sweden)

    Syam Surendran Nair Ambika Devi

    2015-09-01

    Full Text Available Purpose: The aim of this study was to evaluate the fluence for midline and lateralized tumors for volumetric modulated arc therapy (VMAT by using a two-dimensional array.Methods: For this study, we selected 60 patients who were undergoing VMAT. The octavius phantom was computed tomography (CT scanned and imported to the planning system. Verification plans were created for each plan and exported. The measurements were performed using 2D seven29 ion chamber array. Fluence measurement values for all the delivered plans were analyzed using VeriSoft software. The TPS calculated values were then compared with the measured gamma values. Results: The gamma pass percentage for midline tumors was found to be higher than that for lateralized tumors. The standard deviations between the gamma values for midline and lateralized tumors were 1.96 and 2.86, respectively. Moreover, the standard deviations between the point doses for midline and lateralized tumors were 0.360 and 0.283, respectively. The mean gamma passing rate was 96.96% for midline tumors and 96.57% for lateralized tumors for 3%DD/3-mm criteria. There is no significance found in the gamma values for midline and lateralized tumors with p-value 0.08. Conclusion: No particular correlation was found between the gamma pass percentage for midline tumors and that for lateralized tumors. Only a marginal difference was found in the gamma pass percentage.

  6. Intensity modulated radiotherapy versus volumetric modulated arc therapy in breast cancer: A comparative dosimetric analysis

    Directory of Open Access Journals (Sweden)

    KR Muralidhar

    2015-01-01

    Full Text Available Purpose: Intensity modulated radiotherapy (IMRT and volumetric modulated arc therapy (VMAT has the capacity to optimize the dose distribution. We analyzed the dosimetric differences of plans in treatment planning system (TPS between VMAT and IMRT in treating breast cancer. Methods: Fourteen patients were simulated, planned, and treated with VMAT using single, double or partial arcs. IMRT treatments were generated using 4 to 5 tangential IMRT fields for the same patients. All treatment plans were planned for 50 Gy in 25 fractions. The VMAT and IMRT plans were compared using the planning target volume (PTV dose and doses to the other organs at risk (OARs. Results: For the PTV, comparable minimum, mean, maximum, median, and modal dose as well equivalent sphere diameter of the structure (Equis were observed between VMAT and IMRT plans and found that these values were significantly equal in both techniques. The right lung mean and modal doses were considerably higher in VMAT plans while maximum value was considerably lower when compared with IMRT plans. The left lung mean and modal doses were higher with VMAT while maximum doses were higher in IMRT plans. The mean dose to the heart and maximum dose to the spinal cord was lower with IMRT. The mean dose to the body was higher in VMAT plans while the maximum dose was higher in IMRT plans. Conclusion: Four field tangential IMRT delivered comparable PTV dose with generally less dose to normal tissues in our breast cancer treatment study. The IMRT plans typically had more favourable dose characteristics to the lung, heart, and spinal cord and body dose when compared with VMAT. The only minor advantage of VMAT for breast cases was slightly better PTV coverage.

  7. Quantitative attenuation analysis for identification of early Barrett's neoplasia in volumetric laser endomicroscopy.

    Science.gov (United States)

    Swager, Anne-Fre; Faber, Dirk J; de Bruin, Daniel M; Weusten, Bas L; Meijer, Sybren L; Bergman, Jacques J; Curvers, Wouter L; van Leeuwen, Ton G

    2017-08-01

    Early neoplasia in Barrett’s esophagus (BE) is difficult to detect. Volumetric laser endomicroscopy (VLE) incorporates optical coherence tomography, providing a circumferential scan of the esophageal wall layers. The attenuation coefficient (μVLE) quantifies decay of detected backscattered light versus depth, and could potentially improve BE neoplasia detection. The aim is to investigate feasibility of μVLE for identification of early BE neoplasia. In vivo and ex vivo VLE scans with histological correlation from BE patients ± neoplasia were used. Quantification by μVLE was performed manually on areas of interest (AoIs) to differentiate neoplasia from nondysplastic (ND)BE. From ex vivo VLE scans from 16 patients (13 with neoplasia), 68 AoIs were analyzed. Median μVLE values (mm−1) were 3.7 [2.1 to 4.4 interquartile range (IQR)] for NDBE and 4.0 (2.5 to 4.9 IQR) for neoplasia, not statistically different (p=0.82). Fourteen in vivo scans were used: nine from neoplastic and five from NDBE patients. Median μVLE values were 1.8 (1.5 to 2.6 IQR) for NDBE and 2.1 (1.9 to 2.6 IQR) for neoplasia, with no statistically significant difference (p=0.37). In conclusion, there was no significant difference in μVLE values in VLE scans from early neoplasia versus NDBE. Future studies with a larger sample size should explore other quantitative methods for detection of neoplasia during BE surveillance.

  8. Radiation therapy for gastric mucosa-associated lymphoid tissue lymphoma: Dose-volumetric analysis and its clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyeon Won; Kim, Tae Hyun; Choi, Il Ju; Kim, Chan Gyoo; Lee, Jong Yeul; Cho, Soo Jeong; Eom, Hyeon Seok; Moon, Sung Ho; Kim, Dae Yong [Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of)

    2016-09-15

    To assess the clinical outcomes of radiotherapy (RT) using two-dimensional (2D) and three-dimensional conformal RT (3D-CRT) for patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma to evaluate the effectiveness of involved field RT with moderate-dose and to evaluate the benefit of 3D-CRT comparing with 2D-RT. Between July 2003 and March 2015, 33 patients with stage IE and IIE gastric MALT lymphoma received RT were analyzed. Of 33 patients, 17 patients (51.5%) were Helicobacter pylori (HP) negative and 16 patients (48.5%) were HP positive but refractory to HP eradication (HPE). The 2D-RT (n = 14) and 3D-CRT (n = 19) were performed and total dose was 30.6 Gy/17 fractions. Of 11 patients who RT planning data were available, dose-volumetric parameters between 2D-RT and 3D-CRT plans was compared. All patients reached complete remission (CR) eventually and median time to CR was 3 months (range, 1 to 15 months). No local relapse occurred and one patient died with second primary malignancy. Tumor response, survival, and toxicity were not significantly different between 2D-RT and 3D-CRT (p > 0.05, each). In analysis for dose-volumetric parameters, Dmax and CI for PTV were significantly lower in 3D-CRT plans than 2D-RT plans (p < 0.05, each) and Dmean and V15 for right kidney and Dmean for left kidney were significantly lower in 3D-CRT than 2D-RT (p < 0.05, each). Our data suggested that involved field RT with moderate-dose for gastric MALT lymphoma could be promising and 3D-CRT could be considered to improve the target coverage and reduce radiation dose to the both kidneys.

  9. Neural Systems Underlying Emotional and Non-emotional Interference Processing: An ALE Meta-Analysis of Functional Neuroimaging Studies

    Science.gov (United States)

    Xu, Min; Xu, Guiping; Yang, Yang

    2016-01-01

    Understanding how the nature of interference might influence the recruitments of the neural systems is considered as the key to understanding cognitive control. Although, interference processing in the emotional domain has recently attracted great interest, the question of whether there are separable neural patterns for emotional and non-emotional interference processing remains open. Here, we performed an activation likelihood estimation meta-analysis of 78 neuroimaging experiments, and examined common and distinct neural systems for emotional and non-emotional interference processing. We examined brain activation in three domains of interference processing: emotional verbal interference in the face-word conflict task, non-emotional verbal interference in the color-word Stroop task, and non-emotional spatial interference in the Simon, SRC and Flanker tasks. Our results show that the dorsal anterior cingulate cortex (ACC) was recruited for both emotional and non-emotional interference. In addition, the right anterior insula, presupplementary motor area (pre-SMA), and right inferior frontal gyrus (IFG) were activated by interference processing across both emotional and non-emotional domains. In light of these results, we propose that the anterior insular cortex may serve to integrate information from different dimensions and work together with the dorsal ACC to detect and monitor conflicts, whereas pre-SMA and right IFG may be recruited to inhibit inappropriate responses. In contrast, the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC) showed different degrees of activation and distinct lateralization patterns for different processing domains, which suggests that these regions may implement cognitive control based on the specific task requirements. PMID:27895564

  10. Neural networks involved in adolescent reward processing: An activation likelihood estimation meta-analysis of functional neuroimaging studies.

    Science.gov (United States)

    Silverman, Merav H; Jedd, Kelly; Luciana, Monica

    2015-11-15

    Behavioral responses to, and the neural processing of, rewards change dramatically during adolescence and may contribute to observed increases in risk-taking during this developmental period. Functional MRI (fMRI) studies suggest differences between adolescents and adults in neural activation during reward processing, but findings are contradictory, and effects have been found in non-predicted directions. The current study uses an activation likelihood estimation (ALE) approach for quantitative meta-analysis of functional neuroimaging studies to: (1) confirm the network of brain regions involved in adolescents' reward processing, (2) identify regions involved in specific stages (anticipation, outcome) and valence (positive, negative) of reward processing, and (3) identify differences in activation likelihood between adolescent and adult reward-related brain activation. Results reveal a subcortical network of brain regions involved in adolescent reward processing similar to that found in adults with major hubs including the ventral and dorsal striatum, insula, and posterior cingulate cortex (PCC). Contrast analyses find that adolescents exhibit greater likelihood of activation in the insula while processing anticipation relative to outcome and greater likelihood of activation in the putamen and amygdala during outcome relative to anticipation. While processing positive compared to negative valence, adolescents show increased likelihood for activation in the posterior cingulate cortex (PCC) and ventral striatum. Contrasting adolescent reward processing with the existing ALE of adult reward processing reveals increased likelihood for activation in limbic, frontolimbic, and striatal regions in adolescents compared with adults. Unlike adolescents, adults also activate executive control regions of the frontal and parietal lobes. These findings support hypothesized elevations in motivated activity during adolescence.

  11. Informing the Structure of Executive Function in Children: A Meta-Analysis of Functional Neuroimaging Data.

    Science.gov (United States)

    McKenna, Róisín; Rushe, T; Woodcock, Kate A

    2017-01-01

    The structure of executive function (EF) has been the focus of much debate for decades. What is more, the complexity and diversity provided by the developmental period only adds to this contention. The development of executive function plays an integral part in the expression of children's behavioral, cognitive, social, and emotional capabilities. Understanding how these processes are constructed during development allows for effective measurement of EF in this population. This meta-analysis aims to contribute to a better understanding of the structure of executive function in children. A coordinate-based meta-analysis was conducted (using BrainMap GingerALE 2.3), which incorporated studies administering functional magnetic resonance imaging (fMRI) during inhibition, switching, and working memory updating tasks in typical children (aged 6-18 years). The neural activation common across all executive tasks was compared to that shared by tasks pertaining only to inhibition, switching or updating, which are commonly considered to be fundamental executive processes. Results support the existence of partially separable but partially overlapping inhibition, switching, and updating executive processes at a neural level, in children over 6 years. Further, the shared neural activation across all tasks (associated with a proposed "unitary" component of executive function) overlapped to different degrees with the activation associated with each individual executive process. These findings provide evidence to support the suggestion that one of the most influential structural models of executive functioning in adults can also be applied to children of this age. However, the findings also call for careful consideration and measurement of both specific executive processes, and unitary executive function in this population. Furthermore, a need is highlighted for a new systematic developmental model, which captures the integrative nature of executive function in children.

  12. Processing of primary and secondary rewards: a quantitative meta-analysis and review of human functional neuroimaging studies

    NARCIS (Netherlands)

    Sescousse, G.T.; Caldu, X.; Segura, B.; Dreher, J.C.

    2013-01-01

    One fundamental question concerning brain reward mechanisms is to determine how reward-related activity is influenced by the nature of rewards. Here, we review the neuroimaging literature and explicitly assess to what extent the representations of primary and secondary rewards overlap in the human b

  13. Self-reflection and the brain : A theoretical review and meta-analysis of neuroimaging studies with implications for schizophrenia

    NARCIS (Netherlands)

    van der Meer, Lisette; Costafreda, Sergi; Aleman, Andre; David, Anthony S.

    2010-01-01

    Several studies have investigated the neural correlates of self-reflection. In the paradigm most commonly used to address this concept, a subject is presented with trait adjectives or sentences and asked whether they describe him or her. Functional neuroimaging research has revealed a set of regions

  14. Looking for neuroimaging markers in frontotemporal lobar degeneration clinical trials : A multi-voxel pattern analysis study in Granulin disease

    NARCIS (Netherlands)

    Premi, Enrico; Cauda, Franco; Costa, Tommaso; Diano, M.; Gazzina, Stefano; Gualeni, Vera; Alberici, Antonella; Archetti, Silvana; Magoni, Mauro; Gasparotti, Roberto; Padovani, Alessandro; Borroni, Barbara

    2016-01-01

    In light of future pharmacological interventions, neuroimaging markers able to assess the response to treatment would be crucial. In Granulin (GRN) disease, preclinical data will prompt pharmacological trials in the future. Two main points need to be assessed: 1) to identify target regions in

  15. Prefrontal Cortex and Executive Functions in Healthy Adults: A Meta-Analysis of Structural Neuroimaging Studies

    Science.gov (United States)

    Yuan, Peng; Raz, Naftali

    2014-01-01

    Lesion studies link the prefrontal cortex (PFC) to executive functions. However, the evidence from in vivo investigations in healthy people is mixed, and there are no quantitative estimates of the association strength. To examine the relationship between PFC volume and cortical thickness with executive cognition in healthy adults, we conducted a meta-analysis of studies that assessed executive functions and PFC volume (31 samples,) and PFC thickness (10 samples) in vivo, N=3272 participants. We found that larger PFC volume and greater PFC thickness were associated with better executive performance. Stronger associations between executive functions and PFC volume were linked to greater variance in the sample age but was unrelated to the mean age of a sample. Strength of association between cognitive and neuroanatomical indices depended on the executive task used in the study. PFC volume correlated stronger with Wisconsin Card Sorting Test than with digit backwards span, Trail Making Test and verbal fluency. Significant effect size was observed in lateral and medial but not orbital PFC. The results support the “bigger is better” hypothesis of brain-behavior relation in healthy adults and suggest different neural correlates across the neuropsychological tests used to assess executive functions. PMID:24568942

  16. Volumetric Virtual Environments

    Institute of Scientific and Technical Information of China (English)

    HE Taosong

    2000-01-01

    Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VR system, specifically the modeling, rendering, and manipulations of a volumetric scene.Techniques such as voxel-based object simplification, accelerated volume rendering,fast stereo volume rendering, and volumetric "collision detection" are introduced and improved, with the idea of demonstrating the possibilities and potential benefits of incorporating volumetric models into VR systems.

  17. Brain signature of chronic orofacial pain: a systematic review and meta-analysis on neuroimaging research of trigeminal neuropathic pain and temporomandibular joint disorders.

    Science.gov (United States)

    Lin, Chia-Shu

    2014-01-01

    Brain neuroimaging has been widely used to investigate the bran signature of chronic orofacial pain, including trigeminal neuropathic pain (TNP) and pain related to temporomandibular joint disorders (TMD). We here systematically reviewed the neuroimaging literature regarding the functional and structural changes in the brain of TNP and TMD pain patients, using a computerized search of journal articles via PubMed. Ten TNP studies and 14 TMD studies were reviewed. Study quality and risk of bias were assessed based on the criteria of patient selection, the history of medication, the use of standardized pain/psychological assessments, and the model and statistics of imaging analyses. Qualitative meta-analysis was performed by examining the brain regions which showed significant changes in either brain functions (including the blood-oxygen-level dependent signal, cerebral blood flow and the magnetic resonance spectroscopy signal) or brain structure (including gray matter and white matter anatomy). We hypothesized that the neuroimaging findings would display a common pattern as well as distinct patterns of brain signature in the disorders. This major hypothesis was supported by the following findings: (1) TNP and TMD patients showed consistent functional/structural changes in the thalamus and the primary somatosensory cortex, indicating the thalamocortical pathway as the major site of plasticity. (2) The TNP patients showed more alterations at the thalamocortical pathway, and the two disorders showed distinct patterns of thalamic and insular connectivity. Additionally, functional and structural changes were frequently reported in the prefrontal cortex and the basal ganglia, suggesting the role of cognitive modulation and reward processing in chronic orofacial pain. The findings highlight the potential for brain neuroimaging as an investigating tool for understanding chronic orofacial pain.

  18. Neuroimaging of epilepsy

    Science.gov (United States)

    Cendes, Fernando; Theodore, William H.; Brinkmann, Benjamin H.; Sulc, Vlastimil; Cascino, Gregory D.

    2017-01-01

    Imaging is pivotal in the evaluation and management of patients with seizure disorders. Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, low-grade glial neoplasms and malformations of cortical development has been demonstrated. Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment. This chapter highlights neuroimaging developments and innovations, and provides a comprehensive overview of the imaging strategies used to improve the care and management of people with epilepsy. PMID:27430454

  19. Neuroimaging of epilepsy.

    Science.gov (United States)

    Cendes, Fernando; Theodore, William H; Brinkmann, Benjamin H; Sulc, Vlastimil; Cascino, Gregory D

    2016-01-01

    Imaging is pivotal in the evaluation and management of patients with seizure disorders. Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, low-grade glial neoplasms and malformations of cortical development has been demonstrated. Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment. This chapter highlights neuroimaging developments and innovations, and provides a comprehensive overview of the imaging strategies used to improve the care and management of people with epilepsy. © 2016 Elsevier B.V. All rights reserved.

  20. Volumetric analysis of the normal infant brain and in intrauterine growth retardation

    DEFF Research Database (Denmark)

    Toft, P B; Leth, H; Ring, P B

    1995-01-01

    and the volumes were determined by encircling each structure of interest on every slice. Segmentation into grey matter, white matter and CSF was done by semi-automatic discriminant analysis. Growth charts for the cerebrum, cerebellum, corpora striata, thalami, ventricles, and grey and white matter are provided...

  1. Trabecular bone characterization on the continuum of plates and rods using in vivo MR imaging and volumetric topological analysis.

    Science.gov (United States)

    Chen, Cheng; Jin, Dakai; Liu, Yinxiao; Wehrli, Felix W; Chang, Gregory; Snyder, Peter J; Regatte, Ravinder R; Saha, Punam K

    2016-09-21

    Osteoporosis is associated with increased risk of fractures, which is clinically defined by low bone mineral density. Increasing evidence suggests that trabecular bone (TB) micro-architecture is an important determinant of bone strength and fracture risk. We present an improved volumetric topological analysis algorithm based on fuzzy skeletonization, results of its application on in vivo MR imaging, and compare its performance with digital topological analysis. The new VTA method eliminates data loss in the binarization step and yields accurate and robust measures of local plate-width for individual trabeculae, which allows classification of TB structures on the continuum between perfect plates and rods. The repeat-scan reproducibility of the method was evaluated on in vivo MRI of distal femur and distal radius, and high intra-class correlation coefficients between 0.93 and 0.97 were observed. The method's ability to detect treatment effects on TB micro-architecture was examined in a 2 years testosterone study on hypogonadal men. It was observed from experimental results that average plate-width and plate-to-rod ratio significantly improved after 6 months and the improvement was found to continue at 12 and 24 months. The bone density of plate-like trabeculae was found to increase by 6.5% (p  =  0.06), 7.2% (p  =  0.07) and 16.2% (p  =  0.003) at 6, 12, 24 months, respectively. While the density of rod-like trabeculae did not change significantly, even at 24 months. A comparative study showed that VTA has enhanced ability to detect treatment effects in TB micro-architecture as compared to conventional method of digital topological analysis for plate/rod characterization in terms of both percent change and effect-size.

  2. Three-dimensional MRI perfusion maps: a step beyond volumetric analysis in mental disorders.

    Science.gov (United States)

    Fabene, Paolo F; Farace, Paolo; Brambilla, Paolo; Andreone, Nicola; Cerini, Roberto; Pelizza, Luisa; Versace, Amelia; Rambaldelli, Gianluca; Birbaumer, Niels; Tansella, Michele; Sbarbati, Andrea

    2007-01-01

    A new type of magnetic resonance imaging analysis, based on fusion of three-dimensional reconstructions of time-to-peak parametric maps and high-resolution T1-weighted images, is proposed in order to evaluate the perfusion of selected volumes of interest. Because in recent years a wealth of data have suggested the crucial involvement of vascular alterations in mental diseases, we tested our new method on a restricted sample of schizophrenic patients and matched healthy controls. The perfusion of the whole brain was compared with that of the caudate nucleus by means of intrasubject analysis. As expected, owing to the encephalic vascular pattern, a significantly lower time-to-peak was observed in the caudate nucleus than in the whole brain in all healthy controls, indicating that the suggested method has enough sensitivity to detect subtle perfusion changes even in small volumes of interest. Interestingly, a less uniform pattern was observed in the schizophrenic patients. The latter finding needs to be replicated in an adequate number of subjects. In summary, the three-dimensional analysis method we propose has been shown to be a feasible tool for revealing subtle vascular changes both in normal subjects and in pathological conditions.

  3. Ethics of neuroimaging after serious brain injury.

    Science.gov (United States)

    Weijer, Charles; Peterson, Andrew; Webster, Fiona; Graham, Mackenzie; Cruse, Damian; Fernández-Espejo, Davinia; Gofton, Teneille; Gonzalez-Lara, Laura E; Lazosky, Andrea; Naci, Lorina; Norton, Loretta; Speechley, Kathy; Young, Bryan; Owen, Adrian M

    2014-05-20

    development of a quality of life instrument adapted for neuroimaging. Project 3 will use grounded theory interviews to document families' understanding of the patient's condition, expectations of neuroimaging, and the impact of the results of neuroimaging. Project 4 will provide an ethical analysis of neuroimaging to investigate residual cognitive function in comatose patients within days of serious brain injury.

  4. Size-based emphysema cluster analysis on low attenuation area in 3D volumetric CT: comparison with pulmonary functional test

    Science.gov (United States)

    Lee, Minho; Kim, Namkug; Lee, Sang Min; Seo, Joon Beom; Oh, Sang Young

    2015-03-01

    To quantify low attenuation area (LAA) of emphysematous regions according to cluster size in 3D volumetric CT data of chronic obstructive pulmonary disease (COPD) patients and to compare these indices with their pulmonary functional test (PFT). Sixty patients with COPD were scanned by a more than 16-multi detector row CT scanner (Siemens Sensation 16 and 64) within 0.75mm collimation. Based on these LAA masks, a length scale analysis to estimate each emphysema LAA's size was performed as follows. At first, Gaussian low pass filter from 30mm to 1mm kernel size with 1mm interval on the mask was performed from large to small size, iteratively. Centroid voxels resistant to the each filter were selected and dilated by the size of the kernel, which was regarded as the specific size emphysema mask. The slopes of area and number of size based LAA (slope of semi-log plot) were analyzed and compared with PFT. PFT parameters including DLco, FEV1, and FEV1/FVC were significantly (all p-value< 0.002) correlated with the slopes (r-values; -0.73, 0.54, 0.69, respectively) and EI (r-values; -0.84, -0.60, -0.68, respectively). In addition, the D independently contributed regression for FEV1 and FEV1/FVC (adjust R sq. of regression study: EI only, 0.70, 0.45; EI and D, 0.71, 0.51, respectively). By the size based LAA segmentation and analysis, we evaluated the Ds of area, number, and distribution of size based LAA, which would be independent factors for predictor of PFT parameters.

  5. Volumetric topological analysis: a novel method for trabecular bone characterization on the continuum between plates and rods

    Science.gov (United States)

    Saha, Punam K.; Xu, Yan; Liang, Guoyuan; Duan, Hong

    2009-02-01

    Trabecular bone (TB) is a complex quasi-random network of interconnected struts and plates. TB constantly remodels to adapt dynamically to the stresses to which it is subjected (Wolff's Law). In osteoporosis, this dynamic equilibrium between bone formation and resorption is perturbed, leading to bone loss and structural deterioration, both increasing fracture risk. Bone's mechanical competence can only be partly explained by variations in bone mineral density, which led to the notion of bone structural quality. Previously, we developed digital topological analysis or DTA which classifies plates, rods, profiles, edges and junctions in a TB skeletal representation. Although the method has become quite popular, a major limitation is that DTA produces hard classifications only, failing to distinguish between narrow and wide plates. Here, we present a new method called volumetric topological analysis or VTA for quantification of regional topology in complex quasi-random TB networks. At each TB voxel, the method uniquely classifies the topology on the continuum between perfect plates and rods. Therefore, the method is capable of detecting early alterations of trabeculae from plates to rods according to the known etiology of osteoporotic bone loss. Here, novel ideas of geodesic distance transform, geodesic scale and feature propagation have been introduced and combined with DTA and fuzzy distance transform methods conceiving the new VTA technology. The method has been applied to MDCT and μCT images of a cadaveric distal tibia specimen and the results have been quantitatively evaluated. Specifically, intra- and inter-modality reproducibility of the method has been examined and the results are found very promising.

  6. Volumetric Analysis of Carotid Plaque Components and Cerebral Microbleeds: A Correlative Study.

    Science.gov (United States)

    Saba, Luca; Sanfilippo, Roberto; di Martino, Michele; Porcu, Michele; Montisci, Roberto; Lucatelli, Pierleone; Anzidei, Michele; Francone, Marco; Suri, Jasjit S

    2017-03-01

    The purpose of this work was to explore the association between carotid plaque volume (total and the subcomponents) and cerebral microbleeds (CMBs). Seventy-two consecutive (male 53; median age 64) patients were retrospectively analyzed. Carotid arteries were studied by using a 16-detector-row computed tomography scanner whereas brain was explored with a 1.5 Tesla system. CMBs were studied using a T2*-weighted gradient-recalled echo sequence. CMBs were classified as from absent (grade 1) to severe (grade 4). Component types of the carotid plaque were defined according to the following Hounsfield unit (HU) ranges: lipid less than 60 HU; fibrous tissue from 60 to 130 HU; calcification greater than 130 HU, and plaque volumes of each component were calculated. Each carotid artery was analyzed by 2 observers. The prevalence of CMBs was 35.3%. A statistically significant difference was observed between symptomatic (40%) and asymptomatic (11%) patients (P value = .001; OR = 6.07). Linear regression analysis demonstrated an association between the number of CMBs and the symptoms (P = .0018). Receiver operating characteristics curve analysis found an association between the carotid plaque subcomponents and CMBs (Az = .608, .621, and .615 for calcified, lipid, and mixed components, respectively), and Mann-Whitney test confirmed this association in particular for the lipid components (P value = .0267). Results of this study confirm the association between CMBs and symptoms and that there is an increased number of CMBs in symptomatic patients. Moreover, we found that an increased volume of the fatty component is associated with the presence and number of CMBs. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Standardization of a Volumetric Displacement Measurement for Two-Body Abrasion Scratch Test Data Analysis

    Science.gov (United States)

    Street, K. W. Jr.; Kobrick, R. L.; Klaus, D. M.

    2011-01-01

    A limitation has been identified in the existing test standards used for making controlled, two-body abrasion scratch measurements based solely on the width of the resultant score on the surface of the material. A new, more robust method is proposed for analyzing a surface scratch that takes into account the full three-dimensional profile of the displaced material. To accomplish this, a set of four volume- displacement metrics was systematically defined by normalizing the overall surface profile to denote statistically the area of relevance, termed the Zone of Interaction. From this baseline, depth of the trough and height of the plowed material are factored into the overall deformation assessment. Proof-of-concept data were collected and analyzed to demonstrate the performance of this proposed methodology. This technique takes advantage of advanced imaging capabilities that allow resolution of the scratched surface to be quantified in greater detail than was previously achievable. When reviewing existing data analysis techniques for conducting two-body abrasive scratch tests, it was found that the ASTM International Standard G 171 specified a generic metric based only on visually determined scratch width as a way to compare abraded materials. A limitation to this method was identified in that the scratch width is based on optical surface measurements, manually defined by approximating the boundaries, but does not consider the three-dimensional volume of material that was displaced. With large, potentially irregular deformations occurring on softer materials, it becomes unclear where to systematically determine the scratch width. Specifically, surface scratches on different samples may look the same from a top view, resulting in an identical scratch width measurement, but may vary in actual penetration depth and/or plowing deformation. Therefore, two different scratch profiles would be measured as having identical abrasion properties, although they differ

  8. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular within the neuroimaging community. Such methods attempt...... to predict or decode experimentally defined cognitive states based on brain scans. The topics covered in the dissertation are divided into two broad parts: The first part investigates the relative importance of model selection on the brain patterns extracted form analysis models. Typical neuroimaging data...... of model regularization parameter choices on the model generalization, the reliability of the spatial brain patterns extracted from the analysis model, and the ability of the resulting model to identify relevant brain networks defining the underlying neural encoding of the experiment. We show that known...

  9. Bone bruise in acute traumatic patellar dislocation: volumetric magnetic resonance imaging analysis with follow-up mean of 12 months

    Energy Technology Data Exchange (ETDEWEB)

    Paakkala, Antti; Paakkala, Timo [Tampere University Hospital, Department of Radiology, Tampere (Finland); Sillanpaeae, Petri; Maeenpaeae, Heikki [Tampere University Hospital, Department of Orthopaedics and Traumatology, Tampere (Finland); Huhtala, Heini [University of Tampere, School of Public Health, Tampere (Finland)

    2010-07-15

    The aim of the study was to assess volumetric analysis of bone bruises in acute primary traumatic patellar dislocation by magnetic resonance imaging (MRI) and resolving resolution of bruises in follow-up MRI. MRI was performed in 23 cases. A follow-up examination was done at a mean of 12 months after dislocation. Volumes of patellar and femur bruises for every patient were evaluated separately by two musculoskeletal radiologists, and mean values of the bruises were assessed. Other MRI findings were evaluated, together with agreement by consensus. Bone bruise volumes were compared with other MR findings. In the acute study 100% of patients showed bruising of the lateral femoral condyle and 96% bruising of the patella. The bruise was located at the medial femoral condyle in 30% and at the patellar median ridge in 74% of patients. The median volume of the femoral bruise was 25,831 mm{sup 3} and of the patellar bruise 2,832 mm{sup 3}. At the follow-up study 22% of patients showed bruising of the lateral femoral condyle and 39% bruising of the patella, the median volumes of the bruises being 5,062 mm{sup 3} and 1,380 mm{sup 3}, respectively. Larger patellar bruise volume correlated with larger femur bruise volume in the acute (r=0.389, P=0.074) and the follow-up (r=1.000, P<0.01) studies. Other MRI findings did not correlate significantly with bone bruise volumes. Bone bruising is the commonest finding in cases of acute patellar dislocation, being seen even 1 year after trauma and indicating significant bone trabecular injury in the patellofemoral joint. A large bruise volume may be associated with subsequent chondral lesion progression at the patella. We concluded that the measurement of bone bruise volume in patients with acute patellar dislocation is a reproducible method but requires further studies to evaluate its clinical use. (orig.)

  10. Quantitative volumetric analysis of the optic radiation in the normal human brain using diffusion tensor magnetic resonance imaging-based tractography

    Institute of Scientific and Technical Information of China (English)

    Dong-Hoon Lee; Ji-Won Park; Cheol-Pyo Hong

    2014-01-01

    To attain the volumetric information of the optic radiation in normal human brains, we per-formed diffusion tensor imaging examination in 13 healthy volunteers. Simultaneously, we used a brain normalization method to reduce individual brain variation and increase the accuracy of volumetric information analysis. In addition, tractography-based group mapping method was also used to investigate the probability and distribution of the optic radiation pathways. Our results showed that the measured optic radiation ifber tract volume was a range of about 0.16%and that the fractional anisotropy value was about 0.53. Moreover, the optic radiation probability ifber pathway that was determined with diffusion tensor tractography-based group mapping was able to detect the location relatively accurately. We believe that our methods and results are help-ful in the study of optic radiation ifber tract information.

  11. Neuroimaging in epilepsy

    Directory of Open Access Journals (Sweden)

    Shahina Bano

    2011-01-01

    Full Text Available Epilepsy is the most common neurological disease worldwide and is second only to stroke in causing neurological morbidity. Neuroimaging plays a very important role in the diagnosis and treatment of patients with epilepsy. This review article highlights the specific role of various imaging modalities in patients with epilepsy, and their practical applications in the management of epileptic patients.

  12. Neuroimaging in Epilepsy.

    Science.gov (United States)

    Middlebrooks, Erik H; Ver Hoef, Lawrence; Szaflarski, Jerzy P

    2017-04-01

    In recent years, the field of neuroimaging has undergone dramatic development. Specifically, of importance for clinicians and researchers managing patients with epilepsies, new methods of brain imaging in search of the seizure-producing abnormalities have been implemented, and older methods have undergone additional refinement. Methodology to predict seizure freedom and cognitive outcome has also rapidly progressed. In general, the image data processing methods are very different and more complicated than even a decade ago. In this review, we identify the recent developments in neuroimaging that are aimed at improved management of epilepsy patients. Advances in structural imaging, diffusion imaging, fMRI, structural and functional connectivity, hybrid imaging methods, quantitative neuroimaging, and machine-learning are discussed. We also briefly summarize the potential new developments that may shape the field of neuroimaging in the near future and may advance not only our understanding of epileptic networks as the source of treatment-resistant seizures but also better define the areas that need to be treated in order to provide the patients with better long-term outcomes.

  13. Texture analysis on the fluence map to evaluate the degree of modulation for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, So-Yeon [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Kim, Il Han [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Department of Radiation Oncology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Ye, Sung-Joon [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744, (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 433-270 (Korea, Republic of); Carlson, Joel [Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 433-270 (Korea, Republic of); and others

    2014-11-01

    Purpose: Texture analysis on fluence maps was performed to evaluate the degree of modulation for volumetric modulated arc therapy (VMAT) plans. Methods: A total of six textural features including angular second moment, inverse difference moment, contrast, variance, correlation, and entropy were calculated for fluence maps generated from 20 prostate and 20 head and neck VMAT plans. For each of the textural features, particular displacement distances (d) of 1, 5, and 10 were adopted. To investigate the deliverability of each VMAT plan, gamma passing rates of pretreatment quality assurance, and differences in modulating parameters such as multileaf collimator (MLC) positions, gantry angles, and monitor units at each control point between VMAT plans and dynamic log files registered by the Linac control system during delivery were acquired. Furthermore, differences between the original VMAT plan and the plan reconstructed from the dynamic log files were also investigated. To test the performance of the textural features as indicators for the modulation degree of VMAT plans, Spearman’s rank correlation coefficients (r{sub s}) with the plan deliverability were calculated. For comparison purposes, conventional modulation indices for VMAT including the modulation complexity score for VMAT, leaf travel modulation complexity score, and modulation index supporting station parameter optimized radiation therapy (MI{sub SPORT}) were calculated, and their correlations were analyzed in the same way. Results: There was no particular textural feature which always showed superior correlations with every type of plan deliverability. Considering the results comprehensively, contrast (d = 1) and variance (d = 1) generally showed considerable correlations with every type of plan deliverability. These textural features always showed higher correlations to the plan deliverability than did the conventional modulation indices, except in the case of modulating parameter differences. The r

  14. Dynamic GSCA (Generalized Structured Component Analysis) with Applications to the Analysis of Effective Connectivity in Functional Neuroimaging Data

    Science.gov (United States)

    Jung, Kwanghee; Takane, Yoshio; Hwang, Heungsun; Woodward, Todd S.

    2012-01-01

    We propose a new method of structural equation modeling (SEM) for longitudinal and time series data, named Dynamic GSCA (Generalized Structured Component Analysis). The proposed method extends the original GSCA by incorporating a multivariate autoregressive model to account for the dynamic nature of data taken over time. Dynamic GSCA also…

  15. A comparison of neuroimaging findings in childhood onset schizophrenia and autism spectrum disorder: a review of the literature

    Directory of Open Access Journals (Sweden)

    Danielle Andrea Baribeau

    2013-12-01

    Full Text Available Background: Autism spectrum disorder (ASD and childhood onset schizophrenia (COS are pediatric neurodevelopmental disorders associated with significant morbidity. Both conditions are thought to share an underlying genetic architecture. A comparison of neuroimaging findings across ASD and COS with a focus on altered neurodevelopmental trajectories can shed light on potential clinical biomarkers and may highlight an underlying etiopathogenesis. Methods: A comprehensive review of the medical literature was conducted to summarize neuroimaging data with respect to both conditions in terms of structural imaging (including volumetric analysis, cortical thickness and morphology, and region of interest studies, white matter analysis (include volumetric analysis and diffusion tensor imaging and functional connectivity. Results: In ASD, a pattern of early brain overgrowth in the first few years of life is followed by dysmaturation in adolescence. Functional analyses have suggested impaired long-range connectivity as well as increased local and/or subcortical connectivity in this condition. In COS, deficits in cerebral volume, cortical thickness, and white matter maturation seem most pronounced in childhood and adolescence, and may level off in adulthood. Deficits in local connectivity, with increased long-range connectivity have been proposed, in keeping with exaggerated cortical thinning.Conclusions: The neuroimaging literature supports a neurodevelopmental origin of both ASD and COS and provides evidence for dynamic changes in both conditions that vary across space and time in the developing brain. Looking forward, imaging studies which capture the early post natal period, which are longitudinal and prospective, and which maximize the signal to noise ratio across heterogeneous conditions will be required to translate research findings into a clinical environment.

  16. Simultaneous and in situ analysis of thermal and volumetric properties of starch gelatinization over wide pressure and temperature ranges.

    Science.gov (United States)

    Randzio, Stanislaw L; Orlowska, Marta

    2005-01-01

    A method for simultaneous and in situ analysis of thermal and volumetric properties of starch gelatinization from 0.1 to 100 MPa and from 283 to 430 K is described. The temperature of a very sensitive calorimetric detector containing a starch-water emulsion at a selected pressure is programmed to rise at a slow rate; volume variations are performed automatically to keep the selected pressure constant while the heat exchange rate and the volume are recorded. The method is demonstrated with a novel investigation of pressure effects on a sequence of three phase transitions in an aqueous emulsion of wheat starch (56 wt % water). The volume changes during the main endothermic transition (M), associated with melting of the crystalline part of the starch granules and a helix-coil transformation in amylopectin, but also with an important swelling, were separated into a volume increase associated with swelling and a volume decrease associated with the transition itself. Thermodynamic parameters for this transition together with their pressure dependencies have been obtained from four independent experiments at each pressure. The data are thermodynamically consistent, but are poorly described by the Clapeyron equation. The negative volume change of the slow exothermic transition (A) appearing just after the main endothermic transition (M) is small, spread out over a wide temperature interval, and occurs at higher temperatures with increasing pressures. This transition is probably associated with reassociation of the unwound helixes of amylopectin with parts of amylopectin molecules other than their original helix duplex partner. The positive volume change of the high-temperature, endothermic transition (N) with a small enthalpy change is probably associated with a nematic-isotropic transformation ending the formation of a homogeneous SOL phase (in the sense of Flory), and is also pushed to higher temperatures with increasing pressures. Knowledge of the state of wheat starch

  17. A study on the correlation between plan complexity and gamma index analysis in patient specific quality assurance of volumetric modulated arc therapy.

    Science.gov (United States)

    Rajasekaran, Dhanabalan; Jeevanandam, Prakash; Sukumar, Prabakar; Ranganathan, Arulpandiyan; Johnjothi, Samdevakumar; Nagarajan, Vivekanandan

    2015-01-01

    To evaluate the new Octavius 4D system for patient specific quality assurance and to study the correlation between plan complexity and gamma index analysis in patient specific quality assurance of VMAT using the Octavius 4D system. McNiven (2010) proposed a study to evaluate the utility of a complexity metric, the Modulation Complexity Score, to evaluate the relationship of the metric with deliverability in IMRT. Evaluation of the Octavius 4D system was carried out by gamma evaluation of user defined MLC created patterns and AAPM TG 119 benchmark plans. The relationship between plan complexity expressed as Modulation Complexity Score (MCS) and the gamma index analysis was established by a planar and volumetric gamma analysis of 106 clinically approved VMAT patient plans of different sites. Average volumetric 3D global gamma evaluation (3 mm/3%) results for the evaluation plans was 97.41% for 6 MV X-rays and 98.30% for 15 MV X-rays. Average MCS values for the head and neck, pelvic and thoracic plans were 0.2224, 0.3615 and 0.1874. Average volumetric 3D global gamma analysis (3 mm/3%) results for the head and neck, pelvic and thoracic VMAT plans were 95.45%, 97.51% and 96.98%, respectively. Out of 90 correlation analyses between the MCS and gamma passing rate, only 3 had the r value greater than 0.5. The Octavius 4D system is a suitable device for patient specific pretreatment QA. Global and local gamma analysis results showed a weak correlation with the MCS.

  18. Neuroimaging in anxiety disorders.

    Science.gov (United States)

    Engel, Kirsten; Bandelow, Borwin; Gruber, Oliver; Wedekind, Dirk

    2009-06-01

    Neuroimaging studies have gained increasing importance in validating neurobiological network hypotheses for anxiety disorders. Functional imaging procedures and radioligand binding studies in healthy subjects and in patients with anxiety disorders provide growing evidence of the existence of a complex anxiety network, including limbic, brainstem, temporal, and prefrontal cortical regions. Obviously, "normal anxiety" does not equal "pathological anxiety" although many phenomena are evident in healthy subjects, however to a lower extent. Differential effects of distinct brain regions and lateralization phenomena in different anxiety disorders are mentioned. An overview of neuroimaging investigations in anxiety disorders is given after a brief summary of results from healthy volunteers. Concluding implications for future research are made by the authors.

  19. Neuroimaging and sleep medicine.

    Science.gov (United States)

    Nofzinger, Eric A

    2005-06-01

    In sleep medicine, patients with sleep disorders are evaluated and treated. The primary assessment tool of the field has traditionally been polysomnography. While polysomnography has been helpful in the evaluation of some sleep disorders, such as sleep apnea syndrome and periodic limb movement disorder, it has been less helpful in others, such as the insomnias, or sleep disorders secondary to mental disorders. These disorders are presumed to stem from some alteration in brain function that disrupts sleep. The development of functional neuroimaging methods provides a means to understand brain function in patients with sleep disorders in a manner not accessible to polysomnography. This paper summarizes functional neuroimaging findings during healthy sleep, then, reviews available studies in sleep disorders patients, and studies addressing the pharmacology of sleep and sleep disorders. Areas in which functional neuroimaging methods may be helpful in sleep medicine, and in which future development is advised, include: (1) clarification of pathophysiology; (2) aid in differential diagnosis; (3) assessment of treatment response; (4) guiding new drug development; and (5) monitoring treatment response.

  20. Neuroimaging in eating disorders

    Directory of Open Access Journals (Sweden)

    Jáuregui-Lobera I

    2011-09-01

    Full Text Available Ignacio Jáuregui-LoberaBehavioral Sciences Institute and Pablo de Olavide University, Seville, SpainAbstract: Neuroimaging techniques have been useful tools for accurate investigation of brain structure and function in eating disorders. Computed tomography, magnetic resonance imaging, positron emission tomography, single photon emission computed tomography, magnetic resonance spectroscopy, and voxel-based morphometry have been the most relevant technologies in this regard. The purpose of this review is to update the existing data on neuroimaging in eating disorders. The main brain changes seem to be reversible to some extent after adequate weight restoration. Brain changes in bulimia nervosa seem to be less pronounced than in anorexia nervosa and are mainly due to chronic dietary restrictions. Different subtypes of eating disorders might be correlated with specific brain functional changes. Moreover, anorectic patients who binge/purge may have different functional brain changes compared with those who do not binge/purge. Functional changes in the brain might have prognostic value, and different changes with respect to the binding potential of 5-HT1A, 5-HT2A, and D2/D3 receptors may be persistent after recovering from an eating disorder.Keywords: neuroimaging, brain changes, brain receptors, anorexia nervosa, bulimia nervosa, eating disorders

  1. In search of the trauma memory: a meta-analysis of functional neuroimaging studies of symptom provocation in posttraumatic stress disorder (PTSD.

    Directory of Open Access Journals (Sweden)

    Gudrun Sartory

    Full Text Available Notwithstanding some discrepancy between results from neuroimaging studies of symptom provocation in posttraumatic stress disorder (PTSD, there is broad agreement as to the neural circuit underlying this disorder. It is thought to be characterized by an exaggerated amygdalar and decreased medial prefrontal activation to which the elevated anxiety state and concomitant inadequate emotional regulation are attributed. However, the proposed circuit falls short of accounting for the main symptom, unique among anxiety disorders to PTSD, namely, reexperiencing the precipitating event in the form of recurrent, distressing images and recollections. Owing to the technical demands, neuroimaging studies are usually carried out with small sample sizes. A meta-analysis of their findings is more likely to cast light on the involved cortical areas. Coordinate-based meta-analyses employing ES-SDM (Effect Size Signed Differential Mapping were carried out on 19 studies with 274 PTSD patients. Thirteen of the studies included 145 trauma-exposed control participants. Comparisons between reactions to trauma-related stimuli and a control condition and group comparison of reactions to the trauma-related stimuli were submitted to meta-analysis. Compared to controls and the neutral condition, PTSD patients showed significant activation of the mid-line retrosplenial cortex and precuneus in response to trauma-related stimuli. These midline areas have been implicated in self-referential processing and salient autobiographical memory. PTSD patients also evidenced hyperactivation of the pregenual/anterior cingulate gyrus and bilateral amygdala to trauma-relevant, compared to neutral, stimuli. Patients showed significantly less activation than controls in sensory association areas such as the bilateral temporal gyri and extrastriate area which may indicate that the patients' attention was diverted from the presented stimuli by being focused on the elicited trauma memory. Being

  2. Neuroimaging of consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Cavanna, Andrea Eugenio [Birmingham Univ. (United Kingdom). Dept. of Neuropsychiatry; UCL Institute of Neurology, London (United Kingdom). Sobell Dept. of Motor, Neuroscience and Movement Disorders; Nani, Andrea [Birmingham Univ. (United Kingdom). Research Group BSMHFT; Blumenfeld, Hal [Yale University School of Medicine, New Haven, CT (United States). Depts. of Neurology, Neurobiology and Neurosurgery; Laureys, Steven (ed.) [Liege Univ. (Belgium). Cyclotron Research Centre

    2013-07-01

    An important reference work on a multidisciplinary and rapidly expanding area. Particular focus on the relevance of neuroimaging for the diagnosis and treatment of common neuropsychiatric disorders affecting consciousness. Written by world-class experts in the field. Relevant for clinicians, researchers, and scholars across different specialties. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This book presents the state of the art in neuroimaging exploration of the brain correlates of the alterations in consciousness across these conditions, with a particular focus on the potential applications for diagnosis and management. Although the book has a practical approach and is primarily targeted at neurologists, neuroradiologists, and psychiatrists, a wide range of researchers and health care professionals will find it an essential reference that explains the significance of neuroimaging of consciousness for clinical practice. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This

  3. A novel computer algorithm allows for volumetric and cross-sectional area analysis of indirect decompression following transpsoas lumbar arthrodesis despite variations in MRI technique.

    Science.gov (United States)

    Gates, Timothy A; Vasudevan, Ram R; Miller, Kai J; Stamatopoulou, Vasiliki; Mindea, Stefan A

    2014-03-01

    Many patients present for neurosurgical spine evaluation with MRI studies conducted at facilities outside of the treating medical center. These images often vary widely in technique, for example, variation in slice thickness, number of slices, and gantry angle. While these images may be sufficient in conjunction with a physical exam to make surgical evaluations, we have found they are often incapable of being used for objective post-operative volumetric comparisons. In order to overcome this, we created a computer program that compensates for these variations in MRI technique. For this study, we examined patients who had undergone outside MRI pre-operatively and were deemed appropriate for a lateral retroperitoneal transpsoas lumbar interbody arthrodesis procedure. Volumetric analysis was performed on sagittal and axial T2-weighted pre- and post-operative MRI. The percentage change of central canal volume and foraminal area was calculated for each level. The authors identified five levels with MRI sufficient for volumetric analysis and eight levels (16 foramina) sufficient for foraminal cross-sectional analysis. Through use of our computer algorithm, average central canal volume and foraminal cross-sectional area was calculated to increase by 32.8% and 67.6% respectively following the procedure. These results are consistent with previous study findings and support the idea that restoration of the anterior column via a lateral approach can result in significant indirect decompression of the neural elements. Additionally, the novel algorithm created and used for this study suggests that it can achieve quick measurement and comparison of MRI studies despite variations in pre- and post-operative technique.

  4. Neuroimaging Findings and Repeat Neuroimaging Value in Pediatric Chronic Ataxia.

    Science.gov (United States)

    Salman, Michael S; Chodirker, Bernard N; Bunge, Martin

    2016-11-01

    Chronic ataxia, greater than two months in duration, is encountered relatively commonly in clinical pediatric neurology practise and presents with diagnostic challenges. It is caused by multiple and diverse disorders. Our aims were to describe the neuroimaging features and the value of repeat neuroimaging in pediatric chronic ataxia to ascertain their contribution to the diagnosis and management. A retrospective charts and neuroimaging reports review was undertaken in 177 children with chronic ataxia. Neuroimaging in 130 of 177 patients was also reviewed. Nineteen patients had head computed tomography only, 103 brain magnetic resonance imaging only, and 55 had both. Abnormalities in the cerebellum or other brain regions were associated with ataxia. Neuroimaging was helpful in 73 patients with 30 disorders: It was diagnostic in 9 disorders, narrowed down the diagnostic possibilities in 14 disorders, and revealed important but non-diagnostic abnormalities, e.g. cerebellar atrophy in 7 disorders. Having a normal magnetic resonance imaging scan was mostly seen in genetic diseases or in the early course of ataxia telangiectasia. Repeat neuroimaging, performed in 108 patients, was generally helpful in monitoring disease evolution and in making a diagnosis. Neuroimaging was not directly helpful in 36 patients with 10 disorders or by definition the 55 patients with unknown disease etiology. Normal or abnormal neuroimaging findings and repeat neuroimaging are very valuable in the diagnosis and management of disorders associated with pediatric chronic ataxia.

  5. Conditional averaging on volumetric velocity fields for analysis of the pseudo-periodic organization of jet-in-crossflow vortices

    CERN Document Server

    Cambonie, Tristan

    2014-01-01

    Volumetric velocimetry measurements have been performed on a round jet in crossflow (JICF). Two kind of conditional averaging process are presented : a global conditional average (GCA) and a local conditional average (LCA). Vortices crossing the JICF symmetry plane are used to quantify the jet pseudo-periodicity leading to the GCA and LCA definitions. Because they make possible to improve the velocity field resolution as well as to significantly reduce the experimental noise, these conditional averages are an interesting and efficient way to study the instantaneous swirling structures of this instantaneous flow.

  6. Recommendations for sex/gender neuroimaging research: Key principles and implications for research design, analysis and interpretation

    Directory of Open Access Journals (Sweden)

    Gina eRippon

    2014-08-01

    Full Text Available For over a decade, neuroimaging (NI technologies have had an increasing impact in the study of complex cognitive and social processes. In this emerging field of social cognitive neuroscience, a central goal should be to increase the understanding of the interaction between the neurobiology of the individual and the environment in which s/he develops and functions. The study of the relationship between sex and gender could offer a valuable example of such research. We identify here four main principles that should inform NI research. First, the principle of overlap, arising from evidence of significant overlap of female/male distributions on measures of many gendered behaviours. Second, the principle of mosaicism, arising from evidence that for both behaviour and brain, each individual manifests a complex and idiosyncratic combination of feminine and masculine characteristics. Third, the principle of contingency, arising from evidence that female/male behavioural differences are contingent on time, place, social group and context. Fourth, the principle of entanglement, arising from an awareness that the neural phenotypes that NI techniques measure are a function of the interactive and reciprocal influence of biology and environment. These important principles have emerged and become well-established over the past few decades, but their implications are often not reflected in the design and interpretation of NI sex/gender research. We therefore offer a set of guidelines for researchers to ensure that NI sex/gender research is appropriately designed and interpreted. We hope this ‘toolkit’ will also be of use to editorial boards and journal reviewers, as well as those who view, communicate and interpret such research.

  7. L1 and L2 processing in the bilingual brain: A meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Liu, Hengshuang; Cao, Fan

    2016-08-01

    Neuroimaging studies investigating bilingual processes have produced controversial results in determining similarities versus differences between L1 and L2 neural networks. The current meta-analytic study was conducted to examine what factors play a role in the similarities and differences between L1 and L2 networks with a focus on age of acquisition (AOA) and whether the orthographic transparency of L2 is more or less transparent than that of L1. Using activation likelihood estimation (ALE), we found L2 processing involved more additional regions than L1 for late bilinguals in comparison to early bilinguals, suggesting L2 processing is more demanding in late bilinguals. We also provide direct evidence that AOA of L2 influences L1 processing through the findings that early bilinguals had greater activation in the left fusiform gyrus than late bilinguals during L1 processing even when L1 languages were the same in the two groups, presumably due to greater co-activation of orthography in L1 and L2 in early bilinguals. In addition, we found that the same L2 languages evoked different brain activation patterns depending on whether it was more or less transparent than L1 in orthographic transparency. The bilateral auditory cortex and right precentral gyrus were more involved in shallower-than-L1 L2s, suggesting a "sound-out" strategy for a more regular language by involving the phonological regions and sensorimotor regions to a greater degree. In contrast, the left frontal cortex was more involved in the processing of deeper-than-L1 L2s, presumably due to the increased arbitrariness of mapping between orthography and phonology in L2.

  8. Retrievability of calcium hydroxide intracanal medicament with three calcium chelators, ethylenediaminetetraacetic acid, citric acid, and chitosan from root canals: An in vitro cone beam computed tomography volumetric analysis

    Science.gov (United States)

    Raghu, Ramya; Pradeep, Geethu; Shetty, Ashish; Gautham, P. M.; Puneetha, P. G.; Reddy, T. V. Satyanarayana

    2017-01-01

    Aim: This study compared the amount of aqueous-based and oil-based calcium hydroxide remaining in the canal, after removal with two different chelators 17% EDTA, 20% Citric acid and 0.2% Chitosan in combination with ultrasonic agitation. Methods and Material: Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)2 mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after seven days of incubation. Ca(OH)2 was removed using either 17% EDTA, 20% Citric acid or 0.2% Chitosan in combination with ultrasonic agitation. Statistical analysis used: Volumetric analysis was repeated and percentage difference was calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney U test. Results: All the three chelators failed to remove aqueous-based as well as oil-based Ca(OH)2 completely from the root canal. Aqueous-based Ca(OH)2 was easier to be removed than oil-based Ca(OH)2. 0.2% Chitosan in combination with ultrasonics performed better than 17% EDTA and 20% citric acid in removal of Ca(OH)2. Conclusion: Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)2 remnants than 17% EDTA, 20% Citric acid irrespective of type of vehicle present in the mix. PMID:28761249

  9. Functional neuroimaging of sleep disorders.

    Science.gov (United States)

    Nofzinger, Eric A

    2008-01-01

    Functional neuroimaging methods provide a means to understand brain function in patients with sleep disorders. This paper summarizes functional neuroimaging findings in sleep disorders patients, and studies addressing the pharmacology of sleep and sleep disorders. Areas in which functional neuroimaging methods may be helpful in sleep medicine, and in which future development is advised, include: 1) clarification of pathophysiology; 2) aid in differential diagnosis; 3) assessment of treatment response; 4) guiding new drug development; and 5) monitoring treatment response.

  10. The open-source neuroimaging research enterprise.

    Science.gov (United States)

    Marcus, Daniel S; Archie, Kevin A; Olsen, Timothy R; Ramaratnam, Mohana

    2007-11-01

    While brain imaging in the clinical setting is largely a practice of looking at images, research neuroimaging is a quantitative and integrative enterprise. Images are run through complex batteries of processing and analysis routines to generate numeric measures of brain characteristics. Other measures potentially related to brain function - demographics, genetics, behavioral tests, neuropsychological tests - are key components of most research studies. The canonical scanner - PACS - viewing station axis used in clinical practice is therefore inadequate for supporting neuroimaging research. Here, we model the neuroimaging research enterprise as a workflow. The principal components of the workflow include data acquisition, data archiving, data processing and analysis, and data utilization. We also describe a set of open-source applications to support each step of the workflow and the transitions between these steps. These applications include DIGITAL IMAGING AND COMMUNICATIONS IN MEDICINE viewing and storage tools, the EXTENSIBLE NEUROIMAGING ARCHIVE TOOLKIT data archiving and exploration platform, and an engine for running processing/analysis pipelines. The overall picture presented is aimed to motivate open-source developers to identify key integration and communication points for interoperating with complimentary applications.

  11. Functional and clinical insights from neuroimaging studies in childhood-onset schizophrenia.

    Science.gov (United States)

    Ordóñez, Anna E; Sastry, Nevin V; Gogtay, Nitin

    2015-08-01

    Childhood-onset schizophrenia is a rare pediatric onset psychiatric disorder continuous with and typically more severe than its adult counterpart. Neuroimaging research conducted on this population has revealed similarly severe neural abnormalities. When taken as a whole, neuroimaging research in this population shows generally decreased cortical gray matter coupled with white matter connectivity abnormalities, suggesting an anatomical basis for deficits in executive function. Subcortical abnormalities are pronounced in limbic structures, where volumetric deficits are likely related to social skill deficits, and cerebellar deficits that have been correlated to cognitive abnormalities. Structures relevant to motor processing also show a significant alteration, with volumetric increase in basal ganglia structures likely due to antipsychotic administration. Neuroimaging of this disorder shows an important clinical image of exaggerated cortical loss, altered white matter connectivity, and differences in structural development of subcortical areas during the course of development and provides important background to the disease state.

  12. Radiology resident MR and CT image analysis skill assessment using an interactive volumetric simulation tool - the RadioLOG project

    Energy Technology Data Exchange (ETDEWEB)

    Gondim Teixeira, Pedro Augusto; Leplat, Christophe [CHRU-Nancy Hopital Central, Service d' Imagerie Guilloz, Nancy (France); Universite de Lorraine, IADI U947, Nancy (France); Cendre, Romain [INSERM, CIC-IT 1433, Nancy (France); Hossu, Gabriela; Felblinger, Jacques [Universite de Lorraine, IADI U947, Nancy (France); INSERM, CIC-IT 1433, Nancy (France); Blum, Alain [CHRU-Nancy Hopital Central, Service d' Imagerie Guilloz, Nancy (France); Braun, Marc [CHRU-Nancy Hopital Central, Service de Neuroradiologie, Nancy (France)

    2017-02-15

    Assess the use of a volumetric simulation tool for the evaluation of radiology resident MR and CT interpretation skills. Forty-three participants were evaluated with a software allowing the visualisation of multiple volumetric image series. There were 7 medical students, 28 residents and 8 senior radiologists among the participants. Residents were divided into two sub-groups (novice and advanced). The test was composed of 15 exercises on general radiology and lasted 45 min. Participants answered a questionnaire on their experience with the test using a 5-point Likert scale. This study was approved by the dean of the medical school and did not require ethics committee approval. The reliability of the test was good with a Cronbach alpha value of 0.9. Test scores were significantly different in all sub-groups studies (p < 0.0225). The relation between test scores and the year of residency was logarithmic (R{sup 2} = 0.974). Participants agreed that the test reflected their radiological practice (3.9 ± 0.9 on a 5-point scale) and was better than the conventional evaluation methods (4.6 ± 0.5 on a 5-point scale). This software provides a high quality evaluation tool for the assessment of the interpretation skills in radiology residents. (orig.)

  13. The association of brain structure with gait velocity in older adults: a quantitative volumetric analysis of brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ezzati, Ali [Albert Einstein College of Medicine of Yeshiva University, Saul B. Korey Department of Neurology, Bronx, NY (United States); Montefiore Medical Center, Department of Neurology, Bronx, NY (United States); Katz, Mindy J. [Albert Einstein College of Medicine of Yeshiva University, Saul B. Korey Department of Neurology, Bronx, NY (United States); Lipton, Michael L. [Albert Einstein College of Medicine of Yeshiva University, The Gruss Magnetic Resonance Research Center and Departments of Radiology, Psychiatry and Behavioral Sciences and the Dominick P. Purpura Department of Neuroscience, Bronx, NY (United States); Montefiore Medical Center, The Department of Radiology, Bronx, NY (United States); Lipton, Richard B. [Albert Einstein College of Medicine of Yeshiva University, Saul B. Korey Department of Neurology, Bronx, NY (United States); Albert Einstein College of Medicine of Yeshiva University, Department of Epidemiology and Population Health, Bronx, NY (United States); Verghese, Joe [Albert Einstein College of Medicine of Yeshiva University, Saul B. Korey Department of Neurology, Bronx, NY (United States); Albert Einstein College of Medicine, Division of Cognitive and Motor Aging, Bronx, NY (United States)

    2015-08-15

    While cortical processes play an important role in controlling locomotion, the underlying structural brain changes associated with slowing of gait in aging are not yet fully established. Our study aimed to examine the relationship between cortical gray matter volume (GM), white matter volume (WM), ventricular volume (VV), hippocampal and hippocampal subfield volumes, and gait velocity in older adults free of dementia. Gait and cognitive performance was tested in 112 community-residing adults, age 70 years and over, participating in the Einstein Aging Study. Gait velocity (cm/s) was obtained using an instrumented walkway. Volumetric MRI measures were estimated using a FreeSurfer software. We examined the cross-sectional relationship of GM, WM, VV, and hippocampal total and subfield volumes and gait velocity using linear regression models. In complementary models, the effect of memory performance on the relationship between gait velocity and regional volumes was evaluated. Slower gait velocity was associated with smaller cortical GM and total hippocampal volumes. There was no association between gait velocity and WM or VV. Among hippocampal subfields, only smaller presubiculum volume was significantly associated with decrease in gait velocity. Addition of the memory performance to the models attenuated the association between gait velocity and all volumetric measures. Our findings indicate that total GM and hippocampal volumes as well as specific hippocampal subfield volumes are inversely associated with locomotor function. These associations are probably affected by cognitive status of study population. (orig.)

  14. Volumetric analysis of lung nodules in computed tomography (CT): comparison of two different segmentation algorithm softwares and two different reconstruction filters on automated volume calculation.

    Science.gov (United States)

    Christe, Andreas; Brönnimann, Alain; Vock, Peter

    2014-02-01

    A precise detection of volume change allows for better estimating the biological behavior of the lung nodules. Postprocessing tools with automated detection, segmentation, and volumetric analysis of lung nodules may expedite radiological processes and give additional confidence to the radiologists. To compare two different postprocessing software algorithms (LMS Lung, Median Technologies; LungCARE®, Siemens) in CT volumetric measurement and to analyze the effect of soft (B30) and hard reconstruction filter (B70) on automated volume measurement. Between January 2010 and April 2010, 45 patients with a total of 113 pulmonary nodules were included. The CT exam was performed on a 64-row multidetector CT scanner (Somatom Sensation, Siemens, Erlangen, Germany) with the following parameters: collimation, 24x1.2 mm; pitch, 1.15; voltage, 120 kVp; reference tube current-time, 100 mAs. Automated volumetric measurement of each lung nodule was performed with the two different postprocessing algorithms based on two reconstruction filters (B30 and B70). The average relative volume measurement difference (VME%) and the limits of agreement between two methods were used for comparison. At soft reconstruction filters the LMS system produced mean nodule volumes that were 34.1% (P filters (B30) was significantly larger than with hard filters (B70); 11.2% for LMS and 1.6% for LungCARE®, respectively (both with P filters, 13.6% for soft and 3.8% for hard filters, respectively (P  0.05). There is a substantial inter-software (LMS/LungCARE®) as well as intra-software variability (B30/B70) in lung nodule volume measurement; therefore, it is mandatory to use the same equipment with the same reconstruction filter for the follow-up of lung nodule volume.

  15. Functional neuroimaging of sleep.

    Science.gov (United States)

    Nofzinger, Eric A

    2005-03-01

    Sleep and sleep disorders have traditionally been viewed from a polysomnographic perspective. Although these methods provide information on the timing of various stages of sleep and wakefulness, they do not provide information regarding function in brain structures that have been implicated in the generation of sleep and that may be abnormal in different sleep disorders. Functional neuroimaging methods provide information regarding changes in brain function across the sleep-wake cycle that provides information for models of sleep dysregulation in a variety of sleep disorders. Early studies show reliable increases in function in limbic and anterior paralimbic cortex in rapid eye movement (REM) sleep and decreases in function in higher-order cortical regions in known thalamocortical networks during non-REM sleep. Although most of the early work in this area has been devoted to the study of normal sleep mechanisms, a collection of studies in diverse sleep disorders such as sleep deprivation, depression, insomnia, dyssomnias, narcolepsy, and sleep apnea suggest that functional neuroimaging methods have the potential to clarify the pathophysiology of sleep disorders and to guide treatment strategies.

  16. Neuroimaging in Huntington's disease.

    Science.gov (United States)

    Niccolini, Flavia; Politis, Marios

    2014-06-28

    Huntington's disease (HD) is a progressive and fatal neurodegenerative disorder caused by an expanded trinucleotide CAG sequence in huntingtin gene (HTT) on chromosome 4. HD manifests with chorea, cognitive and psychiatric symptoms. Although advances in genetics allow identification of individuals carrying the HD gene, much is still unknown about the mechanisms underlying the development of overt clinical symptoms and the transitional period between premanifestation and manifestation of the disease. HD has no cure and patients rely only in symptomatic treatment. There is an urgent need to identify biomarkers that are able to monitor disease progression and assess the development and efficacy of novel disease modifying drugs. Over the past years, neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have provided important advances in our understanding of HD. MRI provides information about structural and functional organization of the brain, while PET can detect molecular changes in the brain. MRI and PET are able to detect changes in the brains of HD gene carriers years ahead of the manifestation of the disease and have also proved to be powerful in assessing disease progression. However, no single technique has been validated as an optimal biomarker. An integrative multimodal imaging approach, which combines different MRI and PET techniques, could be recommended for monitoring potential neuroprotective and preventive therapies in HD. In this article we review the current neuroimaging literature in HD.

  17. Systems Biology, Neuroimaging, Neuropsychology, Neuroconnectivity and Traumatic Brain Injury.

    Science.gov (United States)

    Bigler, Erin D

    2016-01-01

    The patient who sustains a traumatic brain injury (TBI) typically undergoes neuroimaging studies, usually in the form of computed tomography (CT) and magnetic resonance imaging (MRI). In most cases the neuroimaging findings are clinically assessed with descriptive statements that provide qualitative information about the presence/absence of visually identifiable abnormalities; though little if any of the potential information in a scan is analyzed in any quantitative manner, except in research settings. Fortunately, major advances have been made, especially during the last decade, in regards to image quantification techniques, especially those that involve automated image analysis methods. This review argues that a systems biology approach to understanding quantitative neuroimaging findings in TBI provides an appropriate framework for better utilizing the information derived from quantitative neuroimaging and its relation with neuropsychological outcome. Different image analysis methods are reviewed in an attempt to integrate quantitative neuroimaging methods with neuropsychological outcome measures and to illustrate how different neuroimaging techniques tap different aspects of TBI-related neuropathology. Likewise, how different neuropathologies may relate to neuropsychological outcome is explored by examining how damage influences brain connectivity and neural networks. Emphasis is placed on the dynamic changes that occur following TBI and how best to capture those pathologies via different neuroimaging methods. However, traditional clinical neuropsychological techniques are not well suited for interpretation based on contemporary and advanced neuroimaging methods and network analyses. Significant improvements need to be made in the cognitive and behavioral assessment of the brain injured individual to better interface with advances in neuroimaging-based network analyses. By viewing both neuroimaging and neuropsychological processes within a systems biology

  18. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular analysis tools within the neuroimaging community. Such methods...... attempt to predict or decode experimentally defined cognitive states based on brain scans. The topics covered in the dissertation are divided into two broad parts: The first part investigates the relative importance of model selection on the brain patterns extracted form analysis models. Typical...... influence of model regularization parameter choices on the model generalization, the reliability of the spatial brain patterns extracted from the analysis model, and the ability of the model to identify relevant brain networks defining the underlying neural encoding of the experiment. We show that known...

  19. Interactive Information Visualization in Neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    1998-01-01

    We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform......We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform...

  20. Interactive Information Visualization in Neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    1998-01-01

    We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform......We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform...

  1. Translational Perspectives for Computational Neuroimaging.

    Science.gov (United States)

    Stephan, Klaas E; Iglesias, Sandra; Heinzle, Jakob; Diaconescu, Andreea O

    2015-08-19

    Functional neuroimaging has made fundamental contributions to our understanding of brain function. It remains challenging, however, to translate these advances into diagnostic tools for psychiatry. Promising new avenues for translation are provided by computational modeling of neuroimaging data. This article reviews contemporary frameworks for computational neuroimaging, with a focus on forward models linking unobservable brain states to measurements. These approaches-biophysical network models, generative models, and model-based fMRI analyses of neuromodulation-strive to move beyond statistical characterizations and toward mechanistic explanations of neuroimaging data. Focusing on schizophrenia as a paradigmatic spectrum disease, we review applications of these models to psychiatric questions, identify methodological challenges, and highlight trends of convergence among computational neuroimaging approaches. We conclude by outlining a translational neuromodeling strategy, highlighting the importance of openly available datasets from prospective patient studies for evaluating the clinical utility of computational models. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Neuroimaging findings in late-onset schizophrenia and bipolar disorder.

    Science.gov (United States)

    Hahn, Changtae; Lim, Hyun Kook; Lee, Chang Uk

    2014-03-01

    In recent years, there has been an increasing interest in late-onset mental disorders. Among them, geriatric schizophrenia and bipolar disorder are significant health care risks and major causes of disability. We discussed whether late-onset schizophrenia (LOS) and late-onset bipolar (LOB) disorder can be a separate entity from early-onset schizophrenia (EOS) and early-onset bipolar (EOB) disorder in a subset of late-life schizophrenia or late-life bipolar disorder through neuroimaging studies. A literature search for imaging studies of LOS or LOB was performed in the PubMed database. Search terms used were "(imaging OR MRI OR CT OR SPECT OR DTI OR PET OR fMRI) AND (schizophrenia or bipolar disorder) AND late onset." Articles that were published in English before October 2013 were included. There were a few neuroimaging studies assessing whether LOS and LOB had different disease-specific neural substrates compared with EOS and EOB. These researches mainly observed volumetric differences in specific brain regions, white matter hyperintensities, diffusion tensor imaging, or functional neuroimaging to explore the differences between LOS and LOB and EOS and EOB. The aim of this review was to highlight the neural substrates involved in LOS and LOB through neuroimaging studies. The exploration of neuroanatomical markers may be the key to the understanding of underlying neurobiology in LOS and LOB.

  3. Neuroimaging of autism

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeven, Judith S.; Cock, Paul de; Lagae, Lieven [University Hospitals of the Catholic University of Leuven, Department of Pediatrics, Leuven (Belgium); Sunaert, Stefan [University Hospitals of the Catholic University of Leuven, Department of Radiology, Leuven (Belgium)

    2010-01-15

    Neuroimaging studies done by means of magnetic resonance imaging (MRI) have provided important insights into the neurobiological basis for autism. The aim of this article is to review the current state of knowledge regarding brain abnormalities in autism. Results of structural MRI studies dealing with total brain volume, the volume of the cerebellum, caudate nucleus, thalamus, amygdala and the area of the corpus callosum are summarised. In the past 5 years also new MRI applications as functional MRI and diffusion tensor imaging brought considerable new insights in the pathophysiological mechanisms of autism. Dysfunctional activation in key areas of verbal and non-verbal communication, social interaction, and executive functions are revised. Finally, we also discuss white matter alterations in important communication pathways in the brain of autistic patients. (orig.)

  4. Neuroimaging Biomarkers for Psychosis

    Science.gov (United States)

    Hager, Brandon M.

    2015-01-01

    Background Biomarkers provide clinicians with a predictable model for the diagnosis, treatment and follow-up of medical ailments. Psychiatry has lagged behind other areas of medicine in the identification of biomarkers for clinical diagnosis and treatment. In this review, we investigated the current state of neuroimaging as it pertains to biomarkers for psychosis. Methods We reviewed systematic reviews and meta-analyses of the structural (sMRI), functional (fMRI), diffusion-tensor (DTI), Positron emission tomography (PET) and spectroscopy (MRS) studies of subjects at-risk or those with an established schizophrenic illness. Only articles reporting effect-sizes and confidence intervals were included in an assessment of robustness. Results Out of the identified meta-analyses and systematic reviews, 21 studies met the inclusion criteria for assessment. There were 13 sMRI, 4 PET, 3 MRS, and 1 DTI studies. The search terms included in the current review encompassed familial high risk (FHR), clinical high risk (CHR), First episode (FES), Chronic (CSZ), schizophrenia spectrum disorders (SSD), and healthy controls (HC). Conclusions Currently, few neuroimaging biomarkers can be considered ready for diagnostic use in patients with psychosis. At least in part, this may be related to the challenges inherent in the current symptom-based approach to classifying these disorders. While available studies suggest a possible value of imaging biomarkers for monitoring disease progression, more systematic research is needed. To date, the best value of imaging data in psychoses has been to shed light on questions of disease pathophysiology, especially through the characterization of endophenotypes. PMID:25883891

  5. Neuroimaging craving: urge intensity matters.

    Science.gov (United States)

    Wilson, Stephen J; Sayette, Michael A

    2015-02-01

    Functional neuroimaging has become an increasingly common tool for studying drug craving. Furthermore, functional neuroimaging studies, which have addressed an incredibly diverse array of questions regarding the nature and treatment of craving, have had a substantial impact on theoretical models of addiction. Here, we offer three points related to this sizeable and influential body of research. First, we assert that the craving most investigators seek to study represents not just a desire but a strong desire to use drugs, consistent with prominent theoretical and clinical descriptions of craving. Secondly, we highlight that, despite the clear conceptual and clinical emphasis on craving as an intense desire, brain imaging studies often have been designed explicitly in a way that reduces the ability to generate powerful cravings. We illustrate this point by reviewing the peak urge levels endorsed by participants in functional magnetic resonance imaging (fMRI) studies of cigarette craving in nicotine-deprived versus non-deprived smokers. Thirdly, we suggest that brain responses measured during mild states of desire (such as following satiety) differ in fundamental ways from those measured during states of overpowering desire (i.e. craving) to use drugs. We support this position by way of a meta-analysis revealing that fMRI cue exposure studies using nicotine-deprived smokers have produced different patterns of brain activation to those using non-deprived smokers. Regarding brain imaging studies of craving, intensity of the urges matter, and more explicit attention to urge intensity in future work has the potential to yield valuable information about the nature of craving. © 2014 Society for the Study of Addiction.

  6. Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC) facilitates finding and comparing neuroimaging resources for functional and structural...

  7. A fully-automatic caudate nucleus segmentation of brain MRI: application in volumetric analysis of pediatric attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Igual, Laura; Soliva, Joan Carles; Hernández-Vela, Antonio; Escalera, Sergio; Jiménez, Xavier; Vilarroya, Oscar; Radeva, Petia

    2011-12-05

    Accurate automatic segmentation of the caudate nucleus in magnetic resonance images (MRI) of the brain is of great interest in the analysis of developmental disorders. Segmentation methods based on a single atlas or on multiple atlases have been shown to suitably localize caudate structure. However, the atlas prior information may not represent the structure of interest correctly. It may therefore be useful to introduce a more flexible technique for accurate segmentations. We present CaudateCut: a new fully-automatic method of segmenting the caudate nucleus in MRI. CaudateCut combines an atlas-based segmentation strategy with the Graph Cut energy-minimization framework. We adapt the Graph Cut model to make it suitable for segmenting small, low-contrast structures, such as the caudate nucleus, by defining new energy function data and boundary potentials. In particular, we exploit information concerning the intensity and geometry, and we add supervised energies based on contextual brain structures. Furthermore, we reinforce boundary detection using a new multi-scale edgeness measure. We apply the novel CaudateCut method to the segmentation of the caudate nucleus to a new set of 39 pediatric attention-deficit/hyperactivity disorder (ADHD) patients and 40 control children, as well as to a public database of 18 subjects. We evaluate the quality of the segmentation using several volumetric and voxel by voxel measures. Our results show improved performance in terms of segmentation compared to state-of-the-art approaches, obtaining a mean overlap of 80.75%. Moreover, we present a quantitative volumetric analysis of caudate abnormalities in pediatric ADHD, the results of which show strong correlation with expert manual analysis. CaudateCut generates segmentation results that are comparable to gold-standard segmentations and which are reliable in the analysis of differentiating neuroanatomical abnormalities between healthy controls and pediatric ADHD.

  8. Neuroimaging of central breathlessness mechanisms.

    Science.gov (United States)

    Pattinson, Kyle T S; Johnson, Miriam J

    2014-09-01

    Breathlessness debilitates millions of people with cardiorespiratory conditions and cancer. Symptoms correlate poorly with the objective measures of disease (e.g. spirometry). Altered brain processing of respiratory sensations may contribute to this disparity. This article summarizes how functional neuroimaging works, focussing on functional MRI (FMRI) and magnetoencephalography, how neuroimaging has shed light on the central mechanisms of breathlessness and thus how it may help target new therapies. Current understanding of central neural activity in breathlessness comes mainly from a small number of studies in healthy volunteers using models of induced acute breathlessness. Parallels with neuroimaging findings in pain and fear or anxiety have been used to interpret the neuroimaging studies of breathlessness to form hypotheses. Despite the lack of recent neuroimaging studies in breathlessness, there have been methodological advances in overcoming confounders with respiratory FMRI. In addition, developing interest in the distinction of emotional from the sensory aspects of breathlessness and the use of opioids for breathlessness has driven mechanistic understandings. Neuroimaging of breathlessness remains in its infancy. However, advances in the understanding of central perception, combined with novel neuroimaging techniques, means that we are poised to increase our understanding of the brain processes of breathlessness and their modulation.

  9. Dimensional and volumetric analysis of the oropharyngeal region in obstructive sleep apnea patients: A cone beam computed tomography study

    Science.gov (United States)

    Tikku, Tripti; Khanna, Rohit; Sachan, Kiran; Agarwal, Akhil; Srivastava, Kamna; Lal, Anubha

    2016-01-01

    Background: Obstructive Sleep Apnea (OSA) is a potentially life-threatening condition in which there is a periodic cessation of breathing (for 10 sec or longer) that occurs during sleep in the presence of inspiratory effort. The aim of the study was to assess volumetric and dimensional differences between OSA patients and normal individuals in the upright posture. Material and Method: The present study was conducted on CBCT scans of 32 patients who were divided into two groups -Group I (control group) and Group II (OSA subjects). Group I consisted of 16 patients with normal airway with ESS score from 2 to 10, STOP BANG Questionnaire score of CBCT for various diagnostic reasons. Group II had patients with ESS score >10, STOP BANG Questionnaire score of > 3, AHI index >5. Linear and angular parameters, volume and minimum cross-section area (MCA) of oropharyngeal airway, anteroposterior length and lateral width at MCA was compared amongst the groups. Results: The oropharyngeal volume, MCA, and the anteroposterior and lateral width of the airway at MCA of the OSA subjects was significantly lesser than that of normal subjects. The length of both soft palate and tongue was significantly more in Group II. The angle between the nasopharyngeal airway and the oropharyngeal airway was significantly more obtuse in Group II. Conclusion: The reduction in oropharyngeal volume in OSA patients could be attributed to different anatomical and pathophysiological factors that were corroborated with the findings of the present study. PMID:27857764

  10. Analysis of inter-fraction and intra-fraction errors during volumetric modulated arc therapy in pancreas Ca

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong Rin; Hong, Taek Kyun; Kang, Tae Yeong; Baeck, Geum Mun; Hong, Dong Ki; Yun, In Ha; Kim, Jin San; Jo, Young Pil [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

    2014-12-15

    To assess target motion during radiotherapy by quantifying daily setup errors and inter-fractional and intra-fractional movements of pancreatic fiducials. Eleven patients were treated via stereotactic body radiotherapy (SBRT) with volumetric modulated arc therapy. Bony setup errors were calculated using cone beam computed tomography (CBCT). Inter-fractional and intrafractional fiducial (seed) motion was determined via cone beam computed tomography (CBCT) projections and orthogonal fluoroscopy. Using an off-line correction protocol, setup errors were 0.0 (-1.7-4.0), 0.3 (-0.5-3.0), and 0.0 (-4.1-6.6) mm for the left-right, anterior-posterior, and superior-inferior directions respectively. Random inter-fractional setup errors in the mean fiducial positions were -0.1, -1.1, and -2.3 mm respectively. Intra-fractional fiducial margins were 9.9, 7.8, and 12.5 mm, respectively. Online inter-fractional and intra-fractional corrections based on daily kV images and CBCT expedites SBRT of pancreatic cancer. Importantly, inter-fractional and intra-fractional motion needs to be measured regularly during treatment of pancreatic cancer to account for variations in patient respiration.

  11. Neuroimaging bei Schlaganfall

    Directory of Open Access Journals (Sweden)

    Nasel Ch

    2013-01-01

    Full Text Available Während zunächst die Differenzialdiagnosen des Schlaganfalls erfasst werden sollten, wurde sehr bald das Neuroimaging in den Dienst der Behandlung der akuten Ischämie gestellt. Hier kommt der neuroradiologischen Bildgebung eine besondere Rolle zu, da zunehmend die Auswahl von Patienten für eine bestimmte Therapie von der Bildgebung abhängt. Der Verlauf von zerebralen Ischämien ist, bedingt durch stark variierende Faktoren wie Kollateralisation, frühe Rekanalisation etc., sehr unterschiedlich. Die multimodale MR- und CTBildgebung, welche eine Kombination aus konventioneller Bildgebung des Gehirns, angiographischen Verfahren und funktionellen Messungen, wie z. B. Perfusionsmessungen, darstellt, kann jede Ischämie sehr genau charakterisieren. Wichtig ist dabei ein klares Interpretationskonzept. Bei Patienten, deren Symptombeginn eindeutig innerhalb der letzten 3–4,5 h liegt, kann die Nativ- CT, am besten in Kombination mit der CTA, als ausreichend zur Durchführung der anerkannten systemischen i.v.-Lyse sowie zur Feststellung eines Gefäßverschlusses, der einer weiteren Behandlung bedarf, angesehen werden. Im Zeitfenster 4,5 h, bei unklarem Zeitfenster oder nach frustraner i.v.-Lyse, ist, insbesondere bei einem im Weiteren geplanten endovaskulären Eingriff, die multimodale MRI mit Anwendung des „Mismatch-match“-Konzepts zwischen diffusionsgewichtetem MRI und Perfusions-MRI jedenfalls die Methode der ersten Wahl. Steht diese nicht zur Verfügung, kann alternativ das multimodale CT eingesetzt werden.

  12. [Mixed states and neuroimaging].

    Science.gov (United States)

    Kaladjian, A; Belzeaux, R; Micoulaud-Franchi, J A; Cermolacce, M; Fakra, E; Azorin, J-M

    2013-12-01

    Despite the growing number of neuroimaging studies in bipolar disorder over the past years, the brain regions involved in mood dysregulation in this disease are still poorly understood. If some neurofunctional abnormalities seem to be independent of mood state, others were preferentially associated with mania or depression, involving the amygdala and other limbic regions as well as ventral frontal regions, with a likely hemispheric lateralization of these abnormalities according to the thymic state that was examined. Very few imaging studies became interested in bipolar patients in a mixed state, making it harder to connect brain malfunction to a given mood state. However, data obtained so far support the hypothesis of a lateralization of brain abnormalities in relation to bipolar symptomatology, suggesting that neurofonctional abnormalities preferentially located in the right ventral frontal and limbic areas may underlie the depressive component, associated with abnormalities of the left similar regions for the manic component. Identification of brain dysfunctions that may explain the emergence of mixed symptoms will likely provide useful information to better understand the respective roles of each hemisphere in the pathophysiology of bipolar disorder. Copyright © 2013 Sociedade Brasileira de Farmacognosia. Published by Elsevier Masson SAS.. All rights reserved.

  13. Neuroimaging with functional near infrared spectroscopy: From formation to interpretation

    Science.gov (United States)

    Herrera-Vega, Javier; Treviño-Palacios, Carlos G.; Orihuela-Espina, Felipe

    2017-09-01

    Functional Near Infrared Spectroscopy (fNIRS) is gaining momentum as a functional neuroimaging modality to investigate the cerebral hemodynamics subsequent to neural metabolism. As other neuroimaging modalities, it is neuroscience's tool to understand brain systems functions at behaviour and cognitive levels. To extract useful knowledge from functional neuroimages it is critical to understand the series of transformations applied during the process of the information retrieval and how they bound the interpretation. This process starts with the irradiation of the head tissues with infrared light to obtain the raw neuroimage and proceeds with computational and statistical analysis revealing hidden associations between pixels intensities and neural activity encoded to end up with the explanation of some particular aspect regarding brain function.To comprehend the overall process involved in fNIRS there is extensive literature addressing each individual step separately. This paper overviews the complete transformation sequence through image formation, reconstruction and analysis to provide an insight of the final functional interpretation.

  14. Functional Neuroimaging of Motor Control inParkinson’s Disease

    DEFF Research Database (Denmark)

    Herz, Damian M; Eickhoff, Simon B; Løkkegaard, Annemette

    2014-01-01

    and yielded consistent alterations in neural activity in patients with PD. Differences in cortical activation between PD patients and healthy controls converged in a left-lateralized fronto-parietal network comprising the presupplementary motor area, primary motor cortex, inferior parietal cortex......Functional neuroimaging has been widely used to study the activation patterns of the motor network in patients with Parkinson's disease (PD), but these studies have yielded conflicting results. This meta-analysis of previous neuroimaging studies was performed to identify patterns of abnormal...... movement-related activation in PD that were consistent across studies. We applied activation likelihood estimation (ALE) of functional neuroimaging studies probing motor function in patients with PD. The meta-analysis encompassed data from 283 patients with PD reported in 24 functional neuroimaging studies...

  15. Comparative analysis of volumetric-modulated arc therapy and intensity-modulated radiotherapy for base of tongue cancer

    Directory of Open Access Journals (Sweden)

    L Nithya

    2014-01-01

    Full Text Available The aim of this study was to compare the various dosimetric parameters of dynamic multileaf collimator (MLC intensity modulated radiation therapy (IMRT plans with volumetric modulated arc therapy (VMAT plans for base of tongue cases. All plans were done in Monaco planning system for Elekta synergy linear accelerator with 80 MLC. IMRT plans were planned with nine stationary beams, and VMAT plans were done for 360° arc with single arc or dual arc. The dose to the planning target volumes (PTV for 70, 63, and 56 Gy was compared. The dose to 95, 98, and 50% volume of PTV were analyzed. The homogeneity index (HI and the conformity index (CI of the PTV 70 were also analyzed. IMRT and VMAT plan showed similar dose coverage, HI, and CI. Maximum dose and dose to 1-cc volume of spinal cord, planning risk volume (PRV cord, and brain stem were compared. IMRT plan and VMAT plan showed similar results except for the 1 cc of PRV cord that received slightly higher dose in VMAT plan. Mean dose and dose to 50% volume of right and left parotid glands were analyzed. VMAT plan gave better sparing of parotid glands than IMRT. In normal tissue dose analyses VMAT was better than IMRT. The number of monitor units (MU required for delivering the good quality of the plan and the time required to deliver the plan for IMRT and VMAT were compared. The number of MUs for VMAT was higher than that of IMRT plans. However, the delivery time was reduced by a factor of two for VMAT compared with IMRT. VMAT plans yielded good quality of the plan compared with IMRT, resulting in reduced treatment time and improved efficiency for base of tongue cases.

  16. Volumetric modulated arc radiotherapy sparing the thyroid gland for early-stage glottic cancer: A dosimetrical analysis.

    Science.gov (United States)

    Kim, Eun Seok; Yeo, Seung-Gu

    2014-06-01

    Previous studies on advanced radiotherapy (RT) techniques for early stage glottic cancer have focused on sparing the carotid artery. However, the aim of the present study was to evaluate the dosimetric advantages of volumetric modulated arc therapy (VMAT) in terms of sparing the thyroid gland in early-stage glottic cancer patients. In total, 15 cT1N0M0 glottic cancer patients treated with definitive RT using VMAT were selected, and for dosimetric comparison, a conventional RT plan comprising opposed-lateral wedged fields was generated for each patient. The carotid artery, thyroid gland and spinal cord were considered organs at risk. The prescription dose was 63 Gy at 2.25 Gy per fraction. For the thyroid gland and carotid artery, all compared parameters were significantly lower with VMAT compared with conventional RT. For the thyroid gland, the median reduction rates of the mean dose (Dmean), the volume receiving ≥30% of the prescription dose (V30) and the V50 were 32.6, 40.9 and 46.0%, respectively. The Dmean was 14.7±2.6 Gy when using VMAT compared with 22.2±3.9 Gy when using conventional RT. The differences between the techniques in terms of planning target volume coverage and dose homogeneity were not significant. When considering a recent normal tissue complication probability model, which indicated the mean thyroid gland dose as the most significant predictor of radiation-induced hypothyroidism, the dosimetric advantage shown in this study may be valuable in reducing hypothyroidism following RT for early stage glottic cancer patients.

  17. Micromechanical analysis of volumetric growth in the context of open systems thermodynamics and configurational mechanics. Application to tumor growth

    Science.gov (United States)

    Ganghoffer, J. F.; Boubaker, M. B.

    2016-11-01

    We adopt in this paper the physically and micromechanically motivated point of view that growth (resp. resorption) occurs as the expansion (resp. contraction) of initially small tissue elements distributed within a host surrounding matrix, due to the interfacial motion of their boundary. The interface motion is controlled by the availability of nutrients and mechanical driving forces resulting from the internal stresses that built in during the growth. A general extremum principle of the zero potential for open systems witnessing a change of their mass due to the diffusion of nutrients is constructed, considering the framework of open systems thermodynamics. We postulate that the shape of the tissue element evolves in such a way as to minimize the zero potential among all possible admissible shapes of the growing tissue elements. The resulting driving force for the motion of the interface sets a surface growth models at the scale of the growing tissue elements, and is conjugated to a driving force identified as the interfacial jump of the normal component of an energy momentum tensor, in line with Hadamard's structure theorem. The balance laws associated with volumetric growth at the mesoscopic level result as the averaging of surface growth mechanisms occurring at the microscopic scale of the growing tissue elements. The average kinematics has been formulated in terms of the effective growth velocity gradient and elastic rate of deformation tensor, both functions of time. This formalism is exemplified by the simulation of the avascular growth of multicell spheroids in the presence of diffusion of nutrients, showing the respective influence of mechanical and chemical driving forces in relation to generation of internal stresses.

  18. Micromechanical analysis of volumetric growth in the context of open systems thermodynamics and configurational mechanics. Application to tumor growth

    Science.gov (United States)

    Ganghoffer, J. F.; Boubaker, M. B.

    2017-03-01

    We adopt in this paper the physically and micromechanically motivated point of view that growth (resp. resorption) occurs as the expansion (resp. contraction) of initially small tissue elements distributed within a host surrounding matrix, due to the interfacial motion of their boundary. The interface motion is controlled by the availability of nutrients and mechanical driving forces resulting from the internal stresses that built in during the growth. A general extremum principle of the zero potential for open systems witnessing a change of their mass due to the diffusion of nutrients is constructed, considering the framework of open systems thermodynamics. We postulate that the shape of the tissue element evolves in such a way as to minimize the zero potential among all possible admissible shapes of the growing tissue elements. The resulting driving force for the motion of the interface sets a surface growth models at the scale of the growing tissue elements, and is conjugated to a driving force identified as the interfacial jump of the normal component of an energy momentum tensor, in line with Hadamard's structure theorem. The balance laws associated with volumetric growth at the mesoscopic level result as the averaging of surface growth mechanisms occurring at the microscopic scale of the growing tissue elements. The average kinematics has been formulated in terms of the effective growth velocity gradient and elastic rate of deformation tensor, both functions of time. This formalism is exemplified by the simulation of the avascular growth of multicell spheroids in the presence of diffusion of nutrients, showing the respective influence of mechanical and chemical driving forces in relation to generation of internal stresses.

  19. Structural Neuroimaging of the Medial Temporal Lobe in Alzheimer's Disease Clinical Trials.

    Science.gov (United States)

    Menéndez-González, Manuel; de Celis Alonso, Benito; Salas-Pacheco, José; Arias-Carrión, Oscar

    2015-01-01

    Atrophy in the medial temporal lobe (MTA) is being used as a criterion to support a diagnosis of Alzheimer's disease (AD). There are several structural neuroimaging approaches for quantifying MTA, including semiquantitative visual rating scales, volumetry (3D), planimetry (2D), and linear measures (1D). Current applications of structural neuroimaging in Alzheimer's disease clinical trials (ADCTs) incorporate it as a tool for improving the selection of subjects for enrollment or for stratification, for tracking disease progression, or providing evidence of target engagement for new therapeutic agents. It may also be used as a surrogate marker, providing evidence of disease-modifying effects. However, despite the widespread use of volumetric magnetic resonance imaging (MRI) in ADCTs, there are some important challenges and limitations, such as difficulties in the interpretation of results, limitations in translating results into clinical practice, and reproducibility issues, among others. Solutions to these issues may arise from other methodologies that are able to link the results of volumetric MRI from trials with conventional MRIs performed in routine clinical practice (linear or planimetric methods). Also of potential benefit are automated volumetry, using indices for comparing the relative rate of atrophy of different regions instead of absolute rates of atrophy, and combining structural neuroimaging with other biomarkers. In this review, authors present the existing structural neuroimaging approaches for MTA quantification. They then discuss solutions to the limitations of the different techniques as well as the current challenges of the field. Finally, they discuss how the current advances in AD neuroimaging can help AD diagnosis.

  20. Neuroimaging in Traumatic Brain Imaging

    OpenAIRE

    Lee, Bruce; Newberg, Andrew

    2005-01-01

    Summary: Traumatic brain injury (TBI) is a common and potentially devastating clinical problem. Because prompt proper management of TBI sequelae can significantly alter the clinical course especially within 48 h of the injury, neuroimaging techniques have become an important part of the diagnostic work up of such patients. In the acute setting, these imaging studies can determine the presence and extent of injury and guide surgical planning and minimally invasive interventions. Neuroimaging a...

  1. [Modern neuroimaging of brain plasticity].

    Science.gov (United States)

    Kasprian, G; Seidel, S

    2010-02-01

    Modern neuroimaging methods offer new insights into the plasticity of the human brain. As the techniques of functional MRI and diffusion tensor imaging are increasingly being applied in a clinical setting, the examiner is now frequently confronted with the interpretation of imaging findings related to regenerative processes in response to lesions of the central and also of the peripheral nervous system. In this article individual results of modern neuroimaging studies are discussed in the context of structural and functional plasticity of the CNS.

  2. Structural brain correlates of interpersonal violence: Systematic review and voxel-based meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Lamsma, Jelle; Mackay, Clare; Fazel, Seena

    2017-09-30

    Owing to inconsistent nomenclature and results, we have undertaken a label-based review and anatomical likelihood estimation (ALE) meta-analysis of studies measuring the quantitative association between regional grey matter (GM) volume and interpersonal violence. Following PRISMA guidelines, we identified studies by searching 3 online databases (Embase, Medline, PsycInfo) and reference lists. Thirty-five studies were included in the label-based review, providing information for 1288 participants and 86 brain regions. Per region, 0-57% of the results indicated significant reductions in GM volume, while 0-23% indicated significant increases. The only region for which more than half of all results indicated significant reductions was the parietal lobe. However, these results were dispersed across subregions. The ALE meta-analysis, which included 6 whole-brain voxel-based morphometry studies totaling 278 participants and reporting 144 foci, showed no significant clusters of reduced GM volume. No material differences were observed when excluding experiments using reactive violence as outcome or subjects diagnosed with psychopathy. Possible explanations for these findings are phenomenological and etiological heterogeneity, and insufficient power in the label-based review and ALE meta-analysis to detect small effects. We recommend that future studies distinguish between subtypes of interpersonal violence, and investigate mediation by underlying emotional and cognitive processes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Automated Voxel-Based Analysis of Volumetric Dynamic Contrast-Enhanced CT Data Improves Measurement of Serial Changes in Tumor Vascular Biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Coolens, Catherine, E-mail: catherine.coolens@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Cancer Center and University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario (Canada); Driscoll, Brandon [Radiation Medicine Program, Princess Margaret Cancer Center and University Health Network, Toronto, Ontario (Canada); Chung, Caroline [Radiation Medicine Program, Princess Margaret Cancer Center and University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Shek, Tina; Gorjizadeh, Alborz [Radiation Medicine Program, Princess Margaret Cancer Center and University Health Network, Toronto, Ontario (Canada); Ménard, Cynthia [Radiation Medicine Program, Princess Margaret Cancer Center and University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Jaffray, David [Radiation Medicine Program, Princess Margaret Cancer Center and University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario (Canada)

    2015-01-01

    Objectives: Development of perfusion imaging as a biomarker requires more robust methodologies for quantification of tumor physiology that allow assessment of volumetric tumor heterogeneity over time. This study proposes a parametric method for automatically analyzing perfused tissue from volumetric dynamic contrast-enhanced (DCE) computed tomography (CT) scans and assesses whether this 4-dimensional (4D) DCE approach is more robust and accurate than conventional, region-of-interest (ROI)-based CT methods in quantifying tumor perfusion with preliminary evaluation in metastatic brain cancer. Methods and Materials: Functional parameter reproducibility and analysis of sensitivity to imaging resolution and arterial input function were evaluated in image sets acquired from a 320-slice CT with a controlled flow phantom and patients with brain metastases, whose treatments were planned for stereotactic radiation surgery and who consented to a research ethics board-approved prospective imaging biomarker study. A voxel-based temporal dynamic analysis (TDA) methodology was used at baseline, at day 7, and at day 20 after treatment. The ability to detect changes in kinetic parameter maps in clinical data sets was investigated for both 4D TDA and conventional 2D ROI-based analysis methods. Results: A total of 7 brain metastases in 3 patients were evaluated over the 3 time points. The 4D TDA method showed improved spatial efficacy and accuracy of perfusion parameters compared to ROI-based DCE analysis (P<.005), with a reproducibility error of less than 2% when tested with DCE phantom data. Clinically, changes in transfer constant from the blood plasma into the extracellular extravascular space (K{sub trans}) were seen when using TDA, with substantially smaller errors than the 2D method on both day 7 post radiation surgery (±13%; P<.05) and by day 20 (±12%; P<.04). Standard methods showed a decrease in K{sub trans} but with large uncertainty (111.6 ± 150.5) %. Conclusions

  4. Addressing Confounding in Predictive Models with an Application to Neuroimaging.

    Science.gov (United States)

    Linn, Kristin A; Gaonkar, Bilwaj; Doshi, Jimit; Davatzikos, Christos; Shinohara, Russell T

    2016-05-01

    Understanding structural changes in the brain that are caused by a particular disease is a major goal of neuroimaging research. Multivariate pattern analysis (MVPA) comprises a collection of tools that can be used to understand complex disease efxcfects across the brain. We discuss several important issues that must be considered when analyzing data from neuroimaging studies using MVPA. In particular, we focus on the consequences of confounding by non-imaging variables such as age and sex on the results of MVPA. After reviewing current practice to address confounding in neuroimaging studies, we propose an alternative approach based on inverse probability weighting. Although the proposed method is motivated by neuroimaging applications, it is broadly applicable to many problems in machine learning and predictive modeling. We demonstrate the advantages of our approach on simulated and real data examples.

  5. Flexible Volumetric Structure

    Science.gov (United States)

    Cagle, Christopher M. (Inventor); Schlecht, Robin W. (Inventor)

    2014-01-01

    A flexible volumetric structure has a first spring that defines a three-dimensional volume and includes a serpentine structure elongatable and compressible along a length thereof. A second spring is coupled to at least one outboard edge region of the first spring. The second spring is a sheet-like structure capable of elongation along an in-plane dimension thereof. The second spring is oriented such that its in-plane dimension is aligned with the length of the first spring's serpentine structure.

  6. Analysis of direct clinical consequences of MLC positional errors in volumetric-modulated arc therapy using 3D dosimetry system.

    Science.gov (United States)

    Nithiyanantham, Karthikeyan; Mani, Ganesh K; Subramani, Vikraman; Mueller, Lutz; Palaniappan, Karrthick K; Kataria, Tejinder

    2015-09-08

    In advanced, intensity-modulated external radiotherapy facility, the multileaf collimator has a decisive role in the beam modulation by creating multiple segments or dynamically varying field shapes to deliver a uniform dose distribution to the target with maximum sparing of normal tissues. The position of each MLC leaf has become more critical for intensity-modulated delivery (step-and-shoot IMRT, dynamic IMRT, and VMAT) compared to 3D CRT, where it defines only field boundaries. We analyzed the impact of the MLC positional errors on the dose distribution for volumetric-modulated arc therapy, using a 3D dosimetry system. A total of 15 VMAT cases, five each for brain, head and neck, and prostate cases, were retrospectively selected for the study. All the plans were generated in Monaco 3.0.0v TPS (Elekta Corporation, Atlanta, GA) and delivered using Elekta Synergy linear accelerator. Systematic errors of +1, +0.5, +0.3, 0, -1, -0.5, -0.3 mm were introduced in the MLC bank of the linear accelerator and the impact on the dose distribution of VMAT delivery was measured using the COMPASS 3D dosim-etry system. All the plans were created using single modulated arcs and the dose calculation was performed using a Monte Carlo algorithm in a grid size of 3 mm. The clinical endpoints D95%, D50%, D2%, and Dmax,D20%, D50% were taken for the evaluation of the target and critical organs doses, respectively. A significant dosimetric effect was found for many cases even with 0.5 mm of MLC positional errors. The average change of dose D 95% to PTV for ± 1 mm, ± 0.5 mm, and ±0.3mm was 5.15%, 2.58%, and 0.96% for brain cases; 7.19%, 3.67%, and 1.56% for head and neck cases; and 8.39%, 4.5%, and 1.86% for prostate cases, respectively. The average deviation of dose Dmax was 5.4%, 2.8%, and 0.83% for brainstem in brain cases; 8.2%, 4.4%, and 1.9% for spinal cord in H&N; and 10.8%, 6.2%, and 2.1% for rectum in prostate cases, respectively. The average changes in dose followed a linear

  7. Neuroimaging findings in primary insomnia.

    Science.gov (United States)

    O'Byrne, J N; Berman Rosa, M; Gouin, J-P; Dang-Vu, T T

    2014-10-01

    State-of-the-art neuroimaging techniques have accelerated progress in the study and understanding of sleep in humans. Neuroimaging studies in primary insomnia remain relatively few, considering the important prevalence of this disorder in the general population. This review examines the contribution of functional and structural neuroimaging to our current understanding of primary insomnia. Functional studies during sleep provided support for the hyperarousal theory of insomnia. Functional neuroimaging also revealed abnormalities in cognitive and emotional processing in primary insomnia. Results from structural studies suggest neuroanatomical alterations in primary insomnia, mostly in the hippocampus, anterior cingulate cortex and orbitofrontal cortex. However, these results are not well replicated across studies. A few magnetic resonance spectroscopy studies revealed abnormalities in neurotransmitter concentrations and bioenergetics in primary insomnia. The inconsistencies among neuroimaging findings on insomnia are likely due to clinical heterogeneity, differences in imaging and overall diversity of techniques and designs employed. Larger samples, replication, as well as innovative methodologies are necessary for the progression of this perplexing, yet promising area of research. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Prognostic value of volumetric parameters of {sup 18}F-FDG PET in non-small-cell lung cancer: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Im, Hyung-Jun [Seoul National University Hospital, Department of Nuclear Medicine, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul (Korea, Republic of); Pak, Kyoungjune [Seoul National University Hospital, Department of Nuclear Medicine, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Pusan National University Hospital, Department of Nuclear Medicine and Biomedical Research Institute, Busan (Korea, Republic of); Cheon, Gi Jeong; Kang, Keon Wook; Chung, June-Key [Seoul National University Hospital, Department of Nuclear Medicine, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Hospital, Cancer Research Institute, Seoul (Korea, Republic of); Kim, Seong-Jang; Kim, In-Joo [Pusan National University Hospital, Department of Nuclear Medicine and Biomedical Research Institute, Busan (Korea, Republic of); Kim, E.E. [Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul (Korea, Republic of); University of California at Irvine, Department of Radiological Science, California, CA (United States); Lee, Dong Soo [Seoul National University Hospital, Department of Nuclear Medicine, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul (Korea, Republic of); Seoul National University Hospital, Cancer Research Institute, Seoul (Korea, Republic of)

    2014-09-06

    We conducted a comprehensive systematic review of the literature on volumetric parameters from {sup 18}F-FDG PET and a meta-analysis of the prognostic value of metabolic tumour volume (MTV) and total lesion glycolysis (TLG) in patients with lung cancer. A systematic search of MEDLINE and EMBASE was performed using the keywords ''positron emission tomography (PET)'', ''lung cancer'', and ''volume''. Inclusion criteria were: {sup 18}F-FDG PET used as an initial imaging tool; studies limited to non-small-cell lung cancer (NSCLC); volume measurement of lung cancer; patients who had not undergone surgery, chemotherapy, or radiotherapy before the PET scan; and studies that reported survival data. Event-free survival and overall survival were evaluated as outcomes. The impact of MTV and TLG on survival was measured in terms of the hazard ratio (HR) effect size. Data from each study were analysed using Review Manager 5.2. Thirteen eligible studies including 1,581 patients were analysed. Patients with high MTV showed a worse prognosis with an HR of 2.71 (95 % CI 1.82 - 4.02, p < 0.00001) for adverse events and an HR of 2.31 (95 % CI 1.54 - 3.47, p < 0.00001) for death. Patients with high TLG also showed a worse prognosis with an HR of 2.35 (95 % CI 1.91 - 2.89, p < 0.00001) for adverse events and an HR of 2.43 (95 % CI 1.89 - 3.11, p < 0.00001) for death. The prognostic value of MTV and TLG remained significant in a subgroup analysis according to TNM stage as well as the methods for defining cut-off values and tumour delineation. Volumetric parameters from {sup 18}F-FDG PET are significant prognostic factors for outcome in patients with NSCLC. Patients with a high MTV or TLG are at higher risk of adverse events and death. MTV and TLG were significant prognostic factors in patients with TNM stage I/II and stage III/IV NSCLC. (orig.)

  9. Accurate 3D point cloud comparison and volumetric change analysis of Terrestrial Laser Scan data in a hard rock coastal cliff environment

    Science.gov (United States)

    Earlie, C. S.; Masselink, G.; Russell, P.; Shail, R.; Kingston, K.

    2013-12-01

    Our understanding of the evolution of hard rock coastlines is limited due to the episodic nature and ';slow' rate at which changes occur. High-resolution surveying techniques, such as Terrestrial Laser Scanning (TLS), have just begun to be adopted as a method of obtaining detailed point cloud data to monitor topographical changes over short periods of time (weeks to months). However, the difficulties involved in comparing consecutive point cloud data sets in a complex three-dimensional plane, such as occlusion due to surface roughness and positioning of data capture point as a result of a consistently changing environment (a beach profile), mean that comparing data sets can lead to errors in the region of 10 - 20 cm. Meshing techniques are often used for point cloud data analysis for simple surfaces, but in surfaces such as rocky cliff faces, this technique has been found to be ineffective. Recession rates of hard rock coastlines in the UK are typically determined using aerial photography or airborne LiDAR data, yet the detail of the important changes occurring to the cliff face and toe are missed using such techniques. In this study we apply an algorithm (M3C2 - Multiscale Model to Model Cloud Comparison), initially developed for analysing fluvial morphological change, that directly compares point to point cloud data using surface normals that are consistent with surface roughness and measure the change that occurs along the normal direction (Lague et al., 2013). The surfaces changes are analysed using a set of user defined scales based on surface roughness and registration error. Once the correct parameters are defined, the volumetric cliff face changes are calculated by integrating the mean distance between the point clouds. The analysis has been undertaken at two hard rock sites identified for their active erosion located on the UK's south west peninsular at Porthleven in south west Cornwall and Godrevy in north Cornwall. Alongside TLS point cloud data, in

  10. Advanced neuroimaging applied to veterans and service personnel with traumatic brain injury: state of the art and potential benefits.

    Science.gov (United States)

    Wilde, Elisabeth A; Bouix, Sylvain; Tate, David F; Lin, Alexander P; Newsome, Mary R; Taylor, Brian A; Stone, James R; Montier, James; Gandy, Samuel E; Biekman, Brian; Shenton, Martha E; York, Gerald

    2015-09-01

    Traumatic brain injury (TBI) remains one of the most prevalent forms of morbidity among Veterans and Service Members, particularly for those engaged in the conflicts in Iraq and Afghanistan. Neuroimaging has been considered a potentially useful diagnostic and prognostic tool across the spectrum of TBI generally, but may have particular importance in military populations where the diagnosis of mild TBI is particularly challenging, given the frequent lack of documentation on the nature of the injuries and mixed etiologies, and highly comorbid with other disorders such as post-traumatic stress disorder, depression, and substance misuse. Imaging has also been employed in attempts to understand better the potential late effects of trauma and to evaluate the effects of promising therapeutic interventions. This review surveys the use of structural and functional neuroimaging techniques utilized in military studies published to date, including the utilization of quantitative fluid attenuated inversion recovery (FLAIR), susceptibility weighted imaging (SWI), volumetric analysis, diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), positron emission tomography (PET), magnetoencephalography (MEG), task-based and resting state functional MRI (fMRI), arterial spin labeling (ASL), and magnetic resonance spectroscopy (MRS). The importance of quality assurance testing in current and future research is also highlighted. Current challenges and limitations of each technique are outlined, and future directions are discussed.

  11. Process conditions and volumetric composition in composites

    DEFF Research Database (Denmark)

    Madsen, Bo

    2013-01-01

    The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated as a fun...... is increased. Altogether, the model is demonstrated to be a valuable tool for a quantitative analysis of the effect of process conditions. Based on the presented findings and considerations, examples of future work are mentioned for the further improvement of the model.......The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated...... as a function of the fiber weight fraction, and where parameters are included for the composite microstructure, and the fiber assembly compaction behavior. Based on experimental data of composites manufactured with different process conditions, together with model predictions, different types of process related...

  12. Sinp 2012: aggiornamenti in neuroimaging

    Directory of Open Access Journals (Sweden)

    Sara D'Alberto

    2012-12-01

    Full Text Available Molti gli aggiornamenti in neurofisiologia e neuroimaging dal congresso annuale della Società Italiana di Neuropsicologia (Sinp tenutosi a Roma a Novembre. Interessanti in modo particolare alcuni studi sui modelli anatomici funzionali nell'anosognosia per l'emiplegia e sulle funzioni della corteccia premotoria ventrale e della giunzione temporo-parietale nella regolazione del senso di "agency".

  13. Finding related functional neuroimaging volumes

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    2004-01-01

    We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving each...

  14. Soil volumetric water content measurements using TDR technique

    Directory of Open Access Journals (Sweden)

    S. Vincenzi

    1996-06-01

    Full Text Available A physical model to measure some hydrological and thermal parameters in soils will to be set up. The vertical profiles of: volumetric water content, matric potential and temperature will be monitored in different soils. The volumetric soil water content is measured by means of the Time Domain Reflectometry (TDR technique. The result of a test to determine experimentally the reproducibility of the volumetric water content measurements is reported together with the methodology and the results of the analysis of the TDR wave forms. The analysis is based on the calculation of the travel time of the TDR signal in the wave guide embedded in the soil.

  15. Nipype: A flexible, lightweight and extensible neuroimaging data processing framework

    Directory of Open Access Journals (Sweden)

    Krzysztof eGorgolewski

    2011-08-01

    Full Text Available Current neuroimaging software offer users an incredible opportunity to analyze their data in different ways, with different underlying assumptions. Several sophisticated software packages (e.g., AFNI, BrainVoyager, FSL, FreeSurfer, Nipy, R, SPM are used to process and analyze large and often diverse (highly multi-dimensional data. However, this heterogeneous collection of specialized applications creates several issues that hinder replicable, efficient and optimal use of neuroimaging analysis approaches: 1 No uniform access to neuroimaging analysis software and usage information; 2 No framework for comparative algorithm development and dissemination; 3 Personnel turnover in laboratories often limits methodological continuity and training new personnel takes time; 4 Neuroimaging software packages do not address computational efficiency; and 5 Methods sections in journal articles are inadequate for reproducing results. To address these issues, we present Nipype (Neuroimaging in Python: Pipelines and Interfaces; http://nipy.org/nipype, an open-source, community-developed, software package and scriptable library. Nipype solves the issues by providing Interfaces to existing neuroimaging software with uniform usage semantics and by facilitating interaction between these packages using Workflows. Nipype provides an environment that encourages interactive exploration of algorithms, eases the design of Workflows within and between packages, allows rapid comparative development of algorithms and reduces the learning curve necessary to use different packages. Nipype supports both local and remote execution on multi-core machines and clusters, without additional scripting. Nipype is BSD licensed, allowing anyone unrestricted usage. An open, community-driven development philosophy allows the software to quickly adapt and address the varied needs of the evolving neuroimaging community, especially in the context of increasing demand for reproducible research.

  16. Model sparsity and brain pattern interpretation of classification models in neuroimaging

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Madsen, Kristoffer Hougaard; Churchill, Nathan W

    2012-01-01

    Interest is increasing in applying discriminative multivariate analysis techniques to the analysis of functional neuroimaging data. Model interpretation is of great importance in the neuroimaging context, and is conventionally based on a ‘brain map’ derived from the classification model...

  17. Machine Learning for Neuroimaging with Scikit-Learn

    Directory of Open Access Journals (Sweden)

    Alexandre eAbraham

    2014-02-01

    Full Text Available Statistical machine learning methods are increasingly used for neuroimaging data analysis. Their main virtue is their ability to model high-dimensional datasets, e.g. multivariate analysis of activation images or resting-state time series. Supervised learning is typically used in decoding or encoding settings to relate brain images to behavioral or clinical observations, while unsupervised learning can uncover hidden structures in sets of images (e.g. resting state functional MRI or find sub-populations in large cohorts. By considering different functional neuroimaging applications, we illustrate how scikit-learn, a Python machine learning library, can be used to perform some key analysis steps. Scikit-learn contains a very large set of statistical learning algorithms, both supervised and unsupervised, and its application to neuroimaging data provides a versatile tool to study the brain.

  18. Machine learning for neuroimaging with scikit-learn.

    Science.gov (United States)

    Abraham, Alexandre; Pedregosa, Fabian; Eickenberg, Michael; Gervais, Philippe; Mueller, Andreas; Kossaifi, Jean; Gramfort, Alexandre; Thirion, Bertrand; Varoquaux, Gaël

    2014-01-01

    Statistical machine learning methods are increasingly used for neuroimaging data analysis. Their main virtue is their ability to model high-dimensional datasets, e.g., multivariate analysis of activation images or resting-state time series. Supervised learning is typically used in decoding or encoding settings to relate brain images to behavioral or clinical observations, while unsupervised learning can uncover hidden structures in sets of images (e.g., resting state functional MRI) or find sub-populations in large cohorts. By considering different functional neuroimaging applications, we illustrate how scikit-learn, a Python machine learning library, can be used to perform some key analysis steps. Scikit-learn contains a very large set of statistical learning algorithms, both supervised and unsupervised, and its application to neuroimaging data provides a versatile tool to study the brain.

  19. Centrality of prefrontal and motor preparation cortices to Tourette Syndrome revealed by meta-analysis of task-based neuroimaging studies.

    Science.gov (United States)

    Polyanska, Liliana; Critchley, Hugo D; Rae, Charlotte L

    2017-01-01

    Tourette Syndrome (TS) is a neurodevelopmental condition characterized by chronic multiple tics, which are experienced as compulsive and 'unwilled'. Patients with TS can differ markedly in the frequency, severity, and bodily distribution of tics. Moreover, there are high comorbidity rates with attention deficit hyperactivity disorder (ADHD), obsessive compulsive disorder (OCD), anxiety disorders, and depression. This complex clinical profile may account for apparent variability of findings across neuroimaging studies that connect neural function to cognitive and motor behavior in TS. Here we crystalized information from neuroimaging regarding the functional circuitry of TS, and furthermore, tested specifically for neural determinants of tic severity, by applying activation likelihood estimation (ALE) meta-analyses to neuroimaging (activation) studies of TS. Fourteen task-based studies (13 fMRI and one H2O-PET) met rigorous inclusion criteria. These studies, encompassing 25 experiments and 651 participants, tested for differences between TS participants and healthy controls across cognitive, motor, perceptual and somatosensory domains. Relative to controls, TS participants showed distributed differences in the activation of prefrontal (inferior, middle, and superior frontal gyri), anterior cingulate, and motor preparation cortices (lateral premotor cortex and supplementary motor area; SMA). Differences also extended into sensory (somatosensory cortex and the lingual gyrus; V4); and temporo-parietal association cortices (posterior superior temporal sulcus, supramarginal gyrus, and retrosplenial cortex). Within TS participants, tic severity (reported using the Yale Global Tic Severity Scale; YGTSS) selectively correlated with engagement of SMA, precentral gyrus, and middle frontal gyrus across tasks. The dispersed involvement of multiple cortical regions with differences in functional reactivity may account for heterogeneity in the symptomatic expression of TS and its

  20. Analyzing neuroimaging data with subclasses: A shrinkage approach.

    Science.gov (United States)

    Höhne, Johannes; Bartz, Daniel; Hebart, Martin N; Müller, Klaus-Robert; Blankertz, Benjamin

    2016-01-01

    Among the numerous methods used to analyze neuroimaging data, Linear Discriminant Analysis (LDA) is commonly applied for binary classification problems. LDAs popularity derives from its simplicity and its competitive classification performance, which has been reported for various types of neuroimaging data. Yet the standard LDA approach proves less than optimal for binary classification problems when additional label information (i.e. subclass labels) is present. Subclass labels allow to model structure in the data, which can be used to facilitate the classification task. In this paper, we illustrate how neuroimaging data exhibit subclass labels that may contain valuable information. We also show that the standard LDA classifier is unable to exploit subclass labels. We introduce a novel method that allows subclass labels to be incorporated efficiently into the classifier. The novel method, which we call Relevance Subclass LDA (RSLDA), computes an individual classification hyperplane for each subclass. It is based on regularized estimators of the subclass mean and uses other subclasses as regularization targets. We demonstrate the applicability and performance of our method on data drawn from two different neuroimaging modalities: (I) EEG data from brain-computer interfacing with event-related potentials, and (II) fMRI data in response to different levels of visual motion. We show that RSLDA outperforms the standard LDA approach for both types of datasets. These findings illustrate the benefits of exploiting subclass structure in neuroimaging data. Finally, we show that our classifier also outputs regularization profiles, enabling researchers to interpret the subclass structure in a meaningful way. RSLDA therefore yields increased classification accuracy as well as a better interpretation of neuroimaging data. Since both results are highly favorable, we suggest to apply RSLDA for various classification problems within neuroimaging and beyond. Copyright © 2015

  1. Volumetric error modeling and sensitivity analysis for a five-axis ultra-precision machine tool%超精密五轴机床的几何误差建模和灵敏度分析

    Institute of Scientific and Technical Information of China (English)

    余文利; 姚鑫骅

    2015-01-01

    Studies the volumetric error modeling and its sensitivity analysis for the purpose of machine design .The volumetric er-ror model of a five-axis machine tool with the configuration of RTTTR is established based on rigid body kinematics and homoge -neous transformation matrix ,in which 37 error components are involved .The sensitivity analysis of volumetric error regarding 37 error components is carried out respectively .The analysis results will be used for the accuracy design and manufacture of a five -axis ultra-precision machine tool .%基于设计出超精密机床的目的,研究了机床的几何误差建模和误差的灵敏度分析。基于刚体运动学和齐次变换矩阵( Homogeneous Transformation Matrix ,HTM)建立了RTTTR配置的超精密五轴机床的几何误差模型,模型涉及37个误差分量。分别对37个误差分量进行了几何误差的灵敏度分析,分析结果将应用于超精密五轴机床的设计与制造上。

  2. Reproducibility of neuroimaging analyses across operating systems.

    Science.gov (United States)

    Glatard, Tristan; Lewis, Lindsay B; Ferreira da Silva, Rafael; Adalat, Reza; Beck, Natacha; Lepage, Claude; Rioux, Pierre; Rousseau, Marc-Etienne; Sherif, Tarek; Deelman, Ewa; Khalili-Mahani, Najmeh; Evans, Alan C

    2015-01-01

    Neuroimaging pipelines are known to generate different results depending on the computing platform where they are compiled and executed. We quantify these differences for brain tissue classification, fMRI analysis, and cortical thickness (CT) extraction, using three of the main neuroimaging packages (FSL, Freesurfer and CIVET) and different versions of GNU/Linux. We also identify some causes of these differences using library and system call interception. We find that these packages use mathematical functions based on single-precision floating-point arithmetic whose implementations in operating systems continue to evolve. While these differences have little or no impact on simple analysis pipelines such as brain extraction and cortical tissue classification, their accumulation creates important differences in longer pipelines such as subcortical tissue classification, fMRI analysis, and cortical thickness extraction. With FSL, most Dice coefficients between subcortical classifications obtained on different operating systems remain above 0.9, but values as low as 0.59 are observed. Independent component analyses (ICA) of fMRI data differ between operating systems in one third of the tested subjects, due to differences in motion correction. With Freesurfer and CIVET, in some brain regions we find an effect of build or operating system on cortical thickness. A first step to correct these reproducibility issues would be to use more precise representations of floating-point numbers in the critical sections of the pipelines. The numerical stability of pipelines should also be reviewed.

  3. Mapping and Analysis of the Connectome of Sympathetic Premotor Neurons in the Rostral Ventrolateral Medulla of the Rat Using a Volumetric Brain Atlas

    Science.gov (United States)

    Dempsey, Bowen; Le, Sheng; Turner, Anita; Bokiniec, Phil; Ramadas, Radhika; Bjaalie, Jan G.; Menuet, Clement; Neve, Rachael; Allen, Andrew M.; Goodchild, Ann K.; McMullan, Simon

    2017-01-01

    Spinally projecting neurons in the rostral ventrolateral medulla (RVLM) play a critical role in the generation of vasomotor sympathetic tone and are thought to receive convergent input from neurons at every level of the neuraxis; the factors that determine their ongoing activity remain unresolved. In this study we use a genetically restricted viral tracing strategy to definitively map their spatially diffuse connectome. We infected bulbospinal RVLM neurons with a recombinant rabies variant that drives reporter expression in monosynaptically connected input neurons and mapped their distribution using an MRI-based volumetric atlas and a novel image alignment and visualization tool that efficiently translates the positions of neurons captured in conventional photomicrographs to Cartesian coordinates. We identified prominent inputs from well-established neurohumoral and viscero-sympathetic sensory actuators, medullary autonomic and respiratory subnuclei, and supramedullary autonomic nuclei. The majority of inputs lay within the brainstem (88–94%), and included putative respiratory neurons in the pre-Bötzinger Complex and post-inspiratory complex that are therefore likely to underlie respiratory-sympathetic coupling. We also discovered a substantial and previously unrecognized input from the region immediately ventral to nucleus prepositus hypoglossi. In contrast, RVLM sympathetic premotor neurons were only sparsely innervated by suprapontine structures including the paraventricular nucleus, lateral hypothalamus, periaqueductal gray, and superior colliculus, and we found almost no evidence of direct inputs from the cortex or amygdala. Our approach can be used to quantify, standardize and share complete neuroanatomical datasets, and therefore provides researchers with a platform for presentation, analysis and independent reanalysis of connectomic data.

  4. MR assessment of lumbar disk herniation treated with oxygen-ozone diskolysis: the role of DWI and related ADC versus intervertebral disk volumetric analysis for detecting treatment response.

    Science.gov (United States)

    Splendiani, A; Perri, M; Conchiglia, A; Fasano, F; Di Egidio, G; Masciocchi, C; Gallucci, M

    2013-06-01

    We prospectively assessed the diagnostic criteria of morphologic MRI study (MMS) and the accuracy of DWI and related ADC values (DWI-ADC) versus intervertebral disk volumetric analysis (IDVA) for predicting shrinkage of lumbar disk herniation treated with oxygen-ozone (O2-O3) diskolysis. Sixty-eight patients (36 men and 32 women; mean age 39) with lumbosciatica underwent O2-O3 diskolysis. The six-month MRI follow-up was performed with FSE-T2 and T2-fat, SE-T1 and DWI-weighted images. IDVA was determined using OsiriX(®). Diagnostic criteria and accuracy were evaluated with regards to DWI and related ADC in detecting response to ozone therapy. Fifty-eight of 68 patients had successful outcomes (responders), whereas ten patients showed unsatisfactory outcomes (non-responders). MMS showed that a centrally located herniated disk and grade 1 nerve root compression were more common in the responder group (p < 0.05). DWI-ADC and IDVA showed statistically significant shrinkage in the sixth month of follow-up (p < 0.05) with a mean ADC value reduction of 2.10 × 10(-3) mm(2)/s +/- 0.19 SD in the second month of follow-up (p < 0.05). DWI-ADC had an accuracy of 0.81 in detecting response to therapy around the second month of follow-up. DWI-ADC appear to be useful adjuncts to MMS in the follow-up of patients undergoing O2-O3 diskolysis.

  5. Postmortem volumetric CT data analysis of pulmonary air/gas content with regard to the cause of death for investigating terminal respiratory function in forensic autopsy.

    Science.gov (United States)

    Sogawa, Nozomi; Michiue, Tomomi; Ishikawa, Takaki; Kawamoto, Osamu; Oritani, Shigeki; Maeda, Hitoshi

    2014-08-01

    Postmortem CT (PMCT) is useful to investigate air/gas distribution and content in body cavities and viscera. The present study investigated the procedure to estimate total lung air/gas content and aeration ratio as possible indices of terminal respiratory function, using three-dimensional (3-D) PMCT data analysis of forensic autopsy cases without putrefactive gas formation (within 3 days postmortem, n=75), and analyzed the volumetric data with regard to the cause of death. When 3-D bilateral lung images were reconstructed using an image analyzer, combined lung volume was larger in drowning (n=12) than in alcohol/sedative-hypnotic intoxication (n=8) and sudden cardiac death (SCD; n=10), and intermediate in other cases, including mechanical asphyxiation (n=12), fire fatalities due to burns (n=6) and carbon monoxide intoxication (n=7), fatal methamphetamine abuse (n=7), hyperthermia (heatstroke; n=6) and fatal hypothermia (cold exposure; n=7). Air/gas content of the lung as detected using HU interval between -2000 and -400 ('effective' lung aeration areas) and between -2000 and -191 (total lung aeration areas) as well as the ratios to total lung volume ('effective' and total lung aeration ratios, respectively) was higher in mechanical asphyxiation, drowning, fatal burns and hypothermia (cold exposure) than in SCD, and was intermediate in other cases. 'Effective' and total lung aeration ratios may be useful for comparisons between specific causes of death to discriminate between hypothermia (cold exposure) and drug intoxication, and between SCD and other causes of death, respectively. These findings provide interesting insights into potential efficacy of PMCT data analyses of lung volume and CT density as well as lung air/gas content and aeration ratio with regard to the cause of death, as possible indicators of terminal respiratory function, as part of virtual autopsy of the viscera in situ.

  6. Neuroimaging for psychotherapy research: current trends.

    Science.gov (United States)

    Weingarten, Carol P; Strauman, Timothy J

    2015-01-01

    This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research. We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research. We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive compulsive disorder (OCD), and schizophrenia. The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research.

  7. [Correlation between EEG and neuroimaging].

    Science.gov (United States)

    Tobimatsu, Shozo

    2012-01-01

    The present state of knowledge of physiological mechanisms underlying nonepileptiform EEG abnormalities is reviewed to clarify the correlation between EEG and neuroimaging. Focal and widespread slow waves, background abnormalities, and bursts of rhythmic slow activity are discussed. EEG phenomena were correlated with lesion size, location, type (white matter vs. gray matter, high density vs. low density), and mass effect. Clinical and experimental accumulated over the past five decades suggest that polymorphic slow activity is generated in cerebral cortex by layers of pyramidal cells and is probably due to partial deafferentation from subcortical areas. Unilateral background activity changes are probably thalamic dysfunction, and bilateral paroxysmal slow activity is due to abnormal thalamocortical circuits combined with cortical pathology. Paroxysmal discharges indicate the presence of epilepsy with possible brain lesion(s). The EEG is a functional test and provides us complementary information to neuroimaging studies.

  8. FUNCTIONAL NEUROIMAGING IN GERIATRIC DEPRESSION

    Science.gov (United States)

    Gunning, Faith M.; Smith, Gwenn S.

    2012-01-01

    Synopsis Abnormalities in specific cerebral networks likely confer vulnerability that increases the susceptibility for development of geriatric depression and impact the course of symptoms. Functional neuroimaging enables the in vivo identification of alterations in cerebral function that not only characterize disease vulnerability, but also may contribute to variability in depressive symptoms and antidepressant response. Judicious use of functional neuroimaging tools can advance pathophysiological models of geriatric depression. Furthermore, due to the age-related vulnerability of specific brain systems that have been implicated in mood disorders, geriatric depression provides a logical context within which to study the role of specific functional abnormalities in both antidepressant response and key behavioral and cognitive abnormalities of mood disorders. PMID:21536165

  9. Chemical Analysis Method for Carbon Bearing Refractory Products——Determination of Magnesium Oxide Content by CyDTA Volumetric Method

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui

    2007-01-01

    @@ GB/T 13246 - 91 1 Scope This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method. This standard applies to the determination of magnesium oxide content in between 60% and 85% in magnesia-carbon bricks

  10. Neuroimaging Evidence of Comprehension Monitoring

    OpenAIRE

    Linda Baker; Alisa Zeliger-Kandasamy; Laura U. DeWyngaert

    2014-01-01

    The purpose of this article is to synthesize the emerging neuroimaging literature that reveals how the brain responds when readers and listeners encounter texts that demand monitoring of their ongoing comprehension processes. Much of this research has been undertaken by cognitive scientists who do not frame their work in metacognitive terms, and therefore it is less likely to be familiar to psychologists who study metacognition in educational contexts. The important role of metacognition in t...

  11. Can neuroimaging disentangle bipolar disorder?

    Science.gov (United States)

    Hozer, Franz; Houenou, Josselin

    2016-05-01

    Bipolar disorder heterogeneity is large, leading to difficulties in identifying neuropathophysiological and etiological mechanisms and hindering the formation of clinically homogeneous patient groups in clinical trials. Identifying markers of clinically more homogeneous groups would help disentangle BD heterogeneity. Neuroimaging may aid in identifying such groups by highlighting specific biomarkers of BD subtypes or clinical dimensions. We performed a systematic literature search of the neuroimaging literature assessing biomarkers of relevant BD phenotypes (type-I vs. II, presence vs. absence of psychotic features, suicidal behavior and impulsivity, rapid cycling, good vs. poor medication response, age at onset, cognitive performance and circadian abnormalities). Consistent biomarkers were associated with suicidal behavior, i.e. frontal/anterior alterations (prefrontal and cingulate grey matter, prefrontal white matter) in patients with a history of suicide attempts; and with cognitive performance, i.e. involvement of frontal and temporal regions, superior and inferior longitudinal fasciculus, right thalamic radiation, and corpus callosum in executive dysfunctions. For the other dimensions and sub-types studied, no consistent biomarkers were identified. Studies were heterogeneous both in methodology and outcome. Though theoretically promising, neuroimaging has not yet proven capable of disentangling subtypes and dimensions of bipolar disorder, due to high between-study heterogeneity. We issue recommendations for future studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.

    Directory of Open Access Journals (Sweden)

    Hirotsugu Ohkubo

    Full Text Available Although several computer-aided computed tomography (CT analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF, it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.The purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.A total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT, the normally attenuated lung volume as defined from -950 HU to -701 Hounsfield unit (NL, the volume of the whole lung (WL, and the percentage of NL to WL (NL%, were calculated.CT indices (MCT, WL, and NL closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC (r = 0.92, P <0.0001. NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI, 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05].The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

  13. Building better biomarkers: brain models in translational neuroimaging.

    Science.gov (United States)

    Woo, Choong-Wan; Chang, Luke J; Lindquist, Martin A; Wager, Tor D

    2017-02-23

    Despite its great promise, neuroimaging has yet to substantially impact clinical practice and public health. However, a developing synergy between emerging analysis techniques and data-sharing initiatives has the potential to transform the role of neuroimaging in clinical applications. We review the state of translational neuroimaging and outline an approach to developing brain signatures that can be shared, tested in multiple contexts and applied in clinical settings. The approach rests on three pillars: (i) the use of multivariate pattern-recognition techniques to develop brain signatures for clinical outcomes and relevant mental processes; (ii) assessment and optimization of their diagnostic value; and (iii) a program of broad exploration followed by increasingly rigorous assessment of generalizability across samples, research contexts and populations. Increasingly sophisticated models based on these principles will help to overcome some of the obstacles on the road from basic neuroscience to better health and will ultimately serve both basic and applied goals.

  14. Visualization of Nonlinear Classification Models in Neuroimaging - Signed Sensitivity Maps

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Schmah, Tanya; Madsen, Kristoffer Hougaard

    2012-01-01

    Classification models are becoming increasing popular tools in the analysis of neuroimaging data sets. Besides obtaining good prediction accuracy, a competing goal is to interpret how the classifier works. From a neuroscientific perspective, we are interested in the brain pattern reflecting...

  15. Brain volumetric abnormalities in patients with anorexia and bulimia nervosa: a voxel-based morphometry study.

    Science.gov (United States)

    Amianto, Federico; Caroppo, Paola; D'Agata, Federico; Spalatro, Angela; Lavagnino, Luca; Caglio, Marcella; Righi, Dorico; Bergui, Mauro; Abbate-Daga, Giovanni; Rigardetto, Roberto; Mortara, Paolo; Fassino, Secondo

    2013-09-30

    Recent studies focussing on neuroimaging features of eating disorders have observed that anorexia nervosa (AN) is characterized by significant grey matter (GM) atrophy in many brain regions, especially in the cerebellum and anterior cingulate cortex. To date, no studies have found GM atrophy in bulimia nervosa (BN) or have directly compared patients with AN and BN. We used voxel-based morphometry (VBM) to characterize brain abnormalities in AN and BN patients, comparing them with each other and with a control group, and correlating brain volume with clinical features. We recruited 17 AN, 13 BN and 14 healthy controls. All subjects underwent high-resolution magnetic resonance imaging (MRI) with a T1-weighted 3D image. VBM analysis was carried out with the FSL-VBM 4.1 tool. We found no global atrophy, but regional GM reduction in AN with respect to controls and BN in the cerebellum, fusiform area, supplementary motor area, and occipital cortex, and in the caudate in BN compared to AN and controls. Both groups of patients had a volumetric increase bilaterally in somatosensory regions with respect to controls, in areas that are typically involved in the sensory-motor integration of body stimuli and in mental representation of the body image. Our VBM study documented, for the first time in BN patients, the presence of volumetric alterations and replicated previous findings in AN patients. We evidenced morphological differences between AN and BN, demonstrating in the latter atrophy of the caudate nucleus, a region involved in reward mechanisms and processes of self-regulation, perhaps involved in the genesis of the binge-eating behaviors of this disorder. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. Consensus paper: combining transcranial stimulation with neuroimaging

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Bergmann, Til O; Bestmann, Sven

    2009-01-01

    In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during...... neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce...... information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need...

  17. Dosimetric and volumetric changes in the rectum and bladder in patients receiving CBCT-guided prostate IMRT: analysis based on daily CBCT dose calculation.

    Science.gov (United States)

    Pearson, David; Gill, Sukhdeep K; Campbell, Nina; Reddy, Krishna

    2016-11-08

    Delivered dose can be calculated by transferring the planned treatment beams onto the daily CBCT. Bladder and rectum volumetric doses were calculated and cor-related to the daily bladder and rectum fullness. Patients for this study underwent hypofractionated prostate IMRT to 70 Gy in 28 fractions. Daily CBCT was utilized for image guidance. A clinically acceptable plan was created using a CTV-to-PTV uniform margin of 5 mm. Image fusion was performed to transfer the bladder and rectum contours onto each CBCT. Contours were then edited to match the anatomy of each CBCT. Using the daily treatment isocenter, the planned beams were transferred onto the CBCT and daily and cumulative DVHs calculated. For the results a total of 168 daily CBCTs were evaluated. The bladder was found to be smaller for 74.7% of the 168 daily CBCTs accessed in this study. This reduction in volume correlated to an increase in the cumulative bladder V70 Gy from 9.47% on the planning CT to 10.99% during treatment. V70Gy for the rectum was 7.27% on the planning CT, when all six patients were averaged, and increased to 11.56% on the average of all daily treatment CBCTs. Increases in volumetric rectum dose correlated with increases in rectal volume. For one patient, the rectum and blad-der absolute V70 Gy, averaged over the course of treatment, increased by 295% and 61%, respectively. Larger variations in the daily bladder and rectal volume were observed and these correlated to large deviations from the volumetric dose received by these structures. In summary, bladder and rectum volume changes during treatment have an effect on the cumulative dose received by these organs. It was observed that the volumetric dose received by the bladder decreases as the volume of the bladder increases. The inverse was true for the rectum.

  18. Neuroimaging in Restless Legs Syndrome.

    Science.gov (United States)

    Provini, Federica; Chiaro, Giacomo

    2015-09-01

    Neuroimaging studies are of crucial relevance in defining the pathophysiology of restless legs syndrome (RLS). MRI studies showed no structural brain lesions and confirmed a central iron deficiency. Structural and functional studies showed an involvement of the thalamus, sensorimotor cortical areas, and cerebellum in RLS and assessed neurotransmission abnormalities in the dopaminergic and opiate systems. Finally, glutamatergic hyperactivity has been proposed as a cause of disrupted and shortened sleep in RLS. Differences among the results of the studies make it difficult to draw any definitive conclusions, thus, suggesting the need for future research.

  19. Test Facility for Volumetric Absorber

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, M.; Dibowski, G.; Pfander, M.; Sack, J. P.; Schwarzbozl, P.; Ulmer, S.

    2006-07-01

    Long-time testing of volumetric absorber modules is an inevitable measure to gain the experience and reliability required for the commercialization of the open volumetric receiver technology. While solar tower test facilities are necessary for performance measurements of complete volumetric receivers, the long-term stability of individual components can be tested in less expensive test setups. For the qualification of the aging effects of operating cycles on single elements of new absorber materials and designs, a test facility was developed and constructed in the framework of the KOSMOSOL project. In order to provide the concentrated solar radiation level, the absorber test facility is integrated into a parabolic dish system at the Plataforma Solar de Almeria (PSA) in Spain. Several new designs of ceramic absorbers were developed and tested during the last months. (Author)

  20. Delirium and hypovitaminosis D: neuroimaging findings.

    Science.gov (United States)

    Bourgeois, James A; Hategan, Ana; Ford, Jennifer; Tisi, Daniel K; Xiong, Glen L

    2015-01-01

    The authors examined the frequency of neuroimaging findings of cortical atrophy and/or cerebrovascular disease in patients with delirium with hypovitaminosis D and normal vitamin D levels. Of 32 patients with delirium with hypovitaminosis D who were neuroimaged, 91.4% had neuroimaging findings, despite only five cases having a comorbid diagnosis of dementia. Similar frequencies of cortical atrophy and/or cerebrovascular disease were found in patients with delirium with normal vitamin D levels. Further research with a larger sample size is needed to compare neuroimaging findings between normal patients and patients with hypovitaminosis D with delirium.

  1. NeuroDebian Virtual Machine Deployment Facilitates Trainee-Driven Bedside Neuroimaging Research.

    Science.gov (United States)

    Cohen, Alexander; Kenney-Jung, Daniel; Botha, Hugo; Tillema, Jan-Mendelt

    2016-09-21

    Freely available software, derived from the past 2 decades of neuroimaging research, is significantly more flexible for research purposes than presently available clinical tools. Here, we describe and demonstrate the utility of rapidly deployable analysis software to facilitate trainee-driven translational neuroimaging research. A recipe and video tutorial were created to guide the creation of a NeuroDebian-based virtual computer that conforms to current neuroimaging research standards and can exist within a HIPAA-compliant system. This allows for retrieval of clinical imaging data, conversion to standard file formats, and rapid visualization and quantification of individual patients' cortical and subcortical anatomy. As an example, we apply this pipeline to a pediatric patient's data to illustrate the advantages of research-derived neuroimaging tools in asking quantitative questions "at the bedside." Our goal is to provide a path of entry for trainees to become familiar with common neuroimaging tools and foster an increased interest in translational research.

  2. Neuroimaging in Selected Nigerian Epileptic Patients: A Decade of ...

    African Journals Online (AJOL)

    Neuroimaging in Selected Nigerian Epileptic Patients: A Decade of Experience. ... The study sets out to highlight the relevance of neuroimaging in the management of ... The neuroimaging was done in various centres in Nigeria and abroad.

  3. Neuroimaging studies of the hippocampus in schizophrenia.

    Science.gov (United States)

    Heckers, S

    2001-01-01

    Three neuroimaging techniques, morphometric neuroimaging, magnetic resonance spectroscopy, and functional neuroimaging, have provided evidence for abnormal hippocampal structure and function in schizophrenia. Hippocampal volume reduction is now one of the most consistent structural abnormalities found in schizophrenia: it is present at the onset of the illness and, to a lesser degree, in first-degree relatives of schizophrenic probands. Decreased levels of N-acetyl-aspartate point towards a cellular basis of such volume changes. Functional neuroimaging studies have demonstrated abnormal levels of hippocampal activity at rest, during the experience of auditory hallucinations, and during the performance of memory retrieval tasks. These results of neuroimaging studies complement evidence from post-mortem and behavioral studies, which have found regionally specific abnormalities of the hippocampus and of memory function in schizophrenia.

  4. Update on neuroimaging phenotypes of mid-hindbrain malformations

    Energy Technology Data Exchange (ETDEWEB)

    Jissendi-Tchofo, Patrice [University Hospital of Lille (CHRU), Department of Neuroradiology, MRI 3T Research, Plateforme Imagerie du vivant, IMPRT-IFR 114, Lille-Cedex (France); CHU Saint-Pierre, Radiology Department, Pediatric Neuroradiology Section, Brussels (Belgium); Severino, Mariasavina [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Nguema-Edzang, Beatrice; Toure, Cisse; Soto Ares, Gustavo [University Hospital of Lille (CHRU), Department of Neuroradiology, MRI 3T Research, Plateforme Imagerie du vivant, IMPRT-IFR 114, Lille-Cedex (France); Barkovich, Anthony James [University of California, Neuroradiology Section, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States)

    2014-10-23

    Neuroimaging techniques including structural magnetic resonance imaging (MRI) and functional positron emission tomography (PET) are useful in categorizing various midbrain-hindbrain (MHB) malformations, both in allowing diagnosis and in helping to understand the developmental processes that were disturbed. Brain imaging phenotypes of numerous malformations are characteristic features that help in guiding the genetic testing in case of direct neuroimaging-genotype correlation or, at least, to differentiate among MHB malformations entities. The present review aims to provide the reader with an update of the use of neuroimaging applications in the fine analysis of MHB malformations, using a comprehensive, recently proposed developmental and genetic classification. We have performed an extensive systematic review of the literature, from the embryology main steps of MHB development through the malformations entities, with regard to their molecular and genetic basis, conventional MRI features, and other neuroimaging characteristics. We discuss disorders in which imaging features are distinctive and how these features reflect the structural and functional impairment of the brain. Recognition of specific MRI phenotypes, including advanced imaging features, is useful to recognize the MHB malformation entities, to suggest genetic investigations, and, eventually, to monitor the disease outcome after supportive therapies. (orig.)

  5. Development of PowerMap: a software package for statistical power calculation in neuroimaging studies.

    Science.gov (United States)

    Joyce, Karen E; Hayasaka, Satoru

    2012-10-01

    Although there are a number of statistical software tools for voxel-based massively univariate analysis of neuroimaging data, such as fMRI (functional MRI), PET (positron emission tomography), and VBM (voxel-based morphometry), very few software tools exist for power and sample size calculation for neuroimaging studies. Unlike typical biomedical studies, outcomes from neuroimaging studies are 3D images of correlated voxels, requiring a correction for massive multiple comparisons. Thus, a specialized power calculation tool is needed for planning neuroimaging studies. To facilitate this process, we developed a software tool specifically designed for neuroimaging data. The software tool, called PowerMap, implements theoretical power calculation algorithms based on non-central random field theory. It can also calculate power for statistical analyses with FDR (false discovery rate) corrections. This GUI (graphical user interface)-based tool enables neuroimaging researchers without advanced knowledge in imaging statistics to calculate power and sample size in the form of 3D images. In this paper, we provide an overview of the statistical framework behind the PowerMap tool. Three worked examples are also provided, a regression analysis, an ANOVA (analysis of variance), and a two-sample T-test, in order to demonstrate the study planning process with PowerMap. We envision that PowerMap will be a great aide for future neuroimaging research.

  6. Volumetric composition in composites and historical data

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2013-01-01

    guidance to the optimal combination of fibre content, matrix content and porosity content, in order to achieve the best obtainable properties. Several composite materials systems have been shown to be handleable with this model. An extensive series of experimental data for the system of cellulose fibres...... and polymer (resin) was produced in 1942 – 1944, and these data have been (re-)analysed by the volumetric composition model, and the property values for density, stiffness and strength have been evaluated. Good agreement has been obtained and some further observations have been extracted from the analysis....

  7. Neuroimaging of classic neuralgic amyotrophy.

    Science.gov (United States)

    Lieba-Samal, Doris; Jengojan, Suren; Kasprian, Gregor; Wöber, Christian; Bodner, Gerd

    2016-12-01

    Neuralgic amyotrophy (NA) often imposes diagnostic problems. Recently, MRI and high-resolution ultrasound (HRUS) have proven useful in diagnosing peripheral nerve disorders. We performed a chart and imaging review of patients who were examined using neuroimaging and who were referred because of clinically diagnosed NA between March 1, 2014 and May 1, 2015. Six patients were included. All underwent HRUS, and 5 underwent MRI. Time from onset to evaluation ranged from 2 weeks to 6 months. HRUS showed segmental swelling of all clinically affected nerves/trunks. Atrophy of muscles was detected in those assessed >1 month after onset. MRI showed T2-weighted hyperintensity in all clinically affected nerves, except for the long thoracic nerve, and denervation edema of muscles. HRUS and MRI are valuable diagnostic tools in NA. This could change the diagnostic approach from one now focused on excluding other disorders to confirming NA through imaging markers. Muscle Nerve 54: 1079-1085, 2016. © 2016 Wiley Periodicals, Inc.

  8. 4D-SPECT/CT in orthopaedics: a new method of combined quantitative volumetric 3D analysis of SPECT/CT tracer uptake and component position measurements in patients after total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, Helmut; Falkowski, Anna L.; Forrer, Flavio [Kantonsspital Baselland, Institute for Radiology and Nuclear Medicine, Bruderholz (Switzerland); Henckel, Johann [Imperial College London, London (United Kingdom); Hirschmann, Michael T. [Kantonsspital Baselland, Department of Orthopaedic Surgery and Traumatology, Bruderholz (Switzerland)

    2013-09-15

    The purpose was to evaluate the intra- and inter-observer reliability of combined quantitative 3D-volumetric single-photon emission computed tomography (SPECT)/CT analysis including size, intensity and localisation of tracer uptake regions and total knee arthroplasty (TKA) position. Tc-99m-HDP-SPECT/CT of 100 knees after TKA were prospectively analysed. The anatomical areas represented by a previously validated localisation scheme were 3D-volumetrically analysed. The maximum intensity was recorded for each anatomical area. Ratios between the respective value and the mid-shaft of the femur as the reference were calculated. Femoral and tibial TKA position (varus-valgus, flexion-extension, internal rotation- external rotation) were determined on 3D-CT. Two consultant radiologists/nuclear medicine physicians interpreted the SPECT/CTs twice with a 2-week interval. The inter- and intra-observer reliability was determined (ICCs). Kappa values were calculated for the area with the highest tracer uptake between the observers. The measurements of tracer uptake intensity showed excellent inter- and intra-observer reliabilities for all regions (tibia, femur and patella). Only the tibial shaft area showed ICCs <0.89. The kappa values were almost perfect (0.856, p < 0.001; 95 % CI 0.778, 0.922). For measurements of the TKA position, there was strong agreement within and between the readings of the two observers; the ICCs for the orientation of TKA components for inter- and intra-observer reliability were nearly perfect (ICCs >0.84). This combined 3D-volumetric standardised method of analysing the location, size and the intensity of SPECT/CT tracer uptake regions (''hotspots'') and the determination of the TKA position was highly reliable and represents a novel promising approach to biomechanics. (orig.)

  9. Ethical issues in neuroimaging health research: an IPA study with research participants.

    Science.gov (United States)

    Shaw, Rachel L; Senior, Carl; Peel, Elizabeth; Cooke, Richard; Donnelly, Louise S

    2008-11-01

    Neuroimaging is increasingly used to understand conditions like stroke and epilepsy. However, there is growing recognition that neuroimaging can raise ethical issues. We used interpretative phenomenological analysis to analyse interview data pre-and post-scan to explore these ethical issues. Findings show participants can become anxious prior to scanning and the protocol for managing incidental findings is unclear. Participants lacked a frame of reference to contextualize their expectations and often drew on medical narratives. Recommendations to reduce anxiety include dialogue between researcher and participant to clarify understanding during consent and the use of a ;virtual tour' of the neuroimaging experience.

  10. A comparison of substantia nigra T1 hyperintensity in Parkinson's disease dementia, Alzheimer's disease and age-matched controls: Volumetric analysis of neuromelanin imaging

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Won Jin; Park, Ju Yeon; Yun, Won Sung; Jeon, Ji Yeong; Moon, Yeon Sil; Kim, Hee Jin; Han, Seol Heui [Konkuk University School of Medicine, Seoul (Korea, Republic of); Kwak, Ki Chang; Lee, Jong Min [Dept. of Biomedical Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-09-15

    Neuromelanin loss of substantia nigra (SN) can be visualized as a T1 signal reduction on T1-weighted high-resolution imaging. We investigated whether volumetric analysis of T1 hyperintensity for SN could be used to differentiate between Parkinson's disease dementia (PDD), Alzheimer's disease (AD) and age-matched controls. This retrospective study enrolled 10 patients with PDD, 18 patients with AD, and 13 age-matched healthy elderly controls. MR imaging was performed at 3 tesla. To measure the T1 hyperintense area of SN, we obtained an axial thin section high-resolution T1-weighted fast spin echo sequence. The volumes of interest for the T1 hyperintense SN were drawn onto heavily T1-weighted FSE sequences through midbrain level, using the MIPAV software. The measurement differences were tested using the Kruskal-Wallis test followed by a post hoc comparison. A comparison of the three groups showed significant differences in terms of volume of T1 hyperintensity (p < 0.001, Bonferroni corrected). The volume of T1 hyperintensity was significantly lower in PDD than in AD and normal controls (p < 0.005, Bonferroni corrected). However, the volume of T1 hyperintensity was not different between AD and normal controls (p = 0.136, Bonferroni corrected). The volumetric measurement of the T1 hyperintensity of SN can be an imaging marker for evaluating neuromelanin loss in neurodegenerative diseases and a differential in PDD and AD cases.

  11. Neuroimaging Evidence of Comprehension Monitoring

    Directory of Open Access Journals (Sweden)

    Linda Baker

    2014-04-01

    Full Text Available The purpose of this article is to synthesize the emerging neuroimaging literature that reveals how the brain responds when readers and listeners encounter texts that demand monitoring of their ongoing comprehension processes. Much of this research has been undertaken by cognitive scientists who do not frame their work in metacognitive terms, and therefore it is less likely to be familiar to psychologists who study metacognition in educational contexts. The important role of metacognition in the development and use of academic skills is widely recognized. Metacognition is typically defined as the awareness and control of one's own cognitive processes. In the domain of reading, the most important metacognitive skill is comprehension monitoring, the evaluation and regulation of comprehension. Readers who monitor their understanding realize when they have encountered difficulty making sense of the text, and they apply error correction procedures to attempt to resolve the difficulty. Metacognition depends on executive control skills that continue to develop into early adulthood, in parallel with the maturation of the executive control regions of the prefrontal cortex. Functional magnetic resonance imaging (fMRI and event-related potentials (ERP have been used for some time to study neural correlates of basic reading processes such as word identification, but it is only within recent years that researchers have turned to the higher-level processes of text comprehension. The article describes illustrative studies that reveal changes in neural activity when adults apply lexical, syntactic, or semantic standards to evaluate their understanding.

  12. Learning Neuroimaging. 100 essential cases

    Energy Technology Data Exchange (ETDEWEB)

    Asis Bravo-Rodriguez, Francisco de [Reina Sofia University Hospital, Cordoba (Spain). Diagnostic and Therapeutics Neuroradiology; Diaz-Aguilera, Rocio [Alto Guadalquivir Hospital, Andujar, Jaen (Spain). Dept. of Radiology; Hygino da Cruz, Luiz Celso [Universidade Federal do Rio de Janeiro (Brazil). CDPI and IRM Ressonancia Magnetica

    2012-07-01

    Neuroradiology is the branch of radiology that comprises both imaging and invasive procedures related to the brain, spine and spinal cord, head, neck, organs of special sense (eyes, ears, nose), cranial and spinal nerves, and cranial, cervical, and spinal vessels. Special training and skills are required to enable the neuroradiologist to function as an expert diagnostic and therapeutic consultant and practitioner. In addition to knowledge of imaging findings, the neuroradiologist is required to learn the fundamentals of structural and functional neuroanatomy, neuropathology, and neuropathophysiology as well as the clinical manifestations of diseases of the brain, spine and spinal cord, head, neck, and organs of special sense. This book is intended as an introduction to neuroradiology and aims to provide the reader with a comprehensive overview of this highly specialized radiological subspecialty. One hundred illustrated cases from clinical practice are presented in a standard way. Each case is supported by representative images and is divided into three parts: a brief summary of the patient's medical history, a discussion of the disease, and a description of the most characteristic imaging features of the disorder. The focus is not only on common neuroradiological entities such as stroke and acute head trauma but also on less frequent disorders that the practitioner should recognize. Learning Neuroimaging: 100 Essential Cases is an ideal resource for neuroradiology and radiology residents, neurology residents, neurosurgery residents, nurses, radiology technicians, and medical students. (orig.)

  13. Neuroimaging of motor neuron diseases.

    Science.gov (United States)

    Kassubek, Jan; Ludolph, Albert C; Müller, Hans-Peter

    2012-03-01

    It is agreed that conventional magnetic resonance imaging (MRI) of the brain and spine is one of the core elements in the differential diagnostic work up of patients with clinical signs of motor neuron diseases (MNDs), for example amyotrophic lateral sclerosis (ALS), to exclude MND mimics. However, the sensitivity and specificity of MRI signs in these disorders are moderate to low and do not have an evidence level higher than class IV (good clinical practice point). Currently computerized MRI analyses in ALS and other MNDs are not techniques used for individual diagnosis. However, they have improved the anatomical understanding of pathomorphological alterations in gray and white matter in various MNDs and the changes in functional networks by quantitative comparisons between patients with MND and controls at group level. For multiparametric MRI protocols, including T1-weighted three-dimensional datasets, diffusion-weighted imaging and functional MRI, the potential as a 'dry' surrogate marker is a subject of investigation in natural history studies with well defined patients. The additional value of MRI with respect to early diagnosis at an individual level and for future disease-modifying multicentre trials remains to be defined. There is still the need for more longitudinal studies in the very early stages of disease or when there is clinical uncertainty and for better standardization in the acquisition and postprocessing of computer-based MRI data. These requirements are to be addressed by establishing quality-controlled multicentre neuroimaging databases.

  14. Neuroimaging of the Philadelphia neurodevelopmental cohort.

    Science.gov (United States)

    Satterthwaite, Theodore D; Elliott, Mark A; Ruparel, Kosha; Loughead, James; Prabhakaran, Karthik; Calkins, Monica E; Hopson, Ryan; Jackson, Chad; Keefe, Jack; Riley, Marisa; Mentch, Frank D; Sleiman, Patrick; Verma, Ragini; Davatzikos, Christos; Hakonarson, Hakon; Gur, Ruben C; Gur, Raquel E

    2014-02-01

    The Philadelphia Neurodevelopmental Cohort (PNC) is a large-scale, NIMH funded initiative to understand how brain maturation mediates cognitive development and vulnerability to psychiatric illness, and understand how genetics impacts this process. As part of this study, 1445 adolescents ages 8-21 at enrollment underwent multimodal neuroimaging. Here, we highlight the conceptual basis for the effort, the study design, and the measures available in the dataset. We focus on neuroimaging measures obtained, including T1-weighted structural neuroimaging, diffusion tensor imaging, perfusion neuroimaging using arterial spin labeling, functional imaging tasks of working memory and emotion identification, and resting state imaging of functional connectivity. Furthermore, we provide characteristics regarding the final sample acquired. Finally, we describe mechanisms in place for data sharing that will allow the PNC to become a freely available public resource to advance our understanding of normal and pathological brain development. © 2013 Elsevier Inc. All rights reserved.

  15. Neuroimaging Biomarkers of Neurodegenerative Diseases and Dementia

    Science.gov (United States)

    Risacher, Shannon L.; Saykin, Andrew J.

    2014-01-01

    Neurodegenerative disorders leading to dementia are common diseases that affect many older and some young adults. Neuroimaging methods are important tools for assessing and monitoring pathological brain changes associated with progressive neurodegenerative conditions. In this review, the authors describe key findings from neuroimaging studies (magnetic resonance imaging and radionucleotide imaging) in neurodegenerative disorders, including Alzheimer’s disease (AD) and prodromal stages, familial and atypical AD syndromes, frontotemporal dementia, amyotrophic lateral sclerosis with and without dementia, Parkinson’s disease with and without dementia, dementia with Lewy bodies, Huntington’s disease, multiple sclerosis, HIV-associated neurocognitive disorder, and prion protein associated diseases (i.e., Creutzfeldt-Jakob disease). The authors focus on neuroimaging findings of in vivo pathology in these disorders, as well as the potential for neuroimaging to provide useful information for differential diagnosis of neurodegenerative disorders. PMID:24234359

  16. Volumetric Three-Dimensional Display Systems

    Science.gov (United States)

    Blundell, Barry G.; Schwarz, Adam J.

    2000-03-01

    A comprehensive study of approaches to three-dimensional visualization by volumetric display systems This groundbreaking volume provides an unbiased and in-depth discussion on a broad range of volumetric three-dimensional display systems. It examines the history, development, design, and future of these displays, and considers their potential for application to key areas in which visualization plays a major role. Drawing substantially on material that was previously unpublished or available only in patent form, the authors establish the first comprehensive technical and mathematical formalization of the field, and examine a number of different volumetric architectures. System level design strategies are presented, from which proposals for the next generation of high-definition predictable volumetric systems are developed. To ensure that researchers will benefit from work already completed, they provide: * Descriptions of several recent volumetric display systems prepared from material supplied by the teams that created them * An abstract volumetric display system design paradigm * An historical summary of 90 years of development in volumetric display system technology * An assessment of the strengths and weaknesses of many of the systems proposed to date * A unified presentation of the underlying principles of volumetric display systems * A comprehensive bibliography Beautifully supplemented with 17 color plates that illustrate volumetric images and prototype displays, Volumetric Three-Dimensional Display Systems is an indispensable resource for professionals in imaging systems development, scientific visualization, medical imaging, computer graphics, aerospace, military planning, and CAD/CAE.

  17. The ENIGMA Consortium: large-scale collaborative analyses of neuroimaging and genetic data

    OpenAIRE

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud

    2014-01-01

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of finding...

  18. The ENIGMA Consortium: large-scale collaborative analyses of neuroimaging and genetic data.

    OpenAIRE

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud

    2014-01-01

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of finding...

  19. The ENIGMA Consortium: Large-scale collaborative analyses of neuroimaging and genetic data

    OpenAIRE

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud

    2014-01-01

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of finding...

  20. The ENIGMA Consortium: Large-scale collaborative analyses of neuroimaging and genetic data

    OpenAIRE

    Thompson, Paul; Stein, J.L.; Medland, Sarah Elizabeth; Hibar, Derrek; Vásquez, Arias; Rentería, Miguel; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret; Martin, Nicholas; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud

    2014-01-01

    textabstractThe Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replicatio...

  1. Human neuroimaging as a "Big Data" science.

    Science.gov (United States)

    Van Horn, John Darrell; Toga, Arthur W

    2014-06-01

    The maturation of in vivo neuroimaging has led to incredible quantities of digital information about the human brain. While much is made of the data deluge in science, neuroimaging represents the leading edge of this onslaught of "big data". A range of neuroimaging databasing approaches has streamlined the transmission, storage, and dissemination of data from such brain imaging studies. Yet few, if any, common solutions exist to support the science of neuroimaging. In this article, we discuss how modern neuroimaging research represents a multifactorial and broad ranging data challenge, involving the growing size of the data being acquired; sociological and logistical sharing issues; infrastructural challenges for multi-site, multi-datatype archiving; and the means by which to explore and mine these data. As neuroimaging advances further, e.g. aging, genetics, and age-related disease, new vision is needed to manage and process this information while marshalling of these resources into novel results. Thus, "big data" can become "big" brain science.

  2. Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: A dosimetric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rachit; Wild, Aaron T.; Ziegler, Mark A.; Hooker, Ted K.; Dah, Samson D.; Tran, Phuoc T.; Kang, Jun; Smith, Koren; Zeng, Jing [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Pawlik, Timothy M. [Department of Surgery, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Ford, Eric [Department of Radiation Oncology, Fred Hutchinson Cancer Center, University of Washington, Seattle, WA (United States); Herman, Joseph M., E-mail: jherma15@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States)

    2013-10-01

    Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non–duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25 Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal D{sub max} of<30 Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal D{sub mean}, D{sub max}, D{sub 1cc}, D{sub 4%}, and V{sub 20} {sub Gy} compared with NS plans (all p≤0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V{sub 95%} (p = 0.01) and D{sub mean} (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p<0.001) and the spinal cord (p<0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p<0.001) and delivered treatment 2.4 minutes faster (p<0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at

  3. Analysis of volumetric response of pituitary adenomas receiving adjuvant CyberKnife stereotactic radiosurgery with the application of an exponential fitting model

    Science.gov (United States)

    Yu, Yi-Lin; Yang, Yun-Ju; Lin, Chin; Hsieh, Chih-Chuan; Li, Chiao-Zhu; Feng, Shao-Wei; Tang, Chi-Tun; Chung, Tzu-Tsao; Ma, Hsin-I; Chen, Yuan-Hao; Ju, Da-Tong; Hueng, Dueng-Yuan

    2017-01-01

    Abstract Tumor control rates of pituitary adenomas (PAs) receiving adjuvant CyberKnife stereotactic radiosurgery (CK SRS) are high. However, there is currently no uniform way to estimate the time course of the disease. The aim of this study was to analyze the volumetric responses of PAs after CK SRS and investigate the application of an exponential decay model in calculating an accurate time course and estimation of the eventual outcome. A retrospective review of 34 patients with PAs who received adjuvant CK SRS between 2006 and 2013 was performed. Tumor volume was calculated using the planimetric method. The percent change in tumor volume and tumor volume rate of change were compared at median 4-, 10-, 20-, and 36-month intervals. Tumor responses were classified as: progression for >15% volume increase, regression for ≤15% decrease, and stabilization for ±15% of the baseline volume at the time of last follow-up. For each patient, the volumetric change versus time was fitted with an exponential model. The overall tumor control rate was 94.1% in the 36-month (range 18–87 months) follow-up period (mean volume change of −43.3%). Volume regression (mean decrease of −50.5%) was demonstrated in 27 (79%) patients, tumor stabilization (mean change of −3.7%) in 5 (15%) patients, and tumor progression (mean increase of 28.1%) in 2 (6%) patients (P = 0.001). Tumors that eventually regressed or stabilized had a temporary volume increase of 1.07% and 41.5% at 4 months after CK SRS, respectively (P = 0.017). The tumor volume estimated using the exponential fitting equation demonstrated high positive correlation with the actual volume calculated by magnetic resonance imaging (MRI) as tested by Pearson correlation coefficient (0.9). Transient progression of PAs post-CK SRS was seen in 62.5% of the patients receiving CK SRS, and it was not predictive of eventual volume regression or progression. A three-point exponential model is of potential predictive value

  4. Structural Neuroimaging Findings in Mild Traumatic Brain Injury.

    Science.gov (United States)

    Bigler, Erin D; Abildskov, Tracy J; Goodrich-Hunsaker, Naomi J; Black, Garrett; Christensen, Zachary P; Huff, Trevor; Wood, Dawn-Marie G; Hesselink, John R; Wilde, Elisabeth A; Max, Jeffrey E

    2016-09-01

    Common neuroimaging findings in mild traumatic brain injury (mTBI), including sport-related concussion (SRC), are reviewed based on computed tomography and magnetic resonance imaging (MRI). Common abnormalities radiologically identified on the day of injury, typically a computed tomographic scan, are in the form of contusions, small subarachnoid or intraparenchymal hemorrhages as well as subdural and epidural collections, edema, and skull fractures. Common follow-up neuroimaging findings with MRI include white matter hyperintensities, hypointense signal abnormalities that reflect prior hemorrhage, focal encephalomalacia, presence of atrophy and/or dilated Virchow-Robins perivascular space. The MRI findings from a large pediatric mTBI study show low frequency of positive MRI findings at 6 months postinjury. The review concludes with an examination of some of the advanced MRI-based image analysis methods that can be performed in the patient who has sustained an mTBI.

  5. Multiple comparison procedures for neuroimaging genomewide association studies.

    Science.gov (United States)

    Hua, Wen-Yu; Nichols, Thomas E; Ghosh, Debashis

    2015-01-01

    Recent research in neuroimaging has focused on assessing associations between genetic variants that are measured on a genomewide scale and brain imaging phenotypes. A large number of works in the area apply massively univariate analyses on a genomewide basis to find single nucleotide polymorphisms that influence brain structure. In this paper, we propose using various dimensionality reduction methods on both brain structural MRI scans and genomic data, motivated by the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. We also consider a new multiple testing adjustment method and compare it with two existing false discovery rate (FDR) adjustment methods. The simulation results suggest an increase in power for the proposed method. The real-data analysis suggests that the proposed procedure is able to find associations between genetic variants and brain volume differences that offer potentially new biological insights. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Molecular neuroimaging in degenerative dementias.

    Science.gov (United States)

    Jiménez Bonilla, J F; Carril Carril, J M

    2013-01-01

    In the context of the limitations of structural imaging, brain perfusion and metabolism using SPECT and PET have provided relevant information for the study of cognitive decline. The introduction of the radiotracers for cerebral amyloid imaging has changed the diagnostic strategy regarding Alzheimer's disease, which is currently considered to be a "continuum." According to this new paradigm, the increasing amyloid load would be associated to the preclinical phase and mild cognitive impairment. It has been possible to observe "in vivo" images using 11C-PIB and PET scans. The characteristics of the 11C-PIB image include specific high brain cortical area retention in the positive cases with typical distribution pattern and no retention in the negative cases. This, in combination with 18F-FDG PET, is the basis of molecular neuroimaging as a biomarker. At present, its prognostic value is being evaluated in longitudinal studies. 11C-PIB-PET has become the reference radiotracer to evaluate the presence of cerebral amyloid. However, its availability is limited due to the need for a nearby cyclotron. Therefore, 18F labeled radiotracers are being introduced. Our experience in the last two years with 11C-PIB, first in the research phase and then as being clinically applied, has shown the utility of the technique in the clinical field, either alone or in combination with FDG. Thus, amyloid image is a useful tool for the differential diagnosis of dementia and it is a potentially useful method for early diagnosis and evaluation of future treatments. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  7. Automatic segmentation of pulmonary segments from volumetric chest CT scans.

    NARCIS (Netherlands)

    Rikxoort, E.M. van; Hoop, B. de; Vorst, S. van de; Prokop, M.; Ginneken, B. van

    2009-01-01

    Automated extraction of pulmonary anatomy provides a foundation for computerized analysis of computed tomography (CT) scans of the chest. A completely automatic method is presented to segment the lungs, lobes and pulmonary segments from volumetric CT chest scans. The method starts with lung segmenta

  8. Partial Least Squares tutorial for analyzing neuroimaging data

    Directory of Open Access Journals (Sweden)

    Patricia Van Roon

    2014-09-01

    Full Text Available Partial least squares (PLS has become a respected and meaningful soft modeling analysis technique that can be applied to very large datasets where the number of factors or variables is greater than the number of observations. Current biometric studies (e.g., eye movements, EKG, body movements, EEG are often of this nature. PLS eliminates the multiple linear regression issues of over-fitting data by finding a few underlying or latent variables (factors that account for most of the variation in the data. In real-world applications, where linear models do not always apply, PLS can model the non-linear relationship well. This tutorial introduces two PLS methods, PLS Correlation (PLSC and PLS Regression (PLSR and their applications in data analysis which are illustrated with neuroimaging examples. Both methods provide straightforward and comprehensible techniques for determining and modeling relationships between two multivariate data blocks by finding latent variables that best describes the relationships. In the examples, the PLSC will analyze the relationship between neuroimaging data such as Event-Related Potential (ERP amplitude averages from different locations on the scalp with their corresponding behavioural data. Using the same data, the PLSR will be used to model the relationship between neuroimaging and behavioural data. This model will be able to predict future behaviour solely from available neuroimaging data. To find latent variables, Singular Value Decomposition (SVD for PLSC and Non-linear Iterative PArtial Least Squares (NIPALS for PLSR are implemented in this tutorial. SVD decomposes the large data block into three manageable matrices containing a diagonal set of singular values, as well as left and right singular vectors. For PLSR, NIPALS algorithms are used because it provides amore precise estimation of the latent variables. Mathematica notebooks are provided for each PLS method with clearly labeled sections and subsections. The

  9. Sleep neuroimaging and models of consciousness

    Directory of Open Access Journals (Sweden)

    Enzo eTagliazucchi

    2013-05-01

    Full Text Available Human deep sleep is characterized by reduced or absent sensory activity, responsiveness to stimuli and conscious awareness. Given its ubiquity and reversible nature, it represents an attractive paradigm to study the neural changes which accompany the loss of consciousness in humans. In particular, the deepest stages of sleep can serve as an empirical test for the predictions of theoretical models relating the phenomenology of consciousness with underlying neural activity. A relatively recent shift of attention from the analysis of evoked responses towards spontaneous (or ``resting state'' activity has taken place in the neuroimaging community, together with the development of tools suitable to study distributed functional interactions. In this review we focus on recent functional Magnetic Resonance Imaging (fMRI studies of spontaneous activity during sleep and their relationship with theoretical models for human consciousness generation, considering the global workspace theory, the information integration theory and the dynamical core hypothesis. We discuss the venues of research opened by these results, emphasizing the need to extend the analytic methodology in order to obtain a dynamical picture of how functional interactions change over time and how their evolution is modulated during different conscious states. Finally, we discuss the need to experimentally establish absent or reduced conscious content, even when studying the deepest sleep stages.

  10. Volumetric modulated arc radiotherapy of the whole larynx, followed by a single affected vocal cord, for T1a glottic cancer: Dosimetric analysis of a case.

    Science.gov (United States)

    Yeo, Seung-Gu

    2016-03-01

    Radiation therapy (RT) and endolaryngeal surgery are standard treatments for early-stage glottic cancer. They have closely matched oncological outcomes; however, it is debatable which method is superior in terms of functional outcomes. Several dosimetric studies have demonstrated that, compared with conventional RT, intensity-modulated RT (IMRT) reduces unnecessary radiation of the adjacent normal tissues, including the carotid artery and thyroid gland. However, RT targets the whole larynx, whereas endolaryngeal surgery is a highly focused treatment involving the en bloc resection of a tumor with safety margins. For T1a glottic cancer, in which the tumor is limited to one vocal cord, the technical feasibility of targeting IMRT on the single vocal cord affected has been investigated; however, the clinical feasibility and the possibility of inferior local control remain to be elucidated. In the present case study, IMRT was used to treat the whole larynx first, and then to treat a single vocal cord. The patient in the present study had T1a glottic cancer, and received volumetric modulated arc therapy with a total dose of 63 Gy/28 fractions. The first treatment phase (40.5 Gy/18 fractions) targeted the whole larynx to eliminate subclinical disease. The second treatment phase (22.5 Gy/10 fractions) targeted only the involved vocal cord. During this treatment phase, the exposure of the non-involved right vocal cord, the right carotid artery and the thyroid gland to the radiation was lower compared with the continuation of the initial treatment approach. These findings suggested that changing the target volume from the whole larynx to the affected vocal cord during the course of IMRT is feasible for T1a glottic cancer, and that it may reduce functional side effects while maintaining oncological outcomes.

  11. A dosimetric analysis of volumetric-modulated arc radiotherapy with jaw width restriction vs 7 field intensity-modulated radiotherapy for definitive treatment of cervical cancer.

    Science.gov (United States)

    Huang, B; Fang, Z; Huang, Y; Lin, P; Chen, Z

    2014-07-01

    Radiation therapy treatment planning was performed to compare the dosimetric difference between volumetric-modulated arc radiotherapy (RapidArc™ v. 10; Varian® Medical Systems, Palo Alto, CA) and 7-field intensity-modulated radiotherapy (7f-IMRT) in the definitive treatment of cervical cancer. 13 patients with cervical cancer were enrolled in this study. Planning target volume (PTV) 50 and PTV60 were prescribed at a dose of 50 and 60 Gy in 28 fractions, respectively. The dose to the PTV60 was delivered as a simultaneous integrated boost to the pelvic lymph nodes. Owing to the mechanical limitation of the multileaf collimator in which the maximum displacement was limited to 15 cm, two types of RapidArc with different jaw width restrictions (15 and 20-23 cm) were investigated to evaluate their dosimetric differences. The RapidArc plan type with dosimetric superiority was then compared against the 7f-IMRT on the target coverage, sparing of the organs at risk (OARs), monitor units, treatment time and delivery accuracy to determine whether RapidArc is beneficial for the treatment of cervical cancer. The 15-cm jaw width restriction had better performance compared with the restrictions that were longer than 15 cm in the sparing of the OARs. The 15-cm RapidArc spared the OARs, that is, the bladder, rectum, small intestine, femoral heads and bones, and improved treatment efficiency compared with 7f-IMRT. Both techniques delivered a high quality-assurance passing rate (>90%) according to the Γ3mm,3% criterion. RapidArc with a 15-cm jaw width restriction spares the OARs and improves treatment efficiency in cervical cancer compared with 7f-IMRT. This study describes the dosimetric superiority of RapidArc with a 15-cm jaw width restriction and explores the feasibility of using RapidArc for the definitive treatment of cervical cancer.

  12. Can volumetric modulated arc therapy with flattening filter free beams play a role in stereotactic body radiotherapy for liver lesions? A volume-based analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reggiori, Giacomo; Mancosu, Pietro; Castiglioni, Simona; Alongi, Filippo; Pellegrini, Chiara; Lobefalo, Francesca; Catalano, Maddalena; Fogliata, Antonella; Arcangeli, Stefano; Navarria, Piera; Cozzi, Luca; Scorsetti, Marta [IRCCS Istituto Clinico Humanitas, 20089 Rozzano (Milano) (Italy); Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); IRCCS Istituto Clinico Humanitas, 20089 Rozzano (Milano) (Italy); Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); IRCCS Istituto Clinico Humanitas, 20089 Rozzano (Milano) (Italy)

    2012-02-15

    Purpose: To compare volumetric modulated arc therapy with flattening filter free (FFF) and flattening filter (FF) beams in patients with hepatic metastases subject to hypofractionated radiotherapy (RT). Methods: A planning study on 13 virtual lesions of increasing volume was performed. Two single arc plans were optimized with the RapidArc technique using either FFF or FF beams. A second planning study was performed on ten patients treated for liver metastases to validate conclusions. In all cases, a dose of 75 Gy in 3 fractions was prescribed to the planning target volume (PTV) and plans were evaluated in terms of coverage, homogeneity, conformity, mean dose to healthy liver and to healthy tissue. For each parameter, results were expressed in relative terms as the percentage ratio between FFF and FF data. Results: In terms of PTV coverage, conformity index favored FFF for targets of intermediate size while FF resulted more suitable for small (<100 cm{sup 3}) and large (>300 cm{sup 3}) targets. Plans optimized with FFF beams resulted in increased sparing of healthy tissue in {approx_equal}85% of cases. Despite the qualitative results, no statistically significant differences were found between FFF and FF results. Plans optimized with un-flattened beams resulted in higher average MU/Gy than plans with FF beams. A remarkable and significant difference was observed in the beam-on time (BOT) needed to deliver plans. The BOT for FF plans was 8.2 {+-} 1.0 min; for FFF plans BOT was 2.2 {+-} 0.2 min. Conclusions: RapidArc plans optimized using FFF were dosimetrically equivalent to those optimized using FF beams, showing the feasibility of SBRT treatments with FFF beams. Some improvement in healthy tissue sparing was observed when using the FFF modality due to the different beam's profile. The main advantage was a considerable reduction of beam-on time, relevant for SBRT techniques.

  13. Robust regression for large-scale neuroimaging studies.

    Science.gov (United States)

    Fritsch, Virgile; Da Mota, Benoit; Loth, Eva; Varoquaux, Gaël; Banaschewski, Tobias; Barker, Gareth J; Bokde, Arun L W; Brühl, Rüdiger; Butzek, Brigitte; Conrod, Patricia; Flor, Herta; Garavan, Hugh; Lemaitre, Hervé; Mann, Karl; Nees, Frauke; Paus, Tomas; Schad, Daniel J; Schümann, Gunter; Frouin, Vincent; Poline, Jean-Baptiste; Thirion, Bertrand

    2015-05-01

    Multi-subject datasets used in neuroimaging group studies have a complex structure, as they exhibit non-stationary statistical properties across regions and display various artifacts. While studies with small sample sizes can rarely be shown to deviate from standard hypotheses (such as the normality of the residuals) due to the poor sensitivity of normality tests with low degrees of freedom, large-scale studies (e.g. >100 subjects) exhibit more obvious deviations from these hypotheses and call for more refined models for statistical inference. Here, we demonstrate the benefits of robust regression as a tool for analyzing large neuroimaging cohorts. First, we use an analytic test based on robust parameter estimates; based on simulations, this procedure is shown to provide an accurate statistical control without resorting to permutations. Second, we show that robust regression yields more detections than standard algorithms using as an example an imaging genetics study with 392 subjects. Third, we show that robust regression can avoid false positives in a large-scale analysis of brain-behavior relationships with over 1500 subjects. Finally we embed robust regression in the Randomized Parcellation Based Inference (RPBI) method and demonstrate that this combination further improves the sensitivity of tests carried out across the whole brain. Altogether, our results show that robust procedures provide important advantages in large-scale neuroimaging group studies.

  14. The neuroimaging research process from the participants' perspective.

    Science.gov (United States)

    Cooke, Richard; Peel, Elizabeth; Shaw, Rachel L; Senior, Carl

    2007-02-01

    The aim of this study was to investigate participants' experiences of taking part in research conducted using fMRI or MEG procedures. Forty-four participants completed a questionnaire after taking part in either fMRI or MEG experiments; the questionnaire asked about experiences of and attitudes toward fMRI/MEG. Ten follow-up interviews were conducted to enable an in-depth analysis of these attitudes and experiences. The findings were generally positive: all participants thought fMRI and MEG were safe procedures, 93% would recommend participating in neuroimaging research to their friends and family, and participants were positive about participating in future neuroimaging research. However, some negative issues were identified. Some participants reported feeling nervous prior to scanning procedures, several participants reported side-effects after taking part, a number of participants were upset at being in a confined space and some participants did not feel confident about exiting the scanner in an emergency. Several recommendations for researchers are made, including a virtual tour of the scanning equipment during the consenting process in order to better prepare potential participants for the scanning experience and to minimize the potential psychological discomfort sometimes experienced in neuroimaging research.

  15. Meta-analytic methods for neuroimaging data explained

    Directory of Open Access Journals (Sweden)

    Radua Joaquim

    2012-03-01

    Full Text Available Abstract The number of neuroimaging studies has grown exponentially in recent years and their results are not always consistent. Meta-analyses are helpful to summarize this vast literature and also offer insights that are not apparent from the individual studies. In this review, we describe the main methods used for meta-analyzing neuroimaging data, with special emphasis on their relative advantages and disadvantages. We describe and discuss meta-analytical methods for global brain volumes, methods based on regions of interest, label-based reviews, voxel-based meta-analytic methods and online databases. Regions of interest-based methods allow for optimal statistical analyses but are affected by a limited and potentially biased inclusion of brain regions, whilst voxel-based methods benefit from a more exhaustive and unbiased inclusion of studies but are statistically more limited. There are also relevant differences between the different available voxel-based meta-analytic methods, and the field is rapidly evolving to develop more accurate and robust methods. We suggest that in any meta-analysis of neuroimaging data, authors should aim to: only include studies exploring the whole brain; ensure that the same threshold throughout the whole brain is used within each included study; and explore the robustness of the findings via complementary analyses to minimize the risk of false positives.

  16. Neuroimaging essentials in essential tremor: a systematic review.

    Science.gov (United States)

    Sharifi, Sarvi; Nederveen, Aart J; Booij, Jan; van Rootselaar, Anne-Fleur

    2014-01-01

    Essential tremor is regarded to be a disease of the central nervous system. Neuroimaging is a rapidly growing field with potential benefits to both diagnostics and research. The exact role of imaging techniques with respect to essential tremor in research and clinical practice is not clear. A systematic review of the different imaging techniques in essential tremor is lacking in the literature. We performed a systematic literature search combining the terms essential tremor and familial tremor with the following keywords: imaging, mri, vbm, dwi, fmri, pet and spect, both in abbreviated form as well as in full form. We summarize and discuss the quality and the external validity of each study and place the results in the context of existing knowledge regarding the pathophysiology of essential tremor. A total of 48 neuroimaging studies met our search criteria, roughly divided into 19 structural and 29 functional and metabolic studies. The quality of the studies varied, especially concerning inclusion criteria. Functional imaging studies indicated cerebellar hyperactivity during rest and during tremor. The studies also pointed to the involvement of the thalamus, the inferior olive and the red nucleus. Structural studies showed less consistent results. Neuroimaging techniques in essential tremor give insight into the pathophysiology of essential tremor indicating the involvement of the cerebellum as the most consistent finding. GABAergic dysfunction might be a major premise in the pathophysiological hypotheses. Inconsistencies between studies can be partly explained by the inclusion of heterogeneous patient groups. Improvement of scientific research requires more stringent inclusion criteria and application of advanced analysis techniques. Also, the use of multimodal neuroimaging techniques is a promising development in movement disorders research. Currently, the role of imaging techniques in essential tremor in daily clinical practice is limited.

  17. All Photons Imaging Through Volumetric Scattering

    Science.gov (United States)

    Satat, Guy; Heshmat, Barmak; Raviv, Dan; Raskar, Ramesh

    2016-01-01

    Imaging through thick highly scattering media (sample thickness ≫ mean free path) can realize broad applications in biomedical and industrial imaging as well as remote sensing. Here we propose a computational “All Photons Imaging” (API) framework that utilizes time-resolved measurement for imaging through thick volumetric scattering by using both early arrived (non-scattered) and diffused photons. As opposed to other methods which aim to lock on specific photons (coherent, ballistic, acoustically modulated, etc.), this framework aims to use all of the optical signal. Compared to conventional early photon measurements for imaging through a 15 mm tissue phantom, our method shows a two fold improvement in spatial resolution (4db increase in Peak SNR). This all optical, calibration-free framework enables widefield imaging through thick turbid media, and opens new avenues in non-invasive testing, analysis, and diagnosis. PMID:27683065

  18. Neuroimaging of Parkinson's disease: Expanding views.

    Science.gov (United States)

    Weingarten, Carol P; Sundman, Mark H; Hickey, Patrick; Chen, Nan-kuei

    2015-12-01

    Advances in molecular and structural and functional neuroimaging are rapidly expanding the complexity of neurobiological understanding of Parkinson's disease (PD). This review article begins with an introduction to PD neurobiology as a foundation for interpreting neuroimaging findings that may further lead to more integrated and comprehensive understanding of PD. Diverse areas of PD neuroimaging are then reviewed and summarized, including positron emission tomography, single photon emission computed tomography, magnetic resonance spectroscopy and imaging, transcranial sonography, magnetoencephalography, and multimodal imaging, with focus on human studies published over the last five years. These included studies on differential diagnosis, co-morbidity, genetic and prodromal PD, and treatments from L-DOPA to brain stimulation approaches, transplantation and gene therapies. Overall, neuroimaging has shown that PD is a neurodegenerative disorder involving many neurotransmitters, brain regions, structural and functional connections, and neurocognitive systems. A broad neurobiological understanding of PD will be essential for translational efforts to develop better treatments and preventive strategies. Many questions remain and we conclude with some suggestions for future directions of neuroimaging of PD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Neuroimaging and biomarkers in addiction treatment.

    Science.gov (United States)

    Garrison, Kathleen A; Potenza, Marc N

    2014-12-01

    Neuroimaging studies have made a significant contribution to the efforts to identify measurable indices, or biomarkers, of addictions and their treatments. Biomarkers in addiction treatment are needed to provide targets for treatment, detect treatment subgroups, predict treatment response, and broadly improve outcomes. Neuroimaging is important to biomarkers research as it relates neural circuits to both molecular mechanisms and behavior. A focus of recent efforts in neuroimaging in addiction has been to elucidate the neural correlates associated with dimensions of functioning in substance-use and related disorders, such as cue-reactivity, impulsivity, and cognitive control, among others. These dimensions of functioning have been related to addiction treatment outcomes and relapse, and therefore, a better understanding of these dimensions and their neural correlates may help to identify brain-behavior biomarkers of treatment response. This paper reviews recent neuroimaging studies that report potential biomarkers in addiction treatment related to cue-reactivity, impulsivity, and cognitive control, as well as recent advances in neuroimaging that may facilitate efforts to determine reliable biomarkers. This important initial work has begun to identify possible mediators and moderators of treatment response, and multiple promising indices are being tested.

  20. Volumetric and two-dimensional image interpretation show different cognitive processes in learners.

    Science.gov (United States)

    van der Gijp, Anouk; Ravesloot, Cécile J; van der Schaaf, Marieke F; van der Schaaf, Irene C; Huige, Josephine C B M; Vincken, Koen L; Ten Cate, Olle Th J; van Schaik, Jan P J

    2015-05-01

    In current practice, radiologists interpret digital images, including a substantial amount of volumetric images. We hypothesized that interpretation of a stack of a volumetric data set demands different skills than interpretation of two-dimensional (2D) cross-sectional images. This study aimed to investigate and compare knowledge and skills used for interpretation of volumetric versus 2D images. Twenty radiology clerks were asked to think out loud while reading four or five volumetric computed tomography (CT) images in stack mode and four or five 2D CT images. Cases were presented in a digital testing program allowing stack viewing of volumetric data sets and changing views and window settings. Thoughts verbalized by the participants were registered and coded by a framework of knowledge and skills concerning three components: perception, analysis, and synthesis. The components were subdivided into 16 discrete knowledge and skill elements. A within-subject analysis was performed to compare cognitive processes during volumetric image readings versus 2D cross-sectional image readings. Most utterances contained knowledge and skills concerning perception (46%). A smaller part involved synthesis (31%) and analysis (23%). More utterances regarded perception in volumetric image interpretation than in 2D image interpretation (Median 48% vs 35%; z = -3.9; P Cognitive processes in volumetric and 2D cross-sectional image interpretation differ substantially. Volumetric image interpretation draws predominantly on perceptual processes, whereas 2D image interpretation is mainly characterized by synthesis. The results encourage the use of volumetric images for teaching and testing perceptual skills. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  1. Responsible Reporting: Neuroimaging News in the Age of Responsible Research and Innovation.

    Science.gov (United States)

    de Jong, Irja Marije; Kupper, Frank; Arentshorst, Marlous; Broerse, Jacqueline

    2016-08-01

    Besides offering opportunities in both clinical and non-clinical domains, the application of novel neuroimaging technologies raises pressing dilemmas. 'Responsible Research and Innovation' (RRI) aims to stimulate research and innovation activities that take ethical and social considerations into account from the outset. We previously identified that Dutch neuroscientists interpret "responsible innovation" as educating the public on neuroimaging technologies via the popular press. Their aim is to mitigate (neuro)hype, an aim shared with the wider emerging RRI community. Here, we present results of a media-analysis undertaken to establish whether the body of articles in the Dutch popular press presents balanced conversations on neuroimaging research to the public. We found that reporting was mostly positive and framed in terms of (healthcare) progress. There was rarely a balance between technology opportunities and limitations, and even fewer articles addressed societal or ethical aspects of neuroimaging research. Furthermore, neuroimaging metaphors seem to favour oversimplification. Current reporting is therefore more likely to enable hype than to mitigate it. How can neuroscientists, given their self-ascribed social responsibility, address this conundrum? We make a case for a collective and shared responsibility among neuroscientists, journalists and other stakeholders, including funders, committed to responsible reporting on neuroimaging research.

  2. A reduced volumetric expansion factor plot

    Science.gov (United States)

    Hendricks, R. C.

    1979-01-01

    A reduced volumetric expansion factor plot has been constructed for simple fluids which is suitable for engineering computations in heat transfer. Volumetric expansion factors have been found useful in correlating heat transfer data over a wide range of operating conditions including liquids, gases and the near critical region.

  3. Turner syndrome: neuroimaging findings: structural and functional.

    LENUS (Irish Health Repository)

    Mullaney, Ronan

    2009-01-01

    Neuroimaging studies of Turner syndrome can advance our understanding of the X chromosome in brain development, and the modulatory influence of endocrine factors. There is increasing evidence from neuroimaging studies that TX individuals have significant differences in the anatomy, function, and metabolism of a number of brain regions; including the parietal lobe; cerebellum, amygdala, hippocampus; and basal ganglia; and perhaps differences in "connectivity" between frontal and parieto-occipital regions. Finally, there is preliminary evidence that genomic imprinting, sex hormones and growth hormone have significant modulatory effects on brain maturation in TS.

  4. Volumetric motion quantification by 3D tissue phase mapped CMR

    Directory of Open Access Journals (Sweden)

    Lutz Anja

    2012-10-01

    Full Text Available Abstract Background The objective of this study was the quantification of myocardial motion from 3D tissue phase mapped (TPM CMR. Recent work on myocardial motion quantification by TPM has been focussed on multi-slice 2D acquisitions thus excluding motion information from large regions of the left ventricle. Volumetric motion assessment appears an important next step towards the understanding of the volumetric myocardial motion and hence may further improve diagnosis and treatments in patients with myocardial motion abnormalities. Methods Volumetric motion quantification of the complete left ventricle was performed in 12 healthy volunteers and two patients applying a black-blood 3D TPM sequence. The resulting motion field was analysed regarding motion pattern differences between apical and basal locations as well as for asynchronous motion pattern between different myocardial segments in one or more slices. Motion quantification included velocity, torsion, rotation angle and strain derived parameters. Results All investigated motion quantification parameters could be calculated from the 3D-TPM data. Parameters quantifying hypokinetic or asynchronous motion demonstrated differences between motion impaired and healthy myocardium. Conclusions 3D-TPM enables the gapless volumetric quantification of motion abnormalities of the left ventricle, which can be applied in future application as additional information to provide a more detailed analysis of the left ventricular function.

  5. Looking at the brains behind figurative language--a quantitative meta-analysis of neuroimaging studies on metaphor, idiom, and irony processing.

    Science.gov (United States)

    Bohrn, Isabel C; Altmann, Ulrike; Jacobs, Arthur M

    2012-09-01

    A quantitative, coordinate-based meta-analysis combined data from 354 participants across 22 fMRI studies and one positron emission tomography (PET) study to identify the differences in neural correlates of figurative and literal language processing, and to investigate the role of the right hemisphere (RH) in figurative language processing. Studies that reported peak activations in standard space contrasting figurative vs. literal language processing at whole brain level in healthy adults were included. The left and right IFG, large parts of the left temporal lobe, the bilateral medial frontal gyri (medFG) and an area around the left amygdala emerged for figurative language processing across studies. Conditions requiring exclusively literal language processing did not activate any selective regions in most of the cases, but if so they activated the cuneus/precuneus, right MFG and the right IPL. No general RH advantage for metaphor processing could be found. On the contrary, significant clusters of activation for metaphor conditions were mostly lateralized to the left hemisphere (LH). Subgroup comparisons between experiments on metaphors, idioms, and irony/sarcasm revealed shared activations in left frontotemporal regions for idiom and metaphor processing. Irony/sarcasm processing was correlated with activations in midline structures such as the medFG, ACC and cuneus/precuneus. To test the graded salience hypothesis (GSH, Giora, 1997), novel metaphors were contrasted against conventional metaphors. In line with the GSH, RH involvement was found for novel metaphors only. Here we show that more analytic, semantic processes are involved in metaphor comprehension, whereas irony/sarcasm comprehension involves theory of mind processes.

  6. A Systematic Review and Meta-analysis of Neuroimaging in Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD) Taking Attention-Deficit Hyperactivity Disorder (ADHD) Into Account.

    Science.gov (United States)

    Noordermeer, Siri D S; Luman, Marjolein; Oosterlaan, Jaap

    2016-03-01

    Oppositional defiant disorder (ODD) and conduct disorder (CD) are common behavioural disorders in childhood and adolescence and are associated with brain abnormalities. This systematic review and meta-analysis investigates structural (sMRI) and functional MRI (fMRI) findings in individuals with ODD/CD with and without attention-deficit hyperactivity disorder (ADHD). Online databases were searched for controlled studies, resulting in 12 sMRI and 17 fMRI studies. In line with current models on ODD/CD, studies were classified in hot and cool executive functioning (EF). Both the meta-analytic and narrative reviews showed evidence of smaller brain structures and lower brain activity in individuals with ODD/CD in mainly hot EF-related areas: bilateral amygdala, bilateral insula, right striatum, left medial/superior frontal gyrus, and left precuneus. Evidence was present in both structural and functional studies, and irrespective of the presence of ADHD comorbidity. There is strong evidence that abnormalities in the amygdala are specific for ODD/CD as compared to ADHD, and correlational studies further support the association between abnormalities in the amygdala and ODD/CD symptoms. Besides the left precuneus, there was no evidence for abnormalities in typical cool EF related structures, such as the cerebellum and dorsolateral prefrontal cortex. Resulting areas are associated with emotion-processing, error-monitoring, problem-solving and self-control; areas associated with neurocognitive and behavioural deficits implicated in ODD/CD. Our findings confirm the involvement of hot, and to a smaller extent cool, EF associated brain areas in ODD/CD, and support an integrated model for ODD/CD (e.g. Blair, Development and Psychopathology, 17(3), 865-891, 2005).

  7. Traumatic Brain Injury: Nuclear Medicine Neuroimaging

    NARCIS (Netherlands)

    Sánchez-Catasús, Carlos A; Vállez Garcia, David; Le Riverend Morales, Eloísa; Galvizu Sánchez, Reinaldo; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; de Vries, Erik FJ; van Waarde, Aren; Leenders, Klaus L

    2014-01-01

    This chapter provides an up-to-date review of nuclear medicine neuroimaging in traumatic brain injury (TBI). 18F-FDG PET will remain a valuable tool in researching complex mechanisms associated with early metabolic dysfunction in TBI. Although evidence-based imaging studies are needed, 18F-FDG PET i

  8. Ionization penalty in nonlinear Raman neuroimaging.

    Science.gov (United States)

    Voronin, Aleksandr A; Fedotov, Ilya V; Doronina-Amitonova, Lyubov V; Ivashkina, Olga I; Zots, Marina A; Fedotov, Andrei B; Anokhin, Konstantin V; Zheltikov, Aleksei M

    2011-02-15

    Light-assisted ionization accompanying coherent anti-Stokes Raman scattering (CARS) of ultrashort laser pulses in brain tissue is shown to manifest itself in a detectable blueshift of the anti-Stokes signal. This blueshift can serve as an indicator of ionization processes in CARS-based neuroimaging.

  9. Neuroimaging resilience to stress: a review.

    Science.gov (United States)

    van der Werff, S J A; van den Berg, S M; Pannekoek, J N; Elzinga, B M; van der Wee, N J A

    2013-01-01

    There is a high degree of intra-individual variation in how individuals respond to stress. This becomes evident when exploring the development of posttraumatic symptoms or stress-related disorders after exposure to trauma. Whether or not an individual develops posttraumatic symptoms after experiencing a traumatic event is partly dependent on a person's resilience. Resilience can be broadly defined as the dynamic process encompassing positive adaptation within the context of significant adversity. Even though research into the neurobiological basis of resilience is still in its early stages, these insights can have important implications for the prevention and treatment of stress-related disorders. Neuroimaging studies contribute to our knowledge of intra-individual variability in resilience and the development of posttraumatic symptoms or other stress-related disorders. This review provides an overview of neuroimaging findings related to resilience. Structural, resting-state, and task-related neuroimaging results associated with resilience are discussed. There are a limited number of studies available and neuroimaging research of resilience is still in its infancy. The available studies point at brain circuitries involved in stress and emotion regulation, with more efficient processing and regulation associated with resilience.

  10. Neuroimaging resilience to stress: a review

    Directory of Open Access Journals (Sweden)

    Steven J A van der Werff

    2013-05-01

    Full Text Available There is a high degree of intra-individual variation in how individuals respond to stress. This becomes evident when exploring the development of posttraumatic symptoms or stress-related disorders after exposure to trauma. Whether or not an individual develops posttraumatic symptoms after experiencing a traumatic event is partly dependent on a person’s resilience. Resilience can be broadly defined as the dynamic process encompassing positive adaptation within the context of significant adversity. Even though research into the neurobiological basis of resilience is still in its early stages, these insights can have important implications for the prevention and treatment of stress-related disorders. Neuroimaging studies contribute to our knowledge of intra-individual variability in resilience and the development of posttraumatic symptoms or other stress-related disorders. This review provides an overview of neuroimaging findings related to resilience. Structural, resting-state and task-related neuroimaging results associated with resilience are discussed. There are a limited number of studies available and neuroimaging research of resilience is still in its infancy. The available studies point at brain circuitries involved in stress and emotion regulation, with more efficient processing and regulation associated with resilience.

  11. Neuropsychiatric lupus: classification criteria in neuroimaging studies.

    Science.gov (United States)

    Netto, Tania M; Zimmermann, Nicolle; Rueda-Lopes, Fernanda; Bizzo, Bernardo C; Fonseca, Rochele P; Gasparetto, Emerson L

    2013-05-01

    This systematic review described the criteria and main evaluations methods procedures used to classify neuropsychiatric systemic lupus erythematosus (NPSLE) patients. Also, within the evaluations methods, this review aimed to identify the main contributions of neuropsychological measurements in neuroimaging studies. A search was conducted in PubMed, EMBASE and SCOPUS databases with the terms related to neuropsychiatric syndromes, systemic lupus erythematosus, and neuroimaging techniques. Sixty-six abstracts were found; only 20 were completely analyzed and included. Results indicated that the 1999 American College of Rheumatology (ACR) criteria is the most used to classify NPSLE samples together with laboratorial, cognitive, neurological and psychiatric assessment procedures. However, the recommended ACR assessment procedures to classify NPSLE patients are being used incompletely, especially the neuropsychological batteries. Neuropsychological instruments and neuroimaging techniques have been used mostly to characterize NPSLE samples, instead of contributing to their classifications. The most described syndromes in neuroimaging studies have been seizure/cerebrovascular disease followed by cognitive dysfunctions as well as headache disorder.

  12. Neuroimaging studies of social cognition in schizophrenia.

    Science.gov (United States)

    Fujiwara, Hironobu; Yassin, Walid; Murai, Toshiya

    2015-05-01

    Impaired social cognition is considered a core contributor to unfavorable psychosocial functioning in schizophrenia. Rather than being a unitary process, social cognition is a collection of multifaceted processes that recruit multiple brain structures, thus structural and functional neuroimaging techniques are ideal methodologies for revealing the underlying pathophysiology of impaired social cognition. Many neuroimaging studies have suggested that in addition to white-matter deficits, schizophrenia is associated with decreased gray-matter volume in multiple brain areas, especially fronto-temporal and limbic regions. However, few schizophrenia studies have examined associations between brain abnormalities and social cognitive disabilities. During the last decade, we have investigated structural brain abnormalities in schizophrenia using high-resolution magnetic resonance imaging, and our findings have been confirmed by us and others. By assessing different types of social cognitive abilities, structural abnormalities in multiple brain regions have been found to be associated with disabilities in social cognition, such as recognition of facial emotion, theory of mind, and empathy. These structural deficits have also been associated with alexithymia and quality of life in ways that are closely related to the social cognitive disabilities found in schizophrenia. Here, we overview a series of neuroimaging studies from our laboratory that exemplify current research into this topic, and discuss how it can be further tackled using recent advances in neuroimaging technology.

  13. Neuroimaging in childhood headache: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Alexiou, George A. [University of Ioannina, Department of Neurosurgery, Medical School, P.O. Box 103, Ioannina (Greece); Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece)

    2013-07-15

    Headache is a common complaint in children, one that gives rise to considerable parental concern and fear of the presence of a space-occupying lesion. The evaluation and diagnosis of headache is very challenging for paediatricians, and neuroimaging by means of CT or MRI is often requested as part of the investigation. CT exposes children to radiation, while MRI is costly and sometimes requires sedation or general anaesthesia, especially in children younger than 6 years. This review of the literature on the value of neuroimaging in children with headache showed that the rate of pathological findings is generally low. Imaging findings that led to a change in patient management were in almost all cases reported in children with abnormal signs on neurological examination. Neuroimaging should be limited to children with a suspicious clinical history, abnormal neurological findings or other physical signs suggestive of intracranial pathology. Well-designed prospective studies are needed to better define the clinical findings that warrant neuroimaging in children with headache. (orig.)

  14. Neuroimaging resilience to stress: a review

    Science.gov (United States)

    van der Werff, S. J. A.; van den Berg, S. M.; Pannekoek, J. N.; Elzinga, B. M.; van der Wee, N. J. A.

    2013-01-01

    There is a high degree of intra-individual variation in how individuals respond to stress. This becomes evident when exploring the development of posttraumatic symptoms or stress-related disorders after exposure to trauma. Whether or not an individual develops posttraumatic symptoms after experiencing a traumatic event is partly dependent on a person's resilience. Resilience can be broadly defined as the dynamic process encompassing positive adaptation within the context of significant adversity. Even though research into the neurobiological basis of resilience is still in its early stages, these insights can have important implications for the prevention and treatment of stress-related disorders. Neuroimaging studies contribute to our knowledge of intra-individual variability in resilience and the development of posttraumatic symptoms or other stress-related disorders. This review provides an overview of neuroimaging findings related to resilience. Structural, resting-state, and task-related neuroimaging results associated with resilience are discussed. There are a limited number of studies available and neuroimaging research of resilience is still in its infancy. The available studies point at brain circuitries involved in stress and emotion regulation, with more efficient processing and regulation associated with resilience. PMID:23675330

  15. Structural Neuroimaging in Aging and Alzheimer's Disease

    NARCIS (Netherlands)

    Vernooij, Meike W.; Smits, Marion

    2012-01-01

    The role of structural neuroimaging in the diagnosis of Alzheimer's disease (AD) is becoming increasingly important. As a consequence, a basic understanding of what are normal brain changes in aging is key to be able to recognize what is abnormal. The first part of this article discusses normal vers

  16. On small sample experiments in neuroimaging

    DEFF Research Database (Denmark)

    Goutte, Cyril; Hansen, Lars Kai

    1998-01-01

    Most human brain imaging experiments involve a number of subjects that is unusually low by accepted statistical standards. Although there are anumber of practical reasons for using small samples in neuroimaging we need to face the question regarding whether results obtained with only a fewsubjects...

  17. Neuroimaging and Fetal Alcohol Spectrum Disorders

    Science.gov (United States)

    Norman, Andria L.; Crocker, Nicole; Mattson, Sarah N.; Riley, Edward P.

    2009-01-01

    The detrimental effects of prenatal alcohol exposure on the developing brain include structural brain anomalies as well as cognitive and behavioral deficits. Initial neuroimaging studies of fetal alcohol spectrum disorders (FASD) using magnetic resonance imaging (MRI) confirmed previous autopsy reports of overall reduction in brain volume and…

  18. ORIGINAL ARTICLE EEG changes and neuroimaging abnormalities ...

    African Journals Online (AJOL)

    salah

    neuroimaging changes of the brain and EEG abnormalities in correlation to the degree of ... MRI is the method of choice to investigate ... regional gray and white matter volumes .... relation of the cerebellar affection with disease ... were mostly done on mentally retarded cases23 ... vide a certain correlation between the.

  19. Meeting Curation Challenges in a Neuroimaging Group

    Directory of Open Access Journals (Sweden)

    Angus Whyte

    2008-08-01

    Full Text Available The SCARP project is a series of short studies with two aims; firstly to discover more about disciplinary approaches and attitudes to digital curation through ‘immersion’ in selected cases; secondly to apply known good practice, and where possible, identify new lessons from practice in the selected discipline areas. The study summarised here is of the Neuroimaging Group in the University of Edinburgh’s Division of Psychiatry, which plays a leading role in eScience collaborations to improve the infrastructure for neuroimaging data integration and reuse. The Group also aims to address growing data storage and curation needs, given the capabilities afforded by new infrastructure. The study briefly reviews the policy context and current challenges to data integration and sharing in the neuroimaging field. It then describes how curation and preservation risks and opportunities for change were identified throughout the curation lifecycle; and their context appreciated through field study in the research site. The results are consistent with studies of neuroimaging eInfrastructure that emphasise the role of local data sharing and reuse practices. These sustain mutual awareness of datasets and experimental protocols through sharing peer to peer, and among senior researchers and students, enabling continuity in research and flexibility in project work. This “human infrastructure” is taken into account in considering next steps for curation and preservation of the Group’s datasets and a phased approach to supporting data documentation.

  20. PET radioligand injection for pig neuroimaging

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Munk, Ole Lajord; Landau, Anne M.

    2017-01-01

    Pigs are useful models in neuroimaging studies with positron emission tomography. Radiolabeled ligands are injected intravenously at the start of the scan and in pigs, the most easily accessible route of administration is the ear vein. However, in brain studies the short distance between the brai...

  1. On small sample experiments in neuroimaging

    DEFF Research Database (Denmark)

    Goutte, Cyril; Hansen, Lars Kai

    1998-01-01

    Most human brain imaging experiments involve a number of subjects that is unusually low by accepted statistical standards. Although there are anumber of practical reasons for using small samples in neuroimaging we need to face the question regarding whether results obtained with only a fewsubjects...

  2. Volumetric study of the olfactory bulb in patients with chronic rhinonasal sinusitis using MRI

    Directory of Open Access Journals (Sweden)

    Reda A. Alarabawy

    2016-06-01

    Conclusions: MRI with volumetric analysis is a useful tool in assessment of the olfactory bulb volume in patients with olfactory loss and appears to be of help in assessment of the degree of recovery in patients after sinus surgery.

  3. Neuroimaging in psychiatry: an update on neuroimaging in the clinical setting.

    Science.gov (United States)

    Power, Brian D; Nguyen, T; Hayhow, B; Looi, Jcl

    2016-04-01

    We offered guidance on the role of structural and functional neuroimaging modalities for the general psychiatrist and for trainees in the clinical setting. We outlined the utility of neuroimaging modalities in the clinical setting, specifically with a view to understanding the pathophysiology of manifestations of disease. Both structural and functional neuroimaging modalities have a clear role in diagnostic evaluation in the spectrum of neurodegenerative disorders. Whilst the role of neuroimaging in patients with mood, anxiety and psychotic disorders is less clear, structural and functional imaging modalities have utility in the clinical setting in the form of diagnostic refinement and in understanding the pathophysiology of disorders, towards explaining manifestations and planning treatment. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  4. Nipype: a flexible, lightweight and extensible neuroimaging data processing framework in python.

    Science.gov (United States)

    Gorgolewski, Krzysztof; Burns, Christopher D; Madison, Cindee; Clark, Dav; Halchenko, Yaroslav O; Waskom, Michael L; Ghosh, Satrajit S

    2011-01-01

    Current neuroimaging software offer users an incredible opportunity to analyze their data in different ways, with different underlying assumptions. Several sophisticated software packages (e.g., AFNI, BrainVoyager, FSL, FreeSurfer, Nipy, R, SPM) are used to process and analyze large and often diverse (highly multi-dimensional) data. However, this heterogeneous collection of specialized applications creates several issues that hinder replicable, efficient, and optimal use of neuroimaging analysis approaches: (1) No uniform access to neuroimaging analysis software and usage information; (2) No framework for comparative algorithm development and dissemination; (3) Personnel turnover in laboratories often limits methodological continuity and training new personnel takes time; (4) Neuroimaging software packages do not address computational efficiency; and (5) Methods sections in journal articles are inadequate for reproducing results. To address these issues, we present Nipype (Neuroimaging in Python: Pipelines and Interfaces; http://nipy.org/nipype), an open-source, community-developed, software package, and scriptable library. Nipype solves the issues by providing Interfaces to existing neuroimaging software with uniform usage semantics and by facilitating interaction between these packages using Workflows. Nipype provides an environment that encourages interactive exploration of algorithms, eases the design of Workflows within and between packages, allows rapid comparative development of algorithms and reduces the learning curve necessary to use different packages. Nipype supports both local and remote execution on multi-core machines and clusters, without additional scripting. Nipype is Berkeley Software Distribution licensed, allowing anyone unrestricted usage. An open, community-driven development philosophy allows the software to quickly adapt and address the varied needs of the evolving neuroimaging community, especially in the context of increasing demand for

  5. Connectivity network measures predict volumetric atrophy in mild cognitive impairment.

    Science.gov (United States)

    Nir, Talia M; Jahanshad, Neda; Toga, Arthur W; Bernstein, Matt A; Jack, Clifford R; Weiner, Michael W; Thompson, Paul M

    2015-01-01

    Alzheimer's disease (AD) is characterized by cortical atrophy and disrupted anatomic connectivity, and leads to abnormal interactions between neural systems. Diffusion-weighted imaging (DWI) and graph theory can be used to evaluate major brain networks and detect signs of a breakdown in network connectivity. In a longitudinal study using both DWI and standard magnetic resonance imaging (MRI), we assessed baseline white-matter connectivity patterns in 30 subjects with mild cognitive impairment (MCI, mean age 71.8 ± 7.5 years, 18 males and 12 females) from the Alzheimer's Disease Neuroimaging Initiative. Using both standard MRI-based cortical parcellations and whole-brain tractography, we computed baseline connectivity maps from which we calculated global "small-world" architecture measures, including mean clustering coefficient and characteristic path length. We evaluated whether these baseline network measures predicted future volumetric brain atrophy in MCI subjects, who are at risk for developing AD, as determined by 3-dimensional Jacobian "expansion factor maps" between baseline and 6-month follow-up anatomic scans. This study suggests that DWI-based network measures may be a novel predictor of AD progression.

  6. Surfactant enhanced volumetric sweep efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J.H.; Scamehorn, J.F.

    1989-10-01

    Surfactant-enhanced waterflooding is a novel EOR method aimed to improve the volumetric sweep efficiencies in reservoirs. The technique depends upon the ability to induce phase changes in surfactant solutions by mixing with surfactants of opposite charge or with salts of appropriate type. One surfactant or salt solution is injected into the reservoir. It is followed later by injection of another surfactant or salt solution. The sequence of injections is arranged so that the two solutions do not mix until they are into the permeable regions well away from the well bore. When they mix at this point, by design they form a precipitate or gel-like coacervate phase, plugging this permeable region, forcing flow through less permeable regions of the reservoir, improving sweep efficiency. The selectivity of the plugging process is demonstrated by achieving permeability reductions in the high permeable regions of Berea sandstone cores. Strategies were set to obtain a better control over the plug placement and the stability of plugs. A numerical simulator has been developed to investigate the potential increases in oil production of model systems. Furthermore, the hardness tolerance of anionic surfactant solutions is shown to be enhanced by addition of monovalent electrolyte or nonionic surfactants. 34 refs., 32 figs., 8 tabs.

  7. Accelerating Neuroimage Registration through Parallel Computation of Similarity Metric.

    Directory of Open Access Journals (Sweden)

    Yun-Gang Luo

    Full Text Available Neuroimage registration is crucial for brain morphometric analysis and treatment efficacy evaluation. However, existing advanced registration algorithms such as FLIRT and ANTs are not efficient enough for clinical use. In this paper, a GPU implementation of FLIRT with the correlation ratio (CR as the similarity metric and a GPU accelerated correlation coefficient (CC calculation for the symmetric diffeomorphic registration of ANTs have been developed. The comparison with their corresponding original tools shows that our accelerated algorithms can greatly outperform the original algorithm in terms of computational efficiency. This paper demonstrates the great potential of applying these registration tools in clinical applications.

  8. 五轴数控机床的空间误差建模与解耦补偿分析%Volumetric error modeling and decoupled error compensation analysis of five-axis CNC machine tools

    Institute of Scientific and Technical Information of China (English)

    要小鹏; 殷国富; 方辉; 程锦; 李光明

    2011-01-01

    针对五轴联动数控机床的位置与姿态误差补偿过程中各运动轴的误差补偿量与刀具和工件间的误差值耦合关系较为复杂的问题,在解析五轴机床运动学方程的基础上,利用多轴机床的误差运动学原理,建立了用各运动轴坐标系变换矩阵描述的机床误差模型.基于小误差补偿运动假设,分析了误差运动和补偿运动间的相互关系,对五轴机床各运动轴的位置与方向的误差补偿运动进行了解耦,建立了五轴数控机床的一种新的空间几何误差补偿模型和补偿算法.基于此算法开发了具有空间补偿功能的后处理模块,并通过实验验证了该模块在提高机床加工精度方面的有效性.%Aiming at the problem that the position and orientation error compensation of a five-axis machine tool is more complicated because of the complex coupled effects between the joint variables and the position/orientation of the tools and work-piece, the paper gives a volumetric error model by using the coordinate transformation method on the basis of analyzing the kinematics equations of five-axis machine tools and multi-axis machine tools' error kinematics principle. Based on the rigid body kinematics with small error assumption and the analysis of error motions and the compensation motions, a new volumetric error compensation model and a compensation algorithm are presented by decoupling the error compensation motions, thus the position and orientation compensation values of the joint variables can be obtained finally with the model. A new post-processing module was created by the compensation algorithm , and it was tested by experiment with the five-axis machine tools and the experimental results show that the machining accuracy can be improved effectively when using it.

  9. Neuromarketing: the hope and hype of neuroimaging in business.

    Science.gov (United States)

    Ariely, Dan; Berns, Gregory S

    2010-04-01

    The application of neuroimaging methods to product marketing - neuromarketing - has recently gained considerable popularity. We propose that there are two main reasons for this trend. First, the possibility that neuroimaging will become cheaper and faster than other marketing methods; and second, the hope that neuroimaging will provide marketers with information that is not obtainable through conventional marketing methods. Although neuroimaging is unlikely to be cheaper than other tools in the near future, there is growing evidence that it may provide hidden information about the consumer experience. The most promising application of neuroimaging methods to marketing may come before a product is even released - when it is just an idea being developed.

  10. Laser Based 3D Volumetric Display System

    Science.gov (United States)

    1993-03-01

    Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye

  11. Neuroimaging and the search for a cure for Alzheimer disease.

    Science.gov (United States)

    Petrella, Jeffrey R

    2013-12-01

    As radiologists, our role in the workup of the dementia patient has long been limited by the sensitivity of our imaging tools and lack of effective treatment options. Over the past 30 years, we have made tremendous strides in understanding the genetic, molecular, and cellular basis of Alzheimer disease (AD). We now know that the pathologic features of AD are present 1 to 2 decades prior to development of symptoms, though currently approved symptomatic therapies are administered much later in the disease course. The search for true disease-modifying therapy continues and many clinical trials are underway. Current outcome measures, based on cognitive tests, are relatively insensitive to pathologic disease progression, requiring long, expensive trials with large numbers of participants. Biomarkers, including neuroimaging, have great potential to increase the power of trials by matching imaging methodology with therapeutic mechanism. One of the most important advances over the past decade has been the development of in vivo imaging probes targeted to amyloid beta protein, and one agent is already available for clinical use. Additional advances include automated volumetric imaging methods to quantitate cerebral volume loss. Use of such techniques in small, early phase trials are expected to significantly increase the number and quality of candidate drugs for testing in larger trials. In addition to a critical role in trials, structural, molecular, and functional imaging techniques can give us a window on the etiology of AD and other neurodegenerative diseases. This combination of developments has potential to bring diagnostic radiology to the forefront in AD research, therapeutic trials, and patient care. ©RSNA, 2013.

  12. Neuroimaging in Cerebral Palsy – Report from North India

    Directory of Open Access Journals (Sweden)

    Anju AGGARWAL

    2013-11-01

    Full Text Available How to Cite This Article: Aggarwal A, Mittal H, Debnath SKR, Rai A. Neuroimaging in Cerebral Palsy–Report from North India. Iran J Child Neurol. 2013 Autumn; 7(3:41- 46. ObjectiveOnly few Indian reports exist on neuroimaging abnormalities in children with cerebral palsy (CP from India. Materials & MethodsWe studied the clinico-radiological profile of 98 children diagnosed as CP at a tertiary centre in North India. Relevant investigations were carried out to determine the etiology. ResultsAmong the 98 children studied, 80.5% were males and 22.2% were premature. History of birth asphyxia was present in 41.9%. Quadriplegic CP was seen in 77.5%, hemiplegic in 11.5%, and diplegic in 10.5%. Other abnormalities were microcephaly (60.5%, epilepsy (42%, visual abnormality (37%, and hearing abnormality (20%. Neuroimaging was abnormal in 94/98 (95.91%.Abnormalities were periventricular white matter abnormalities (34%, deep grey matter abnormalities (47.8%, malformations (11.7%, and miscellaneous lesions (6.4%. Neuroimaging findings did not relate to the presence of birth asphyxia, sex, epilepsy, gestation, type of CP, or microcephaly. ConclusionsNeuroimaging is helpful for etiological diagnosis, especially malformations.  ReferencesSinghi PD, Ray M, Suri G. Clinical spectrum of cerebral palsy in north India-an analysis of 1000 cases. J Trop Pediatr 2002 48(3; 162-6.Sharma P, Sharma U, Kabra A. Cerebral Palsy-Clinical Profile and Predisposing Factors. Indian Pediatr 1999;36(10:1038-42.Nelson KB, Ellenberg JH. Antecedents of cerebral palsy. Multivariate analysis of risk. N Engl J Med 1986 315(2:81-6.Krägeloh-Mann I, Horber V. The role of magnetic resonance imaging in elucidating the pathogenesis of cerebral palsy: a systematic review. Dev Med Child Neurol 2007; 49(2:144-51.Rosenbaum P, Paneth N, Leviton A, Goldstein M, Bax M, Damiano D, et al. A report: the definition and classification of cerebral palsy April 2006. Dev Med Child Neurol Suppl 2007

  13. Atlas-guided volumetric diffuse optical tomography enhanced by generalized linear model analysis to image risk decision-making responses in young adults.

    Science.gov (United States)

    Lin, Zi-Jing; Li, Lin; Cazzell, Mary; Liu, Hanli

    2014-08-01

    Diffuse optical tomography (DOT) is a variant of functional near infrared spectroscopy and has the capability of mapping or reconstructing three dimensional (3D) hemodynamic changes due to brain activity. Common methods used in DOT image analysis to define brain activation have limitations because the selection of activation period is relatively subjective. General linear model (GLM)-based analysis can overcome this limitation. In this study, we combine the atlas-guided 3D DOT image reconstruction with GLM-based analysis (i.e., voxel-wise GLM analysis) to investigate the brain activity that is associated with risk decision-making processes. Risk decision-making is an important cognitive process and thus is an essential topic in the field of neuroscience. The Balloon Analog Risk Task (BART) is a valid experimental model and has been commonly used to assess human risk-taking actions and tendencies while facing risks. We have used the BART paradigm with a blocked design to investigate brain activations in the prefrontal and frontal cortical areas during decision-making from 37 human participants (22 males and 15 females). Voxel-wise GLM analysis was performed after a human brain atlas template and a depth compensation algorithm were combined to form atlas-guided DOT images. In this work, we wish to demonstrate the excellence of using voxel-wise GLM analysis with DOT to image and study cognitive functions in response to risk decision-making. Results have shown significant hemodynamic changes in the dorsal lateral prefrontal cortex (DLPFC) during the active-choice mode and a different activation pattern between genders; these findings correlate well with published literature in functional magnetic resonance imaging (fMRI) and fNIRS studies.

  14. High-throughput neuroimaging-genetics computational infrastructure.

    Science.gov (United States)

    Dinov, Ivo D; Petrosyan, Petros; Liu, Zhizhong; Eggert, Paul; Hobel, Sam; Vespa, Paul; Woo Moon, Seok; Van Horn, John D; Franco, Joseph; Toga, Arthur W

    2014-01-01

    Many contemporary neuroscientific investigations face significant challenges in terms of data management, computational processing, data mining, and results interpretation. These four pillars define the core infrastructure necessary to plan, organize, orchestrate, validate, and disseminate novel scientific methods, computational resources, and translational healthcare findings. Data management includes protocols for data acquisition, archival, query, transfer, retrieval, and aggregation. Computational processing involves the necessary software, hardware, and networking infrastructure required to handle large amounts of heterogeneous neuroimaging, genetics, clinical, and phenotypic data and meta-data. Data mining refers to the process of automatically extracting data features, characteristics and associations, which are not readily visible by human exploration of the raw dataset. Result interpretation includes scientific visualization, community validation of findings and reproducible findings. In this manuscript we describe the novel high-throughput neuroimaging-genetics computational infrastructure available at the Institute for Neuroimaging and Informatics (INI) and the Laboratory of Neuro Imaging (LONI) at University of Southern California (USC). INI and LONI include ultra-high-field and standard-field MRI brain scanners along with an imaging-genetics database for storing the complete provenance of the raw and derived data and meta-data. In addition, the institute provides a large number of software tools for image and shape analysis, mathematical modeling, genomic sequence processing, and scientific visualization. A unique feature of this architecture is the Pipeline environment, which integrates the data management, processing, transfer, and visualization. Through its client-server architecture, the Pipeline environment provides a graphical user interface for designing, executing, monitoring validating, and disseminating of complex protocols that utilize

  15. Graphical Neuroimaging Informatics: Application to Alzheimer’s Disease

    Science.gov (United States)

    Bowman, Ian; Joshi, Shantanu H.; Greer, Vaughan

    2013-01-01

    The Informatics Visualization for Neuroimaging (INVIZIAN) framework allows one to graphically display image and meta-data information from sizeable collections of neuroimaging data as a whole using a dynamic and compelling user interface. Users can fluidly interact with an entire collection of cortical surfaces using only their mouse. In addition, users can cluster and group brains according in multiple ways for subsequent comparison using graphical data mining tools. In this article, we illustrate the utility of INVIZIAN for simultaneous exploration and mining a large collection of extracted cortical surface data arising in clinical neuroimaging studies of patients with Alzheimer’s Disease, mild cognitive impairment, as well as healthy control subjects. Alzheimer’s Disease is particularly interesting due to the wide-spread effects on cortical architecture and alterations of volume in specific brain areas associated with memory. We demonstrate INVIZIAN’s ability to render multiple brain surfaces from multiple diagnostic groups of subjects, showcase the interactivity of the system, and showcase how INVIZIAN can be employed to generate hypotheses about the collection of data which would be suitable for direct access to the underlying raw data and subsequent formal statistical analysis. Specifically, we use INVIZIAN show how cortical thickness and hippocampal volume differences between group are evident even in the absence of more formal hypothesis testing. In the context of neurological diseases linked to brain aging such as AD, INVIZIAN provides a unique means for considering the entirety of whole brain datasets, look for interesting relationships among them, and thereby derive new ideas for further research and study. PMID:24203652

  16. Neuroimaging Measures as Endophenotypes in Alzheimer's Disease

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    Meredith N. Braskie

    2011-01-01

    Full Text Available Late onset Alzheimer's disease (AD is moderately to highly heritable. Apolipoprotein E allele ε4 (APOE4 has been replicated consistently as an AD risk factor over many studies, and recently confirmed variants in other genes such as CLU, CR1, and PICALM each increase the lifetime risk of AD. However, much of the heritability of AD remains unexplained. AD is a complex disease that is diagnosed largely through neuropsychological testing, though neuroimaging measures may be more sensitive for detecting the incipient disease stages. Difficulties in early diagnosis and variable environmental contributions to the disease can obscure genetic relationships in traditional case-control genetic studies. Neuroimaging measures may be used as endophenotypes for AD, offering a reliable, objective tool to search for possible genetic risk factors. Imaging measures might also clarify the specific mechanisms by which proposed risk factors influence the brain.

  17. Deep learning for neuroimaging: a validation study.

    Science.gov (United States)

    Plis, Sergey M; Hjelm, Devon R; Salakhutdinov, Ruslan; Allen, Elena A; Bockholt, Henry J; Long, Jeffrey D; Johnson, Hans J; Paulsen, Jane S; Turner, Jessica A; Calhoun, Vince D

    2014-01-01

    Deep learning methods have recently made notable advances in the tasks of classification and representation learning. These tasks are important for brain imaging and neuroscience discovery, making the methods attractive for porting to a neuroimager's toolbox. Success of these methods is, in part, explained by the flexibility of deep learning models. However, this flexibility makes the process of porting to new areas a difficult parameter optimization problem. In this work we demonstrate our results (and feasible parameter ranges) in application of deep learning methods to structural and functional brain imaging data. These methods include deep belief networks and their building block the restricted Boltzmann machine. We also describe a novel constraint-based approach to visualizing high dimensional data. We use it to analyze the effect of parameter choices on data transformations. Our results show that deep learning methods are able to learn physiologically important representations and detect latent relations in neuroimaging data.

  18. Neuroimaging studies of self-reflection

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying

    2004-01-01

    This paper reviews some basic findings and methodological issues in neuroimaging studies of self-referential processing.As a general rule,making judgments about one's self,inclusive of personality trait adjectives or current mental states(person's prefer ences,norms,aesthetic values and feeling)uniformly generates medial prefrontal activations,regardless of stimulus materials(words or pictures)and modality(visual or auditory).Cingulate activations are also observed in association with most self-referential processing.Methodological issues include treating self-referential processing as either representing one's own personality traits or representing one's own current mental states.Finally,self-referential processing could Be considered as implement of "I think therefore I am" approach to neuroimaging the self.

  19. Neuroimaging of HIV-associated neurocognitive disorders

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    Michel Elyas Jung Haziot

    Full Text Available ABSTRACT A significant increase in the incidence of cognitive impairment in HIV/AIDS patients has been continuously observed. Consequently, three classification categories of cognitive impairment have been proposed: asymptomatic neurocognitive impairment (ANI and mild neurocognitive disorder (MND, that correspond to the mild and intermediate forms, and HIV-associated dementia (HAD for the most severe cases. HIV-associated neurocognitive disorders (HAND is a broad term that encompasses these three categories. Moreover, the application of neuroimaging methods has led to a major breakthrough in understanding of the neurological changes in HIV, providing greater reliability in the exclusion of associated diseases and allowing earlier diagnosis. Therefore, abnormalities and/or specific neuroimaging elements may soon be incorporated into the HAND classification criteria, which will be of great value in the management of these diseases, including in the optimization of high CNS penetration antiretroviral regimens.

  20. Occipital headaches and neuroimaging in children.

    Science.gov (United States)

    Bear, Joshua J; Gelfand, Amy A; Goadsby, Peter J; Bass, Nancy

    2017-08-01

    To investigate the common thinking, as reinforced by the International Classification of Headache Disorders, 3rd edition (beta), that occipital headaches in children are rare and suggestive of serious intracranial pathology. We performed a retrospective chart review cohort study of all patients ≤18 years of age referred to a university child neurology clinic for headache in 2009. Patients were stratified by headache location: solely occipital, occipital plus other area(s) of head pain, or no occipital involvement. Children with abnormal neurologic examinations were excluded. We assessed location as a predictor of whether neuroimaging was ordered and whether intracranial pathology was found. Analyses were performed with cohort study tools in Stata/SE 13.0 (StataCorp, College Station, TX). A total of 308 patients were included. Median age was 12 years (32 months-18 years), and 57% were female. Headaches were solely occipital in 7% and occipital-plus in 14%. Patients with occipital head pain were more likely to undergo neuroimaging than those without occipital involvement (solely occipital: 95%, relative risk [RR] 10.5, 95% confidence interval [CI] 1.4-77.3; occipital-plus: 88%, RR 3.7, 95% CI 1.5-9.2; no occipital pain: 63%, referent). Occipital pain alone or with other locations was not significantly associated with radiographic evidence of clinically significant intracranial pathology. Children with occipital headache are more likely to undergo neuroimaging. In the absence of concerning features on the history and in the setting of a normal neurologic examination, neuroimaging can be deferred in most pediatric patients when occipital pain is present. © 2017 American Academy of Neurology.

  1. Magnetic Resonance Image Segmentation and its Volumetric Measurement

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    Rahul R. Ambalkar

    2013-02-01

    Full Text Available Image processing techniques make it possible to extract meaningful information from medical images. Magnetic resonance (MR imaging has been widely applied in biological research and diagnostics because of its excellent soft tissue contrast, non-invasive character, high spatial resolution and easy slice selection at any orientation. The MRI-based brain volumetric is concerned with the analysis of volumes and shapes of the structural components of the human brain. It also provides a criterion, by which we recognize the presence of degenerative diseases and characterize their rates of progression to make the diagnosis and treatments as a easy task. In this paper we have proposed an automated method for volumetric measurement of Magnetic Resonance Imaging and used Self Organized Map (SOM clustering method for their segmentations. We have used the MRI data set of 61 slices of 256×256 pixels in DICOM standard format

  2. Sports concussions and aging: a neuroimaging investigation.

    Science.gov (United States)

    Tremblay, Sebastien; De Beaumont, Louis; Henry, Luke C; Boulanger, Yvan; Evans, Alan C; Bourgouin, Pierre; Poirier, Judes; Théoret, Hugo; Lassonde, Maryse

    2013-05-01

    Recent epidemiological and experimental studies suggest a link between cognitive decline in late adulthood and sports concussions sustained in early adulthood. In order to provide the first in vivo neuroanatomical evidence of this relation, the present study probes the neuroimaging profile of former athletes with concussions in relation to cognition. Former athletes who sustained their last sports concussion >3 decades prior to testing were compared with those with no history of traumatic brain injury. Participants underwent quantitative neuroimaging (optimized voxel-based morphometry [VBM], hippocampal volume, and cortical thickness), proton magnetic resonance spectroscopy ((1)H MRS; medial temporal lobes and prefrontal cortices), and neuropsychological testing, and they were genotyped for APOE polymorphisms. Relative to controls, former athletes with concussions exhibited: 1) Abnormal enlargement of the lateral ventricles, 2) cortical thinning in regions more vulnerable to the aging process, 3) various neurometabolic anomalies found across regions of interest, 4) episodic memory and verbal fluency decline. The cognitive deficits correlated with neuroimaging findings in concussed participants. This study unveiled brain anomalies in otherwise healthy former athletes with concussions and associated those manifestations to the long-term detrimental effects of sports concussion on cognitive function. Findings from this study highlight patterns of decline often associated with abnormal aging.

  3. Neuroimaging in nuclear medicine: drug addicted brain

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    Chung, Yong-An; Kim, Dae-Jin [The Catholic University of Korea, Seoul (Korea, Republic of)

    2006-02-15

    Addiction to illicit drugs in one of today's most important social issues. Most addictive drugs lead to irreversible parenchymal changes in the human brain. Neuroimaging data bring to light the pharmacodynamics and pharmacokinetics of the abused drugs, and demonstrate that addiction is a disease of the brain. Continuous researches better illustrate the neurochemical alterations in brain function, and attempt to discover the links to consequent behavioral changes. Newer hypotheses and theories follow the numerous results, and more rational methods of approaching therapy are being developed. Substance abuse is on the rise in Korea, and social interest in the matter as well. On the other hand, diagnosis and treatment of drug addiction is still very difficult, because how the abused substance acts in the brain, or how it leads to behavioral problems in not widely known. Therefore, understanding the mechanism of drug addiction can improve the process of diagnosing addict patients, planning therapy, and predicting the prognosis . Neuroimaging approaches by nuclear medicine methods are expected to objectively judge behavioral and neurochemical changes, and response to treatment. In addition, as genes associated with addictive behavior are discovered, functional nuclear medicine images will aid in the assessment of individuals. Reviewing published literature on neuroimaging regarding nuclear medicine is expected to be of assistance to the management of drug addict patients. What's more, means of applying nuclear medicine to the care of drug addict patients should be investigated further.

  4. Neuroimaging: beginning to appreciate its complexities.

    Science.gov (United States)

    Parens, Erik; Johnston, Josephine

    2014-01-01

    For over a century, scientists have sought to see through the protective shield of the human skull and into the living brain. Today, an array of technologies allows researchers and clinicians to create astonishingly detailed images of our brain's structure as well as colorful depictions of the electrical and physiological changes that occur within it when we see, hear, think and feel. These technologies-and the images they generate-are an increasingly important tool in medicine and science. Given the role that neuroimaging technologies now play in biomedical research, both neuroscientists and nonexperts should aim to be as clear as possible about how neuroimages are made and what they can-and cannot-tell us. Add to this that neuroimages have begun to be used in courtrooms at both the determination of guilt and sentencing stages, that they are being employed by marketers to refine advertisements and develop new products, that they are being sold to consumers for the diagnosis of mental disorders and for the detection of lies, and that they are being employed in arguments about the nature (or absence) of powerful concepts like free will and personhood, and the need for citizens to have a basic understanding of how this technology works and what it can and cannot tell us becomes even more pressing.

  5. Functional neuroimaging in Tourette syndrome: recent perspectives

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    Debes NM

    2017-04-01

    Full Text Available Nanette Mol Debes, Marie Préel, Liselotte Skov Pediatric Department, Tourette Clinic, Herlev University Hospital, Herlev, DenmarkAbstract: The most recent functional neuroimaging studies on Tourette syndrome (TS are reviewed in this paper. Although it can be difficult to compare functional neuroimaging studies due to differences in methods, differences in age of the included subjects, and differences in the extent to which the presence of comorbidity, medical treatment, and severity of tics are considered in the various studies; most studies show that the cortico-striato-thalamo-cortical circuit seems to be involved in the generation of tics. Changes in this circuit seem to be correlated with tic severity. Correlations have been found between the presence of tics and hypermetabolism in various brain regions. Abnormalities of GABAergic, serotonergic, and dopaminergic neurotransmission in patients with TS have been suggested. During tic suppression, increased activity in the inferior frontal gyrus is seen. The premotor cortex might be involved in inhibition of motor control in subjects with TS. The right anterior insula is suggested to be a part of the urge–tic network. Several studies have shown altered motor network activations and sensorimotor gating deficits in subjects with TS. In future studies, inclusion of more well-defined subjects and further examination of premonitory urge and tic suppression is needed in order to increase the knowledge about the pathophysiology and treatment possibilities of TS. Keywords: functional neuroimaging, Tourette syndrome

  6. Traumatic brain injury, neuroimaging, and neurodegeneration.

    Science.gov (United States)

    Bigler, Erin D

    2013-01-01

    Depending on severity, traumatic brain injury (TBI) induces immediate neuropathological effects that in the mildest form may be transient but as severity increases results in neural damage and degeneration. The first phase of neural degeneration is explainable by the primary acute and secondary neuropathological effects initiated by the injury; however, neuroimaging studies demonstrate a prolonged period of pathological changes that progressively occur even during the chronic phase. This review examines how neuroimaging may be used in TBI to understand (1) the dynamic changes that occur in brain development relevant to understanding the effects of TBI and how these relate to developmental stage when the brain is injured, (2) how TBI interferes with age-typical brain development and the effects of aging thereafter, and (3) how TBI results in greater frontotemporolimbic damage, results in cerebral atrophy, and is more disruptive to white matter neural connectivity. Neuroimaging quantification in TBI demonstrates degenerative effects from brain injury over time. An adverse synergistic influence of TBI with aging may predispose the brain injured individual for the development of neuropsychiatric and neurodegenerative disorders long after surviving the brain injury.

  7. Traumatic brain injury, neuroimaging, and neurodegeneration

    Directory of Open Access Journals (Sweden)

    Erin D. Bigler

    2013-08-01

    Full Text Available Depending on severity, traumatic brain injury (TBI induces immediate neuropathological effects that in the mildest form may be transient but as severity increases results in neural damage and degeneration. The first phase of neural degeneration is explainable by the primary acute and secondary neuropathological effects initiated by the injury; however, neuroimaging studies demonstrate a prolonged period of pathological changes that progressively occur even during the chronic phase. This review examines how neuroimaging may be used in TBI to understand (1 the dynamic changes that occur in brain development relevant to understanding the effects of TBI and how these relate to developmental stage when the brain is injured, (2 how TBI interferes with age-typical brain development and the effects of aging thereafter, and (3 how TBI results in greater frontotemporolimbic damage, results in cerebral atrophy, and is more disruptive to white matter neural connectivity. Neuroimaging quantification in TBI demonstrates degenerative effects from brain injury over time. An adverse synergistic influence of TBI with aging may predispose the brain injured individual for the development of neuropsychiatric and neurodegenerative disorders long after surviving the brain injury.

  8. Neuroimaging of Wernicke's encephalopathy and Korsakoff's syndrome.

    Science.gov (United States)

    Jung, Young-Chul; Chanraud, Sandra; Sullivan, Edith V

    2012-06-01

    There is considerable evidence that neuroimaging findings can improve the early diagnosis of Wernicke's encephalopathy (WE) in clinical settings. The most distinctive neuroimaging finding of acute WE are cytotoxic edema and vasogenic edema, which are represented by bilateral symmetric hyperintensity alterations on T2-weighted MR images in the periphery of the third ventricle, periaqueductal area, mammillary bodies and midbrain tectal plate. An initial bout of WE can result in Korsakoff's syndrome (KS), but repeated bouts in conjunction with its typical comorbidity, chronic alcoholism, can result in signs of tissue degeneration in vulnerable brain regions. Chronic abnormalities identified with neuroimaging enable examination of brain damage in living patients with KS and have expanded the understanding of the neuropsychological deficits resulting from thiamine deficiency, alcohol neurotoxicity, and their comorbidity. Brain structure and functional studies indicate that the interactions involving the thalamus, mammillary bodies, hippocampus, frontal lobes, and cerebellum are crucial for memory formation and executive functions, and the interruption of these circuits by WE and chronic alcoholism can contribute substantially to the neuropsychological deficits in KS.

  9. Multimodal Neuroimaging-Informed Clinical Applications in Neuropsychiatric Disorders

    Science.gov (United States)

    O’Halloran, Rafael; Kopell, Brian H.; Sprooten, Emma; Goodman, Wayne K.; Frangou, Sophia

    2016-01-01

    Recent advances in neuroimaging data acquisition and analysis hold the promise to enhance the ability to make diagnostic and prognostic predictions and perform treatment planning in neuropsychiatric disorders. Prior research using a variety of types of neuroimaging techniques has confirmed that neuropsychiatric disorders are associated with dysfunction in anatomical and functional brain circuits. We first discuss current challenges associated with the identification of reliable neuroimaging markers for diagnosis and prognosis in mood disorders and for neurosurgical treatment planning for deep brain stimulation (DBS). We then present data on the use of neuroimaging for the diagnosis and prognosis of mood disorders and for DBS treatment planning. We demonstrate how multivariate analyses of functional activation and connectivity parameters can be used to differentiate patients with bipolar disorder from those with major depressive disorder and non-affective psychosis. We also present data on connectivity parameters that mediate acute treatment response in affective and non-affective psychosis. We then focus on precision mapping of functional connectivity in native space. We describe the benefits of integrating anatomical fiber reconstruction with brain functional parameters and cortical surface measures to derive anatomically informed connectivity metrics within the morphological context of each individual brain. We discuss how this approach may be particularly promising in psychiatry, given the clinical and etiological heterogeneity of the disorders, and particularly in treatment response prediction and planning. Precision mapping of connectivity is essential for DBS. In DBS, treatment electrodes are inserted into positions near key gray matter nodes within the circuits considered relevant to disease expression. However, targeting white matter tracts that underpin connectivity within these circuits may increase treatment efficacy and tolerability therefore relevant

  10. Multimodal neuroimaging-informed clinical applications in neuropsychiatric disorders

    Directory of Open Access Journals (Sweden)

    Rafael eO'Halloran

    2016-04-01

    Full Text Available Recent advances in neuroimaging data acquisition and analysis hold the promise to enhance the ability to make diagnostic and prognostic predictions and perform treatment planning in neuropsychiatric disorders. Prior research using a variety of types of neuroimaging techniques has confirmed that neuropsychiatric disorders are associated with dysfunction in anatomical and functional brain circuits. We first discuss current challenges associated with the identification of reliable neuroimaging markers for diagnosis and prognosis in mood disorders and for neurosurgical treatment planning for deep brain stimulation (DBS. We then present data on the use of neuroimaging for the diagnosis and prognosis of mood disorders and for DBS treatment planning. We demonstrate how multivariate analyses of functional activation and connectivity parameters can be used to differentiate patients with bipolar disorder from those with major depressive disorder and non-affective psychosis. We also present data on connectivity parameters that mediate acute treatment response in affective and non-affective psychosis. We then focus on precision mapping of functional connectivity in native space. We describe the benefits of integrating anatomical fiber reconstruction with brain functional parameters and cortical surface measures to derive anatomically-informed connectivity metrics within the morphological context of each individual brain. We discuss how this approach may be particularly promising in psychiatry, given the clinical and etiological heterogeneity of the disorders, and particularly in treatment response prediction and planning. Precision mapping of connectivity is essential for DBS. In DBS, treatment electrodes are inserted into positions near key grey matter nodes within the circuits considered relevant to disease expression. However, targeting white matter tracts that underpin connectivity within these circuits may increase treatment efficacy and tolerability

  11. Molecular approaches in experimental neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Tavitian, B. [CEA Saclay, 91 - Gif sur Yvette (France)

    2009-07-01

    We quantified and compared six parameters (resolution, depth, sensitivity, portability, quantification and cost) of four molecular imaging techniques (MRI, optics, ultrasound and TEP), with the three types of electromagnetic radiation used in vivo (Frequencies (10{sup 6} to 10{sup 22} Hz), Photonic Energy (10{sup -4} to 10{sup 9} eV) and Wavelengths (10{sup -2} to 10{sup -15} m)). This form of molecular imaging demands the most sensitive technique available (Pl. 26-2 to 26-4). Four examples of experimental in vivo approaches on small animals are shown: molecular passage through the blood-brain barrier (endothelial cells, astrocytes and occludin, pharmacokinetics, studied with PET) (Pl. 2-5 to 2-11); imaging of receptors and ligands, especially peripheral benzodiazepine receptors (PBR) by PET and MRI in the rat (Pl. 2-12 to Pl. 2-15); neuro-pathology of neuro-degenerative and inflammatory diseases and stroke by PET and MRI in the rat (Pl. 2-16 to 2-17); and the study of responses to stimulation explored with in vivo imaging of calcium signals and their variations by photonic analysis, as on the scale of mitochondrial calcium (Pl.2-18 to Pl.2-22). (author)

  12. Deficient Approaches to Human Neuroimaging

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    Johannes eStelzer

    2014-07-01

    Full Text Available Functional magnetic resonance imaging (fMRI is the workhorse of imaging-based human cognitive neuroscience. The use of fMRI is ever-increasing; within the last 4 years more fMRI studies have been published than in the previous 17 years. This large body of research has mainly focused on the functional localization of condition- or stimulus-dependent changes in the blood-oxygenation-level dependent (BOLD signal.In recent years, however, many aspects of the commonly practiced analysis frameworks and methodologies have been critically reassessed. Here we summarize these critiques, providing an overview of the major conceptual and practical deficiencies in widely used brain-mapping approaches, and exemplify some of these issues by the use of imaging data and simulations. In particular, we discuss the inherent pitfalls and shortcomings of methodologies for statistical parametric mapping. Our critique emphasizes recent reports of excessively high numbers of both false positive and false negative findings in fMRI brain mapping. We outline our view regarding the broader scientific implications of these methodological considerations and briefly discuss possible solutions.

  13. A study on nonlinear finite element analysis of laminated rubber bearings. Pt.1. Development of evaluation method for mechanical properties of laminated rubber bearings for horizontal base isolation system considering volumetric deformation of rubber material

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Akihiro; Ohtori, Yasuki; Yabana, Shuichi; Hirata, Kazuta [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan). Abiko Research Lab

    1999-04-01

    The purpose of this research is to develop the evaluation method for mechanical properties of laminated rubber bearings by nonlinear finite element method (FEM) considering the volumetric deformation of natural rubber material. Relationship between pressure and volumetric strain of the natural rubber is obtained from the volumetric tests and is introduced into user-subroutine of the FEM code (ABAQUS). Finite element analyses of natural rubber bearings (NRB) and the natural rubber bearing with lead plug (LRB) are carried out. The results may be summarized as follows; 1) Horizontal, vertical stiffness and effect of shear deformation on vertical stiffness of natural rubber bearings that have various shape are simulated with enough accuracy. 2) Horizontal and vertical stiffness of LRB are also simulated well. (author)

  14. Publication trends in neuroimaging of minimally conscious states

    Directory of Open Access Journals (Sweden)

    Alex Garnett

    2013-09-01

    Full Text Available We used existing and customized bibliometric and scientometric methods to analyze publication trends in neuroimaging research of minimally conscious states and describe the domain in terms of its geographic, contributor, and content features. We considered publication rates for the years 2002–2011, author interconnections, the rate at which new authors are added, and the domains that inform the work of author contributors. We also provided a content analysis of clinical and ethical themes within the relevant literature. We found a 27% growth in the number of papers over the period of study, professional diversity among a wide range of peripheral author contributors but only few authors who dominate the field, and few new technical paradigms and clinical themes that would fundamentally expand the landscape. The results inform both the science of consciousness as well as parallel ethics and policy studies of the potential for translational challenges of neuroimaging in research and health care of people with disordered states of consciousness.

  15. The impact of segmental volumetric changes on functional mitral regurgitation: a study using three-dimensional regional time-volume analysis combined with low-dose dobutamine.

    Science.gov (United States)

    Chen, Xiaofeng; Hsiung, Ming-Chon; Mu, Yuming

    2014-02-01

    Using transthoracic three-dimensional (3D) echo regional volume analysis combined with low-dose dobutamine to investigate the effects on regional volume, mitral configuration and functional mitral regurgitation (FMR). Fifty-six patients with ischemic cardiomyopathy (ICM) were included in this study. The effective regurgitant orifice area (EROA) of FMR secondary to ICM with depressed left ventricular ejection fraction was compared with mitral tenting area and coaptation height (CH) before and after low-dose dobutamine (10 μg/kg per min). Using 3-DQ software we measured and calculated regional stroke-volumes (rSV), the ratio of the rSV to the whole left ventricular stroke volume (rgSVratio) in all 17 segments and the average rgSVratio of 4 anterior-PM attached segments (rgSVratio-aver anter-PM), 4 posterior-PM attached segments (rgSVratio-aver post-PM), 8 PMs attached segments (rgSVratio-aver PMs) and all 17 segments before and after dobutamine. Compared with the resting condition, the SVr and rgSVratio on the basal and mid segments of anterior, lateral, inferior, and posterior walls were increased after dobutamine infusion (P FMR decreasing during low-dose dobutamine is quantitatively associated with the regional LV volume change of attached PMs. Real time transthoracic three-dimensional echocardiography may provide a simple and noninvasive approach to assess regional LV time-volume characteristic during FMR. © 2013, Wiley Periodicals, Inc.

  16. Image fusion analysis of volumetric changes after interstitial low-dose-rate iodine-125 irradiation of supratentorial low-grade gliomas.

    Science.gov (United States)

    Julow, Jeno; Major, Tibor; Mangel, László; Bajzik, Gábor; Viola, Arpad

    2007-04-01

    The aim of this study was to compare the volumes of tumor necrosis, reactive zone and edema with the three-dimensional dose distributions after brachytherapy treatments of gliomas. The investigation was performed an average of 14.2 months after low-dose-rate (125)I interstitial irradiation of 25 inoperable low-grade gliomas. The prescribed dose was 50-60 Gy to the tumor surface. Dose planning and image fusion were performed with the BrainLab-Target 1.19 software. In the CT/ MRI images, the "triple ring" (tumor necrosis, reactive ring and edema) developing after the interstitial irradiation of the brain tumors was examined. The images with the triple ring were fused with the planning images, and the isodose curves were superimposed on them. The volumes of the three regions were measured. The average dose at the necrosis border was determined from the isodose distribution. For quantitative assessment of the dose distributions, the dose nonuniformity ratio (DNR), homogeneity index (HI), coverage index (CI) and conformal index (COIN) were calculated. The relative volumes of the different parts of the triple ring after the interstitial irradiation compared to the reference dose volume were the following: necrosis, 40.9%, reactive zone, 47.1%, and edema, 367%. The tumor necrosis developed at 79.1 Gy on average. The average DNR, HI, CI and COIN were 0.45, 0.24, 0.94 and 0.57, respectively. The image fusion analysis of the volume of tumor necrosis, reactive ring and edema caused by interstitial irradiation and their correlation with the dose distribution provide valuable information for patient follow-up, treatment options, and effects and side effects of radio therapy.

  17. The ENIGMA Consortium: Large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    P.M. Thompson (Paul); J.L. Stein; S.E. Medland (Sarah Elizabeth); D.P. Hibar (Derrek); A.A. Vásquez (Arias); M.E. Rentería (Miguel); R. Toro (Roberto); N. Jahanshad (Neda); G. Schumann (Gunter); B. Franke (Barbara); M.J. Wright (Margaret); N.G. Martin (Nicholas); I. Agartz (Ingrid); M. Alda (Martin); S. Alhusaini (Saud); L. Almasy (Laura); J. Almeida (Julia); K. Alpert (Kathryn); N.C. Andreasen; O.A. Andreassen (Ole); L.G. Apostolova (Liana); K. Appel (Katja); N.J. Armstrong (Nicola); B. Aribisala (Benjamin); M.E. Bastin (Mark); M. Bauer (Michael); C.E. Bearden (Carrie); Ø. Bergmann (Ørjan); E.B. Binder (Elisabeth); J. Blangero (John); H.J. Bockholt; E. Bøen (Erlend); M. Bois (Monique); D.I. Boomsma (Dorret); T. Booth (Tom); I.J. Bowman (Ian); L.B.C. Bralten (Linda); R.M. Brouwer (Rachel); H.G. Brunner; D.G. Brohawn (David); M. Buckner; J.K. Buitelaar (Jan); K. Bulayeva (Kazima); J. Bustillo; V.D. Calhoun (Vince); D.M. Cannon (Dara); R.M. Cantor; M.A. Carless (Melanie); X. Caseras (Xavier); G. Cavalleri (Gianpiero); M.M. Chakravarty (M. Mallar); K.D. Chang (Kiki); C.R.K. Ching (Christopher); A. Christoforou (Andrea); S. Cichon (Sven); V.P. Clark; P. Conrod (Patricia); D. Coppola (Domenico); B. Crespo-Facorro (Benedicto); J.E. Curran (Joanne); M. Czisch (Michael); I.J. Deary (Ian); E.J.C. de Geus (Eco); A. den Braber (Anouk); G. Delvecchio (Giuseppe); C. Depondt (Chantal); L. de Haan (Lieuwe); G.I. de Zubicaray (Greig); D. Dima (Danai); R. Dimitrova (Rali); S. Djurovic (Srdjan); H. Dong (Hongwei); D.J. Donohoe (Dennis); A. Duggirala (Aparna); M.D. Dyer (Matthew); S.M. Ehrlich (Stefan); C.J. Ekman (Carl Johan); T. Elvsåshagen (Torbjørn); L. Emsell (Louise); S. Erk; T. Espeseth (Thomas); J. Fagerness (Jesen); S. Fears (Scott); I. Fedko (Iryna); G. Fernandez (Guillén); S.E. Fisher (Simon); T. Foroud (Tatiana); P.T. Fox (Peter); C. Francks (Clyde); S. Frangou (Sophia); E.M. Frey (Eva Maria); T. Frodl (Thomas); V. Frouin (Vincent); H. Garavan (Hugh); S. Giddaluru (Sudheer); D.C. Glahn (David); B. Godlewska (Beata); R.Z. Goldstein (Rita); R.L. Gollub (Randy); H.J. Grabe (Hans Jörgen); O. Grimm (Oliver); O. Gruber (Oliver); T. Guadalupe (Tulio); R.E. Gur (Raquel); R.C. Gur (Ruben); H.H.H. Göring (Harald); S. Hagenaars (Saskia); T. Hajek (Tomas); G.B. Hall (Garry); J. Hall (Jeremy); J. Hardy (John); C.A. Hartman (Catharina); J. Hass (Johanna); W. Hatton; U.K. Haukvik (Unn); K. Hegenscheid (Katrin); J. Heinz (Judith); I.B. Hickie (Ian); B.C. Ho (Beng ); D. Hoehn (David); P.J. Hoekstra (Pieter); M. Hollinshead (Marisa); A.J. Holmes (Avram); G. Homuth (Georg); M. Hoogman (Martine); L.E. Hong (L.Elliot); N. Hosten (Norbert); J.J. Hottenga (Jouke Jan); H.E. Hulshoff Pol (Hilleke); K.S. Hwang (Kristy); C.R. Jack Jr. (Clifford); S. Jenkinson (Sarah); C. Johnston; E.G. Jönsson (Erik); R.S. Kahn (René); D. Kasperaviciute (Dalia); S. Kelly (Steve); S. Kim (Shinseog); P. Kochunov (Peter); L. Koenders (Laura); B. Krämer (Bernd); J.B.J. Kwok (John); J. Lagopoulos (Jim); G. Laje (Gonzalo); M. Landén (Mikael); B.A. Landman (Bennett); J. Lauriello; S. Lawrie (Stephen); P.H. Lee (Phil); S. Le Hellard (Stephanie); H. Lemaître (Herve); C.D. Leonardo (Cassandra); C.-S. Li (Chiang-shan); B. Liberg (Benny); D.C. Liewald (David C.); X. Liu (Xinmin); L.M. Lopez (Lorna); E. Loth (Eva); A. Lourdusamy (Anbarasu); M. Luciano (Michelle); F. MacCiardi (Fabio); M.W.J. Machielsen (Marise); G.M. MacQueen (Glenda); U.F. Malt (Ulrik); R. Mandl (René); D.S. Manoach (Dara); J.-L. Martinot (Jean-Luc); M. Matarin (Mar); R. Mather; M. Mattheisen (Manuel); M. Mattingsdal (Morten); A. Meyer-Lindenberg; C. McDonald (Colm); A.M. McIntosh (Andrew); F.J. Mcmahon (Francis J); K.L. Mcmahon (Katie); E. Meisenzahl (Eva); I. Melle (Ingrid); Y. Milaneschi (Yuri); S. Mohnke (Sebastian); G.W. Montgomery (Grant); D.W. Morris (Derek W); E.K. Moses (Eric); B.A. Mueller (Bryon ); S. Muñoz Maniega (Susana); T.W. Mühleisen (Thomas); B. Müller-Myhsok (Bertram); B. Mwangi (Benson); M. Nauck (Matthias); K. Nho (Kwangsik); T.E. Nichols (Thomas); L.G. Nilsson; A.C. Nugent (Allison); L. Nyberg (Lisa); R.L. Olvera (Rene); J. Oosterlaan (Jaap); R.A. Ophoff (Roel); M. Pandolfo (Massimo); M. Papalampropoulou-Tsiridou (Melina); M. Papmeyer (Martina); T. Paus (Tomas); Z. Pausova (Zdenka); G. Pearlson (Godfrey); B.W.J.H. Penninx (Brenda); C.P. Peterson (Charles); A. Pfennig (Andrea); M. Phillips (Mary); G.B. Pike (G Bruce); J.B. Poline (Jean Baptiste); S.G. Potkin (Steven); B. Pütz (Benno); A. Ramasamy (Adaikalavan); J. Rasmussen (Jerod); M. Rietschel (Marcella); M. Rijpkema (Mark); S.L. Risacher (Shannon); J.L. Roffman (Joshua); R. Roiz-Santiañez (Roberto); N. Romanczuk-Seiferth (Nina); E.J. Rose (Emma); N.A. Royle (Natalie); D. Rujescu (Dan); M. Ryten (Mina); P.S. Sachdev (Perminder); A. Salami (Alireza); T.D. Satterthwaite (Theodore); J. Savitz (Jonathan); A.J. Saykin (Andrew); C. Scanlon (Cathy); L. Schmaal (Lianne); H. Schnack (Hugo); N.J. Schork (Nicholas); S.C. Schulz (S.Charles); R. Schür (Remmelt); L.J. Seidman (Larry); L. Shen (Li); L. Shoemaker (Lawrence); A. Simmons (Andrew); S.M. Sisodiya (Sanjay); C. Smith (Colin); J.W. Smoller; J.C. Soares (Jair); S.R. Sponheim (Scott); R. Sprooten (Roy); J.M. Starr (John); V.M. Steen (Vidar); S. Strakowski (Stephen); V.M. Strike (Vanessa); J. Sussmann (Jessika); P.G. Sämann (Philipp); A. Teumer (Alexander); A.W. Toga (Arthur); D. Tordesillas-Gutierrez (Diana); D. Trabzuni (Danyah); S. Trost (Sarah); J. Turner (Jessica); M. van den Heuvel (Martijn); N.J. van der Wee (Nic); K.R. van Eijk (Kristel); T.G.M. van Erp (Theo G.); N.E.M. van Haren (Neeltje E.); D. van 't Ent (Dennis); M.J.D. van Tol (Marie-José); M.C. Valdés Hernández (Maria); D.J. Veltman (Dick); A. Versace (Amelia); H. Völzke (Henry); R. Walker (Robert); H.J. Walter (Henrik); L. Wang (Lei); J.M. Wardlaw (J.); M.E. Weale (Michael); M.W. Weiner (Michael); W. Wen (Wei); L.T. Westlye (Lars); H.C. Whalley (Heather); C.D. Whelan (Christopher); T.J.H. White (Tonya); A.M. Winkler (Anderson); K. Wittfeld (Katharina); G. Woldehawariat (Girma); A. Björnsson (Asgeir); D. Zilles (David); M.P. Zwiers (Marcel); A. Thalamuthu (Anbupalam); C.J. Schofield (Christopher); N.B. Freimer (Nelson); N.S. Lawrence (Natalia); D.A. Drevets (Douglas)

    2014-01-01

    textabstractThe Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscien

  18. The ENIGMA Consortium : large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud; Almasy, Laura; Almeida, Jorge; Alpert, Kathryn; Andreasen, Nancy C.; Andreassen, Ole A.; Apostolova, Liana G.; Appel, Katja; Armstrong, Nicola J.; Aribisala, Benjamin; Bastin, Mark E.; Bauer, Michael; Bearden, Carrie E.; Bergmann, Orjan; Binder, Elisabeth B.; Blangero, John; Bockholt, Henry J.; Boen, Erlend; Bois, Catherine; Boomsma, Dorret I.; Booth, Tom; Bowman, Ian J.; Bralten, Janita; Brouwer, Rachel M.; Brunner, Han G.; Brohawn, David G.; Buckner, Randy L.; Buitelaar, Jan; Bulayeva, Kazima; Bustillo, Juan R.; Calhoun, Vince D.; Cannon, Dara M.; Cantor, Rita M.; Carless, Melanie A.; Caseras, Xavier; Cavalleri, Gianpiero L.; Chakravarty, M. Mallar; Chang, Kiki D.; Ching, Christopher R. K.; Christoforou, Andrea; Cichon, Sven; Clark, Vincent P.; Conrod, Patricia; Coppola, Giovanni; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Deary, Ian J.; de Geus, Eco J. C.; den Braber, Anouk; Delvecchio, Giuseppe; Depondt, Chantal; de Haan, Lieuwe; de Zubicaray, Greig I.; Dima, Danai; Dimitrova, Rali; Djurovic, Srdjan; Dong, Hongwei; Donohoe, Gary; Duggirala, Ravindranath; Dyer, Thomas D.; Ehrlich, Stefan; Ekman, Carl Johan; Elvsashagen, Torbjorn; Emsell, Louise; Erk, Susanne; Espeseth, Thomas; Fagerness, Jesen; Fears, Scott; Fedko, Iryna; Fernandez, Guillen; Fisher, Simon E.; Foroud, Tatiana; Fox, Peter T.; Francks, Clyde; Frangou, Sophia; Frey, Eva Maria; Frodl, Thomas; Frouin, Vincent; Garavan, Hugh; Giddaluru, Sudheer; Glahn, David C.; Godlewska, Beata; Goldstein, Rita Z.; Gollub, Randy L.; Grabe, Hans J.; Grimm, Oliver; Gruber, Oliver; Guadalupe, Tulio; Gur, Raquel E.; Gur, Ruben C.; Goering, Harald H. H.; Hagenaars, Saskia; Hajek, Tomas; Hall, Geoffrey B.; Hall, Jeremy; Hardy, John; Hartman, Catharina A.; Hass, Johanna; Hatton, Sean N.; Haukvik, Unn K.; Hegenscheid, Katrin; Heinz, Andreas; Hickie, Ian B.; Ho, Beng-Choon; Hoehn, David; Hoekstra, Pieter J.; Hollinshead, Marisa; Holmes, Avram J.; Homuth, Georg; Hoogman, Martine; Hong, L. Elliot; Hosten, Norbert; Hottenga, Jouke-Jan; Pol, Hilleke E. Hulshoff; Hwang, Kristy S.; Jack, Clifford R.; Jenkinson, Mark; Johnston, Caroline; Joensson, Erik G.; Kahn, Rene S.; Kasperaviciute, Dalia; Kelly, Sinead; Kim, Sungeun; Kochunov, Peter; Koenders, Laura; Kraemer, Bernd; Kwok, John B. J.; Lagopoulos, Jim; Laje, Gonzalo; Landen, Mikael; Landman, Bennett A.; Lauriello, John; Lawrie, Stephen M.; Lee, Phil H.; Le Hellard, Stephanie; Lemaitre, Herve; Leonardo, Cassandra D.; Li, Chiang-shan; Liberg, Benny; Liewald, David C.; Liu, Xinmin; Lopez, Lorna M.; Loth, Eva; Lourdusamy, Anbarasu; Luciano, Michelle; Macciardi, Fabio; Machielsen, Marise W. J.; MacQueen, Glenda M.; Malt, Ulrik F.; Mandl, Rene; Manoach, Dara S.; Martinot, Jean-Luc; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; Mattingsdal, Morten; Meyer-Lindenberg, Andreas; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Meisenzahl, Eva; Melle, Ingrid; Milaneschi, Yuri; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Moses, Eric K.; Mueller, Bryon A.; Munoz Maniega, Susana; Muehleisen, Thomas W.; Mueller-Myhsok, Bertram; Mwangi, Benson; Nauck, Matthias; Nho, Kwangsik; Nichols, Thomas E.; Nilsson, Lars-Goeran; Nugent, Allison C.; Nyberg, Lars; Olvera, Rene L.; Oosterlaan, Jaap; Ophoff, Roel A.; Pandolfo, Massimo; Papalampropoulou-Tsiridou, Melina; Papmeyer, Martina; Paus, Tomas; Pausova, Zdenka; Pearlson, Godfrey D.; Penninx, Brenda W.; Peterson, Charles P.; Pfennig, Andrea; Phillips, Mary; Pike, G. Bruce; Poline, Jean-Baptiste; Potkin, Steven G.; Puetz, Benno; Ramasamy, Adaikalavan; Rasmussen, Jerod; Rietschel, Marcella; Rijpkema, Mark; Risacher, Shannon L.; Roffman, Joshua L.; Roiz-Santianez, Roberto; Romanczuk-Seiferth, Nina; Rose, Emma J.; Royle, Natalie A.; Rujescu, Dan; Ryten, Mina; Sachdev, Perminder S.; Salami, Alireza; Satterthwaite, Theodore D.; Savitz, Jonathan; Saykin, Andrew J.; Scanlon, Cathy; Schmaal, Lianne; Schnack, Hugo G.; Schork, Andrew J.; Schulz, S. Charles; Schuer, Remmelt; Seidman, Larry; Shen, Li; Shoemaker, Jody M.; Simmons, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soares, Jair C.; Sponheim, Scott R.; Sprooten, Emma; Starr, John M.; Steen, Vidar M.; Strakowski, Stephen; Strike, Lachlan; Sussmann, Jessika; Saemann, Philipp G.; Teumer, Alexander; Toga, Arthur W.; Tordesillas-Gutierrez, Diana; Trabzuni, Daniah; Trost, Sarah; Turner, Jessica; Van den Heuvel, Martijn; van der Wee, Nic J.; van Eijk, Kristel; van Erp, Theo G. M.; van Haren, Neeltje E. M.; van 't Ent, Dennis; van Tol, Marie-Jose; Hernandez, Maria C. Valdes; Veltman, Dick J.; Versace, Amelia; Voelzke, Henry; Walker, Robert; Walter, Henrik; Wang, Lei; Wardlaw, Joanna M.; Weale, Michael E.; Weiner, Michael W.; Wen, Wei; Westlye, Lars T.; Whalley, Heather C.; Whelan, Christopher D.; White, Tonya; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Zilles, David; Zwiers, Marcel P.; Thalamuthu, Anbupalam; Schofield, Peter R.; Freimer, Nelson B.; Lawrence, Natalia S.; Drevets, Wayne

    2014-01-01

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics

  19. The ENIGMA Consortium: Large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    P.M. Thompson (Paul); J.L. Stein; S.E. Medland (Sarah Elizabeth); D.P. Hibar (Derrek); A.A. Vásquez (Arias); M.E. Rentería (Miguel); R. Toro (Roberto); N. Jahanshad (Neda); G. Schumann (Gunter); B. Franke (Barbara); M.J. Wright (Margaret); N.G. Martin (Nicholas); I. Agartz (Ingrid); M. Alda (Martin); S. Alhusaini (Saud); L. Almasy (Laura); J. Almeida (Julia); K. Alpert (Kathryn); N.C. Andreasen; O.A. Andreassen (Ole); L.G. Apostolova (Liana); K. Appel (Katja); N.J. Armstrong (Nicola); B. Aribisala (Benjamin); M.E. Bastin (Mark); M. Bauer (Michael); C.E. Bearden (Carrie); Ø. Bergmann (Ørjan); E.B. Binder (Elisabeth); J. Blangero (John); H.J. Bockholt; E. Bøen (Erlend); M. Bois (Monique); D.I. Boomsma (Dorret); T. Booth (Tom); I.J. Bowman (Ian); L.B.C. Bralten (Linda); R.M. Brouwer (Rachel); H.G. Brunner; D.G. Brohawn (David); M. Buckner; J.K. Buitelaar (Jan); K. Bulayeva (Kazima); J. Bustillo; V.D. Calhoun (Vince); D.M. Cannon (Dara); R.M. Cantor; M.A. Carless (Melanie); X. Caseras (Xavier); G. Cavalleri (Gianpiero); M.M. Chakravarty (M. Mallar); K.D. Chang (Kiki); C.R.K. Ching (Christopher); A. Christoforou (Andrea); S. Cichon (Sven); V.P. Clark; P. Conrod (Patricia); D. Coppola (Domenico); B. Crespo-Facorro (Benedicto); J.E. Curran (Joanne); M. Czisch (Michael); I.J. Deary (Ian); E.J.C. de Geus (Eco); A. den Braber (Anouk); G. Delvecchio (Giuseppe); C. Depondt (Chantal); L. de Haan (Lieuwe); G.I. de Zubicaray (Greig); D. Dima (Danai); R. Dimitrova (Rali); S. Djurovic (Srdjan); H. Dong (Hongwei); D.J. Donohoe (Dennis); A. Duggirala (Aparna); M.D. Dyer (Matthew); S.M. Ehrlich (Stefan); C.J. Ekman (Carl Johan); T. Elvsåshagen (Torbjørn); L. Emsell (Louise); S. Erk; T. Espeseth (Thomas); J. Fagerness (Jesen); S. Fears (Scott); I. Fedko (Iryna); G. Fernandez (Guillén); S.E. Fisher (Simon); T. Foroud (Tatiana); P.T. Fox (Peter); C. Francks (Clyde); S. Frangou (Sophia); E.M. Frey (Eva Maria); T. Frodl (Thomas); V. Frouin (Vincent); H. Garavan (Hugh); S. Giddaluru (Sudheer); D.C. Glahn (David); B. Godlewska (Beata); R.Z. Goldstein (Rita); R.L. Gollub (Randy); H.J. Grabe (Hans Jörgen); O. Grimm (Oliver); O. Gruber (Oliver); T. Guadalupe (Tulio); R.E. Gur (Raquel); R.C. Gur (Ruben); H.H.H. Göring (Harald); S. Hagenaars (Saskia); T. Hajek (Tomas); G.B. Hall (Garry); J. Hall (Jeremy); J. Hardy (John); C.A. Hartman (Catharina); J. Hass (Johanna); W. Hatton; U.K. Haukvik (Unn); K. Hegenscheid (Katrin); J. Heinz (Judith); I.B. Hickie (Ian); B.C. Ho (Beng ); D. Hoehn (David); P.J. Hoekstra (Pieter); M. Hollinshead (Marisa); A.J. Holmes (Avram); G. Homuth (Georg); M. Hoogman (Martine); L.E. Hong (L.Elliot); N. Hosten (Norbert); J.J. Hottenga (Jouke Jan); H.E. Hulshoff Pol (Hilleke); K.S. Hwang (Kristy); C.R. Jack Jr. (Clifford); S. Jenkinson (Sarah); C. Johnston; E.G. Jönsson (Erik); R.S. Kahn (René); D. Kasperaviciute (Dalia); S. Kelly (Steve); S. Kim (Shinseog); P. Kochunov (Peter); L. Koenders (Laura); B. Krämer (Bernd); J.B.J. Kwok (John); J. Lagopoulos (Jim); G. Laje (Gonzalo); M. Landén (Mikael); B.A. Landman (Bennett); J. Lauriello; S. Lawrie (Stephen); P.H. Lee (Phil); S. Le Hellard (Stephanie); H. Lemaître (Herve); C.D. Leonardo (Cassandra); C.-S. Li (Chiang-shan); B. Liberg (Benny); D.C. Liewald (David C.); X. Liu (Xinmin); L.M. Lopez (Lorna); E. Loth (Eva); A. Lourdusamy (Anbarasu); M. Luciano (Michelle); F. MacCiardi (Fabio); M.W.J. Machielsen (Marise); G.M. MacQueen (Glenda); U.F. Malt (Ulrik); R. Mandl (René); D.S. Manoach (Dara); J.-L. Martinot (Jean-Luc); M. Matarin (Mar); R. Mather; M. Mattheisen (Manuel); M. Mattingsdal (Morten); A. Meyer-Lindenberg; C. McDonald (Colm); A.M. McIntosh (Andrew); F.J. Mcmahon (Francis J); K.L. Mcmahon (Katie); E. Meisenzahl (Eva); I. Melle (Ingrid); Y. Milaneschi (Yuri); S. Mohnke (Sebastian); G.W. Montgomery (Grant); D.W. Morris (Derek W); E.K. Moses (Eric); B.A. Mueller (Bryon ); S. Muñoz Maniega (Susana); T.W. Mühleisen (Thomas); B. Müller-Myhsok (Bertram); B. Mwangi (Benson); M. Nauck (Matthias); K. Nho (Kwangsik); T.E. Nichols (Thomas); L.G. Nilsson; A.C. Nugent (Allison); L. Nyberg (Lisa); R.L. Olvera (Rene); J. Oosterlaan (Jaap); R.A. Ophoff (Roel); M. Pandolfo (Massimo); M. Papalampropoulou-Tsiridou (Melina); M. Papmeyer (Martina); T. Paus (Tomas); Z. Pausova (Zdenka); G. Pearlson (Godfrey); B.W.J.H. Penninx (Brenda); C.P. Peterson (Charles); A. Pfennig (Andrea); M. Phillips (Mary); G.B. Pike (G Bruce); J.B. Poline (Jean Baptiste); S.G. Potkin (Steven); B. Pütz (Benno); A. Ramasamy (Adaikalavan); J. Rasmussen (Jerod); M. Rietschel (Marcella); M. Rijpkema (Mark); S.L. Risacher (Shannon); J.L. Roffman (Joshua); R. Roiz-Santiañez (Roberto); N. Romanczuk-Seiferth (Nina); E.J. Rose (Emma); N.A. Royle (Natalie); D. Rujescu (Dan); M. Ryten (Mina); P.S. Sachdev (Perminder); A. Salami (Alireza); T.D. Satterthwaite (Theodore); J. Savitz (Jonathan); A.J. Saykin (Andrew); C. Scanlon (Cathy); L. Schmaal (Lianne); H. Schnack (Hugo); N.J. Schork (Nicholas); S.C. Schulz (S.Charles); R. Schür (Remmelt); L.J. Seidman (Larry); L. Shen (Li); L. Shoemaker (Lawrence); A. Simmons (Andrew); S.M. Sisodiya (Sanjay); C. Smith (Colin); J.W. Smoller; J.C. Soares (Jair); S.R. Sponheim (Scott); R. Sprooten (Roy); J.M. Starr (John); V.M. Steen (Vidar); S. Strakowski (Stephen); V.M. Strike (Vanessa); J. Sussmann (Jessika); P.G. Sämann (Philipp); A. Teumer (Alexander); A.W. Toga (Arthur); D. Tordesillas-Gutierrez (Diana); D. Trabzuni (Danyah); S. Trost (Sarah); J. Turner (Jessica); M. van den Heuvel (Martijn); N.J. van der Wee (Nic); K.R. van Eijk (Kristel); T.G.M. van Erp (Theo G.); N.E.M. van Haren (Neeltje E.); D. van 't Ent (Dennis); M.J.D. van Tol (Marie-José); M.C. Valdés Hernández (Maria); D.J. Veltman (Dick); A. Versace (Amelia); H. Völzke (Henry); R. Walker (Robert); H.J. Walter (Henrik); L. Wang (Lei); J.M. Wardlaw (J.); M.E. Weale (Michael); M.W. Weiner (Michael); W. Wen (Wei); L.T. Westlye (Lars); H.C. Whalley (Heather); C.D. Whelan (Christopher); T.J.H. White (Tonya); A.M. Winkler (Anderson); K. Wittfeld (Katharina); G. Woldehawariat (Girma); A. Björnsson (Asgeir); D. Zilles (David); M.P. Zwiers (Marcel); A. Thalamuthu (Anbupalam); C.J. Schofield (Christopher); N.B. Freimer (Nelson); N.S. Lawrence (Natalia); D.A. Drevets (Douglas)

    2014-01-01

    textabstractThe Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in

  20. The ENIGMA Consortium : large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud; Almasy, Laura; Almeida, Jorge; Alpert, Kathryn; Andreasen, Nancy C.; Andreassen, Ole A.; Apostolova, Liana G.; Appel, Katja; Armstrong, Nicola J.; Aribisala, Benjamin; Bastin, Mark E.; Bauer, Michael; Bearden, Carrie E.; Bergmann, Orjan; Binder, Elisabeth B.; Blangero, John; Bockholt, Henry J.; Boen, Erlend; Bois, Catherine; Boomsma, Dorret I.; Booth, Tom; Bowman, Ian J.; Bralten, Janita; Brouwer, Rachel M.; Brunner, Han G.; Brohawn, David G.; Buckner, Randy L.; Buitelaar, Jan; Bulayeva, Kazima; Bustillo, Juan R.; Calhoun, Vince D.; Cannon, Dara M.; Cantor, Rita M.; Carless, Melanie A.; Caseras, Xavier; Cavalleri, Gianpiero L.; Chakravarty, M. Mallar; Chang, Kiki D.; Ching, Christopher R. K.; Christoforou, Andrea; Cichon, Sven; Clark, Vincent P.; Conrod, Patricia; Coppola, Giovanni; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Deary, Ian J.; de Geus, Eco J. C.; den Braber, Anouk; Delvecchio, Giuseppe; Depondt, Chantal; de Haan, Lieuwe; de Zubicaray, Greig I.; Dima, Danai; Dimitrova, Rali; Djurovic, Srdjan; Dong, Hongwei; Donohoe, Gary; Duggirala, Ravindranath; Dyer, Thomas D.; Ehrlich, Stefan; Ekman, Carl Johan; Elvsashagen, Torbjorn; Emsell, Louise; Erk, Susanne; Espeseth, Thomas; Fagerness, Jesen; Fears, Scott; Fedko, Iryna; Fernandez, Guillen; Fisher, Simon E.; Foroud, Tatiana; Fox, Peter T.; Francks, Clyde; Frangou, Sophia; Frey, Eva Maria; Frodl, Thomas; Frouin, Vincent; Garavan, Hugh; Giddaluru, Sudheer; Glahn, David C.; Godlewska, Beata; Goldstein, Rita Z.; Gollub, Randy L.; Grabe, Hans J.; Grimm, Oliver; Gruber, Oliver; Guadalupe, Tulio; Gur, Raquel E.; Gur, Ruben C.; Goering, Harald H. H.; Hagenaars, Saskia; Hajek, Tomas; Hall, Geoffrey B.; Hall, Jeremy; Hardy, John; Hartman, Catharina A.; Hass, Johanna; Hatton, Sean N.; Haukvik, Unn K.; Hegenscheid, Katrin; Heinz, Andreas; Hickie, Ian B.; Ho, Beng-Choon; Hoehn, David; Hoekstra, Pieter J.; Hollinshead, Marisa; Holmes, Avram J.; Homuth, Georg; Hoogman, Martine; Hong, L. Elliot; Hosten, Norbert; Hottenga, Jouke-Jan; Pol, Hilleke E. Hulshoff; Hwang, Kristy S.; Jack, Clifford R.; Jenkinson, Mark; Johnston, Caroline; Joensson, Erik G.; Kahn, Rene S.; Kasperaviciute, Dalia; Kelly, Sinead; Kim, Sungeun; Kochunov, Peter; Koenders, Laura; Kraemer, Bernd; Kwok, John B. J.; Lagopoulos, Jim; Laje, Gonzalo; Landen, Mikael; Landman, Bennett A.; Lauriello, John; Lawrie, Stephen M.; Lee, Phil H.; Le Hellard, Stephanie; Lemaitre, Herve; Leonardo, Cassandra D.; Li, Chiang-shan; Liberg, Benny; Liewald, David C.; Liu, Xinmin; Lopez, Lorna M.; Loth, Eva; Lourdusamy, Anbarasu; Luciano, Michelle; Macciardi, Fabio; Machielsen, Marise W. J.; MacQueen, Glenda M.; Malt, Ulrik F.; Mandl, Rene; Manoach, Dara S.; Martinot, Jean-Luc; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; Mattingsdal, Morten; Meyer-Lindenberg, Andreas; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Meisenzahl, Eva; Melle, Ingrid; Milaneschi, Yuri; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Moses, Eric K.; Mueller, Bryon A.; Munoz Maniega, Susana; Muehleisen, Thomas W.; Mueller-Myhsok, Bertram; Mwangi, Benson; Nauck, Matthias; Nho, Kwangsik; Nichols, Thomas E.; Nilsson, Lars-Goeran; Nugent, Allison C.; Nyberg, Lars; Olvera, Rene L.; Oosterlaan, Jaap; Ophoff, Roel A.; Pandolfo, Massimo; Papalampropoulou-Tsiridou, Melina; Papmeyer, Martina; Paus, Tomas; Pausova, Zdenka; Pearlson, Godfrey D.; Penninx, Brenda W.; Peterson, Charles P.; Pfennig, Andrea; Phillips, Mary; Pike, G. Bruce; Poline, Jean-Baptiste; Potkin, Steven G.; Puetz, Benno; Ramasamy, Adaikalavan; Rasmussen, Jerod; Rietschel, Marcella; Rijpkema, Mark; Risacher, Shannon L.; Roffman, Joshua L.; Roiz-Santianez, Roberto; Romanczuk-Seiferth, Nina; Rose, Emma J.; Royle, Natalie A.; Rujescu, Dan; Ryten, Mina; Sachdev, Perminder S.; Salami, Alireza; Satterthwaite, Theodore D.; Savitz, Jonathan; Saykin, Andrew J.; Scanlon, Cathy; Schmaal, Lianne; Schnack, Hugo G.; Schork, Andrew J.; Schulz, S. Charles; Schuer, Remmelt; Seidman, Larry; Shen, Li; Shoemaker, Jody M.; Simmons, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soares, Jair C.; Sponheim, Scott R.; Sprooten, Emma; Starr, John M.; Steen, Vidar M.; Strakowski, Stephen; Strike, Lachlan; Sussmann, Jessika; Saemann, Philipp G.; Teumer, Alexander; Toga, Arthur W.; Tordesillas-Gutierrez, Diana; Trabzuni, Daniah; Trost, Sarah; Turner, Jessica; Van den Heuvel, Martijn; van der Wee, Nic J.; van Eijk, Kristel; van Erp, Theo G. M.; van Haren, Neeltje E. M.; van 't Ent, Dennis; van Tol, Marie-Jose; Hernandez, Maria C. Valdes; Veltman, Dick J.; Versace, Amelia; Voelzke, Henry; Walker, Robert; Walter, Henrik; Wang, Lei; Wardlaw, Joanna M.; Weale, Michael E.; Weiner, Michael W.; Wen, Wei; Westlye, Lars T.; Whalley, Heather C.; Whelan, Christopher D.; White, Tonya; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Zilles, David; Zwiers, Marcel P.; Thalamuthu, Anbupalam; Schofield, Peter R.; Freimer, Nelson B.; Lawrence, Natalia S.; Drevets, Wayne

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience,

  1. The Quantitative Evaluation of Functional Neuroimaging Experiments: Mutual Information Learning Curves

    DEFF Research Database (Denmark)

    Kjems, Ulrik; Hansen, Lars Kai; Anderson, Jon

    2002-01-01

    Learning curves are presented as an unbiased means for evaluating the performance of models for neuroimaging data analysis. The learning curve measures the predictive performance in terms of the generalization or prediction error as a function of the number of independent examples (e.g., subjects...

  2. Analysis of the Metal hydride Decomposition Temperatures of Zn(BH42 – MgH2 – Tm (Tm = Ni, Ti or Fe Using a Sievert’s Type Volumetric Apparatus

    Directory of Open Access Journals (Sweden)

    Young Jun KWAK

    2017-02-01

    Full Text Available In this work, Zn(BH42, Ni, or Ti were selected as additives to improve the hydriding and dehydriding rates of magnesium. Zn(BH42 was prepared by milling ZnCl2 and NaBH4 in a planetary ball mill under an Ar atmosphere. The prepared Zn(BH42 sample contained NaCl. 13.6 wt% MgH2+49.1 wt% Zn(BH42+30.2 wt% NaCl+7.0 wt% Ni (named 14MgH2+49Zn(BH42+30NaCl+7Ni and 13.6 wt% MgH2+49.1 wt% Zn(BH42+30.2 wt% NaCl+7.0 wt% Ti (named 14MgH2+49Zn(BH42+30NaCl+7Ti samples were prepared by horizontal ball milling. The gas release properties, especially the metal hydride decomposition temperatures (the onset temperature of the metal hydride decomposition and the maximum rate of released gas quantity change with temperature change, of the prepared samples were investigated using a Sievert’s type volumetric apparatus. The quantity of the gas released under 1.0 bar H2 was measured as the temperature was increased and the variation in the rate of released gas quantity Gr change with temperature T change, dGr/dT, as a function of temperature was obtained. This analysis method can be used instead of thermal analysis methods such as thermogravimetric analysis (TGA, differential scanning calorimeter (DSC, and differential thermal analysis (DTA. The investigated properties of the samples were then compared. In the as-milled 14MgH2 +49Zn(BH42+30NaCl+7Ni, it is believed that Zn(BH42 begins to decompose at about 350 K and the rate of Gr change with T change, dGr/dT, reaches its peak at about 390 K, and that MgH2 begins to decompose at about 670 K and dGr/dT reaches its peak at about 698 K.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14270

  3. Neural correlates of fear: insights from neuroimaging

    Directory of Open Access Journals (Sweden)

    Garfinkel SN

    2014-12-01

    Full Text Available Sarah N Garfinkel,1,2 Hugo D Critchley1,2 1Sackler Centre for Consciousness Science, 2Department of Psychiatry, Brighton and Sussex Medical School, University of Sussex, Brighton, UK Abstract: Fear anticipates a challenge to one's well-being and is a reaction to the risk of harm. The expression of fear in the individual is a constellation of physiological, behavioral, cognitive, and experiential responses. Fear indicates risk and will guide adaptive behavior, yet fear is also fundamental to the symptomatology of most psychiatric disorders. Neuroimaging studies of normal and abnormal fear in humans extend knowledge gained from animal experiments. Neuroimaging permits the empirical evaluation of theory (emotions as response tendencies, mental states, and valence and arousal dimensions, and improves our understanding of the mechanisms of how fear is controlled by both cognitive processes and bodily states. Within the human brain, fear engages a set of regions that include insula and anterior cingulate cortices, the amygdala, and dorsal brain-stem centers, such as periaqueductal gray matter. This same fear matrix is also implicated in attentional orienting, mental planning, interoceptive mapping, bodily feelings, novelty and motivational learning, behavioral prioritization, and the control of autonomic arousal. The stereotyped expression of fear can thus be viewed as a special construction from combinations of these processes. An important motivator for understanding neural fear mechanisms is the debilitating clinical expression of anxiety. Neuroimaging studies of anxiety patients highlight the role of learning and memory in pathological fear. Posttraumatic stress disorder is further distinguished by impairment in cognitive control and contextual memory. These processes ultimately need to be targeted for symptomatic recovery. Neuroscientific knowledge of fear has broader relevance to understanding human and societal behavior. As yet, only some of

  4. Utilization of Emergent Neuroimaging for Thrombolysis-Eligible Stroke Patients.

    Science.gov (United States)

    Sanossian, Nerses; Fu, Katherine A; Liebeskind, David S; Starkman, Sidney; Hamilton, Scott; Villablanca, J Pablo; Burgos, Adrian M; Conwit, Robin; Saver, Jeffrey L

    2017-01-01

    Advances in diagnostic imaging of stroke include multimodal techniques such as noninvasive angiography and perfusion imaging. We aimed to characterize trends in neuroimaging utilization among acute stroke patients. Utilization of multimodal imaging for acute stroke in the community has remained largely uncharacterized despite its increased adoption at academic medical centers. We quantified neuroimaging utilization in the emergency department (ED) for 1,700 hyperacute stroke patients presenting Neuroimaging.

  5. Nonequilibrium volumetric response of shocked polymers

    Energy Technology Data Exchange (ETDEWEB)

    Clements, B E [Los Alamos National Laboratory

    2009-01-01

    Polymers are well known for their non-equilibrium deviatoric behavior. However, investigations involving both high rate shock experiments and equilibrium measured thermodynamic quantities remind us that the volumetric behavior also exhibits a non-equilibrium response. Experiments supporting the notion of a non-equilibrium volumetric behavior will be summarized. Following that discussion, a continuum-level theory is proposed that will account for both the equilibrium and non-equilibrium response. Upon finding agreement with experiment, the theory is used to study the relaxation of a shocked polymer back towards its shocked equilibrium state.

  6. Chronic disorders of consciousness: role of neuroimaging

    Science.gov (United States)

    Kremneva, E.; Sergeev, D.; Zmeykina, E.; Legostaeva, L.; Piradov, M.

    2017-08-01

    Chronic disorders of consciousness are clinically challenging conditions, and advanced methods of imaging for better understanding of diagnosis and prognosis are needed. Recent functional neuroradiological studies utilizing PET and fMRI demonstrated that besides widespread neuronal loss disruption of interconnection between certain cortical networks after the injury may also play the leading role in the development of behaviourally assessed unresponsiveness. Functional and structural connectivity, evaluated by neuroimaging approaches, may correlate with clinical status and may also play prognostic role. Integration of data from various diagnostic modalities is needed for further progress in this area.

  7. Neuroimaging of sleep and sleep disorders.

    Science.gov (United States)

    Nofzinger, Eric A

    2006-03-01

    Herein are presented the results of research in the area of sleep neuroimaging over the past year. Significant work has been performed to clarify the basic mechanisms of sleep in humans. New studies also extend prior observations regarding altered brain activation in response to sleep deprivation by adding information regarding vulnerability to sleep deprivation and regarding the influence of task difficulty on aberrant responses. Studies in sleep disorder medicine have yielded significant findings in insomnia, depression, and restless legs syndrome. Extensive advances have been made in the area of sleep apnea where physiologic challenges have been used to probe brain activity in the pathophysiology of sleep apnea syndrome.

  8. [Conversion disorder : functional neuroimaging and neurobiological mechanisms].

    Science.gov (United States)

    Lejeune, J; Piette, C; Salmon, E; Scantamburlo, G

    2017-04-01

    Conversion disorder is a psychiatric disorder often encountered in neurology services. This condition without organic lesions was and still is sometimes referred as an imaginary illness or feigning. However, the absence of organic lesions does not exclude the possibility of cerebral dysfunction. The etiologic mechanisms underlying this disorder remain uncertain even today.The advent of cognitive and functional imaging opens up a field of exploration for psychiatry in understanding the neurobiological mechanisms underlying mental disorders and especially the conversion disorder. This article reports several neuroimaging studies of conversion disorder and attempts to generate hypotheses about neurobiological mechanisms.

  9. Epistemological considerations on neuroimaging--a crucial prerequisite for neuroethics.

    Science.gov (United States)

    Huber, Christian G; Huber, Johannes

    2009-07-01

    Whereas ethical considerations on imaging techniques and interpretations of neuroimaging results flourish, there is not much work on their preconditions. In this paper, therefore, we discuss epistemological considerations on neuroimaging and their implications for neuroethics. Neuroimaging uses indirect methods to generate data about surrogate parameters for mental processes, and there are many determinants influencing the results, including current hypotheses and the state of knowledge. This leads to an interdependence between hypotheses and data. Additionally, different levels of description are involved, especially when experiments are designed to answer questions pertaining to broad concepts like the self, empathy or moral intentions. Interdisciplinary theoretical frameworks are needed to integrate findings from the life sciences and the humanities and to translate between them. While these epistemological issues are not specific for neuroimaging, there are some reasons why they are of special importance in this context: Due to their inferential proximity, 'neuro-images' seem to be self-evident, suggesting directness of observation and objectivity. This has to be critically discussed to prevent overinterpretation. Additionally, there is a high level of attention to neuroimaging, leading to a high frequency of presentation of neuroimaging data and making the critical examination of their epistemological properties even more pressing. Epistemological considerations are an important prerequisite for neuroethics. The presentation and communication of the results of neuroimaging studies, the potential generation of new phenomena and new 'dysfunctions' through neuroimaging, and the influence on central concepts at the foundations of ethics will be important future topics for this discipline.

  10. Neuroimaging for patient selection for medial temporal lobe epilepsy surgery: Part 1 Structural neuroimaging.

    Science.gov (United States)

    Stylianou, Petros; Hoffmann, Chen; Blat, Ilan; Harnof, Sagi

    2016-01-01

    The objective of part one of this review is to present the structural neuroimaging techniques that are currently used to evaluate patients with temporal lobe epilepsy (TLE), and to discuss their potential to define patient eligibility for medial temporal lobe surgery. A PubMed query, using Medline and Embase, and subsequent review, was performed for all English language studies published after 1990, reporting neuroimaging methods for the evaluation of patients with TLE. The extracted data included demographic variables, population and study design, imaging methods, gold standard methods, imaging findings, surgical outcomes and conclusions. Overall, 56 papers were reviewed, including a total of 1517 patients. This review highlights the following structural neuroimaging techniques: MRI, diffusion-weighted imaging, tractography, electroencephalography and magnetoencephalography. The developments in neuroimaging during the last decades have led to remarkable improvements in surgical precision, postsurgical outcome, prognosis, and the rate of seizure control in patients with TLE. The use of multiple imaging methods provides improved outcomes, and further improvements will be possible with future studies of larger patient cohorts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Serial volumetric registration of pulmonary CT studies

    Science.gov (United States)

    Silva, José Silvestre; Silva, Augusto; Sousa Santos, Beatriz

    2008-03-01

    Detailed morphological analysis of pulmonary structures and tissue, provided by modern CT scanners, is of utmost importance as in the case of oncological applications both for diagnosis, treatment, and follow-up. In this case, a patient may go through several tomographic studies throughout a period of time originating volumetric sets of image data that must be appropriately registered in order to track suspicious radiological findings. The structures or regions of interest may change their position or shape in CT exams acquired at different moments, due to postural, physiologic or pathologic changes, so, the exams should be registered before any follow-up information can be extracted. Postural mismatching throughout time is practically impossible to avoid being particularly evident when imaging is performed at the limiting spatial resolution. In this paper, we propose a method for intra-patient registration of pulmonary CT studies, to assist in the management of the oncological pathology. Our method takes advantage of prior segmentation work. In the first step, the pulmonary segmentation is performed where trachea and main bronchi are identified. Then, the registration method proceeds with a longitudinal alignment based on morphological features of the lungs, such as the position of the carina, the pulmonary areas, the centers of mass and the pulmonary trans-axial principal axis. The final step corresponds to the trans-axial registration of the corresponding pulmonary masked regions. This is accomplished by a pairwise sectional registration process driven by an iterative search of the affine transformation parameters leading to optimal similarity metrics. Results with several cases of intra-patient, intra-modality registration, up to 7 time points, show that this method provides accurate registration which is needed for quantitative tracking of lesions and the development of image fusion strategies that may effectively assist the follow-up process.

  12. Neuroimaging. Recent issues and future progresses

    Energy Technology Data Exchange (ETDEWEB)

    Fukuyama, Hidenao [Kyoto Univ. (Japan). Graduate School of Medicine

    2002-07-01

    Recent advances in the technology of non-invasive neuroimaging techniques, include X-ray CT, magnetic resonance imaging, positron CT, etc. The trend of neuroimaging is from the diagnosis of the brain structural change to the functional localization of the brain function with accurate topographical data. Brain activation studies disclosed the responsible regions in the brain for various kinds of paradigms, including motor, sensory, cognitive functions. Another aspect of brain imaging shows the pathophysiological changes of the neurological disorders, such as Alzheimer's disease by abnormal CBF or metabolism changes. It is very important to note that the neurotransmitter receptor imaging is now available for various kinds of transmitters. We recently developed a new tracer for nicotinic type acetylcholine receptor, which might be involved in the pathophysiology of Alzheimer's disease and its treatment. In the near future, we will be able to visualize the proteins in the brain such as amyloid protein, which will make us to diagnose Alzheimer's patients accurately, and with respect to neuroscience research, not only neuronal functional localizations but also relationship between them will become important to disclose the functional aspects of the brain. (author)

  13. Neuroimaging features of Cornelia de Lange syndrome.

    Science.gov (United States)

    Whitehead, Matthew T; Nagaraj, Usha D; Pearl, Phillip L

    2015-07-01

    Cornelia de Lange syndrome is a rare genetic disease characterized by distinctive facial dysmorphia and dwarfism. Multiple organ system involvement is typical. Various central nervous system (CNS) aberrations have been described in the pathology literature; however, the spectrum of neuroimaging manifestations is less well documented. To present neuroimaging findings from a series of eight patients with Cornelia de Lange syndrome. The CT/MR database at a single academic children's hospital was searched for the terms "Cornelia," "Brachmann" and "de Lange." The search yielded 18 exams from 16 patients. Two non-CNS and six exams without available images were excluded. Ten exams from eight patients were evaluated by a board-certified neuroradiologist. All patients had skull base dysplasia, most with an unusual coronal basioccipital cleft (7/8). All brain MR exams showed microcephaly, volume loss and gyral simplification (5/5). Six patients had an absent massa intermedia. Four patients had small globe anterior segments; three had optic pathway hypoplasia. Basilar artery fenestration was present in two patients; vertebrobasilar hypoplasia was present in one patient. The inner ear vestibules were dysplastic in two patients. One patient had pachymeningeal thickening. Spinal anomalies included scoliosis, segmentation anomalies, endplate irregularities, basilar invagination, foramen magnum stenosis and tethered spinal cord. Typical imaging manifestations of Cornelia de Lange syndrome include skull base dysplasia with coronal clival cleft, cerebral and brainstem volume loss, and gyral simplification. Membranous labyrinth dysplasia, anterior segment and optic pathway hypoplasia, basilar artery fenestration, absent massa intermedia and spinal anomalies may also be present.

  14. Neuroimaging of herpesvirus infections in children

    Energy Technology Data Exchange (ETDEWEB)

    Baskin, Henry J. [Cincinnati Children' s Medical Center, Department of Radiology, Cincinnati, OH (United States); Hedlund, Gary [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States)

    2007-10-15

    Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics. (orig.)

  15. Auditory verbal hallucinations: neuroimaging and treatment.

    Science.gov (United States)

    Bohlken, M M; Hugdahl, K; Sommer, I E C

    2017-01-01

    Auditory verbal hallucinations (AVH) are a frequently occurring phenomenon in the general population and are considered a psychotic symptom when presented in the context of a psychiatric disorder. Neuroimaging literature has shown that AVH are subserved by a variety of alterations in brain structure and function, which primarily concentrate around brain regions associated with the processing of auditory verbal stimuli and with executive control functions. However, the direction of association between AVH and brain function remains equivocal in certain research areas and needs to be carefully reviewed and interpreted. When AVH have significant impact on daily functioning, several efficacious treatments can be attempted such as antipsychotic medication, brain stimulation and cognitive-behavioural therapy. Interestingly, the neural correlates of these treatments largely overlap with brain regions involved in AVH. This suggests that the efficacy of treatment corresponds to a normalization of AVH-related brain activity. In this selected review, we give a compact yet comprehensive overview of the structural and functional neuroimaging literature on AVH, with a special focus on the neural correlates of efficacious treatment.

  16. Neuroimaging in Huntington’s disease

    Science.gov (United States)

    Niccolini, Flavia; Politis, Marios

    2014-01-01

    Huntington’s disease (HD) is a progressive and fatal neurodegenerative disorder caused by an expanded trinucleotide CAG sequence in huntingtin gene (HTT) on chromosome 4. HD manifests with chorea, cognitive and psychiatric symptoms. Although advances in genetics allow identification of individuals carrying the HD gene, much is still unknown about the mechanisms underlying the development of overt clinical symptoms and the transitional period between premanifestation and manifestation of the disease. HD has no cure and patients rely only in symptomatic treatment. There is an urgent need to identify biomarkers that are able to monitor disease progression and assess the development and efficacy of novel disease modifying drugs. Over the past years, neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have provided important advances in our understanding of HD. MRI provides information about structural and functional organization of the brain, while PET can detect molecular changes in the brain. MRI and PET are able to detect changes in the brains of HD gene carriers years ahead of the manifestation of the disease and have also proved to be powerful in assessing disease progression. However, no single technique has been validated as an optimal biomarker. An integrative multimodal imaging approach, which combines different MRI and PET techniques, could be recommended for monitoring potential neuroprotective and preventive therapies in HD. In this article we review the current neuroimaging literature in HD. PMID:24976932

  17. Neuroimaging genetic approaches to Posttraumatic Stress Disorder.

    Science.gov (United States)

    Lebois, Lauren A M; Wolff, Jonathan D; Ressler, Kerry J

    2016-10-01

    Neuroimaging genetic studies that associate genetic and epigenetic variation with neural activity or structure provide an opportunity to link genes to psychiatric disorders, often before psychopathology is discernable in behavior. Here we review neuroimaging genetics studies with participants who have Posttraumatic Stress Disorder (PTSD). Results show that genes related to the physiological stress response (e.g., glucocorticoid receptor and activity, neuroendocrine release), learning and memory (e.g., plasticity), mood, and pain perception are tied to neural intermediate phenotypes associated with PTSD. These genes are associated with and sometimes predict neural structure and function in areas involved in attention, executive function, memory, decision-making, emotion regulation, salience of potential threats, and pain perception. Evidence suggests these risk polymorphisms and neural intermediate phenotypes are vulnerabilities toward developing PTSD in the aftermath of trauma, or vulnerabilities toward particular symptoms once PTSD has developed. Work distinguishing between the re-experiencing and dissociative sub-types of PTSD, and examining other PTSD symptom clusters in addition to the re-experiencing and hyperarousal symptoms, will further clarify neurobiological mechanisms and inconsistent findings. Furthermore, an exciting possibility is that genetic associations with PTSD may eventually be understood through differential intermediate phenotypes of neural circuit structure and function, possibly underlying the different symptom clusters seen within PTSD. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Indexing Volumetric Shapes with Matching and Packing.

    Science.gov (United States)

    Koes, David Ryan; Camacho, Carlos J

    2015-04-01

    We describe a novel algorithm for bulk-loading an index with high-dimensional data and apply it to the problem of volumetric shape matching. Our matching and packing algorithm is a general approach for packing data according to a similarity metric. First an approximate k-nearest neighbor graph is constructed using vantage-point initialization, an improvement to previous work that decreases construction time while improving the quality of approximation. Then graph matching is iteratively performed to pack related items closely together. The end result is a dense index with good performance. We define a new query specification for shape matching that uses minimum and maximum shape constraints to explicitly specify the spatial requirements of the desired shape. This specification provides a natural language for performing volumetric shape matching and is readily supported by the geometry-based similarity search (GSS) tree, an indexing structure that maintains explicit representations of volumetric shape. We describe our implementation of a GSS tree for volumetric shape matching and provide a comprehensive evaluation of parameter sensitivity, performance, and scalability. Compared to previous bulk-loading algorithms, we find that matching and packing can construct a GSS-tree index in the same amount of time that is denser, flatter, and better performing, with an observed average performance improvement of 2X.

  19. Neuroimaging in stroke and non-stroke pusher patients

    Directory of Open Access Journals (Sweden)

    Taiza Elaine Grespan Santos-Pontelli

    2011-12-01

    Full Text Available Pusher behavior (PB is a disorder of postural control affecting patients with encephalic lesions. This study has aimed to identify the brain substrates that are critical for the occurrence of PB, to analyze the influence of the midline shift (MS and hemorrhagic stroke volume (HSV on the severity and prognosis of the PB. We identified 31 pusher patients of a neurological unit, mean age 67.4±11.89, 61.3% male. Additional neurological and functional examinations were assessed. Neuroimaging workup included measurement of the MS, the HSV in patients with hemorrhagic stroke, the analysis of the vascular territory, etiology and side of the lesion. Lesions in the parietal region (p=0.041 and thalamus (p=0.001 were significantly more frequent in PB patients. Neither the MS nor the HSV were correlated with the PB severity or recovery time.

  20. Fusing multiple neuroimaging modalities to assess group differences in perception-action coupling.

    Science.gov (United States)

    Muraskin, Jordan; Sherwin, Jason; Lieberman, Gregory; Garcia, Javier O; Verstynen, Timothy; Vettel, Jean M; Sajda, Paul

    2017-01-01

    In the last few decades, non-invasive neuroimaging has revealed macro-scale brain dynamics that underlie perception, cognition and action. Advances in non-invasive neuroimaging target two capabilities; 1) increased spatial and temporal resolution of measured neural activity, and 2) innovative methodologies to extract brain-behavior relationships from evolving neuroimaging technology. We target the second. Our novel methodology integrated three neuroimaging methodologies and elucidated expertise-dependent differences in functional (fused EEG-fMRI) and structural (dMRI) brain networks for a perception-action coupling task. A set of baseball players and controls performed a Go/No-Go task designed to mimic the situation of hitting a baseball. In the functional analysis, our novel fusion methodology identifies 50ms windows with predictive EEG neural correlates of expertise and fuses these temporal windows with fMRI activity in a whole-brain 2mm voxel analysis, revealing time-localized correlations of expertise at a spatial scale of millimeters. The spatiotemporal cascade of brain activity reflecting expertise differences begins as early as 200ms after the pitch starts and lasting up to 700ms afterwards. Network differences are spatially localized to include motor and visual processing areas, providing evidence for differences in perception-action coupling between the groups. Furthermore, an analysis of structural connectivity revealed that the players have significantly more connections between cerebellar and left frontal/motor regions, and many of the functional activation differences between the groups are located within structurally defined network modules that differentiate expertise. In short, our novel method illustrates how multimodal neuroimaging can provide specific macro-scale insights into the functional and structural correlates of expertise development.

  1. 皮质下型血管性认知障碍的核磁共振视觉半定量分析%The MRI semi-volumetric analysis of subcortical vascular cognitive impairment

    Institute of Scientific and Technical Information of China (English)

    徐群; 曹雯炜; 周滟; 李焰生

    2013-01-01

    目的明确皮质下型血管性认知障碍( s-VCI)的影像标志物。方法92例皮质下缺血性血管病( SIVD)患者,经神经心理检查和临床访谈,分为无认知障碍(NCI)组29例、血管性轻度认知障碍(VaMCI)组39例和血管性痴呆(VaD)组24例。登记并比较不同认知组患者的人口学、血管危险因素和影像学资料。结果三组患者在皮质下白质腔隙性梗死( LI)数量、白质病变(WML)评分、内侧颞叶萎缩(MTA)(均P<0.01)和皮质萎缩(CA)(P<0.05)评分方面的差异有统计学意义。其中,VaMCI和VaD组的白质LI数目高于NCI组(分别P<0.01和P<0.05));VaD组的WML程度重于VaMCI组和NCI组(均P<0.01);VaD组的MTA评分高于NCI组( P<0.01);VaD组和VaMCI组的CA评分高于NCI组(均P<0.05)。两个认知障碍组的WML程度、MTA评分、CA评分、皮质下白质LI数目(均P<0.01)和所有LI总数高于NCI组( P<0.05)。 Logistic回归分析显示教育程度低、糖尿病、白质的LI、MTA和CA评分是s-VCI的独立危险因素。结论 s-VCI与低教育水平、糖尿病、皮质下白质损伤和皮质及内侧颞叶萎缩独立相关。%Objective To explore the neuroimaging markers of subcortical vascular cognitive impairment ( s-VCI) . Methods Based on the detailed neuropsychological tests and clinical interview , 92 subjects with subcortical ischemic vascular disease ( SIVD ) were recruited and classified into three groups according to their cognitive state, 29 patients with no cognitive impairment (NCI), 39 patients with vascular mild cognitive impairment ( VaMCI ) , and 24 patients with vascular dementia ( VaD ) . Their demographic , vascular risk factors and neuroimaging data were compared . Results The differences between the three groups in the number of subcortical white matter lacunar infarcts ( LI) as well as the scores of the white matter lesions ( WML) , medial

  2. AN ATTRIBUTION OF CAVITATION RESONANCE: VOLUMETRIC OSCILLATIONS OF CLOUD

    Institute of Scientific and Technical Information of China (English)

    ZUO Zhi-gang; LI Sheng-cai; LIU Shu-hong; LI Shuang; CHEN Hui

    2009-01-01

    In order to further verify the proposed theory of cavitation resonance, as well as to proceed the investigations into microscopic level, a series of studies are being carried out on the Warwick venturi. The analysis of the oscillation characteristics of the cavitation resonance has conclusively verified the macro-mechanism proposed through previous studies on other cavitating flows by the authors. The initial observations using high-speed photographic approach have revealed a new attribution of cavitation resonance. That is, the volumetric oscillation of cavitation cloud is associated with the cavitation resonance, which is a collective behaviour of the bubbles in the cloud.

  3. Modeling Latency and Shape Changes in Trial Based Neuroimaging Data

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai; Madsen, Kristoffer Hougaard

    2011-01-01

    To overcome poor signal-to-noise ratios in neuroimaging, data sets are often acquired over repeated trials that form a three-way array of spacetimetrials. As neuroimaging data contain multiple inter-mixed signal components blind signal separation and decomposition methods are frequently invoked...

  4. Turner Syndrome: Neuroimaging Findings--Structural and Functional

    Science.gov (United States)

    Mullaney, Ronan; Murphy, Declan

    2009-01-01

    Neuroimaging studies of Turner syndrome can advance our understanding of the X chromosome in brain development, and the modulatory influence of endocrine factors. There is increasing evidence from neuroimaging studies that TX individuals have significant differences in the anatomy, function, and metabolism of a number of brain regions; including…

  5. Schizophrenia: What do we know from neuroimaging research?

    NARCIS (Netherlands)

    Noort, M.W.M.L. van den; Bosch, M.P.C.; Zedlitz, A.M.E.E.; Hadzibeganovic, T.; Kralingen, R.B.A.S. van

    2009-01-01

    Objectives A summary of the main neuroimaging findings in the field of schizophrenia will be given in order to get a better understanding of this disorder. Methods The authors conducted an extensive literature review, using PubMed and the internet. Results Neuroimaging research on schizophrenia has

  6. Multimodal neuroimaging in presurgical evaluation of drug-resistant epilepsy

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2014-01-01

    Full Text Available Intracranial EEG (icEEG monitoring is critical in epilepsy surgical planning, but it has limitations. The advances of neuroimaging have made it possible to reveal epileptic abnormalities that could not be identified previously and improve the localization of the seizure focus and the vital cortex. A frequently asked question in the field is whether non-invasive neuroimaging could replace invasive icEEG or reduce the need for icEEG in presurgical evaluation. This review considers promising neuroimaging techniques in epilepsy presurgical assessment in order to address this question. In addition, due to large variations in the accuracies of neuroimaging across epilepsy centers, multicenter neuroimaging studies are reviewed, and there is much need for randomized controlled trials (RCTs to better reveal the utility of presurgical neuroimaging. The results of multiple studies indicate that non-invasive neuroimaging could not replace invasive icEEG in surgical planning especially in non-lesional or extratemporal lobe epilepsies, but it could reduce the need for icEEG in certain cases. With technical advances, multimodal neuroimaging may play a greater role in presurgical evaluation to reduce the costs and risks of epilepsy surgery, and provide surgical options for more patients with drug-resistant epilepsy.

  7. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Madsen, Kristoffer Hougaard; Lund, Torben Ellegaard

    2011-01-01

    There is significant current interest in decoding mental states from neuroimages. In this context kernel methods, e.g., support vector machines (SVM) are frequently adopted to learn statistical relations between patterns of brain activation and experimental conditions. In this paper we focus......, and conclude that the sensitivity map is a versatile and computationally efficient tool for visualization of nonlinear kernel models in neuroimaging....

  8. Multimodal neuroimaging in presurgical evaluation of drug-resistant epilepsy.

    Science.gov (United States)

    Zhang, Jing; Liu, Weifang; Chen, Hui; Xia, Hong; Zhou, Zhen; Mei, Shanshan; Liu, Qingzhu; Li, Yunlin

    2014-01-01

    Intracranial EEG (icEEG) monitoring is critical in epilepsy surgical planning, but it has limitations. The advances of neuroimaging have made it possible to reveal epileptic abnormalities that could not be identified previously and improve the localization of the seizure focus and the vital cortex. A frequently asked question in the field is whether non-invasive neuroimaging could replace invasive icEEG or reduce the need for icEEG in presurgical evaluation. This review considers promising neuroimaging techniques in epilepsy presurgical assessment in order to address this question. In addition, due to large variations in the accuracies of neuroimaging across epilepsy centers, multicenter neuroimaging studies are reviewed, and there is much need for randomized controlled trials (RCTs) to better reveal the utility of presurgical neuroimaging. The results of multiple studies indicate that non-invasive neuroimaging could not replace invasive icEEG in surgical planning especially in non-lesional or extratemporal lobe epilepsies, but it could reduce the need for icEEG in certain cases. With technical advances, multimodal neuroimaging may play a greater role in presurgical evaluation to reduce the costs and risks of epilepsy surgery, and provide surgical options for more patients with drug-resistant epilepsy.

  9. Retrospective study on structural neuroimaging in first-episode psychosis

    Directory of Open Access Journals (Sweden)

    Ricardo Coentre

    2016-05-01

    Full Text Available Background. No consensus between guidelines exists regarding neuroimaging in first-episode psychosis. The purpose of this study is to assess anomalies found in structural neuroimaging exams (brain computed tomography (CT and magnetic resonance imaging (MRI in the initial medical work-up of patients presenting first-episode psychosis. Methods. The study subjects were 32 patients aged 18–48 years (mean age: 29.6 years, consecutively admitted with first-episode psychosis diagnosis. Socio-demographic and clinical data and neuroimaging exams (CT and MRI were retrospectively studied. Diagnostic assessments were made using the Operational Criteria Checklist +. Neuroimaging images (CT and MRI and respective reports were analysed by an experienced consultant psychiatrist. Results. None of the patients had abnormalities in neuroimaging exams responsible for psychotic symptoms. Thirty-seven percent of patients had incidental brain findings not causally related to the psychosis (brain atrophy, arachnoid cyst, asymmetric lateral ventricles, dilated lateral ventricles, plagiocephaly and falx cerebri calcification. No further medical referral was needed for any of these patients. No significant differences regarding gender, age, diagnosis, duration of untreated psychosis, in-stay and cannabis use were found between patients who had neuroimaging abnormalities versus those without. Discussion. This study suggests that structural neuroimaging exams reveal scarce abnormalities in young patients with first-episode psychosis. Structural neuroimaging is especially useful in first-episode psychosis patients with neurological symptoms, atypical clinical picture and old age.

  10. Neuropathology of mild traumatic brain injury: relationship to neuroimaging findings.

    Science.gov (United States)

    Bigler, Erin D; Maxwell, William L

    2012-06-01

    Neuroimaging identified abnormalities associated with traumatic brain injury (TBI) are but gross indicators that reflect underlying trauma-induced neuropathology at the cellular level. This review examines how cellular pathology relates to neuroimaging findings with the objective of more closely relating how neuroimaging findings reveal underlying neuropathology. Throughout this review an attempt will be made to relate what is directly known from post-mortem microscopic and gross anatomical studies of TBI of all severity levels to the types of lesions and abnormalities observed in contemporary neuroimaging of TBI, with an emphasis on mild traumatic brain injury (mTBI). However, it is impossible to discuss the neuropathology of mTBI without discussing what occurs with more severe injury and viewing pathological changes on some continuum from the mildest to the most severe. Historical milestones in understanding the neuropathology of mTBI are reviewed along with implications for future directions in the examination of neuroimaging and neuropathological correlates of TBI.

  11. Systematic review of structural and functional neuroimaging findings in children and adults with CKD.

    Science.gov (United States)

    Moodalbail, Divya G; Reiser, Kathryn A; Detre, John A; Schultz, Robert T; Herrington, John D; Davatzikos, Christos; Doshi, Jimit J; Erus, Guray; Liu, Hua-Shan; Radcliffe, Jerilynn; Furth, Susan L; Hooper, Stephen R

    2013-08-01

    CKD has been linked with cognitive deficits and affective disorders in multiple studies. Analysis of structural and functional neuroimaging in adults and children with kidney disease may provide additional important insights into the pathobiology of this relationship. This paper comprehensively reviews neuroimaging studies in both children and adults. Major databases (PsychLit, MEDLINE, WorldCat, ArticleFirst, PubMed, Ovid MEDLINE) were searched using consistent search terms, and studies published between 1975 and 2012 were included if their samples focused on CKD as the primary disease process. Exclusion criteria included case reports, chapters, and review articles. This systematic process yielded 43 studies for inclusion (30 in adults, 13 in children). Findings from this review identified several clear trends: (1) presence of cerebral atrophy and cerebral density changes in patients with CKD; (2) cerebral vascular disease, including deep white matter hyperintensities, white matter lesions, cerebral microbleeds, silent cerebral infarction, and cortical infarction, in patients with CKD; and (3) similarities in regional cerebral blood flow between patients with CKD and those with affective disorders. These findings document the importance of neuroimaging procedures in understanding the effect of CKD on brain structure, function, and associated behaviors. Results provide a developmental linkage between childhood and adulthood, with respect to the effect of CKD on brain functioning across the lifespan, with strong implications for a cerebrovascular mechanism contributing to this developmental linkage. Use of neuroimaging methods to corroborate manifest neuropsychological deficits or perhaps to indicate preventive actions may prove useful to individuals with CKD.

  12. Is advanced neuroimaging for neuroradiologists? A systematic review of the scientific literature of the last decade.

    Science.gov (United States)

    Cocozza, Sirio; Russo, Camilla; Pontillo, Giuseppe; Ugga, Lorenzo; Macera, Antonio; Cervo, Amedeo; De Liso, Maria; Di Paolo, Nilde; Ginocchio, Maria Isabella; Giordano, Flavio; Leone, Giuseppe; Rusconi, Giovanni; Stanzione, Arnaldo; Briganti, Francesco; Quarantelli, Mario; Caranci, Ferdinando; D'Amico, Alessandra; Elefante, Andrea; Tedeschi, Enrico; Brunetti, Arturo

    2016-12-01

    To evaluate if advanced neuroimaging research is mainly conducted by imaging specialists, we investigated the number of first authorships by radiologists and non-radiologist scientists in articles published in the field of advanced neuroimaging in the past 10 years. Articles in the field of advanced neuroimaging identified in this retrospective bibliometric analysis were divided in four groups, depending on the imaging technique used. For all included studies, educational background of the first authors was recorded (based on available online curriculum vitae) and classified in subgroups, depending on their specialty. Finally, journal impact factors were recorded and comparatively assessed among subgroups as a metric of research quality. A total number of 3831 articles were included in the study. Radiologists accounted as first authors for only 12.8 % of these publications, while 56.9 % of first authors were researchers without a medical degree. Mean impact factor (IF) of journals with non-MD researchers as first authors was significantly higher than the MD subgroup (p articles authored by other MD specialists (p articles was the lowest among all subgroups. These results, taken together, should question the radiology community about its future role in the development of advanced neuroimaging.

  13. Visualization and unsupervised predictive clustering of high-dimensional multimodal neuroimaging data.

    Science.gov (United States)

    Mwangi, Benson; Soares, Jair C; Hasan, Khader M

    2014-10-30

    Neuroimaging machine learning studies have largely utilized supervised algorithms - meaning they require both neuroimaging scan data and corresponding target variables (e.g. healthy vs. diseased) to be successfully 'trained' for a prediction task. Noticeably, this approach may not be optimal or possible when the global structure of the data is not well known and the researcher does not have an a priori model to fit the data. We set out to investigate the utility of an unsupervised machine learning technique; t-distributed stochastic neighbour embedding (t-SNE) in identifying 'unseen' sample population patterns that may exist in high-dimensional neuroimaging data. Multimodal neuroimaging scans from 92 healthy subjects were pre-processed using atlas-based methods, integrated and input into the t-SNE algorithm. Patterns and clusters discovered by the algorithm were visualized using a 2D scatter plot and further analyzed using the K-means clustering algorithm. t-SNE was evaluated against classical principal component analysis. Remarkably, based on unlabelled multimodal scan data, t-SNE separated study subjects into two very distinct clusters which corresponded to subjects' gender labels (cluster silhouette index value=0.79). The resulting clusters were used to develop an unsupervised minimum distance clustering model which identified 93.5% of subjects' gender. Notably, from a neuropsychiatric perspective this method may allow discovery of data-driven disease phenotypes or sub-types of treatment responders. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Neuroimaging Evaluation for First Attack of Unprovoked Nonfebrile Seizure in Pediatrics: When to Order?

    Science.gov (United States)

    Sadeq, Hussain; Karim, Jumanah; Marwan, Yousef; AlSaleem, Talal

    2016-01-01

    To assess the value of neuroimaging studies in evaluating pediatric patients presenting with a first attack of nonfebrile seizure. We reviewed the medical records of pediatric patients aged 28 days to 12 years who were admitted between 1 January and 31 December 2013 with a first attack of unprovoked, afebrile seizure. These patients had undergone neuroimaging studies. The exclusion criterion was patients with known predisposing conditions for seizure. The computed tomography (CT) scan and magnetic resonance imaging (MRI) results were either normal or abnormal, and the abnormal ones were further classified into clinically insignificant or significant. Descriptive analysis was performed to summarize the data. Fifty children were identified with a mean age of 5.2 ± 3.8 years. Of the 50 subjects, 29 (58.0%) were males and 21 (42.0%) were females. Sixteen patients (32.0%) had abnormal neuroimaging studies (CT scan, MRI or both); however, only 1 was considered to have a clinically significant abnormality, later diagnosed as Moyamoya disease. In this study, the neuroimaging studies were found not to be useful in evaluating pediatric patients presenting with a first attack of unprovoked, nonfebrile seizures. © 2015 S. Karger AG, Basel.

  15. Volumetric localization of epileptic activities in tuberous sclerosis using synthetic aperture magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Zheng [Hospital for Sick Children, Research Institute, Toronto (Canada); Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Xiang, Jing [Hospital for Sick Children, Research Institute, Toronto (Canada); Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Holowka, Stephanie; Chuang, Sylvester [Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Hunjan, Amrita; Sharma, Rohit; Otsubo, Hiroshi [Hospital for Sick Children, Division of Neurology, Toronto (Canada)

    2006-01-01

    Magnetoencephalography (MEG) is a novel noninvasive technique for localizing epileptic zones. Tuberous sclerosis complex (TSC) is often associated with medically refractory epilepsy with multiple epileptic zones. Surgical treatment of TSC requires accurate localization of epileptogenic tubers. The objective of this study was to introduce a new MEG technique, synthetic aperture magnetometry (SAM), to volumetrically localize irritable zones and clarify the correlations between SAM, dipole modeling and anatomical tubers. Eight pediatric patients with TSC confirmed by clinical and neuroimaging findings were retrospectively studied. MEG data were recorded using a whole-cortex CTF OMEGA system. Sleep deprivation was employed to provoke epileptiform activity. Irritable zones were localized using both dipole modeling and SAM. MRI detected 42 tubers in the eight patients. Dipole modeling localized 28 irritable zones, and 19 out of the 28 zones were near tubers (19/42, 45%). SAM found 51 irritable zones, and 31 out of the 51 zones were near tubers (31/42, 74%). Among the 51 irritable zones determined by SAM, thirty-five zones were in 1-35 Hz, nine zones were in 35-60 Hz, and seven zones were in 60-120 Hz. The new method, SAM, yielded very plausible equivalent sources for patients who showed anatomical tubers on MRI. Compared to conventional dipole modeling, SAM appeared to offer increased detection of irritable zones and beneficial volumetric and frequency descriptions. (orig.)

  16. Longitudinal Volumetric Brain Changes in Autism Spectrum Disorder Ages 6–35 Years

    Science.gov (United States)

    Lange, Nicholas; Travers, Brittany G.; Bigler, Erin D.; Prigge, Molly B.D.; Froehlich, Alyson L.; Nielsen, Jared A.; Cariello, Annahir N.; Zielinski, Brandon A.; Anderson, Jeffrey S.; Fletcher, P. Thomas; Alexander, Andrew A.; Lainhart, Janet E.

    2014-01-01

    participants scanned over an eight-year period. This initial analysis includes between one and three high-quality scans per participant that have been processed and segmented to date, with 21% having one scan, 27% with two scans and 52% with three scans in the ASD sample; corresponding percentages for the TDC sample are 30%, 30%, and 40%. The proportion of participants with multiple scans (79% of ASDs and 68% of TDCs) was high in comparison to that of large longitudinal neuroimaging studies of typical development. We provide volumetric growth curves for the entire brain, total gray matter (GM), frontal GM, temporal GM, parietal GM, occipital GM, total cortical white matter (WM), corpus callosum, caudate, thalamus, total cerebellum, and total ventricles. Mean volume of cortical WM was reduced significantly. Mean ventricular volume was increased in the ASD sample relative to the TDCs across the broad age range studied. Decreases in regional mean volumes in the ASD sample most often were due to decreases during late adolescence and adulthood. The growth curve of whole brain volume over time showed increased volumes in young children with autism, and subsequently decreased during adolescence to meet the TDC curve between 10 and 15 years of age. The volume of many structures continued to decline atypically into adulthood in the ASD sample. The data suggest that ASD is a dynamic disorder with complex changes in whole and regional brain volumes that change over time from childhood into adulthood. PMID:25381736

  17. New advances in fetal MR neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Garel, Catherine [Hopital Robert Debre, Department of Paediatric Imaging, Paris (France)

    2006-07-15

    MR is now routinely and widely used in fetal neuroimaging and has proven to be valuable in the detection of many cerebral lesions, either genetically determined or acquired in utero. However, its efficiency has certain limits in the detection of diffuse white-matter abnormalities, the evaluation of fibre development and the demonstration of metabolic disorders. Moreover, conventional fetal MR imaging provides only a morphological approach to the fetal brain. New techniques such as diffusion-weighted imaging, diffusion tensor imaging, proton MR spectroscopy and functional MR imaging are developing. The majority of these are not used routinely. The principles, aims, technical problems and possible applications of these techniques for imaging the fetus are discussed. (orig.)

  18. Histiocytosis: a review focusing on neuroimaging findings

    Directory of Open Access Journals (Sweden)

    Larissa Barcessat Gabbay

    2014-07-01

    Full Text Available Objective: Histiocytosis is a systemic disease that usually affects the central nervous system. The aim of this study is to discuss the neuroimaging characteristics of Langerhans cell histiocytosis (LCH, the most common of these diseases; and the non-Langerhans cells histiocytosis (NLCH, which includes entities such as hemophagocytic syndrome, Erdheim-Chester and Rosai-Dorfman diseases. Method: Literature review and illustrative cases with pathologic confirmation. Results: In LCH, the most common findings are 1 osseous lesions in the craniofacial bones and/or skull base; 2 intracranial, extra-axial changes; 3 intra-axial parenchymal changes (white and gray matter; 4 atrophy. Among the NLCH, diagnosis usually requires correlation with clinical and laboratory criteria. The spectrum of presentation includes intraparenchymal involvement, meningeal lesions, orbits and paranasal sinus involvement. Conclusion: It is important the recognition of the most common imaging patterns, in order to include LCH and NLCH in the differential diagnosis, whenever pertinent.

  19. The teen brain: insights from neuroimaging.

    Science.gov (United States)

    Giedd, Jay N

    2008-04-01

    Few parents of a teenager are surprised to hear that the brain of a 16-year-old is different from the brain of an 8-year-old. Yet to pin down these differences in a rigorous scientific way has been elusive. Magnetic resonance imaging, with the capacity to provide exquisitely accurate quantifications of brain anatomy and physiology without the use of ionizing radiation, has launched a new era of adolescent neuroscience. Longitudinal studies of subjects from ages 3-30 years demonstrate a general pattern of childhood peaks of gray matter followed by adolescent declines, functional and structural increases in connectivity and integrative processing, and a changing balance between limbic/subcortical and frontal lobe functions, extending well into young adulthood. Although overinterpretation and premature application of neuroimaging findings for diagnostic purposes remains a risk, converging data from multiple imaging modalities is beginning to elucidate the implications of these brain changes on cognition, emotion, and behavior.

  20. [Functional neuroimaging of auditory hallucinations in schizophrenia].

    Science.gov (United States)

    Font, M; Parellada, E; Fernández-Egea, E; Bernardo, M; Lomeña, F

    2003-01-01

    The neurobiological bases underlying the generation of auditory hallucinations, a distressing and paradigmatic symptom of schizophrenia, are still unknown in spite of in-depth phenomenological descriptions. This work aims to make a critical review of the latest published literature in recent years, focusing on functional neuroimaging studies (PET, SPECT, fMRI) of auditory hallucinations. Thus, the studies are classified according to whether they are sensory activation, trait and state. The two main hypotheses proposed to explain the phenomenon, external speech vs. subvocal or inner speech, are also explained. Finally, the latest unitary theory as well as the limitations the studies published are commented on. The need to continue investigating in this field, that is still underdeveloped, is posed in order to understand better the etiopathogenesis of auditory hallucinations in schizophrenia.

  1. How Shakespeare tempests the brain: neuroimaging insights.

    Science.gov (United States)

    Keidel, James L; Davis, Philip M; Gonzalez-Diaz, Victorina; Martin, Clara D; Thierry, Guillaume

    2013-04-01

    Shakespeare made extensive use of the functional shift (FS), a rhetorical device involving a change in the grammatical status of words, e.g., using nouns as verbs. Previous work using event-related brain potentials showed how FS triggers a surprise effect inviting mental re-evaluation, seemingly independent of semantic processing. Here, we used functional magnetic resonance imaging to investigate brain activation in participants making judgements on the semantic relationship between sentences -some containing a Shakespearean FS- and subsequently presented words. Behavioural performance in the semantic decision task was high and unaffected by sentence type. However, neuroimaging results showed that sentences featuring FS elicited significant activation beyond regions classically activated by typical language tasks, including the left caudate nucleus, the right inferior frontal gyrus and the right inferior temporal gyrus. These findings show how Shakespeare's grammatical exploration forces the listener to take a more active role in integrating the meaning of what is said.

  2. Neuroimaging for drug addiction and related behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Parvaz M. A.; Parvaz, M.A.; Alia-Klein, N.; Woicik,P.A.; Volkow, N.D.; Goldstein, R.Z.

    2011-10-01

    In this review, we highlight the role of neuroimaging techniques in studying the emotional and cognitive-behavioral components of the addiction syndrome by focusing on the neural substrates subserving them. The phenomenology of drug addiction can be characterized by a recurrent pattern of subjective experiences that includes drug intoxication, craving, bingeing, and withdrawal with the cycle culminating in a persistent preoccupation with obtaining, consuming, and recovering from the drug. In the past two decades, imaging studies of drug addiction have demonstrated deficits in brain circuits related to reward and impulsivity. The current review focuses on studies employing positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and electroencephalography (EEG) to investigate these behaviors in drug-addicted human populations. We begin with a brief account of drug addiction followed by a technical account of each of these imaging modalities. We then discuss how these techniques have uniquely contributed to a deeper understanding of addictive behaviors.

  3. Neuroimaging features of Cornelia de Lange syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, Matthew T. [Department of Radiology, Washington, DC (United States); Nagaraj, Usha D. [Department of Radiology, Washington, DC (United States); Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States); Pearl, Phillip L. [Department of Radiology, Washington, DC (United States); Boston Children' s Hospital, Department of Neurology, Boston, MA (United States)

    2015-08-15

    Cornelia de Lange syndrome is a rare genetic disease characterized by distinctive facial dysmorphia and dwarfism. Multiple organ system involvement is typical. Various central nervous system (CNS) aberrations have been described in the pathology literature; however, the spectrum of neuroimaging manifestations is less well documented. To present neuroimaging findings from a series of eight patients with Cornelia de Lange syndrome. The CT/MR database at a single academic children's hospital was searched for the terms ''Cornelia'', ''Brachmann'' and ''de Lange.'' The search yielded 18 exams from 16 patients. Two non-CNS and six exams without available images were excluded. Ten exams from eight patients were evaluated by a board-certified neuroradiologist. All patients had skull base dysplasia, most with an unusual coronal basioccipital cleft (7/8). All brain MR exams showed microcephaly, volume loss and gyral simplification (5/5). Six patients had an absent massa intermedia. Four patients had small globe anterior segments; three had optic pathway hypoplasia. Basilar artery fenestration was present in two patients; vertebrobasilar hypoplasia was present in one patient. The inner ear vestibules were dysplastic in two patients. One patient had pachymeningeal thickening. Spinal anomalies included scoliosis, segmentation anomalies, endplate irregularities, basilar invagination, foramen magnum stenosis and tethered spinal cord. Typical imaging manifestations of Cornelia de Lange syndrome include skull base dysplasia with coronal clival cleft, cerebral and brainstem volume loss, and gyral simplification. Membranous labyrinth dysplasia, anterior segment and optic pathway hypoplasia, basilar artery fenestration, absent massa intermedia and spinal anomalies may also be present. (orig.)

  4. Source Localization of Brain States Associated with Canonical Neuroimaging Postures.

    Science.gov (United States)

    Lifshitz, Michael; Thibault, Robert T; Roth, Raquel R; Raz, Amir

    2017-02-14

    Cognitive neuroscientists rarely consider the influence that body position exerts on brain activity; yet, postural variation holds important implications for the acquisition and interpretation of neuroimaging data. Whereas participants in most behavioral and EEG experiments sit upright, many prominent brain imaging techniques (e.g., fMRI) require participants to lie supine. Here we demonstrate that physical comportment profoundly alters baseline brain activity as measured by magnetoencephalography (MEG)-an imaging modality that permits multipostural acquisition. We collected resting-state MEG data from 12 healthy participants in three postures (lying supine, reclining at 45°, and sitting upright). Source-modeling analysis revealed a broadly distributed influence of posture on resting brain function. Sitting upright versus lying supine was associated with greater high-frequency (i.e., beta and gamma) activity in widespread parieto-occipital cortex. Moreover, sitting upright and reclined postures correlated with dampened activity in prefrontal regions across a range of bandwidths (i.e., from alpha to low gamma). The observed effects were large, with a mean Cohen's d of 0.95 (SD = 0.23). In addition to neural activity, physiological parameters such as muscle tension and eye blinks may have contributed to these posture-dependent changes in brain signal. Regardless of the underlying mechanisms, however, the present results have important implications for the acquisition and interpretation of multimodal imaging data (e.g., studies combining fMRI or PET with EEG or MEG). More broadly, our findings indicate that generalizing results-from supine neuroimaging measurements to erect positions typical of ecological human behavior-would call for considering the influence that posture wields on brain dynamics.

  5. Combined surface and volumetric occlusion shading

    KAUST Repository

    Schott, Matthias O.

    2012-02-01

    In this paper, a method for interactive direct volume rendering is proposed that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The proposed algorithm extends the recently proposed Directional Occlusion Shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. © 2012 IEEE.

  6. Visualization of volumetric seismic data

    Science.gov (United States)

    Spickermann, Dela; Böttinger, Michael; Ashfaq Ahmed, Khawar; Gajewski, Dirk

    2015-04-01

    Mostly driven by demands of high quality subsurface imaging, highly specialized tools and methods have been developed to support the processing, visualization and interpretation of seismic data. 3D seismic data acquisition and 4D time-lapse seismic monitoring are well-established techniques in academia and industry, producing large amounts of data to be processed, visualized and interpreted. In this context, interactive 3D visualization methods proved to be valuable for the analysis of 3D seismic data cubes - especially for sedimentary environments with continuous horizons. In crystalline and hard rock environments, where hydraulic stimulation techniques may be applied to produce geothermal energy, interpretation of the seismic data is a more challenging problem. Instead of continuous reflection horizons, the imaging targets are often steep dipping faults, causing a lot of diffractions. Without further preprocessing these geological structures are often hidden behind the noise in the data. In this PICO presentation we will present a workflow consisting of data processing steps, which enhance the signal-to-noise ratio, followed by a visualization step based on the use the commercially available general purpose 3D visualization system Avizo. Specifically, we have used Avizo Earth, an extension to Avizo, which supports the import of seismic data in SEG-Y format and offers easy access to state-of-the-art 3D visualization methods at interactive frame rates, even for large seismic data cubes. In seismic interpretation using visualization, interactivity is a key requirement for understanding complex 3D structures. In order to enable an easy communication of the insights gained during the interactive visualization process, animations of the visualized data were created which support the spatial understanding of the data.

  7. MR volumetric assessment of endolymphatic hydrops

    Energy Technology Data Exchange (ETDEWEB)

    Guerkov, R.; Berman, A.; Jerin, C.; Krause, E. [University of Munich, Department of Otorhinolaryngology Head and Neck Surgery, Grosshadern Medical Centre, Munich (Germany); University of Munich, German Centre for Vertigo and Balance Disorders, Grosshadern Medical Centre, Marchioninistr. 15, 81377, Munich (Germany); Dietrich, O.; Flatz, W.; Ertl-Wagner, B. [University of Munich, Institute of Clinical Radiology, Grosshadern Medical Centre, Munich (Germany); Keeser, D. [University of Munich, Institute of Clinical Radiology, Grosshadern Medical Centre, Munich (Germany); University of Munich, German Centre for Vertigo and Balance Disorders, Grosshadern Medical Centre, Marchioninistr. 15, 81377, Munich (Germany); University of Munich, Department of Psychiatry and Psychotherapy, Innenstadtkliniken Medical Centre, Munich (Germany)

    2014-10-16

    We aimed to volumetrically quantify endolymph and perilymph spaces of the inner ear in order to establish a methodological basis for further investigations into the pathophysiology and therapeutic monitoring of Meniere's disease. Sixteen patients (eight females, aged 38-71 years) with definite unilateral Meniere's disease were included in this study. Magnetic resonance (MR) cisternography with a T2-SPACE sequence was combined with a Real reconstruction inversion recovery (Real-IR) sequence for delineation of inner ear fluid spaces. Machine learning and automated local thresholding segmentation algorithms were applied for three-dimensional (3D) reconstruction and volumetric quantification of endolymphatic hydrops. Test-retest reliability was assessed by the intra-class coefficient; correlation of cochlear endolymph volume ratio with hearing function was assessed by the Pearson correlation coefficient. Endolymph volume ratios could be reliably measured in all patients, with a mean (range) value of 15 % (2-25) for the cochlea and 28 % (12-40) for the vestibulum. Test-retest reliability was excellent, with an intra-class coefficient of 0.99. Cochlear endolymphatic hydrops was significantly correlated with hearing loss (r = 0.747, p = 0.001). MR imaging after local contrast application and image processing, including machine learning and automated local thresholding, enable the volumetric quantification of endolymphatic hydrops. This allows for a quantitative assessment of the effect of therapeutic interventions on endolymphatic hydrops. (orig.)

  8. Volumetric structural magnetic resonance imaging findings in pediatric posttraumatic stress disorder and obsessive-compulsive disorder: a systematic review

    Directory of Open Access Journals (Sweden)

    Fatima eAhmed

    2012-12-01

    Full Text Available Objectives: Structural magnetic resonance imaging (sMRI studies of anxiety disorders in children and adolescents are limited. Posttraumatic stress disorder (PTSD and obsessive-compulsive disorder (OCD have been best studied in this regard. We systematically reviewed structural neuroimaging findings in pediatric PTSD and OCD. Methods: The literature was reviewed for all sMRI studies examining volumetric parameters using PubMed, ScienceDirect and PsychInfo databases, with no limit on the time frame of publication. Nine studies in pediatric PTSD and 6 in OCD were suitable for inclusion. Results: Volumetric findings were inconsistent in both disorders. In PTSD, findings suggest increased as well as decreased volumes of the prefrontal cortex (PFC and corpus callosum; whilst in OCD studies indicate volumetric increase of the putamen, with inconsistent findings for the anterior cingulate cortex (ACC and frontal regions. Conclusions: Methodological differences may account for some of this inconsistency and additional volume-based studies in pediatric anxiety disorders using more uniform approaches are needed.

  9. Estimation of volumetric breast density for breast cancer risk prediction

    Science.gov (United States)

    Pawluczyk, Olga; Yaffe, Martin J.; Boyd, Norman F.; Jong, Roberta A.

    2000-04-01

    Mammographic density (MD) has been shown to be a strong risk predictor for breast cancer. Compared to subjective assessment by a radiologist, computer-aided analysis of digitized mammograms provides a quantitative and more reproducible method for assessing breast density. However, the current methods of estimating breast density based on the area of bright signal in a mammogram do not reflect the true, volumetric quantity of dense tissue in the breast. A computerized method to estimate the amount of radiographically dense tissue in the overall volume of the breast has been developed to provide an automatic, user-independent tool for breast cancer risk assessment. The procedure for volumetric density estimation consists of first correcting the image for inhomogeneity, then performing a volume density calculation. First, optical sensitometry is used to convert all images to the logarithm of relative exposure (LRE), in order to simplify the image correction operations. The field non-uniformity correction, which takes into account heel effect, inverse square law, path obliquity and intrinsic field and grid non- uniformity is obtained by imaging a spherical section PMMA phantom. The processed LRE image of the phantom is then used as a correction offset for actual mammograms. From information about the thickness and placement of the breast, as well as the parameters of a breast-like calibration step wedge placed in the mammogram, MD of the breast is calculated. Post processing and a simple calibration phantom enable user- independent, reliable and repeatable volumetric estimation of density in breast-equivalent phantoms. Initial results obtained on known density phantoms show the estimation to vary less than 5% in MD from the actual value. This can be compared to estimated mammographic density differences of 30% between the true and non-corrected values. Since a more simplistic breast density measurement based on the projected area has been shown to be a strong indicator

  10. Neuroimaging of resilience to stress: current state of affairs.

    Science.gov (United States)

    van der Werff, Steven J A; Pannekoek, J Nienke; Stein, Dan J; van der Wee, Nic J A

    2013-09-01

    Resilience is defined as a dynamic, multidimensional process encompassing positive adaptation within the context of significant adversity. The complex nature of this construct makes it a difficult topic to study in neuroimaging research; however, in this article, we propose ways to operationalize resilience. The limited amount of structural and functional neuroimaging studies specifically designed to examine resilience have mainly focused on investigating alterations in regions of the brain involved in emotion and stress regulation circuitry. In the future, neuroimaging of resilience is expected to benefit from functional and structural connectivity approaches and the use of novel imaging task paradigms.

  11. Volumetric response classification in metastatic solid tumors on MSCT: Initial results in a whole-body setting

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, A.M., E-mail: a.wulff@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Fabel, M. [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Freitag-Wolf, S., E-mail: freitag@medinfo.uni-kiel.de [Institut für Medizinische Informatik und Statistik, Brunswiker Str. 10, 24105 Kiel (Germany); Tepper, M., E-mail: m.tepper@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Knabe, H.M., E-mail: h.knabe@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Schäfer, J.P., E-mail: jp.schaefer@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Jansen, O., E-mail: o.jansen@neurorad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Bolte, H., E-mail: hendrik.bolte@ukmuenster.de [Klinik für Nuklearmedizin, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster (Germany)

    2013-10-01

    Purpose: To examine technical parameters of measurement accuracy and differences in tumor response classification using RECIST 1.1 and volumetric assessment in three common metastasis types (lung nodules, liver lesions, lymph node metastasis) simultaneously. Materials and methods: 56 consecutive patients (32 female) aged 41–82 years with a wide range of metastatic solid tumors were examined with MSCT for baseline and follow up. Images were evaluated by three experienced radiologists using manual measurements and semi-automatic lesion segmentation. Institutional ethics review was obtained and all patients gave written informed consent. Data analysis comprised interobserver variability operationalized as coefficient of variation and categorical response classification according to RECIST 1.1 for both manual and volumetric measures. Continuous data were assessed for statistical significance with Wilcoxon signed-rank test and categorical data with Fleiss kappa. Results: Interobserver variability was 6.3% (IQR 4.6%) for manual and 4.1% (IQR 4.4%) for volumetrically obtained sum of relevant diameters (p < 0.05, corrected). 4–8 patients’ response to therapy was classified differently across observers by using volumetry compared to standard manual measurements. Fleiss kappa revealed no significant difference in categorical agreement of response classification between manual (0.7558) and volumetric (0.7623) measurements. Conclusion: Under standard RECIST thresholds there was no advantage of volumetric compared to manual response evaluation. However volumetric assessment yielded significantly lower interobserver variability. This may allow narrower thresholds for volumetric response classification in the future.

  12. EVALUATION OF NEUROIMAGING IN CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    S.H. Hasanpour avanji

    2008-11-01

    Full Text Available ObjectiveCerebral palsy (CP, a common static motor neurological disorder of childhood with wide spectrum of underlying etiologies, can be demonstrated with different neuro imaging techniques. We undertook this study to investigate the diagnosis of intracranial lesions in children with CP and its correlation between clinical deficits and neuroradiological findings.Materials and methodsIn this prospective hospital-based study, the data of 120 patients with CP, aged below 18 years, referring to the neurology clinic of the Ali Asghar Pediatric hospital in Tehran was studied; data on their cranial neuroimaging findings was analyzed any possible association(s between the gestational ages, prenatal history and neurological deficits were investigated.ResultsOf the 120 patients, 72 (60% were male; 75% were aged below 7 years.Common predisposing factors were prenatal asphyxia, LBW, prematurity and toxemia of pregnancy. Of the 120 cases, 90%(107 had spastic CP, with the quadriplegic type being the most common (54%, followed by spastic paraplegia (21%; twenty-four patients (20% had significant Preventricular Leucomalacia (PVL, a finding more common among those born pre-term.Sixteen patients had hemiplegic CP, 14 of whom showed unilateral lesions on brain MRI imaging. Ten (8% had extra pyramidal CP, a condition more common among term born infants, while six of the 10(72% showed significant abnormalities on the basal ganglia. Cerebral atrophy was seen in 60 (50% of patients and PVL in 20%; encephalomalacia, gliosis, middle cerebral artery infarcts, PVL and gliosis indicated hypoxia as a risk factor for CP. Extent of MRI lesions correlated with the severity of neurological deficits in CP lesions, which were more extensive in Quadriplegics and double hemiplegics rather than paraplegics, and among those delivered preterm as compared to those born at term.ConclusionRadiological findings were found to be closely related to the type of CP and the neurological

  13. Neuroimaging biomarkers of preterm brain injury: toward developing the preterm connectome

    Energy Technology Data Exchange (ETDEWEB)

    Panigrahy, Ashok [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Children' s Hospital of Pittsburgh of UPMC, Department of Pediatric Radiology, Pittsburgh, PA (United States); Wisnowski, Jessica L. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Furtado, Andre [Children' s Hospital of Pittsburgh of UPMC, Department of Pediatric Radiology, Pittsburgh, PA (United States); Lepore, Natasha [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Paquette, Lisa [Children' s Hospital Los Angeles, Center for Fetal and Neonatal Medicine, Los Angeles, CA (United States); Bluml, Stefan [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Southern California, Department of Biomedical Engineering, Los Angeles, CA (United States)

    2012-01-15

    For typically developing infants, the last trimester of fetal development extending into the first post-natal months is a period of rapid brain development. Infants who are born premature face significant risk of brain injury (e.g., intraventricular or germinal matrix hemorrhage and periventricular leukomalacia) from complications in the perinatal period and also potential long-term neurodevelopmental disabilities because these early injuries can interrupt normal brain maturation. Neuroimaging has played an important role in the diagnosis and management of the preterm infant. Both cranial US and conventional MRI techniques are useful in diagnostic and prognostic evaluation of preterm brain development and injury. Cranial US is highly sensitive for intraventricular hemorrhage (IVH) and provides prognostic information regarding cerebral palsy. Data are limited regarding the utility of MRI as a routine screening instrument for brain injury for all preterm infants. However, MRI might provide diagnostic or prognostic information regarding PVL and other types of preterm brain injury in the setting of specific clinical indications and risk factors. Further development of advanced MR techniques like volumetric MR imaging, diffusion tensor imaging, metabolic imaging (MR spectroscopy) and functional connectivity are necessary to provide additional insight into the molecular, cellular and systems processes that underlie brain development and outcome in the preterm infant. The adult concept of the ''connectome'' is also relevant in understanding brain networks that underlie the preterm brain. Knowledge of the preterm connectome will provide a framework for understanding preterm brain function and dysfunction, and potentially even a roadmap for brain plasticity. By combining conventional imaging techniques with more advanced techniques, neuroimaging findings will likely be used not only as diagnostic and prognostic tools, but also as biomarkers for long

  14. Neuroimaging biomarkers of preterm brain injury: toward developing the preterm connectome

    Science.gov (United States)

    Panigrahy, Ashok; Wisnowski, Jessica L.; Furtado, Andre; Lepore, Natasha; Paquette, Lisa; Bluml, Stefan

    2013-01-01

    For typically developing infants, the last trimester of fetal development extending into the first post-natal months is a period of rapid brain development. Infants who are born premature face significant risk of brain injury (e.g., intraventricular or germinal matrix hemorrhage and periventricular leukomalacia) from complications in the perinatal period and also potential long-term neurodevelopmental disabilities because these early injuries can interrupt normal brain maturation. Neuroimaging has played an important role in the diagnosis and management of the preterm infant. Both cranial US and conventional MRI techniques are useful in diagnostic and prognostic evaluation of preterm brain development and injury. Cranial US is highly sensitive for intraventricular hemorrhage IVH and provides prognostic information regarding cerebral palsy. Data are limited regarding the utility of MRI as a routine screening instrument for brain injury for all preterm infants. However, MRI might provide diagnostic or prognostic information regarding PVL and other types of preterm brain injury in the setting of specific clinical indications and risk factors. Further development of advanced MR techniques like volumetric MR imaging, diffusion tensor imaging, metabolic imaging (MR spectroscopy) and functional connectivity are necessary to provide additional insight into the molecular, cellular and systems processes that underlie brain development and outcome in the preterm infant. The adult concept of the “connectome” is also relevant in understanding brain networks that underlie the preterm brain. Knowledge of the preterm connectome will provide a framework for understanding preterm brain function and dysfunction, and potentially even a roadmap for brain plasticity. By combining conventional imaging techniques with more advanced techniques, neuroimaging findings will likely be used not only as diagnostic and prognostic tools, but also as biomarkers for long-term neurodevelopmental

  15. Volumetric properties of human islet amyloid polypeptide in liquid water.

    Science.gov (United States)

    Brovchenko, I; Andrews, M N; Oleinikova, A

    2010-04-28

    The volumetric properties of human islet amyloid polypeptide (hIAPP) in water were studied in a wide temperature range by computer simulations. The intrinsic density rho(p) and the intrinsic thermal expansion coefficient alpha(p) of hIAPP were evaluated by taking into account the difference between the volumetric properties of hydration and bulk water. The density of hydration water rho(h) was found to decrease almost linearly with temperature upon heating and its thermal expansion coefficient was found to be notably higher than that of bulk water. The peptide surface exposed to water is more hydrophobic and its rho(h) is smaller in conformation with a larger number of intrapeptide hydrogen bonds. The two hIAPP peptides studied (with and without disulfide bridge) show negative alpha(p), which is close to zero at 250 K and decreases to approximately -1.5 x 10(-3) K(-1) upon heating to 450 K. The analysis of various structural properties of peptides shows a correlation between the intrinsic peptide volumes and the number of intrapeptide hydrogen bonds. The obtained negative values of alpha(p) can be attributed to the shrinkage of the inner voids of the peptides upon heating.

  16. Influence of Cobb Angle and ISIS2 Surface Topography Volumetric Asymmetry on Scoliosis Research Society-22 Outcome Scores in Scoliosis.

    Science.gov (United States)

    Brewer, Paul; Berryman, Fiona; Baker, De; Pynsent, Paul; Gardner, Adrian

    2013-11-01

    Retrospective sequential patient series. To establish the relationship between the magnitude of the deformity in scoliosis and patients' perception of their condition, as measured with Scoliosis Research Society-22 scores. A total of 93 untreated patients with adolescent idiopathic scoliosis were included retrospectively. The Cobb angle was measured from a plain radiograph, and volumetric asymmetry was measured by ISIS2 surface topography. The association between Scoliosis Research Society scores for function, pain, self-image, and mental health against Cobb angle and volumetric asymmetry was investigated using the Pearson correlation coefficient. Correlation of both Cobb angle and volumetric asymmetry with function and pain was weak (all self-image, was higher, although still moderate (-.37 for Cobb angle and -.44 for volumetric asymmetry). Both were statistically significant (Cobb angle, p = .0002; volumetric asymmetry; p = .00001). Cobb angle contributed 13.8% to the linear relationship with self-image, whereas volumetric asymmetry contributed 19.3%. For mental health, correlation was statistically significant with Cobb angle (p = .011) and volumetric asymmetry (p = .0005), but the correlation was low to moderate (-.26 and -.35, respectively). Cobb angle contributed 6.9% to the linear relationship with mental health, whereas volumetric asymmetry contributed 12.4%. Volumetric asymmetry correlates better with both mental health and self-image compared with Cobb angle, but the correlation was only moderate. This study suggests that a patient's own perception of self-image and mental health is multifactorial and not completely explained through present objective measurements of the size of the deformity. This helps to explain the difficulties in any objective analysis of a problem with multifactorial perception issues. Further study is required to investigate other physical aspects of the deformity that may have a role in how patients view themselves. Copyright

  17. Neuroimaging in Social Anxiety Disorder ? a meta-analytic review resulting in a new neurofunctional model

    OpenAIRE

    Br?hl, Annette Beatrix; Delsignore, Aba; Komossa, Katja; Weidt, Steffi

    2014-01-01

    This is the author's accepted manuscript. The final version is printed by Elsevier in Neuroscience & Biobehavioral Reviews here: http://www.sciencedirect.com/science/article/pii/S0149763414002012. Social anxiety disorder (SAD) is one of the most frequent anxiety disorders. The landmark meta-analysis of functional neuroimaging studies by Etkin & Wager (2007) revealed primarily the typical fear circuit as overactive in SAD. Since then, new methodological developments such as functional conne...

  18. Neuroimaging for spine and spinal cord surgery

    Energy Technology Data Exchange (ETDEWEB)

    Koyanagi, Izumi [Hokkaido Neurosurgical Memorial Hospital (Japan); Iwasaki, Yoshinobu; Hida, Kazutoshi

    2001-01-01

    Recent advances in neuroimaging of the spine and spinal cord are described based upon our clinical experiences with spinal disorders. Preoperative neuroradiological examinations, including magnetic resonance (MR) imaging and computerized tomography (CT) with three-dimensional reconstruction (3D-CT), were retrospectively analyzed in patients with cervical spondylosis or ossification of the posterior longitudinal ligament (130 cases), spinal trauma (43 cases) and intramedullary spinal cord tumors (92 cases). CT scan and 3D-CT were useful in elucidating the spine pathology associated with degenerative and traumatic spine diseases. Visualization of the deformity of the spine or fracture-dislocation of the spinal column with 3D-CT helped to determine the correct surgical treatment. MR imaging was most important in the diagnosis of both spine and spinal cord abnormalities. The axial MR images of the spinal cord were essential in understanding the laterality of the spinal cord compression in spinal column disorders and in determining surgical approaches to the intramedullary lesions. Although non-invasive diagnostic modalities such as MR imaging and CT scans are adequate for deciding which surgical treatment to use in the majority of spine and spinal cord disorders, conventional myelography is still needed in the diagnosis of nerve root compression in some cases of cervical spondylosis. (author)

  19. Neuroimaging of Fear-Associated Learning.

    Science.gov (United States)

    Greco, John A; Liberzon, Israel

    2016-01-01

    Fear conditioning has been commonly used as a model of emotional learning in animals and, with the introduction of functional neuroimaging techniques, has proven useful in establishing the neurocircuitry of emotional learning in humans. Studies of fear acquisition suggest that regions such as amygdala, insula, anterior cingulate cortex, and hippocampus play an important role in acquisition of fear, whereas studies of fear extinction suggest that the amygdala is also crucial for safety learning. Extinction retention testing points to the ventromedial prefrontal cortex as an essential region in the recall of the safety trace, and explicit learning of fear and safety associations recruits additional cortical and subcortical regions. Importantly, many of these findings have implications in our understanding of the pathophysiology of psychiatric disease. Recent studies using clinical populations have lent insight into the changes in regional activity in specific disorders, and treatment studies have shown how pharmaceutical and other therapeutic interventions modulate brain activation during emotional learning. Finally, research investigating individual differences in neurotransmitter receptor genotypes has highlighted the contribution of these systems in fear-associated learning.

  20. Neuroimaging revolutionizes therapeutic approaches to chronic pain

    Directory of Open Access Journals (Sweden)

    Borsook David

    2007-09-01

    Full Text Available Abstract An understanding of how the brain changes in chronic pain or responds to pharmacological or other therapeutic interventions has been significantly changed as a result of developments in neuroimaging of the CNS. These developments have occurred in 3 domains : (1 Anatomical Imaging which has demonstrated changes in brain volume in chronic pain; (2 Functional Imaging (fMRI that has demonstrated an altered state in the brain in chronic pain conditions including back pain, neuropathic pain, and complex regional pain syndromes. In addition the response of the brain to drugs has provided new insights into how these may modify normal and abnormal circuits (phMRI or pharmacological MRI; (3 Chemical Imaging (Magnetic Resonance Spectroscopy or MRS has helped our understanding of measures of chemical changes in chronic pain. Taken together these three domains have already changed the way in which we think of pain – it should now be considered an altered brain state in which there may be altered functional connections or systems and a state that has components of degenerative aspects of the CNS.

  1. Neuroimaging in pre-motor Parkinson's disease

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    Thomas R. Barber

    2017-01-01

    Full Text Available The process of neurodegeneration in Parkinson's disease begins long before the onset of clinical motor symptoms, resulting in substantial cell loss by the time a diagnosis can be made. The period between the onset of neurodegeneration and the development of motoric disease would be the ideal time to intervene with disease modifying therapies. This pre-motor phase can last many years, but the lack of a specific clinical phenotype means that objective biomarkers are needed to reliably detect prodromal disease. In recent years, recognition that patients with REM sleep behaviour disorder (RBD are at particularly high risk of future parkinsonism has enabled the development of large prodromal cohorts in which to investigate novel biomarkers, and neuroimaging has generated some of the most promising results to date. Here we review investigations undertaken in RBD and other pre-clinical cohorts, including modalities that are well established in clinical Parkinson's as well as novel imaging methods. Techniques such as high resolution MRI of the substantia nigra and functional imaging of Parkinsonian brain networks have great potential to facilitate early diagnosis. Further longitudinal studies will establish their true value in quantifying prodromal neurodegeneration and predicting future Parkinson's.

  2. Structural and functional neuroimaging in intractable epilepsy

    Directory of Open Access Journals (Sweden)

    Chinchure Swati

    2010-01-01

    Full Text Available Medical management remains unsatisfactory in about a third of patients with epilepsy and some of them are candidates for resective epilepsy surgery. Structural and functional neuroimaging plays an important role in the identification of the precise cortical region responsible for seizures and is very crucial for a good surgical outcome. Furthermore, identification of eloquent cortical areas near the region to be resected is essential to avoid postoperative neurologic deficit. The magnetic resonance imaging (MRI protocol for epilepsy can be individually tailored depending on the seizure semiology and possibly electroencephalography. New MRI techniques demonstrate the structure of the brain in fine detail, help in understanding the underlying pathology, and demonstrate functional activity of the brain with high spatial and temporal resolution. Metabolic imaging techniques, such as positron emission tomography (PET and single photon emission tomography (SPECT visualize metabolic alterations of the brain in the ictal and interictal states. In MR-negative epilepsy patients, these techniques may have localizing value. The proper use and interpretation of the findings provided by these new technologies is crucial. In this review article, we discuss various conventional and advanced MRI techniques, interpretation of various findings, and the role of functional imaging modalities, such as functional MRI, PET, and SPECT in the localization of epileptogenic substrate as well as for understanding the pathophysiology, propagation, and neurochemical correlates of epilepsy.

  3. Neuroimaging biomarkers in mild traumatic brain injury (mTBI).

    Science.gov (United States)

    Bigler, Erin D

    2013-09-01

    Reviewed herein are contemporary neuroimaging methods that detect abnormalities associated with mild traumatic brain injury (mTBI). Despite advances in demonstrating underlying neuropathology in a subset of individuals who sustain mTBI, considerable disagreement persists in neuropsychology about mTBI outcome and metrics for evaluation. This review outlines a thesis for the select use of sensitive neuroimaging methods as potential biomarkers of brain injury recognizing that the majority of individuals who sustain an mTBI recover without neuroimaging signs or neuropsychological sequelae detected with methods currently applied. Magnetic resonance imaging (MRI) provides several measures that could serve as mTBI biomarkers including the detection of hemosiderin and white matter abnormalities, assessment of white matter integrity derived from diffusion tensor imaging (DTI), and quantitative measures that directly assess neuroanatomy. Improved prediction of neuropsychological outcomes in mTBI may be achieved with the use of targeted neuroimaging markers.

  4. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  5. The Java Image Science Toolkit (JIST) for rapid prototyping and publishing of neuroimaging software.

    Science.gov (United States)

    Lucas, Blake C; Bogovic, John A; Carass, Aaron; Bazin, Pierre-Louis; Prince, Jerry L; Pham, Dzung L; Landman, Bennett A

    2010-03-01

    Non-invasive neuroimaging techniques enable extraordinarily sensitive and specific in vivo study of the structure, functional response and connectivity of biological mechanisms. With these advanced methods comes a heavy reliance on computer-based processing, analysis and interpretation. While the neuroimaging community has produced many excellent academic and commercial tool packages, new tools are often required to interpret new modalities and paradigms. Developing custom tools and ensuring interoperability with existing tools is a significant hurdle. To address these limitations, we present a new framework for algorithm development that implicitly ensures tool interoperability, generates graphical user interfaces, provides advanced batch processing tools, and, most importantly, requires minimal additional programming or computational overhead. Java-based rapid prototyping with this system is an efficient and practical approach to evaluate new algorithms since the proposed system ensures that rapidly constructed prototypes are actually fully-functional processing modules with support for multiple GUI's, a broad range of file formats, and distributed computation. Herein, we demonstrate MRI image processing with the proposed system for cortical surface extraction in large cross-sectional cohorts, provide a system for fully automated diffusion tensor image analysis, and illustrate how the system can be used as a simulation framework for the development of a new image analysis method. The system is released as open source under the Lesser GNU Public License (LGPL) through the Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC).

  6. The Java Image Science Toolkit (JIST) for Rapid Prototyping and Publishing of Neuroimaging Software

    Science.gov (United States)

    Lucas, Blake C.; Bogovic, John A.; Carass, Aaron; Bazin, Pierre-Louis; Prince, Jerry L.; Pham, Dzung

    2010-01-01

    Non-invasive neuroimaging techniques enable extraordinarily sensitive and specific in vivo study of the structure, functional response and connectivity of biological mechanisms. With these advanced methods comes a heavy reliance on computer-based processing, analysis and interpretation. While the neuroimaging community has produced many excellent academic and commercial tool packages, new tools are often required to interpret new modalities and paradigms. Developing custom tools and ensuring interoperability with existing tools is a significant hurdle. To address these limitations, we present a new framework for algorithm development that implicitly ensures tool interoperability, generates graphical user interfaces, provides advanced batch processing tools, and, most importantly, requires minimal additional programming or computational overhead. Java-based rapid prototyping with this system is an efficient and practical approach to evaluate new algorithms since the proposed system ensures that rapidly constructed prototypes are actually fully-functional processing modules with support for multiple GUI's, a broad range of file formats, and distributed computation. Herein, we demonstrate MRI image processing with the proposed system for cortical surface extraction in large cross-sectional cohorts, provide a system for fully automated diffusion tensor image analysis, and illustrate how the system can be used as a simulation framework for the development of a new image analysis method. The system is released as open source under the Lesser GNU Public License (LGPL) through the Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC). PMID:20077162

  7. Neuroimaging findings in treatment-resistant schizophrenia: a systematic review

    Science.gov (United States)

    Nakajima, Shinichiro; Takeuchi, Hiroyoshi; Plitman, Eric; Fervaha, Gagan; Gerretsen, Philip; Caravaggio, Fernando; Chung, Jun Ku; Iwata, Yusuke; Remington, Gary; Graff-Guerrero, Ariel

    2015-01-01

    Background Recent developments in neuroimaging have advanced understanding biological mechanisms underlying schizophrenia. However, neuroimaging correlates of treatment-resistant schizophrenia (TRS) and superior effects of clozapine on TRS remain unclear. Methods Systematic search was performed to identify neuroimaging characteristics unique to TRS and ultra-resistant schizophrenia (i.e. clozapine-resistant [URS]), and clozapine's efficacy in TRS using Embase, Medline, and PsychInfo. Search terms included (schizophreni*) and (resistan* OR refractory OR clozapine) and (ASL OR CT OR DTI OR FMRI OR MRI OR MRS OR NIRS OR PET OR SPECT). Results 25 neuroimaging studies have investigated TRS and effects of clozapine. Only 5 studies have compared TRS and non-TRS, collectively providing no replicated neuroimaging finding specific to TRS. Studies comparing TRS and healthy controls suggest hypometabolism in the prefrontal cortex, hypermetabolism in the basal ganglia, and structural anomalies in the corpus callosum contribute to TRS. Clozapine may increase prefrontal hypoactivation in TRS although this was not related to clinical improvement; in contrast, evidence has suggested a link between clozapine efficacy and decreased metabolism in the basal ganglia and thalamus. Conclusion Existing literature does not elucidate neuroimaging correlates specific to TRS or URS, which, if present, might also shed light on clozapine's efficacy in TRS. This said, leads from other lines of investigation, including the glutamatergic system can prove useful in guiding future neuroimaging studies focused on, in particular, the frontocortical-basal ganglia-thalamic circuits. Critical to the success of this work will be precise subtyping of study subjects based on treatment response/nonresponse and the use of multimodal neuroimaging. PMID:25684554

  8. Neuroimaging findings in pediatric sports-related concussion.

    Science.gov (United States)

    Ellis, Michael J; Leiter, Jeff; Hall, Thomas; McDonald, Patrick J; Sawyer, Scott; Silver, Norm; Bunge, Martin; Essig, Marco

    2015-09-01

    The goal in this review was to summarize the results of clinical neuroimaging studies performed in patients with sports-related concussion (SRC) who were referred to a multidisciplinar ypediatric concussion program. The authors conducted a retrospective review of medical records and neuroimaging findings for all patients referred to a multidisciplinary pediatric concussion program between September 2013 and July 2014. Inclusion criteria were as follows: 1) age ≤ 19 years; and 2) physician-diagnosed SRC. All patients underwent evaluation and follow-up by the same neurosurgeon. The 2 outcomes examined in this review were the frequency of neuroimaging studies performed in this population (including CT and MRI) and the findings of those studies. Clinical indications for neuroimaging and the impact of neuroimaging findings on clinical decision making were summarized where available. This investigation was approved by the local institutional ethics review board. A total of 151 patients (mean age 14 years, 59% female) were included this study. Overall, 36 patients (24%) underwent neuroimaging studies, the results of which were normal in 78% of cases. Sixteen percent of patients underwent CT imaging; results were normal in 79% of cases. Abnormal CT findings included the following: arachnoid cyst (1 patient), skull fracture (2 patients), suspected intracranial hemorrhage (1 patient), and suspected hemorrhage into an arachnoid cyst (1 patient). Eleven percent of patients underwent MRI; results were normal in 75% of cases. Abnormal MRI findings included the following: intraparenchymal hemorrhage and sylvian fissure arachnoid cyst (1 patient); nonhemorrhagic contusion (1 patient); demyelinating disease (1 patient); and posterior fossa arachnoid cyst, cerebellar volume loss, and nonspecific white matter changes (1 patient). Results of clinical neuroimaging studies are normal in the majority of pediatric patients with SRC. However, in selected cases neuroimaging can provide

  9. A SUBDIVISION SCHEME FOR VOLUMETRIC MODELS

    Institute of Scientific and Technical Information of China (English)

    GhulamMustafa; LiuXuefeng

    2005-01-01

    In this paper, a subdivision scheme which generalizes a surface scheme in previous papers to volume meshes is designed. The scheme exhibits significant control over shrink-age/size of volumetric models. It also has the ability to conveniently incorporate boundaries and creases into a smooth limit shape of models. The method presented here is much simpler and easier as compared to MacCracken and Joy's. This method makes no restrictions on the local topology of meshes. Particularly, it can be applied without any change to meshes of nonmanifold topology.

  10. IMITATION OF STANDARD VOLUMETRIC ACTIVITY METAL SAMPLES

    Directory of Open Access Journals (Sweden)

    A. I. Zhukouski

    2016-01-01

    Full Text Available Due to the specific character of problems in the field of ionizing radiation spectroscopy, the R&D and making process of standard volumetric activity metal samples (standard samples for calibration and verification of spectrometric equipment is not only expensive, but also requires the use of highly qualified experts and a unique specific equipment. Theoretical and experimental studies performed have shown the possibility to use imitators as a set of alternating point sources of gamma radiation and metal plates and their use along with standard volumetric activity metal samples for calibration of scintillation-based detectors used in radiation control in metallurgy. Response functions or instrumental spectra of such spectrometer to radionuclides like 137Cs, 134Cs, 152Eu, 154Eu, 60Co, 54Mn, 232Th, 226Ra, 65Zn, 125Sb+125mTe, 106Ru+106Rh, 94Nb, 110mAg, 233U, 234U, 235U and 238U are required for calibration in a given measurement geometry. Standard samples in the form of a probe made of melt metal of a certain diameter and height are used in such measurements. However, the production of reference materials is costly and even problematic for such radionuclides as 94Nb, 125Sb+125mTe, 234U, 235U  etc. A recognized solution to solve this problem is to use the Monte-Carlo simulation method. Instrumental experimental and theoretical spectra obtained by using standard samples and their imitators show a high compliance between experimental spectra of real samples and the theoretical ones of their Monte-Carlo models, between spectra of real samples and the ones of their imitators and finally, between experimental spectra of real sample imitators and the theoretical ones of their Monte-Carlo models. They also have shown the adequacy and consistency of the approach in using a combination of metal scattering layers and reference point gamma-ray sources instead of standard volumetric activity metal samples. As for using several reference point gamma-ray sources

  11. Magnetic volumetric hologram memory with magnetic garnet.

    Science.gov (United States)

    Nakamura, Yuichi; Takagi, Hiroyuki; Lim, Pang Boey; Inoue, Mitsuteru

    2014-06-30

    Holographic memory is a promising next-generation optical memory that has a higher recording density and a higher transfer rate than other types of memory. In holographic memory, magnetic garnet films can serve as rewritable holographic memory media by use of magneto-optical effect. We have now demonstrated that a magnetic hologram can be recorded volumetrically in a ferromagnetic garnet film and that the signal image can be reconstructed from it for the first time. In addition, multiplicity of the magnetic hologram was also confirmed; the image could be reconstructed from a spot overlapped by other spots.

  12. Automated volumetric grid generation for finite element modeling of human hand joints

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K.; Underhill, K. [Lawrence Livermore National Lab., CA (United States); Rainsberger, R. [XYZ Scientific Applications, Inc., Livermore, CA (United States)

    1995-02-01

    We are developing techniques for finite element analysis of human joints. These techniques need to provide high quality results rapidly in order to be useful to a physician. The research presented here increases model quality and decreases user input time by automating the volumetric mesh generation step.

  13. Functional neuroimaging of traumatic brain injury: advances and clinical utility

    Directory of Open Access Journals (Sweden)

    Irimia A

    2015-09-01

    Full Text Available Andrei Irimia, John Darrell Van Horn USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA Abstract: Functional deficits due to traumatic brain injury (TBI can have significant and enduring consequences upon patients’ life quality and expectancy. Although functional neuroimaging is essential for understanding TBI pathophysiology, an insufficient amount of effort has been dedicated to the task of translating functional neuroimaging findings into information with clinical utility. The purpose of this review is to summarize the use of functional neuroimaging techniques – especially functional magnetic resonance imaging, diffusion tensor imaging, positron emission tomography, magnetic resonance spectroscopy, and electroencephalography – for advancing current knowledge of TBI-related brain dysfunction and for improving the rehabilitation of TBI patients. We focus on seven core areas of functional deficits, namely consciousness, motor function, attention, memory, higher cognition, personality, and affect, and, for each of these, we summarize recent findings from neuroimaging studies which have provided substantial insight into brain function changes due to TBI. Recommendations are also provided to aid in setting the direction of future neuroimaging research and for understanding brain function changes after TBI. Keywords: cognitive decline, personality change, magnetic resonance imaging, diffusion tensor imaging

  14. Human Neuroimaging as a “Big Data” Science

    Science.gov (United States)

    Van Horn, John Darrell; Toga, Arthur W.

    2013-01-01

    The maturation of in vivo neuroimaging has lead to incredible quantities of digital information about the human brain. While much is made of the data deluge in science, neuroimaging represents the leading edge of this onslaught of “big data”. A range of neuroimaging databasing approaches has streamlined the transmission, storage, and dissemination of data from such brain imaging studies. Yet few, if any, common solutions exist to support the science of neuroimaging. In this article, we discuss how modern neuroimaging research represents a mutifactorial and broad ranging data challenge, involving the growing size of the data being acquired; sociologial and logistical sharing issues; infrastructural challenges for multi-site, multi-datatype archiving; and the means by which to explore and mine these data. As neuroimaging advances further, e.g. aging, genetics, and age-related disease, new vision is needed to manage and process this information while marshalling of these resources into novel results. Thus, “big data” can become “big” brain science. PMID:24113873

  15. Neuroimaging in autism--from basic science to translational research.

    Science.gov (United States)

    Ecker, Christine; Murphy, Declan

    2014-02-01

    Over the past decade, human neuroimaging studies have provided invaluable insights into the neural substrates that underlie autism spectrum disorder (ASD). Although observations from multiple neuroimaging approaches converge in suggesting that changes in brain structure, functioning and connectivity are associated with ASD, the neurobiology of this disorder is complex, and considerable aetiological and phenotypic heterogeneity exists among individuals on the autism spectrum. Characterization of the neurobiological alterations that underlie ASD and development of novel pharmacotherapies for ASD, therefore, requires multidisciplinary collaboration. Consequently, pressure is growing to combine neuroimaging data with information provided by other disciplines to translate research findings into clinically useful biomarkers. So far, however, neuroimaging studies in patients with ASD have mainly been conducted in isolation, and the low specificity of neuroimaging measures has hindered the development of biomarkers that could aid clinical trials and/or facilitate patient identification. Novel approaches to acquiring and analysing data on brain characteristics are currently being developed to overcome these inherent limitations, and to integrate neuroimaging into translational research. Here, we discuss promising new studies of cortical pathology in patients with ASD, and outline how the novel insights thereby obtained could inform diagnosis and treatment of ASD in the future.

  16. Neuroimaging findings in treatment-resistant schizophrenia: A systematic review: Lack of neuroimaging correlates of treatment-resistant schizophrenia.

    Science.gov (United States)

    Nakajima, Shinichiro; Takeuchi, Hiroyoshi; Plitman, Eric; Fervaha, Gagan; Gerretsen, Philip; Caravaggio, Fernando; Chung, Jun Ku; Iwata, Yusuke; Remington, Gary; Graff-Guerrero, Ariel

    2015-05-01

    Recent developments in neuroimaging have advanced the understanding of biological mechanisms underlying schizophrenia. However, neuroimaging correlates of treatment-resistant schizophrenia (TRS) and superior effects of clozapine on TRS remain unclear. Systematic search was performed to identify neuroimaging characteristics unique to TRS and ultra-resistant schizophrenia (i.e. clozapine-resistant [URS]), and clozapine's efficacy in TRS using Embase, Medline, and PsychInfo. Search terms included (schizophreni*) and (resistan* OR refractory OR clozapine) and (ASL OR CT OR DTI OR FMRI OR MRI OR MRS OR NIRS OR PET OR SPECT). 25 neuroimaging studies have investigated TRS and effects of clozapine. Only 5 studies have compared TRS and non-TRS, collectively providing no replicated neuroimaging finding specific to TRS. Studies comparing TRS and healthy controls suggest that hypometabolism in the prefrontal cortex, hypermetabolism in the basal ganglia, and structural anomalies in the corpus callosum contribute to TRS. Clozapine may increase prefrontal hypoactivation in TRS although this was not related to clinical improvement; in contrast, evidence has suggested a link between clozapine efficacy and decreased metabolism in the basal ganglia and thalamus. Existing literature does not elucidate neuroimaging correlates specific to TRS or URS, which, if present, might also shed light on clozapine's efficacy in TRS. This said, leads from other lines of investigation, including the glutamatergic system can prove useful in guiding future neuroimaging studies focused on, in particular, the frontocortical-basal ganglia-thalamic circuits. Critical to the success of this work will be precise subtyping of study subjects based on treatment response/nonresponse and the use of multimodal neuroimaging. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Advanced Neuroimaging of Cerebral Small Vessel Disease.

    Science.gov (United States)

    Blair, Gordon W; Hernandez, Maria Valdez; Thrippleton, Michael J; Doubal, Fergus N; Wardlaw, Joanna M

    2017-07-01

    Cerebral small vessel disease (SVD) is characterised by damage to deep grey and white matter structures of the brain and is responsible for a diverse range of clinical problems that include stroke and dementia. In this review, we describe advances in neuroimaging published since January 2015, mainly with magnetic resonance imaging (MRI), that, in general, are improving quantification, observation and investigation of SVD focussing on three areas: quantifying the total SVD burden, imaging brain microstructural integrity and imaging vascular malfunction. Methods to capture 'whole brain SVD burden' across the spectrum of SVD imaging changes will be useful for patient stratification in clinical trials, an approach that we are already testing. More sophisticated imaging measures of SVD microstructural damage are allowing the disease to be studied at earlier stages, will help identify specific factors that are important in development of overt SVD imaging features and in understanding why specific clinical consequences may occur. Imaging vascular function will help establish the precise blood vessel and blood flow alterations at early disease stages and, together with microstructural integrity measures, may provide important surrogate endpoints in clinical trials testing new interventions. Better knowledge of SVD pathophysiology will help identify new treatment targets, improve patient stratification and may in future increase efficiency of clinical trials through smaller sample sizes or shorter follow-up periods. However, most of these methods are not yet sufficiently mature to use with confidence in clinical trials, although rapid advances in the field suggest that reliable quantification of SVD lesion burden, tissue microstructural integrity and vascular dysfunction are imminent.

  18. Neuroimaging characteristics of dementia with Lewy bodies.

    Science.gov (United States)

    Mak, Elijah; Su, Li; Williams, Guy B; O'Brien, John T

    2014-01-01

    This review summarises the findings and applications from neuroimaging studies in dementia with Lewy bodies (DLB), highlighting key differences between DLB and other subtypes of dementia. We also discuss the increasingly important role of imaging biomarkers in differential diagnosis and outline promising areas for future research in DLB. DLB shares common clinical, neuropsychological and pathological features with Parkinson's disease dementia and other dementia subtypes, such as Alzheimer's disease. Despite the development of consensus diagnostic criteria, the sensitivity for differential diagnosis of DLB in clinical practice remains low and many DLB patients will be misdiagnosed. The importance of developing accurate imaging markers in dementia is highlighted by the potential for treatments targeting specific molecular abnormalities as well as the responsiveness to cholinesterase inhibitors and marked neuroleptic sensitivity of DLB. We review various brain imaging techniques that have been applied to investigate DLB, including the characteristic nigrostriatal degeneration in DLB using positron emission tomography (PET) and single-photon emission computed tomography (SPECT) tracers. Dopamine transporter loss has proven to reliably differentiate DLB from other dementias and has been incorporated into the revised clinical diagnostic criteria for DLB. To date, this remains the 'gold standard' for diagnostic imaging of DLB. Regional cerebral blood flow, 18 F-fluorodeoxygluclose-PET and SPECT have also identified marked deficits in the occipital regions with relative sparing of the medial temporal lobe when compared to Alzheimer's disease. In addition, structural, diffusion, and functional magnetic resonance imaging techniques have shown alterations in structure, white matter integrity, and functional activity in DLB. We argue that the multimodal identification of DLB-specific biomarkers has the potential to improve ante-mortem diagnosis and contribute to our

  19. A neuroimaging study in childhood autism

    Directory of Open Access Journals (Sweden)

    Mohammad S. I. Mullick

    2016-08-01

    Full Text Available Background: Childhood autism is now widely viewed as being of developmental neurological origin. Abnormality in neuroimaging is reported in autism.Objectives: To delineate the proportion of structural magnetic resonance imaging (MRI and electro encephalography (EEG abnormality among the children with Autism and to assess any association of MRI and EEG changes with co morbid mental illness.Methods: It was a cross sectional descriptive study done at a child and adolescent consultation centre, Dhaka. The study was Carried out from January 2009 to December 2009. Both boys and girls were included in the study. A total of 42 children with childhood autism aged between two and 12 years partici­pated in this study. Diagnosis of autism was based on ICD-10(DCR criteria. Results: Abnormalities were found to be 35.7% in MRI and 42.9% in EEG. EEG abnormalities were found in the form of defuse slow waves activities, generalized faster activities, epileptogenic discharge and mixed discharge. The abnormalities in MRI was found in the form of diffuse cortical atrophic changes, focal cortical atrophy in frontal and temporal cortex with widening of major sulci, prominent ventricles, periventricular degeneration and abnormal basal ganglia. EEG changes were significantly associated with increased number of co-morbid illness (mental retardation, epilepsy and others. Conclusion: A number of abnom1alities that observed in the present study indicative of relations between structural and physiological dysfunctions and childhood autism. Further exploratory and in-depth researches are certainly required in this field. Intervention of autism needs to address co morbidities for better outcome.

  20. Structural neuroimaging across early-stage psychosis: Aberrations in neurobiological trajectories and implications for the staging model.

    Science.gov (United States)

    Bartholomeusz, Cali F; Cropley, Vanessa L; Wannan, Cassandra; Di Biase, Maria; McGorry, Patrick D; Pantelis, Christos

    2017-05-01

    This review critically examines the structural neuroimaging evidence in psychotic illness, with a focus on longitudinal imaging across the first-episode psychosis and ultra-high-risk of psychosis illness stages. A thorough search of the literature involving specifically longitudinal neuroimaging in early illness stages of psychosis was conducted. The evidence supporting abnormalities in brain morphology and altered neurodevelopmental trajectories is discussed in the context of a clinical staging model. In general, grey matter (and, to a lesser extent, white matter) declines across multiple frontal, temporal (especially superior regions), insular and parietal regions during the first episode of psychosis, which has a steeper trajectory than that of age-matched healthy counterparts. Although the ultra-high-risk of psychosis literature is considerably mixed, evidence indicates that certain volumetric structural aberrations predate psychotic illness onset (e.g. prefrontal cortex thinning), while other abnormalities present in ultra-high-risk of psychosis populations are potentially non-psychosis-specific (e.g. hippocampal volume reductions). We highlight the advantages of longitudinal designs, discuss the implications such studies have on clinical staging and provide directions for future research.

  1. Neuroimaging studies of cognitive remediation in schizophrenia: A systematic and critical review

    Science.gov (United States)

    Penadés, Rafael; González-Rodríguez, Alexandre; Catalán, Rosa; Segura, Bàrbara; Bernardo, Miquel; Junqué, Carme

    2017-01-01

    AIM To examine the effects of cognitive remediation therapies on brain functioning through neuroimaging procedures in patients with schizophrenia. METHODS A systematic, computerised literature search was conducted in the PubMed/Medline and PsychInfo databases. The search was performed through February 2016 without any restrictions on language or publication date. The search was performed using the following search terms: [(“cogniti*” and “remediation” or “training” or “enhancement”) and (“fMRI” or “MRI” or “PET” or “SPECT”) and (schizophrenia or schiz*)]. The search was accompanied by a manual online search and a review of the references from each of the papers selected, and those papers fulfilling our inclusion criteria were also included. RESULTS A total of 101 studies were found, but only 18 of them fulfilled the inclusion criteria. These studies indicated that cognitive remediation improves brain activation in neuroimaging studies. The most commonly reported changes were those that involved the prefrontal and thalamic regions. Those findings are in agreement with the hypofrontality hypothesis, which proposes that frontal hypoactivation is the underlying mechanism of cognitive impairments in schizophrenia. Nonetheless, great heterogeneity among the studies was found. They presented different hypotheses, different results and different findings. The results of more recent studies interpreted cognitive recovery within broader frameworks, namely, as amelioration of the efficiency of different networks. Furthermore, advances in neuroimaging methodologies, such as the use of whole-brain analysis, tractography, graph analysis, and other sophisticated methodologies of data processing, might be conditioning the interpretation of results and generating new theoretical frameworks. Additionally, structural changes were described in both the grey and white matter, suggesting a neuroprotective effect of cognitive remediation. Cognitive

  2. ANIMA: A data-sharing initiative for neuroimaging meta-analyses.

    Science.gov (United States)

    Reid, Andrew T; Bzdok, Danilo; Genon, Sarah; Langner, Robert; Müller, Veronika I; Eickhoff, Claudia R; Hoffstaedter, Felix; Cieslik, Edna-Clarisse; Fox, Peter T; Laird, Angela R; Amunts, Katrin; Caspers, Svenja; Eickhoff, Simon B

    2016-01-01

    Meta-analytic techniques allow cognitive neuroscientists to pool large amounts of data across many individual task-based functional neuroimaging experiments. These methods have been aided by the introduction of online databases such as Brainmap.org or Neurosynth.org, which collate peak activation coordinates obtained from thousands of published studies. Findings from meta-analytic studies typically include brain regions which are consistently activated across studies for specific contrasts, investigating cognitive or clinical hypotheses. These regions can be subsequently used as the basis for seed-based connectivity analysis, or formally compared to neuroimaging data in order to help interpret new findings. To facilitate such approaches, we have developed a new online repository of meta-analytic neuroimaging results, named the Archive of Neuroimaging Meta-analyses (ANIMA). The ANIMA platform consists of an intuitive online interface for querying, downloading, and contributing data from published meta-analytic studies. Additionally, to aid the process of organizing, visualizing, and working with these data, we present an open-source desktop application called Volume Viewer. Volume Viewer allows users to easily arrange imaging data into composite stacks, and save these sessions as individual files, which can also be uploaded to the ANIMA database. The application also allows users to perform basic functions, such as computing conjunctions between images, or extracting regions-of-interest or peak coordinates for further analysis. The introduction of this new resource will enhance the ability of researchers to both share their findings and incorporate existing meta-analytic results into their own research.

  3. Volumetric properties of water/AOT/isooctane microemulsions.

    Science.gov (United States)

    Du, Changfei; He, Wei; Yin, Tianxiang; Shen, Weiguo

    2014-12-23

    The densities of AOT/isooctane micelles and water/AOT/isooctane microemulsions with the molar ratios R of water to AOT being 2, 8, 10, 12, 16, 18, 20, 25, 30, and 40 were measured at 303.15 K. The apparent specific volumes of AOT and the quasi-component water/AOT at various concentrations were calculated and used to estimate the volumetric properties of AOT and water in the droplets and in the continuous oil phase, to discuss the interaction between the droplets, and to determine the critical micelle concentration and the critical microemulsion concentrations. A thermodynamic model was proposed to analysis the stability boundary of the microemulsion droplets, which confirms the maximum value of R being about 65 for the stable AOT/water/isooctane microemulsion droplets.

  4. Out-of-core clustering of volumetric datasets

    Institute of Scientific and Technical Information of China (English)

    GRANBERG Carl J.; LI Ling

    2006-01-01

    In this paper we present a novel method for dividing and clustering large volumetric scalar out-of-core datasets. This work is based on the Ordered Cluster Binary Tree (OCBT) structure created using a top-down or divisive clustering method. The OCBT structure allows fast and efficient sub volume queries to be made in combination with level of detail (LOD) queries of the tree. The initial partitioning of the large out-of-core dataset is done by using non-axis aligned planes calculated using Principal Component Analysis (PCA). A hybrid OCBT structure is also proposed where an in-core cluster binary tree is combined with a large out-of-core file.

  5. Species-specific contribution of volumetric growth and tissue convergence to posterior body elongation in vertebrates.

    Science.gov (United States)

    Steventon, Ben; Duarte, Fernando; Lagadec, Ronan; Mazan, Sylvie; Nicolas, Jean-François; Hirsinger, Estelle

    2016-05-15

    Posterior body elongation is a widespread mechanism propelling the generation of the metazoan body plan. The posterior growth model predicts that a posterior growth zone generates sufficient tissue volume to elongate the posterior body. However, there are energy supply-related differences between vertebrates in the degree to which growth occurs concomitantly with embryogenesis. By applying a multi-scalar morphometric analysis in zebrafish embryos, we show that posterior body elongation is generated by an influx of cells from lateral regions, by convergence-extension of cells as they exit the tailbud, and finally by a late volumetric growth in the spinal cord and notochord. Importantly, the unsegmented region does not generate additional tissue volume. Fibroblast growth factor inhibition blocks tissue convergence rather than volumetric growth, showing that a conserved molecular mechanism can control convergent morphogenesis through different cell behaviours. Finally, via a comparative morphometric analysis in lamprey, dogfish, zebrafish and mouse, we propose that elongation via posterior volumetric growth is linked to increased energy supply and is associated with an overall increase in volumetric growth and elongation. © 2016. Published by The Company of Biologists Ltd.

  6. The functional neuroanatomy of the human orbitofrontal cortex: evidence from neuroimaging and neuropsychology.

    Science.gov (United States)

    Kringelbach, Morten L; Rolls, Edmund T

    2004-04-01

    The human orbitofrontal cortex is an important brain region for the processing of rewards and punishments, which is a prerequisite for the complex and flexible emotional and social behaviour which contributes to the evolutionary success of humans. Yet much remains to be discovered about the functions of this key brain region, and new evidence from functional neuroimaging and clinical neuropsychology is affording new insights into the different functions of the human orbitofrontal cortex. We review the neuroanatomical and neuropsychological literature on the human orbitofrontal cortex, and propose two distinct trends of neural activity based on a meta-analysis of neuroimaging studies. One is a mediolateral distinction, whereby medial orbitofrontal cortex activity is related to monitoring the reward value of many different reinforcers, whereas lateral orbitofrontal cortex activity is related to the evaluation of punishers which may lead to a change in ongoing behaviour. The second is a posterior-anterior distinction with more complex or abstract reinforcers (such as monetary gain and loss) represented more anteriorly in the orbitofrontal cortex than simpler reinforcers such as taste or pain. Finally, we propose new neuroimaging methods for obtaining further evidence on the localisation of function in the human orbitofrontal cortex.

  7. The ENIGMA Consortium: large-scale collaborative analyses of neuroimaging and genetic data.

    Science.gov (United States)

    Thompson, Paul M; Stein, Jason L; Medland, Sarah E; Hibar, Derrek P; Vasquez, Alejandro Arias; Renteria, Miguel E; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J; Martin, Nicholas G; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud; Almasy, Laura; Almeida, Jorge; Alpert, Kathryn; Andreasen, Nancy C; Andreassen, Ole A; Apostolova, Liana G; Appel, Katja; Armstrong, Nicola J; Aribisala, Benjamin; Bastin, Mark E; Bauer, Michael; Bearden, Carrie E; Bergmann, Orjan; Binder, Elisabeth B; Blangero, John; Bockholt, Henry J; Bøen, Erlend; Bois, Catherine; Boomsma, Dorret I; Booth, Tom; Bowman, Ian J; Bralten, Janita; Brouwer, Rachel M; Brunner, Han G; Brohawn, David G; Buckner, Randy L; Buitelaar, Jan; Bulayeva, Kazima; Bustillo, Juan R; Calhoun, Vince D; Cannon, Dara M; Cantor, Rita M; Carless, Melanie A; Caseras, Xavier; Cavalleri, Gianpiero L; Chakravarty, M Mallar; Chang, Kiki D; Ching, Christopher R K; Christoforou, Andrea; Cichon, Sven; Clark, Vincent P; Conrod, Patricia; Coppola, Giovanni; Crespo-Facorro, Benedicto; Curran, Joanne E; Czisch, Michael; Deary, Ian J; de Geus, Eco J C; den Braber, Anouk; Delvecchio, Giuseppe; Depondt, Chantal; de Haan, Lieuwe; de Zubicaray, Greig I; Dima, Danai; Dimitrova, Rali; Djurovic, Srdjan; Dong, Hongwei; Donohoe, Gary; Duggirala, Ravindranath; Dyer, Thomas D; Ehrlich, Stefan; Ekman, Carl Johan; Elvsåshagen, Torbjørn; Emsell, Louise; Erk, Susanne; Espeseth, Thomas; Fagerness, Jesen; Fears, Scott; Fedko, Iryna; Fernández, Guillén; Fisher, Simon E; Foroud, Tatiana; Fox, Peter T; Francks, Clyde; Frangou, Sophia; Frey, Eva Maria; Frodl, Thomas; Frouin, Vincent; Garavan, Hugh; Giddaluru, Sudheer; Glahn, David C; Godlewska, Beata; Goldstein, Rita Z; Gollub, Randy L; Grabe, Hans J; Grimm, Oliver; Gruber, Oliver; Guadalupe, Tulio; Gur, Raquel E; Gur, Ruben C; Göring, Harald H H; Hagenaars, Saskia; Hajek, Tomas; Hall, Geoffrey B; Hall, Jeremy; Hardy, John; Hartman, Catharina A; Hass, Johanna; Hatton, Sean N; Haukvik, Unn K; Hegenscheid, Katrin; Heinz, Andreas; Hickie, Ian B; Ho, Beng-Choon; Hoehn, David; Hoekstra, Pieter J; Hollinshead, Marisa; Holmes, Avram J; Homuth, Georg; Hoogman, Martine; Hong, L Elliot; Hosten, Norbert; Hottenga, Jouke-Jan; Hulshoff Pol, Hilleke E; Hwang, Kristy S; Jack, Clifford R; Jenkinson, Mark; Johnston, Caroline; Jönsson, Erik G; Kahn, René S; Kasperaviciute, Dalia; Kelly, Sinead; Kim, Sungeun; Kochunov, Peter; Koenders, Laura; Krämer, Bernd; Kwok, John B J; Lagopoulos, Jim; Laje, Gonzalo; Landen, Mikael; Landman, Bennett A; Lauriello, John; Lawrie, Stephen M; Lee, Phil H; Le Hellard, Stephanie; Lemaître, Herve; Leonardo, Cassandra D; Li, Chiang-Shan; Liberg, Benny; Liewald, David C; Liu, Xinmin; Lopez, Lorna M; Loth, Eva; Lourdusamy, Anbarasu; Luciano, Michelle; Macciardi, Fabio; Machielsen, Marise W J; Macqueen, Glenda M; Malt, Ulrik F; Mandl, René; Manoach, Dara S; Martinot, Jean-Luc; Matarin, Mar; Mather, Karen A; Mattheisen, Manuel; Mattingsdal, Morten; Meyer-Lindenberg, Andreas; McDonald, Colm; McIntosh, Andrew M; McMahon, Francis J; McMahon, Katie L; Meisenzahl, Eva; Melle, Ingrid; Milaneschi, Yuri; Mohnke, Sebastian; Montgomery, Grant W; Morris, Derek W; Moses, Eric K; Mueller, Bryon A; Muñoz Maniega, Susana; Mühleisen, Thomas W; Müller-Myhsok, Bertram; Mwangi, Benson; Nauck, Matthias; Nho, Kwangsik; Nichols, Thomas E; Nilsson, Lars-Göran; Nugent, Allison C; Nyberg, Lars; Olvera, Rene L; Oosterlaan, Jaap; Ophoff, Roel A; Pandolfo, Massimo; Papalampropoulou-Tsiridou, Melina; Papmeyer, Martina; Paus, Tomas; Pausova, Zdenka; Pearlson, Godfrey D; Penninx, Brenda W; Peterson, Charles P; Pfennig, Andrea; Phillips, Mary; Pike, G Bruce; Poline, Jean-Baptiste; Potkin, Steven G; Pütz, Benno; Ramasamy, Adaikalavan; Rasmussen, Jerod; Rietschel, Marcella; Rijpkema, Mark; Risacher, Shannon L; Roffman, Joshua L; Roiz-Santiañez, Roberto; Romanczuk-Seiferth, Nina; Rose, Emma J; Royle, Natalie A; Rujescu, Dan; Ryten, Mina; Sachdev, Perminder S; Salami, Alireza; Satterthwaite, Theodore D; Savitz, Jonathan; Saykin, Andrew J; Scanlon, Cathy; Schmaal, Lianne; Schnack, Hugo G; Schork, Andrew J; Schulz, S Charles; Schür, Remmelt; Seidman, Larry; Shen, Li; Shoemaker, Jody M; Simmons, Andrew; Sisodiya, Sanjay M; Smith, Colin; Smoller, Jordan W; Soares, Jair C; Sponheim, Scott R; Sprooten, Emma; Starr, John M; Steen, Vidar M; Strakowski, Stephen; Strike, Lachlan; Sussmann, Jessika; Sämann, Philipp G; Teumer, Alexander; Toga, Arthur W; Tordesillas-Gutierrez, Diana; Trabzuni, Daniah; Trost, Sarah; Turner, Jessica; Van den Heuvel, Martijn; van der Wee, Nic J; van Eijk, Kristel; van Erp, Theo G M; van Haren, Neeltje E M; van 't Ent, Dennis; van Tol, Marie-Jose; Valdés Hernández, Maria C; Veltman, Dick J; Versace, Amelia; Völzke, Henry; Walker, Robert; Walter, Henrik; Wang, Lei; Wardlaw, Joanna M; Weale, Michael E; Weiner, Michael W; Wen, Wei; Westlye, Lars T; Whalley, Heather C; Whelan, Christopher D; White, Tonya; Winkler, Anderson M; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Zilles, David; Zwiers, Marcel P; Thalamuthu, Anbupalam; Schofield, Peter R; Freimer, Nelson B; Lawrence, Natalia S; Drevets, Wayne

    2014-06-01

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of findings, in a total of 24,997 subjects. By meta-analyzing results from many sites, ENIGMA has detected factors that affect the brain that no individual site could detect on its own, and that require larger numbers of subjects than any individual neuroimaging study has currently collected. ENIGMA's first project was a genome-wide association study identifying common variants in the genome associated with hippocampal volume or intracranial volume. Continuing work is exploring genetic associations with subcortical volumes (ENIGMA2) and white matter microstructure (ENIGMA-DTI). Working groups also focus on understanding how schizophrenia, bipolar illness, major depression and attention deficit/hyperactivity disorder (ADHD) affect the brain. We review the current progress of the ENIGMA Consortium, along with challenges and unexpected discoveries made on the way.

  8. Disentangling volumetric and hydrational properties of proteins.

    Science.gov (United States)

    Voloshin, Vladimir P; Medvedev, Nikolai N; Smolin, Nikolai; Geiger, Alfons; Winter, Roland

    2015-02-05

    We used molecular dynamics simulations of a typical monomeric protein, SNase, in combination with Voronoi-Delaunay tessellation to study and analyze the temperature dependence of the apparent volume, Vapp, of the solute. We show that the void volume, VB, created in the boundary region between solute and solvent, determines the temperature dependence of Vapp to a major extent. The less pronounced but still significant temperature dependence of the molecular volume of the solute, VM, is essentially the result of the expansivity of its internal voids, as the van der Waals contribution to VM is practically independent of temperature. Results for polypeptides of different chemical nature feature a similar temperature behavior, suggesting that the boundary/hydration contribution seems to be a universal part of the temperature dependence of Vapp. The results presented here shine new light on the discussion surrounding the physical basis for understanding and decomposing the volumetric properties of proteins and biomolecules in general.

  9. Neuroimaging in Mental Health Care: Voices in Translation

    Directory of Open Access Journals (Sweden)

    Emily L. Borgelt

    2012-10-01

    Full Text Available Images of brain function, popularly called neuroimages, have become a mainstay of contemporary communication about neuroscience and mental health. Paralleling media coverage of neuroimaging research and the high visibility of clinics selling scans is pressure from sponsors to move basic research about brain function along the translational pathway. Indeed, neuroimaging benefit mental health care with early or tailored intervention, opportunities for education and planning, and access to resources afforded by objectification of disorder. However, risks of premature technology transfer, such as misinterpretation, misrepresentation, and increased stigmatization, could compromise patient care.Stakeholder views on neuroimaging for mental health care are a largely untapped resource of information and guidance for translational efforts. We argue that the insights of key stakeholders – researchers, healthcare providers, patients, and families - have an essential role to play upstream in professional, critical, and ethical discourse about neuroimaging in mental health. Here we integrate previously orthogonal lines of inquiry involving stakeholder research to describe the translational landscape as well as challenges on its horizon.

  10. Near-infrared neuroimaging with NinPy

    Directory of Open Access Journals (Sweden)

    Gary E Strangman

    2009-05-01

    Full Text Available There has been substantial recent growth in the use of non-invasive optical brain imaging in studies of human brain function in health and disease. Near-infrared neuroimaging (NIN is one of the most promising of these techniques and, although NIN hardware continues to evolve at a rapid pace, software tools supporting optical data acquisition, image processing, statistical modeling and visualization remain less refined. Python, a modular and computationally efficient development language, can support functional neuroimaging studies of diverse design and implementation. In particular, Python's easily readable syntax and modular architecture allow swift prototyping followed by efficient transition to stable production systems. As an introduction to our ongoing efforts to develop Python software tools for structural and functional neuroimaging, we discuss: (i the role of noninvasive diffuse optical imaging in measuring brain function, (ii the key computational requirements to support NIN experiments, (iii our collection of software tools to support near-infrared neuroimaging, called NinPy, and (iv future extensions of these tools that will allow integration of optical with other structural and functional neuroimaging data sources. Source code for the software discussed here will be made available at www.nmr.mgh.harvard.edu/Neural_SystemsGroup/software.html.

  11. Optimising neuroimaging effectiveness in a district general hospital.

    Science.gov (United States)

    McCarron, M O; Wade, C; McCarron, P

    2014-01-01

    Diagnostic accuracy in neurology frequently depends on clinical assessment and neuroimaging interpretation. We assessed neuroimaging discrepancy rates in reported findings between general radiologists and neuroradiologists among patients from a district general hospital (DGH). A neuroradiologist's report was sought on selected DGH patients over 28 months. Pre-planned outcomes included comparisons of primary findings (main diagnosis or abnormality), secondary findings (differential diagnoses and incidental findings) and advice from neuroradiologists for further investigations. A total of 233 patients (119 men and 114 women), mean age 47.2 (SD 17.8) years were studied: 43 had a computed tomography (CT) brain scan only, 37 had CT and magnetic resonance imaging (MRI) scans and 153 had only MRI scans. Discrepancies in the primary diagnosis/abnormality were identified in 33 patients (14.2%). This included 7 of 43 patients (16.3%) who had a CT brain scan as their only neuroimaging. Secondary outcomes differed in 50 patients (21.5%). Neuroradiologists recommended further neuroimaging for 29 patients (12.4%). The most common discrepancies in the primary diagnosis/abnormality were misinterpreting normal for hippocampal sclerosis and missed posterior fossa lesions. There was no evidence of temporal changes in discrepancy rates. Selecting CT and MR neuroimaging studies from general hospitals for reviewing by neuroradiologists is an important and effective way of optimising management of neurological patients.

  12. Neuroimaging of Parkinson’s Disease: Expanding views

    Science.gov (United States)

    Weingarten, Carol P.; Sundman, Mark H.; Hickey, Patrick; Chen, Nankuei

    2015-01-01

    Advances in molecular and structural and functional neuroimaging are rapidly expanding the complexity of neurobiological understanding of Parkinson’s disease (PD). This review article begins with an introduction to PD neurobiology as a foundation for interpreting neuroimaging findings that may further lead to more integrated and comprehensive understanding of PD. Diverse areas of PD neuroimaging are then reviewed and summarized, including positron emission tomography, single photon emission computed tomography, magnetic resonance spectroscopy and imaging, transcranial sonography, magnetoencephalography, and multimodal imaging, with focus on human studies published over the last five years. These included studies on differential diagnosis, co-morbidity, genetic and prodromal PD, and treatments from L-DOPA to brain stimulation approaches, transplantation and gene therapies. Overall, neuroimaging has shown that PD is a neurodegenerative disorder involving many neurotransmitters, brain regions, structural and functional connections, and neurocognitive systems. A broad neurobiological understanding of PD will be essential for translational efforts to develop better treatments and preventive strategies. Many questions remain and we conclude with some suggestions for future directions of neuroimaging of PD. PMID:26409344

  13. Neuroimaging in Parkinson disease: from research setting to clinical practice.

    Science.gov (United States)

    Politis, Marios

    2014-12-01

    Over the past three decades, neuroimaging studies-including structural, functional and molecular modalities-have provided invaluable insights into the mechanisms underlying Parkinson disease (PD). Observations from multimodal neuroimaging techniques have indicated changes in brain structure and metabolic activity, and an array of neurochemical changes that affect receptor sites and neurotransmitter systems. Characterization of the neurobiological alterations that lead to phenotypic heterogeneity in patients with PD has considerably aided the in vivo investigation of aetiology and pathophysiology, and the identification of novel targets for pharmacological or surgical treatments, including cell therapy. Although PD is now considered to be very complex, no neuroimaging modalities are specifically recommended for routine use in clinical practice. However, conventional MRI and dopamine transporter imaging are commonly used as adjuvant tools in the differential diagnosis between PD and nondegenerative causes of parkinsonism. First-line neuroimaging tools that could have an impact on patient prognosis and treatment strategies remain elusive. This Review discusses the lessons learnt from decades of neuroimaging research in PD, and the promising new approaches with potential applicability to clinical practice.

  14. A Technique for Volumetric CSG Based on Morphology

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2001-01-01

    In this paper, a new technique for volumetric CSG is presented. The technique requires the input volumes to correspond to solids which fulfill a voxelization suitability criterion. Assume the CSG operation is union. The volumetric union of two such volumes is defined in terms of the voxelization...

  15. Effects of Different Reconstruction Parameters on CT Volumetric Measurement 
of Pulmonary Nodules

    Directory of Open Access Journals (Sweden)

    Rongrong YANG

    2012-02-01

    Full Text Available Background and objective It has been proven that volumetric measurements could detect subtle changes in small pulmonary nodules in serial CT scans, and thus may play an important role in the follow-up of indeterminate pulmonary nodules and in differentiating malignant nodules from benign nodules. The current study aims to evaluate the effects of different reconstruction parameters on the volumetric measurements of pulmonary nodules in chest CT scans. Methods Thirty subjects who underwent chest CT scan because of indeterminate pulmonary nodules in General Hospital of Tianjin Medical University from December 2009 to August 2011 were retrospectively analyzed. A total of 52 pulmonary nodules were included, and all CT data were reconstructed using three reconstruction algorithms and three slice thicknesses. The volumetric measurements of the nodules were performed using the advanced lung analysis (ALA software. The effects of the reconstruction algorithms, slice thicknesses, and nodule diameters on the volumetric measurements were assessed using the multivariate analysis of variance for repeated measures, the correlation analysis, and the Bland-Altman method. Results The reconstruction algorithms (F=13.6, P<0.001 and slice thicknesses (F=4.4, P=0.02 had significant effects on the measured volume of pulmonary nodules. In addition, the coefficients of variation of nine measurements were inversely related with nodule diameter (r=-0.814, P<0.001. The volume measured at the 2.5 mm slice thickness had poor agreement with the volumes measured at 1.25 mm and 0.625 mm, respectively. Moreover, the best agreement was achieved between the slice thicknesses of 1.25 mm and 0.625 mm using the bone algorithm. Conclusion Reconstruction algorithms and slice thicknesses have significant impacts on the volumetric measurements of lung nodules, especially for the small nodules. Therefore, the reconstruction setting in serial CT scans should be consistent in the follow

  16. Clinical and neuroimaging study of spinocerebellar ataxia type 2

    Directory of Open Access Journals (Sweden)

    JIN Miao

    2013-06-01

    Full Text Available Background Spinocerebellar ataxia type 2 (SCA2 is an autosomal dominant genetic disease characterized by cerebellar ataxia, ophthalmoplegia, slow saccade, hyporeflexia, action tremor, cognitive decline and peripheral neuropathy. The brain MRI shows obvious atrophy of cerebellum and brainstem, indicating typical change of olivopontocerebellar atrophy. SCA2 is caused by an expanded cytosine-adenine-guanine (CAG trinucleotide repeat in the encoding region of ATXN2. The normal CAG repeats range from 13 to 31, and ataxic phenotype occurs when the repeats are more than 34. This study focused on the clinical and imaging features of 5 SCA2 families confirmed by genetic testing. The correlation between phenotype and genotype was analyzed. Methods The pathological CAG triplet repeat expansions of SCA1-3, 6, 7, 17 and dentatorubral-pallidoluysian atrophy (DRPLA genes were analyzed in the probands of 708 autosomal dominant SCA families and 119 sporadic SCA cases. The CAG repeat of ATXN2 gene was amplified by polymerase chain reaction (PCR and agarose gel electrophoresis. Fragment analysis based on CEQ8000 sequencer were applied to analyze expanded alleles. Results Expanded CAG repeats of ATXN2 gene were detected in 45 probands of SCA2 families. Most of the patients manifested with the typical clinical features of SCA2 such as cerebellar ataxia, ophthalmoplegia, slow saccade and hyporeflexia. Some of them also associated with action tremor. The brain MRI showed obvious atrophy of cerebellum and brainstem. The correlation between clinical features and CAG repeat of ATXN2 gene was studied carefully in 5 families. Conclusion Genetic analysis provides the basis for the diagnosis of SCA2. Clinical and neuroimaging features are very helpful in the diagnosis and differential diagnosis of this disease. For the identification of cases carrying intermediate allele, it is important to combine clinical, imaging features with dynamic mutation analysis in the affected

  17. The Road Ahead to Cure Alzheimer’s Disease: Development of Biological Markers and Neuroimaging Methods for Prevention Trials Across all Stages and Target Populations

    Science.gov (United States)

    Cavedo, E.; Lista, S.; Khachaturian, Z.; Aisen, P.; Amouyel, P.; Herholz, K.; Jack, C.R.; Sperling, R.; Cummings, J.; Blennow, K.; O’Bryant, S.; Frisoni, G.B.; Khachaturian, A.; Kivipelto, M.; Klunk, W.; Broich, K.; Andrieu, S.; de Schotten, M. Thiebaut; Mangin, J.-F.; Lammertsma, A.A.; Johnson, K.; Teipel, S.; Drzezga, A.; Bokde, A.; Colliot, O.; Bakardjian, H.; Zetterberg, H.; Dubois, B.; Vellas, B.; Schneider, L.S.; Hampel, H.

    2015-01-01

    Alzheimer’s disease (AD) is a slowly progressing non-linear dynamic brain disease in which pathophysiological abnormalities, detectable in vivo by biological markers, precede overt clinical symptoms by many years to decades. Use of these biomarkers for the detection of early and preclinical AD has become of central importance following publication of two international expert working group’s revised criteria for the diagnosis of AD dementia, mild cognitive impairment (MCI) due to AD, prodromal AD and preclinical AD. As a consequence of matured research evidence six AD biomarkers are sufficiently validated and partly qualified to be incorporated into operationalized clinical diagnostic criteria and use in primary and secondary prevention trials. These biomarkers fall into two molecular categories: biomarkers of amyloid-beta (Aβ) deposition and plaque formation as well as of tau-protein related hyperphosphorylation and neurodegeneration. Three of the six gold-standard (“core feasible) biomarkers are neuroimaging measures and three are cerebrospinal fluid (CSF) analytes. CSF Aβ1-42 (Aβ1-42), also expressed as Aβ1-42 : Aβ1-40 ratio, T-tau, and P-tau Thr181 & Thr231 proteins have proven diagnostic accuracy and risk enhancement in prodromal MCI and AD dementia. Conversely, having all three biomarkers in the normal range rules out AD. Intermediate conditions require further patient follow-up. Magnetic resonance imaging (MRI) at increasing field strength and resolution allows detecting the evolution of distinct types of structural and functional abnormality pattern throughout early to late AD stages. Anatomical or volumetric MRI is the most widely used technique and provides local and global measures of atrophy. The revised diagnostic criteria for “prodromal AD” and “mild cognitive impairment due to AD” include hippocampal atrophy (as the fourth validated biomarker), which is considered an indicator of regional neuronal injury. Advanced image analysis

  18. Looking inside the brain the power of neuroimaging

    CERN Document Server

    Le Bihan, Denis

    2014-01-01

    It is now possible to witness human brain activity while we are talking, reading, or thinking, thanks to revolutionary neuroimaging techniques like magnetic resonance imaging (MRI). These groundbreaking advances have opened infinite fields of investigation—into such areas as musical perception, brain development in utero, and faulty brain connections leading to psychiatric disorders—and have raised unprecedented ethical issues. In Looking Inside the Brain, one of the leading pioneers of the field, Denis Le Bihan, offers an engaging account of the sophisticated interdisciplinary research in physics, neuroscience, and medicine that have led to the remarkable neuroimaging methods that give us a detailed look into the human brain. Introducing neurological anatomy and physiology, Le Bihan walks readers through the historical evolution of imaging technology—from the x-ray and CT scan to the PET scan and MRI—and he explains how neuroimaging uncovers afflictions like stroke or cancer and the workings of high...

  19. Neuroethics, neuroimaging, and disorders of consciousness: promise or peril?

    Science.gov (United States)

    Fins, Joseph J

    2011-01-01

    The advent of powerful neuroimaging tools such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) has begun to redefine how we diagnose, define, and understand disorders of consciousness such as the vegetative and minimally conscious states. In my paper, I review how research using these methods is both elucidating these brain states and creating diagnostic dilemmas related to their classification as the specificity and sensitivity of traditional behavior-based assessments are weighed against sensitive but not yet fully validated neuroimaging data. I also consider how these methods are being studied as potential communication vectors for therapeutic use in subjects who heretofore have been thought to be unresponsive or minimally conscious. I conclude by considering the ethical challenges posed by novel diagnostic and therapeutic neuroimaging applications and contextualize these scientific developments against the broader needs of patients and families touched by severe brain injury.

  20. When Should Neuroimaging be Applied in the Criminal Court?

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2014-01-01

    When does neuroimaging constitute a sufficiently developed technology to be put into use in the work of determining whether or not a defendant is guilty of crime? This question constitutes the starting point of the present paper. First, it is suggested that an overall answer is provided by what...... is referred to as the “ideal comparative view.” Secondly, it is—on the ground of this view—argued that the answer as to whether neuroimaging technology should be applied presupposes penal theoretical considerations. Thirdly, it is argued that the retributivist theory of punishment is not well......-suited for delivering the sort of theoretical guidance that is required for assessing the desirability of using neuroimaging in the work of the criminal court....

  1. Ischemic Stroke Treatment Trials: Neuroimaging Advancements and Implications.

    Science.gov (United States)

    Patel, Vivek P; Heit, Jeremy J

    2017-06-01

    There have been significant advancements in the treatment of acute ischemic stroke in the last 2 decades. Recent trials have placed a significant emphasis on minimizing the time from symptom onset to stroke treatment by reperfusion therapies, which decreases the cerebral infarct volume and improves clinical outcomes. These clinical advances have paralleled and been aided by advances in neuroimaging. However, controversy remains regarding how much time should be spent on neuroimaging evaluation versus expediting patient treatment. In this review article, we examine the key endovascular stroke trials published in the past 25 years, and we briefly highlight the failures and successes of endovascular stroke trials performed in the past 4 years. We also discuss the advantages and disadvantages of using time from symptom onset versus neuroimaging in determining endovascular stroke therapy candidacy.

  2. Multiple sclerosis in malaysia: demographics, clinical features, and neuroimaging characteristics.

    Science.gov (United States)

    Viswanathan, S; Rose, N; Masita, A; Dhaliwal, J S; Puvanarajah, S D; Rafia, M H; Muda, S

    2013-01-01

    Background. Multiple sclerosis (MS) is an uncommon disease in multiracial Malaysia. Diagnosing patients with idiopathic inflammatory demyelinating diseases has been greatly aided by the evolution in diagnostic criterion, the identification of new biomarkers, and improved accessibility to neuroimaging in the country. Objectives. To investigate the spectrum of multiple sclerosis in Malaysia. Methods. Retrospective analysis with longitudinal follow-up of patients referred to a single tertiary medical center with neurology services in Malaysia. Results. Out of 245 patients with idiopathic inflammatory demyelinating disease, 104 patients had multiple sclerosis. Female to male ratio was 5 : 1. Mean age at onset was 28.6 ± 9.9 years. The Malays were the predominant racial group affected followed by the Chinese, Indians, and other indigenous groups. Subgroup analysis revealed more Chinese having neuromyelitis optica and its spectrum disorders rather than multiple sclerosis. Positive family history was reported in 5%. Optic neuritis and myelitis were the commonest presentations at onset of disease, and relapsing remitting course was the commonest disease pattern observed. Oligoclonal band positivity was 57.6%. At disease onset, 61.5% and 66.4% fulfilled the 2005 and 2010 McDonald's criteria for dissemination in space. Mean cord lesion length was 1.86 ± 1.65 vertebral segments in the relapsing remitting group as opposed to 6.25 ± 5.18 vertebral segments in patients with neuromyelitis optica and its spectrum disorders. Conclusion. The spectrum of multiple sclerosis in Malaysia has changed over the years. Further advancement in diagnostic criteria will no doubt continue to contribute to the evolution of this disease here.

  3. Multiple Sclerosis in Malaysia: Demographics, Clinical Features, and Neuroimaging Characteristics

    Directory of Open Access Journals (Sweden)

    S. Viswanathan

    2013-01-01

    Full Text Available Background. Multiple sclerosis (MS is an uncommon disease in multiracial Malaysia. Diagnosing patients with idiopathic inflammatory demyelinating diseases has been greatly aided by the evolution in diagnostic criterion, the identification of new biomarkers, and improved accessibility to neuroimaging in the country. Objectives. To investigate the spectrum of multiple sclerosis in Malaysia. Methods. Retrospective analysis with longitudinal follow-up of patients referred to a single tertiary medical center with neurology services in Malaysia. Results. Out of 245 patients with idiopathic inflammatory demyelinating disease, 104 patients had multiple sclerosis. Female to male ratio was 5 : 1. Mean age at onset was 28.6 ± 9.9 years. The Malays were the predominant racial group affected followed by the Chinese, Indians, and other indigenous groups. Subgroup analysis revealed more Chinese having neuromyelitis optica and its spectrum disorders rather than multiple sclerosis. Positive family history was reported in 5%. Optic neuritis and myelitis were the commonest presentations at onset of disease, and relapsing remitting course was the commonest disease pattern observed. Oligoclonal band positivity was 57.6%. At disease onset, 61.5% and 66.4% fulfilled the 2005 and 2010 McDonald’s criteria for dissemination in space. Mean cord lesion length was 1.86 ± 1.65 vertebral segments in the relapsing remitting group as opposed to 6.25 ± 5.18 vertebral segments in patients with neuromyelitis optica and its spectrum disorders. Conclusion. The spectrum of multiple sclerosis in Malaysia has changed over the years. Further advancement in diagnostic criteria will no doubt continue to contribute to the evolution of this disease here.

  4. Incidental Findings in Neuroimaging: Ethical and Medicolegal Considerations.

    Science.gov (United States)

    Leung, Lawrence

    2013-01-01

    With the rapid advances in neurosciences in the last three decades, there has been an exponential increase in the use of neuroimaging both in basic sciences and clinical research involving human subjects. During routine neuroimaging, incidental findings that are not part of the protocol or scope of research agenda can occur and they often pose a challenge as to how they should be handled to abide by the medicolegal principles of research ethics. This paper reviews the issue from various ethical (do no harm, general duty to rescue, and mutual benefits and owing) and medicolegal perspectives (legal liability, fiduciary duties, Law of Tort, and Law of Contract) with a suggested protocol of approach.

  5. Neuroimaging and clinical neurophysiology in cluster headache and trigeminal autonomic cephalalgias

    DEFF Research Database (Denmark)

    Friberg, Lars; Sandrini, Giorgio; Perrotta, Armando

    2010-01-01

    Clinical neurophysiology and neuroimaging are two non-invasive approaches used to investigate the pathophysiological basis of primary headaches, including cluster headache (CH) and other trigeminal autonomic cephalalgias (TACs). Modern neuroimaging has revolutionized our understanding...

  6. Iterative reconstruction of volumetric particle distribution

    Science.gov (United States)

    Wieneke, Bernhard

    2013-02-01

    For tracking the motion of illuminated particles in space and time several volumetric flow measurement techniques are available like 3D-particle tracking velocimetry (3D-PTV) recording images from typically three to four viewing directions. For higher seeding densities and the same experimental setup, tomographic PIV (Tomo-PIV) reconstructs voxel intensities using an iterative tomographic reconstruction algorithm (e.g. multiplicative algebraic reconstruction technique, MART) followed by cross-correlation of sub-volumes computing instantaneous 3D flow fields on a regular grid. A novel hybrid algorithm is proposed here that similar to MART iteratively reconstructs 3D-particle locations by comparing the recorded images with the projections calculated from the particle distribution in the volume. But like 3D-PTV, particles are represented by 3D-positions instead of voxel-based intensity blobs as in MART. Detailed knowledge of the optical transfer function and the particle image shape is mandatory, which may differ for different positions in the volume and for each camera. Using synthetic data it is shown that this method is capable of reconstructing densely seeded flows up to about 0.05 ppp with similar accuracy as Tomo-PIV. Finally the method is validated with experimental data.

  7. Planning analysis for locally advanced lung cancer: dosimetric and efficiency comparisons between intensity-modulated radiotherapy (IMRT, single-arc/partial-arc volumetric modulated arc therapy (SA/PA-VMAT

    Directory of Open Access Journals (Sweden)

    Zhou Xiaojuan

    2011-10-01

    Full Text Available Abstract Purpose To analyze the differences between the intensity-modulated radiotherapy (IMRT, single/partial-arc volumetric modulated arc therapy (SA/PA-VMAT techniques in treatment planning for locally advanced lung cancer. Materials and methods 12 patients were retrospectively studied. In each patient's case, several parameters were analyzed based on the dose-volume histograms (DVH of the IMRT, SA/PA-VMAT plans respectively. Also, each plan was delivered to a phantom for time comparison. Results The SA-VMAT plans showed the superior target dose coverage, although the minimum/mean/maximum doses to the target were similar. For the total and contralateral lungs, the higher V5/10, lower V20/30 and mean lung dose (MLD were observed in the SA/PA-VMAT plans (p 20, V30 and MLD of the controlateral lung more notably, comparing to those parameters of the IMRT and SA-VMAT plans respectively. The delivered monitor units (MUs and treatment times were reduced significantly with VMAT plans, especially PA-VMAT plans (for MUs: mean 458.3 vs. 439.2 vs. 435.7 MUs, p vs. 10.6 vs. 6.4 minutes, p Conclusions The SA-VMAT technique achieves highly conformal dose distribution to the target. Comparing to the IMRT plans, the higher V5/10, lower V20/30 and MLD were observed in the total and contralateral lungs in the VMAT plans, especially in the PA-VMAT plans. The SA/PA-VMAT plans also reduced treatment time with more efficient dose delivering. But the clinical benefit of the VMAT technique for locally advanced lung cancer needs further investigations.

  8. 25 years of neuroimaging in amyotrophic lateral sclerosis

    Science.gov (United States)

    Foerster, Bradley R.; Welsh, Robert C.; Feldman, Eva L.

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which a precise cause has not yet been identified. Standard CT or MRI evaluation does not demonstrate gross structural nervous system changes in ALS, so conventional neuroimaging techniques have provided little insight into the pathophysiology of this disease. Advanced neuroimaging techniques—such as structural MRI, diffusion tensor imaging and proton magnetic resonance spectroscopy—allow evaluation of alterations of the nervous system in ALS. These alterations include focal loss of grey and white matter and reductions in white matter tract integrity, as well as changes in neural networks and in the chemistry, metabolism and receptor distribution in the brain. Given their potential for investigation of both brain structure and function, advanced neuroimaging methods offer important opportunities to improve diagnosis, guide prognosis, and direct future treatment strategies in ALS. In this article, we review the contributions made by various advanced neuroimaging techniques to our understanding of the impact of ALS on different brain regions, and the potential role of such measures in biomarker development. PMID:23917850

  9. Neuroimaging of aggressive and violent behaviour in children and adolescents

    Directory of Open Access Journals (Sweden)

    Philipp Sterzer

    2009-10-01

    Full Text Available In recent years, a number of functional and structural neuroimaging studies have investigated the neural bases of aggressive and violent behaviour in children and adolescents. Most functional neuroimaging studies have persued the hypothesis that pathological aggression is a consequence of deficits in the neural circuits involved in emotion processing. There is converging evidence for deficient neural responses to emotional stimuli in youths with a propensity towards aggressive behaviour. In addition, recent neuroimaging work has suggested that aggressive behaviour is also associated with abnormalities in neural processes that subserve both the inhibitory control of behaviour and the flexible adaptation of behaviour in accord with reinforcement information. Structural neuroimaging studies in children and adolescents with conduct problems are still scarce, but point to deficits in brain structures in volved in the processing of social information and in the regulation of social and goal directed behaviour. The indisputable progress that this research field has made in recent years notwithstanding, the overall picture is still rather patchy and there are inconsistencies between studies that await clarification. Despite this, we attempt to provide an integrated view on the neural abnormalities that may contribute to various forms of juvenile aggression and violence, and discuss research strategies that may help to provide a more profound understanding of these important issues in the future.

  10. Memory Systems, Processing Modes, and Components: Functional Neuroimaging Evidence

    Science.gov (United States)

    Cabeza, Roberto; Moscovitch, Morris

    2013-01-01

    In the 1980s and 1990s, there was a major theoretical debate in the memory domain regarding the multiple memory systems and processing modes frameworks. The components of processing framework argued for a middle ground: Instead of neatly divided memory systems or processing modes, this framework proposed the existence of numerous processing components that are recruited in different combinations by memory tasks and yield complex patterns of associations and dissociations. Because behavioral evidence was not sufficient to decide among these three frameworks, the debate was largely abandoned. However, functional neuroimaging evidence accumulated during the last two decades resolves the stalemate, because this evidence is more consistent with the components framework than with the other two frameworks. For example, functional neuroimaging evidence shows that brain regions attributed to one memory system can contribute to tasks associated with other memory systems and that brain regions attributed to the same processing mode (perceptual or conceptual) can be dissociated from each other. Functional neuroimaging evidence suggests that memory processes are supported by transient interactions between a few regions called process-specific alliances. These conceptual developments are an example of how functional neuroimaging can contribute to theoretical debates in cognitive psychology. PMID:24163702

  11. Neuroimaging Research with Children: Ethical Issues and Case Scenarios

    Science.gov (United States)

    Coch, Donna

    2007-01-01

    There are few available resources for learning and teaching about ethical issues in neuroimaging research with children, who constitute a special and vulnerable population. Here, a brief review of ethical issues in developmental research, situated within the emerging field of neuroethics, highlights the increasingly interdisciplinary nature of…

  12. Functional Neuroimaging of Appetite and Gut–Brain Interactions

    NARCIS (Netherlands)

    Smeets, P.A.M.; Preissl, Hubert

    2016-01-01

    Ultimately, eating decisions are made in the brain, based on the integration
    of multiple neural and hormonal signals. Since the early 1990s the use of
    functional
    neuroimaging techniques has continued to increase. Their application
    in the study of the regulation of food intake and gut

  13. Uncovering the etiology of conversion disorder: insights from functional neuroimaging

    Science.gov (United States)

    Ejareh dar, Maryam; Kanaan, Richard AA

    2016-01-01

    Conversion disorder (CD) is a syndrome of neurological symptoms arising without organic cause, arguably in response to emotional stress, but the exact neural substrates of these symptoms and the underlying mechanisms remain poorly understood with the hunt for a biological basis afoot for centuries. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from CDs in both motor and nonmotor domains. This review summarizes recent functional neuroimaging studies including functional magnetic resonance imaging (fMRI), single photon emission computerized tomography (SPECT), and positron emission tomography (PET) to see whether they bring us closer to understanding the etiology of CD. Convergent functional neuroimaging findings suggest alterations in brain circuits that could point to different mechanisms for manifesting functional neurological symptoms, in contrast with feigning or healthy controls. Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors implicate a specific response to trauma. No comprehensive theory emerges from these clues, and all results remain preliminary, but functional neuroimaging has at least given grounds for hope that a model for CD may soon be found. PMID:26834476

  14. 25 years of neuroimaging in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Foerster, Bradley R; Welsh, Robert C; Feldman, Eva L

    2013-09-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which a precise cause has not yet been identified. Standard CT or MRI evaluation does not demonstrate gross structural nervous system changes in ALS, so conventional neuroimaging techniques have provided little insight into the pathophysiology of this disease. Advanced neuroimaging techniques--such as structural MRI, diffusion tensor imaging and proton magnetic resonance spectroscopy--allow evaluation of alterations of the nervous system in ALS. These alterations include focal loss of grey and white matter and reductions in white matter tract integrity, as well as changes in neural networks and in the chemistry, metabolism and receptor distribution in the brain. Given their potential for investigation of both brain structure and function, advanced neuroimaging methods offer important opportunities to improve diagnosis, guide prognosis, and direct future treatment strategies in ALS. In this article, we review the contributions made by various advanced neuroimaging techniques to our understanding of the impact of ALS on different brain regions, and the potential role of such measures in biomarker development.

  15. Testing for difference between two groups of functional neuroimaging experiments

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Chen, Andrew C. N.; Hansen, Lars Kai

    2004-01-01

    We describe a meta-analytic method that tests for the difference between two groups of functional neuroimaging experiments. We use kernel density estimation in three-dimensional brain space to convert points representing focal brain activations into a voxel-based representation. We find the maximum...

  16. Neuroimaging training among neuropsychologists: A survey of the state of current training and recommendations for trainees

    OpenAIRE

    2013-01-01

    Neuroimaging has gained widespread use in neuropsychological research and practice. However, there are neither established guidelines on how neuropsychologists might become competent researchers or consumers of neuroimaging data, nor any published studies describing the state of neuroimaging training among neuropsychologists. We report the results of two online surveys, one of 13 expert neuropsychologist-neuroimagers, whose responses informed the formulation of a second, larger survey to neur...

  17. Area and volumetric density estimation in processed full-field digital mammograms for risk assessment of breast cancer.

    Directory of Open Access Journals (Sweden)

    Abbas Cheddad

    Full Text Available INTRODUCTION: Mammographic density, the white radiolucent part of a mammogram, is a marker of breast cancer risk and mammographic sensitivity. There are several means of measuring mammographic density, among which are area-based and volumetric-based approaches. Current volumetric methods use only unprocessed, raw mammograms, which is a problematic restriction since such raw mammograms are normally not stored. We describe fully automated methods for measuring both area and volumetric mammographic density from processed images. METHODS: The data set used in this study comprises raw and processed images of the same view from 1462 women. We developed two algorithms for processed images, an automated area-based approach (CASAM-Area and a volumetric-based approach (CASAM-Vol. The latter method was based on training a random forest prediction model with image statistical features as predictors, against a volumetric measure, Volpara, for corresponding raw images. We contrast the three methods, CASAM-Area, CASAM-Vol and Volpara directly and in terms of association with breast cancer risk and a known genetic variant for mammographic density and breast cancer, rs10995190 in the gene ZNF365. Associations with breast cancer risk were evaluated using images from 47 breast cancer cases and 1011 control subjects. The genetic association analysis was based on 1011 control subjects. RESULTS: All three measures of mammographic density were associated with breast cancer risk and rs10995190 (p0.10 for risk, p>0.03 for rs10995190. CONCLUSIONS: Our results show that it is possible to obtain reliable automated measures of volumetric and area mammographic density from processed digital images. Area and volumetric measures of density on processed digital images performed similar in terms of risk and genetic association.

  18. A review of neuroimaging studies of anxiety disorders in China.

    Science.gov (United States)

    Chen, Jing; Shi, Shenxun

    2011-01-01

    Anxiety disorders are highly prevalent internationally, and constitute a substantial social and economic burden for patients, their families, and society. A number of neuroimaging studies have investigated the etiology of anxiety disorders in China in the last decade. We discuss the findings of these studies, and compare them with the results of neuroimaging studies of anxiety disorders outside China. A literature search was conducted using the Chinese BioMedical Literature Database, the Chinese Scientific and Technical Periodicals Database, the Chinese Journal Full-text Database, and PubMed, from 1989 to April 2009. We selected neuroimaging studies in which all participants and researchers were Chinese. Twenty-five studies fit our inclusion criteria. Nine studies examined general anxiety disorder (GAD) and/or panic disorder (PD), eight examined obsessive-compulsive disorder (OCD), and eight examined posttraumatic stress disorder (PTSD). Our literature review revealed several general findings. First, reduced regional cerebral blood flow (rCBF) was found in the frontal lobe and temporal lobe in patients with GAD and PD compared with healthy controls. Second, when viewing images with negative and positive valence, relatively increased or decreased activation was found in several brain areas in patients with GAD and PD, respectively. Third, studies with positron emission tomography (PET) and magnetic resonance spectroscopy (MRS) imaging revealed that OCD patients exhibited hyperperfusion and hypoperfusion in some brain regions compared with healthy controls. Neuroimaging studies of PTSD indicate that the hippocampal volume and the N-acetylaspartic acid (NAA) level and the NAA/creatine ratio in the hippocampus are decreased in patients relative to controls. Neuroimaging studies within and outside China have provided evidence of specific neurobiological changes associated with anxiety disorders. However, results have not been entirely consistent across different studies

  19. The Neuro-Image: Alain Resnais's Digital Cinema without the Digits

    NARCIS (Netherlands)

    Pisters, P.

    2011-01-01

    This paper proposes to read cinema in the digital age as a new type of image, the neuroimage. Going back to Gilles Deleuze's cinema books and it is argued that the neuro-image is based in the future. The cinema of Alain Resnais is analyzed as a neuro-image and digital cinema .

  20. The Neuro-Image: Alain Resnais's Digital Cinema without the Digits

    NARCIS (Netherlands)

    Pisters, P.

    2011-01-01

    This paper proposes to read cinema in the digital age as a new type of image, the neuroimage. Going back to Gilles Deleuze's cinema books and it is argued that the neuro-image is based in the future. The cinema of Alain Resnais is analyzed as a neuro-image and digital cinema .

  1. Web-based interactive visualization in a Grid-enabled neuroimaging application using HTML5.

    Science.gov (United States)

    Siewert, René; Specovius, Svenja; Wu, Jie; Krefting, Dagmar

    2012-01-01

    Interactive visualization and correction of intermediate results are required in many medical image analysis pipelines. To allow certain interaction in the remote execution of compute- and data-intensive applications, new features of HTML5 are used. They allow for transparent integration of user interaction into Grid- or Cloud-enabled scientific workflows. Both 2D and 3D visualization and data manipulation can be performed through a scientific gateway without the need to install specific software or web browser plugins. The possibilities of web-based visualization are presented along the FreeSurfer-pipeline, a popular compute- and data-intensive software tool for quantitative neuroimaging.

  2. Characterizing volumetric deformation behavior of naturally occuring bituminous sand materials

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2009-05-01

    Full Text Available newly proposed hydrostatic compression test procedure. The test procedure applies field loading conditions of off-road construction and mining equipment to closely simulate the volumetric deformation and stiffness behaviour of oil sand materials. Based...

  3. Hyperspectral image classification based on volumetric texture and dimensionality reduction

    Science.gov (United States)

    Su, Hongjun; Sheng, Yehua; Du, Peijun; Chen, Chen; Liu, Kui

    2015-06-01

    A novel approach using volumetric texture and reduced-spectral features is presented for hyperspectral image classification. Using this approach, the volumetric textural features were extracted by volumetric gray-level co-occurrence matrices (VGLCM). The spectral features were extracted by minimum estimated abundance covariance (MEAC) and linear prediction (LP)-based band selection, and a semi-supervised k-means (SKM) clustering method with deleting the worst cluster (SKMd) bandclustering algorithms. Moreover, four feature combination schemes were designed for hyperspectral image classification by using spectral and textural features. It has been proven that the proposed method using VGLCM outperforms the gray-level co-occurrence matrices (GLCM) method, and the experimental results indicate that the combination of spectral information with volumetric textural features leads to an improved classification performance in hyperspectral imagery.

  4. Designing remote web-based mechanical-volumetric flow meter ...

    African Journals Online (AJOL)

    ... remote web-based mechanical-volumetric flow meter reading systems based on ... damage and also provides the ability to control and manage consumption. ... existing infrastructure of the telecommunications is used in data transmission.

  5. Water content influence on thermal and volumetric properties of wheat starch gelatinization under 10 MPa.

    Science.gov (United States)

    Orlowska, Marta; Randzio, Stanislaw L

    2010-02-01

    A transitiometric in situ analysis of wheat starch aqueous suspensions heated over a temperature range from 285 K to 415 K under isobaric conditions of 10 MPa is presented. Measurements were performed at four selected water concentrations: 56.0%, 64.7%, 73.5%, and 82.4% weight/water. Thermal and volumetric properties and their water content dependencies have been determined for three successive starch phase transformations occurred during wheat starch gelatinization.

  6. Hepatosplenic volumetric assessment at MDCT for staging liver fibrosis.

    Science.gov (United States)

    Pickhardt, Perry J; Malecki, Kyle; Hunt, Oliver F; Beaumont, Claire; Kloke, John; Ziemlewicz, Timothy J; Lubner, Meghan G

    2017-07-01

    To investigate hepatosplenic volumetry at MDCT for non-invasive prediction of hepatic fibrosis. Hepatosplenic volume analysis in 624 patients (mean age, 48.8 years; 311 M/313 F) at MDCT was performed using dedicated software and compared against pathological fibrosis stage (F0 = 374; F1 = 48; F2 = 40; F3 = 65; F4 = 97). The liver segmental volume ratio (LSVR) was defined by Couinaud segments I-III over segments IV-VIII. All pre-cirrhotic fibrosis stages (METAVIR F1-F3) were based on liver biopsy within 1 year of MDCT. LSVR and total splenic volumes increased with stage of fibrosis, with mean(±SD) values of: F0: 0.26 ± 0.06 and 215.1 ± 88.5 mm(3); F1: 0.25 ± 0.08 and 294.8 ± 153.4 mm(3); F2: 0.331 ± 0.12 and 291.6 ± 197.1 mm(3); F3: 0.39 ± 0.15 and 509.6 ± 402.6 mm(3); F4: 0.56 ± 0.30 and 790.7 ± 450.3 mm(3), respectively. Total hepatic volumes showed poor discrimination (F0: 1674 ± 320 mm(3); F4: 1631 ± 691 mm(3)). For discriminating advanced fibrosis (≥F3), the ROC AUC values for LSVR, total liver volume, splenic volume and LSVR/spleen combined were 0.863, 0.506, 0.890 and 0.947, respectively. Relative changes in segmental liver volumes and total splenic volume allow for non-invasive staging of hepatic fibrosis, whereas total liver volume is a poor predictor. Unlike liver biopsy or elastography, these CT volumetric biomarkers can be obtained retrospectively on routine scans obtained for other indications. • Regional changes in hepatic volume (LSVR) correlate well with degree of fibrosis. • Total liver volume is a very poor predictor of underlying fibrosis. • Total splenic volume is associated with the degree of hepatic fibrosis. • Hepatosplenic volume assessment is comparable to elastography for staging fibrosis. • Unlike elastography, volumetric analysis can be performed retrospectively.

  7. Increasing the volumetric efficiency of Diesel engines by intake pipes

    Science.gov (United States)

    List, Hans

    1933-01-01

    Development of a method for calculating the volumetric efficiency of piston engines with intake pipes. Application of this method to the scavenging pumps of two-stroke-cycle engines with crankcase scavenging and to four-stroke-cycle engines. The utility of the method is demonstrated by volumetric-efficiency tests of the two-stroke-cycle engines with crankcase scavenging. Its practical application to the calculation of intake pipes is illustrated by example.

  8. Parkinson's disease: diagnostic utility of volumetric imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei-Che; Chen, Meng-Hsiang [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Diagnostic Radiology, Kaohsiung (China); Chou, Kun-Hsien [National Yang-Ming University, Brain Research Center, Taipei (China); Lee, Pei-Lin [National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Tsai, Nai-Wen; Lu, Cheng-Hsien [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Neurology, Kaohsiung (China); Chen, Hsiu-Ling [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Diagnostic Radiology, Kaohsiung (China); National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Hsu, Ai-Ling [National Taiwan University, Institute of Biomedical Electronics and Bioinformatics, Taipei (China); Huang, Yung-Cheng [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Nuclear Medicine, Kaohsiung (China); Lin, Ching-Po [National Yang-Ming University, Brain Research Center, Taipei (China); National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China)

    2017-04-15

    This paper aims to examine the effectiveness of structural imaging as an aid in the diagnosis of Parkinson's disease (PD). High-resolution T{sub 1}-weighted magnetic resonance imaging was performed in 72 patients with idiopathic PD (mean age, 61.08 years) and 73 healthy subjects (mean age, 58.96 years). The whole brain was parcellated into 95 regions of interest using composite anatomical atlases, and region volumes were calculated. Three diagnostic classifiers were constructed using binary multiple logistic regression modeling: the (i) basal ganglion prior classifier, (ii) data-driven classifier, and (iii) basal ganglion prior/data-driven hybrid classifier. Leave-one-out cross validation was used to unbiasedly evaluate the predictive accuracy of imaging features. Pearson's correlation analysis was further performed to correlate outcome measurement using the best PD classifier with disease severity. Smaller volume in susceptible regions is diagnostic for Parkinson's disease. Compared with the other two classifiers, the basal ganglion prior/data-driven hybrid classifier had the highest diagnostic reliability with a sensitivity of 74%, specificity of 75%, and accuracy of 74%. Furthermore, outcome measurement using this classifier was associated with disease severity. Brain structural volumetric analysis with multiple logistic regression modeling can be a complementary tool for diagnosing PD. (orig.)

  9. Volumetric optoacoustic monitoring of endovenous laser treatments

    Science.gov (United States)

    Fehm, Thomas F.; Deán-Ben, Xosé L.; Schaur, Peter; Sroka, Ronald; Razansky, Daniel

    2016-03-01

    Chronic venous insufficiency (CVI) is one of the most common medical conditions with reported prevalence estimates as high as 30% in the adult population. Although conservative management with compression therapy may improve the symptoms associated with CVI, healing often demands invasive procedures. Besides established surgical methods like vein stripping or bypassing, endovenous laser therapy (ELT) emerged as a promising novel treatment option during the last 15 years offering multiple advantages such as less pain and faster recovery. Much of the treatment success hereby depends on monitoring of the treatment progression using clinical imaging modalities such as Doppler ultrasound. The latter however do not provide sufficient contrast, spatial resolution and three-dimensional imaging capacity which is necessary for accurate online lesion assessment during treatment. As a consequence, incidence of recanalization, lack of vessel occlusion and collateral damage remains highly variable among patients. In this study, we examined the capacity of volumetric optoacoustic tomography (VOT) for real-time monitoring of ELT using an ex-vivo ox foot model. ELT was performed on subcutaneous veins while optoacoustic signals were acquired and reconstructed in real-time and at a spatial resolution in the order of 200μm. VOT images showed spatio-temporal maps of the lesion progression, characteristics of the vessel wall, and position of the ablation fiber's tip during the pull back. It was also possible to correlate the images with the temperature elevation measured in the area adjacent to the ablation spot. We conclude that VOT is a promising tool for providing online feedback during endovenous laser therapy.

  10. Treatment planning for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bedford, James L. [Joint Department of Physics, Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom)

    2009-11-15

    Purpose: Volumetric modulated arc therapy (VMAT) is a specific type of intensity-modulated radiation therapy (IMRT) in which the gantry speed, multileaf collimator (MLC) leaf position, and dose rate vary continuously during delivery. A treatment planning system for VMAT is presented. Methods: Arc control points are created uniformly throughout one or more arcs. An iterative least-squares algorithm is used to generate a fluence profile at every control point. The control points are then grouped and all of the control points in a given group are used to approximate the fluence profiles. A direct-aperture optimization is then used to improve the solution, taking into account the allowed range of leaf motion of the MLC. Dose is calculated using a fast convolution algorithm and the motion between control points is approximated by 100 interpolated dose calculation points. The method has been applied to five cases, consisting of lung, rectum, prostate and seminal vesicles, prostate and pelvic lymph nodes, and head and neck. The resulting plans have been compared with segmental (step-and-shoot) IMRT and delivered and verified on an Elekta Synergy to ensure practicality. Results: For the lung, prostate and seminal vesicles, and rectum cases, VMAT provides a plan of similar quality to segmental IMRT but with faster delivery by up to a factor of 4. For the prostate and pelvic nodes and head-and-neck cases, the critical structure doses are reduced with VMAT, both of these cases having a longer delivery time than IMRT. The plans in general verify successfully, although the agreement between planned and measured doses is not very close for the more complex cases, particularly the head-and-neck case. Conclusions: Depending upon the emphasis in the treatment planning, VMAT provides treatment plans which are higher in quality and/or faster to deliver than IMRT. The scheme described has been successfully introduced into clinical use.

  11. Assessing the feasibility of volumetric-modulated arc therapy using simultaneous integrated boost (SIB-VMAT): An analysis for complex head-neck, high-risk prostate and rectal cancer cases.

    Science.gov (United States)

    Cilla, Savino; Deodato, Francesco; Digesù, Cinzia; Macchia, Gabriella; Picardi, Vincenzo; Ferro, Marica; Sallustio, Giuseppina; De Spirito, Marco; Piermattei, Angelo; Morganti, Alessio G

    2014-01-01

    Intensity-modulated radiotherapy (IMRT) allowed the simultaneous delivery of different doses to different target volumes within a single fraction, an approach called simultaneous integrated boost (SIB). As consequence, the fraction dose to the boost volume can be increased while keeping low doses to the elective volumes, and the number of fractions and overall treatment time will be reduced, translating into better radiobiological effectiveness. In recent years, volumetric-modulated arc therapy (VMAT) has been shown to provide similar plan quality with respect to fixed-field IMRT but with large reduction in treatment time and monitor units (MUs) number. However, the feasibility of VMAT when used with SIB strategy has few investigations to date. We explored the potential of VMAT in a SIB strategy for complex cancer sites. A total of 15 patients were selected, including 5 head-and-neck, 5 high-risk prostate, and 5 rectal cancer cases. Both a double-arc VMAT and a 7-field IMRT plan were generated for each case using Oncentra MasterPlan treatment planning system for an Elekta Precise linac. Dosimetric indexes for targets and organs at risk (OARs) were compared based on dose-volume histograms. Conformity index, homogeneity index, and dose-contrast index were used for target analyses. The equivalent uniform doses and the normal tissue complication probabilities were calculated for main OARs. MUs number and treatment time were analyzed to score treatment efficiency. Pretreatment dosimetry was performed using 2-dimensional (2D)-array dosimeter. SIB-VMAT plans showed a high level of fluence modulation needed for SIB treatments, high conformal dose distribution, similar target coverage, and a tendency to improve OARs sparing compared with the benchmark SIB-IMRT plans. The median treatment times reduced from 13 to 20 minutes to approximately 5 minutes for all cases with SIB-VMAT, with a MUs reduction up to 22.5%. The 2D-array ion-chambers' measurements reported an agreement

  12. Assessing the feasibility of volumetric-modulated arc therapy using simultaneous integrated boost (SIB-VMAT): An analysis for complex head-neck, high-risk prostate and rectal cancer cases

    Energy Technology Data Exchange (ETDEWEB)

    Cilla, Savino, E-mail: savinocilla@gmail.com [Medical Physics Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Deodato, Francesco; Digesù, Cinzia; Macchia, Gabriella; Picardi, Vincenzo; Ferro, Marica [Radiation Oncology Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); Sallustio, Giuseppina [Radiology Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy); De Spirito, Marco; Piermattei, Angelo [Physics Institute, Università Cattolica del Sacro Cuore, Rome (Italy); Morganti, Alessio G. [Radiation Oncology Unit, Fondazione di ricerca e cura “Giovanni Paolo II,” Università Cattolica del Sacro Cuore, Campobasso (Italy)

    2014-04-01

    Intensity-modulated radiotherapy (IMRT) allowed the simultaneous delivery of different doses to different target volumes within a single fraction, an approach called simultaneous integrated boost (SIB). As consequence, the fraction dose to the boost volume can be increased while keeping low doses to the elective volumes, and the number of fractions and overall treatment time will be reduced, translating into better radiobiological effectiveness. In recent years, volumetric-modulated arc therapy (VMAT) has been shown to provide similar plan quality with respect to fixed-field IMRT but with large reduction in treatment time and monitor units (MUs) number. However, the feasibility of VMAT when used with SIB strategy has few investigations to date. We explored the potential of VMAT in a SIB strategy for complex cancer sites. A total of 15 patients were selected, including 5 head-and-neck, 5 high-risk prostate, and 5 rectal cancer cases. Both a double-arc VMAT and a 7-field IMRT plan were generated for each case using Oncentra MasterPlan treatment planning system for an Elekta Precise linac. Dosimetric indexes for targets and organs at risk (OARs) were compared based on dose-volume histograms. Conformity index, homogeneity index, and dose-contrast index were used for target analyses. The equivalent uniform doses and the normal tissue complication probabilities were calculated for main OARs. MUs number and treatment time were analyzed to score treatment efficiency. Pretreatment dosimetry was performed using 2-dimensional (2D)-array dosimeter. SIB-VMAT plans showed a high level of fluence modulation needed for SIB treatments, high conformal dose distribution, similar target coverage, and a tendency to improve OARs sparing compared with the benchmark SIB-IMRT plans. The median treatment times reduced from 13 to 20 minutes to approximately 5 minutes for all cases with SIB-VMAT, with a MUs reduction up to 22.5%. The 2D-array ion-chambers' measurements reported an

  13. Neuroimaging standards for research into small vessel disease and its contribution to ageing and neurodegeneration.

    Science.gov (United States)

    Wardlaw, Joanna M; Smith, Eric E; Biessels, Geert J; Cordonnier, Charlotte; Fazekas, Franz; Frayne, Richard; Lindley, Richard I; O'Brien, John T; Barkhof, Frederik; Benavente, Oscar R; Black, Sandra E; Brayne, Carol; Breteler, Monique; Chabriat, Hugues; Decarli, Charles; de Leeuw, Frank-Erik; Doubal, Fergus; Duering, Marco; Fox, Nick C; Greenberg, Steven; Hachinski, Vladimir; Kilimann, Ingo; Mok, Vincent; Oostenbrugge, Robert van; Pantoni, Leonardo; Speck, Oliver; Stephan, Blossom C M; Teipel, Stefan; Viswanathan, Anand; Werring, David; Chen, Christopher; Smith, Colin; van Buchem, Mark; Norrving, Bo; Gorelick, Philip B; Dichgans, Martin

    2013-08-01

    Cerebral small vessel disease (SVD) is a common accompaniment of ageing. Features seen on neuroimaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. SVD can present as a stroke or cognitive decline, or can have few or no symptoms. SVD frequently coexists with neurodegenerative disease, and can exacerbate cognitive deficits, physical disabilities, and other symptoms of neurodegeneration. Terminology and definitions for imaging the features of SVD vary widely, which is also true for protocols for image acquisition and image analysis. This lack of consistency hampers progress in identifying the contribution of SVD to the pathophysiology and clinical features of common neurodegenerative diseases. We are an international working group from the Centres of Excellence in Neurodegeneration. We completed a structured process to develop definitions and imaging standards for markers and consequences of SVD. We aimed to achieve the following: first, to provide a common advisory about terms and definitions for features visible on MRI; second, to suggest minimum standards for image acquisition and analysis; third, to agree on standards for scientific reporting of changes related to SVD on neuroimaging; and fourth, to review emerging imaging methods for detection and quantification of preclinical manifestations of SVD. Our findings and recommendations apply to research studies, and can be used in the clinical setting to standardise image interpretation, acquisition, and reporting. This Position Paper summarises the main outcomes of this international effort to provide the STandards for ReportIng Vascular changes on nEuroimaging (STRIVE). Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Visualization and volumetric structures from MR images of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Parvin, B.; Johnston, W.; Robertson, D.

    1994-03-01

    Pinta is a system for segmentation and visualization of anatomical structures obtained from serial sections reconstructed from magnetic resonance imaging. The system approaches the segmentation problem by assigning each volumetric region to an anatomical structure. This is accomplished by satisfying constraints at the pixel level, slice level, and volumetric level. Each slice is represented by an attributed graph, where nodes correspond to regions and links correspond to the relations between regions. These regions are obtained by grouping pixels based on similarity and proximity. The slice level attributed graphs are then coerced to form a volumetric attributed graph, where volumetric consistency can be verified. The main novelty of our approach is in the use of the volumetric graph to ensure consistency from symbolic representations obtained from individual slices. In this fashion, the system allows errors to be made at the slice level, yet removes them when the volumetric consistency cannot be verified. Once the segmentation is complete, the 3D surfaces of the brain can be constructed and visualized.

  15. Soft bilateral filtering volumetric shadows using cube shadow maps

    Science.gov (United States)

    Ali, Hatam H.; Sunar, Mohd Shahrizal; Kolivand, Hoshang

    2017-01-01

    Volumetric shadows often increase the realism of rendered scenes in computer graphics. Typical volumetric shadows techniques do not provide a smooth transition effect in real-time with conservation on crispness of boundaries. This research presents a new technique for generating high quality volumetric shadows by sampling and interpolation. Contrary to conventional ray marching method, which requires extensive time, this proposed technique adopts downsampling in calculating ray marching. Furthermore, light scattering is computed in High Dynamic Range buffer to generate tone mapping. The bilateral interpolation is used along a view rays to smooth transition of volumetric shadows with respect to preserving-edges. In addition, this technique applied a cube shadow map to create multiple shadows. The contribution of this technique isreducing the number of sample points in evaluating light scattering and then introducing bilateral interpolation to improve volumetric shadows. This contribution is done by removing the inherent deficiencies significantly in shadow maps. This technique allows obtaining soft marvelous volumetric shadows, having a good performance and high quality, which show its potential for interactive applications. PMID:28632740

  16. Prediction of breast cancer recurrence using lymph node metabolic and volumetric parameters from (18)F-FDG PET/CT in operable triple-negative breast cancer.

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    Kim, Yong-Il; Kim, Yong Joong; Paeng, Jin Chul; Cheon, Gi Jeong; Lee, Dong Soo; Chung, June-Key; Kang, Keon Wook

    2017-06-14

    Triple-negative breast cancer has a poor prognosis. We evaluated several metabolic and volumetric parameters from preoperative (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the prognosis of triple-negative breast cancer and compared them with current clinicopathologic parameters. A total of 228 patients with triple-negative breast cancer (mean age 47.0 ± 10.8 years, all women) who had undergone preoperative PET/CT were included. The PET/CT metabolic parameters evaluated included maximum, peak, and mean standardized uptake values (SUVmax, SUVpeak, and SUVmean, respectively). The volumetric parameters evaluated included metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Metabolic and volumetric parameters were evaluated separately for tumor (T) and lymph nodes (N). The prognostic value of these parameters was compared with that of clinicopathologic parameters. All lymph node metabolic and volumetric parameters showed significant differences between patients with and without recurrence. However, tumor metabolic and volumetric parameters showed no significant differences. In a univariate survival analysis, all lymph node metabolic and volumetric parameters (SUVmax-N, SUVpeak-N, SUVmean-N, MTV-N, and TLG-N; all P triple-negative breast cancer after surgery. Lymph node metabolic and volumetric parameters were useful parameters for evaluating prognosis in patients with triple-negative breast cancer by (18)F-FDG PET/CT, rather than tumor parameters.

  17. A review of neuroimaging studies of anxiety disorders in China

    Directory of Open Access Journals (Sweden)

    Chen J

    2011-05-01

    Full Text Available Jing Chen, Shenxun ShiDepartment of Psychiatry, Huashan Hospital, Fudan University, Shanghai, ChinaBackground: Anxiety disorders are highly prevalent internationally, and constitute a substantial social and economic burden for patients, their families, and society. A number of neuroimaging studies have investigated the etiology of anxiety disorders in China in the last decade. We discuss the findings of these studies, and compare them with the results of neuroimaging studies of anxiety disorders outside China.Method: A literature search was conducted using the Chinese BioMedical Literature Database, the Chinese Scientific and Technical Periodicals Database, the Chinese Journal Full-text Database, and PubMed, from 1989 to April 2009. We selected neuroimaging studies in which all participants and researchers were Chinese.Results: Twenty-five studies fit our inclusion criteria. Nine studies examined general anxiety disorder (GAD and/or panic disorder (PD, eight examined obsessive-compulsive disorder (OCD, and eight examined posttraumatic stress disorder (PTSD. Our literature review revealed several general findings. First, reduced regional cerebral blood flow (rCBF was found in the frontal lobe and temporal lobe in patients with GAD and PD compared with healthy controls. Second, when viewing images with negative and positive valence, relatively increased or decreased activation was found in several brain areas in patients with GAD and PD, respectively. Third, studies with positron emission tomography (PET and magnetic resonance spectroscopy (MRS imaging revealed that OCD patients exhibited hyperperfusion and hypoperfusion in some brain regions compared with healthy controls. Neuroimaging studies of PTSD indicate that the hippocampal volume and the N-acetylaspartic acid (NAA level and the NAA/creatine ratio in the hippocampus are decreased in patients relative to controls.Conclusion: Neuroimaging studies within and outside China have provided

  18. Neuroimaging abnormalities in clade C HIV are independent of Tat genetic diversity.

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    Paul, Robert H; Phillips, Sarah; Hoare, Jacqueline; Laidlaw, David H; Cabeen, Ryan; Olbricht, Gayla R; Su, Yuqing; Stein, Dan J; Engelbrecht, Susan; Seedat, Soraya; Salminen, Lauren E; Baker, Laurie M; Heaps, Jodi; Joska, John

    2017-04-01

    Controversy remains regarding the neurotoxicity of clade C human immunodeficiency virus (HIV-C). When examined in preclinical studies, a cysteine to serine substitution in the C31 dicysteine motif of the HIV-C Tat protein (C31S) results in less severe brain injury compared to other viral clades. By contrast, patient cohort studies identify significant neuropsychological impairment among HIV-C individuals independent of Tat variability. The present study clarified this discrepancy by examining neuroimaging markers of brain integrity among HIV-C individuals with and without the Tat substitution. Thirty-seven HIV-C individuals with the Tat C31S substitution, 109 HIV-C individuals without the Tat substitution (C31C), and 34 HIV- controls underwent 3T structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Volumes were determined for the caudate, putamen, thalamus, corpus callosum, total gray matter, and total white matter. DTI metrics included fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). Tracts of interest included the anterior thalamic radiation (ATR), cingulum bundle (CING), uncinate fasciculus (UNC), and corpus callosum (CC). HIV+ individuals exhibited smaller volumes in subcortical gray matter, total gray matter and total white matter compared to HIV- controls. HIV+ individuals also exhibited DTI abnormalities across multiple tracts compared to HIV- controls. By contrast, neither volumetric nor diffusion indices differed significantly between the Tat C31S and C31C groups. Tat C31S status is not a sufficient biomarker of HIV-related brain integrity in patient populations. Clinical attention directed at brain health is warranted for all HIV+ individuals, independent of Tat C31S or clade C status.

  19. Neuroimaging of goal-directed behavior in midlife women.

    Science.gov (United States)

    Bosak, Kelly; Martin, Laura

    2014-01-01

    Motivational interventions to improve health behaviors based on conventional cognitive and behavioral theories have been extensively studied; however, advances in neuroimaging technology make it possible to assess the neurophysiological basis of health behaviors, such as physical activity. The goals of this approach are to support new interventions to achieve optimal outcomes. This study used functional magnetic resonance imaging (fMRI) to assess differences in brain responses in healthy weight to obese midlife women during a goal-directed decision task. Thirty nondiabetic, midlife (age 47-55 years) women with body mass index (BMI) ranging from 18.5 to 40 kg/m were recruited. A descriptive, correlational design was used to assess the relationship between brain activations and weight status. Participants underwent a goal-directed behavior task in the fMRI scanner consisting of a learning and implementation phase. The task was designed to assess both goal-directed and habitual behaviors. One participant was omitted from the analysis because of excessive motion (>4 mm), and six were omitted because of fewer than 50% correct responses on the exit survey. Four participants developed claustrophobia in the scanner and were disqualified from further participation. The remaining 19 participants were included in the final analysis. Brain responses while participants learned goal-directed behavior showed a positive correlation with BMI in the dorsomedial prefrontal cortex (dmPFC) and a negative correlation with BMI in the insula. During the implementation of goal-directed behavior, brain responses in the dorsolateral prefrontal cortex (dlPFC) negatively correlated with BMI. These results indicate that overweight women activate regions associated with cognitive control to a greater degree than healthy weight women during goal-directed learning. The brain regions activated (dmPFC, dlPFC, insula) are associated with cognitive control and self-regulation. On the other hand

  20. Numerical evaluation of an innovative cup layout for open volumetric solar air receivers

    Science.gov (United States)

    Cagnoli, Mattia; Savoldi, Laura; Zanino, Roberto; Zaversky, Fritz

    2016-05-01

    This paper proposes an innovative volumetric solar absorber design to be used in high-temperature air receivers of solar power tower plants. The innovative absorber, a so-called CPC-stacked-plate configuration, applies the well-known principle of a compound parabolic concentrator (CPC) for the first time in a volumetric solar receiver, heating air to high temperatures. The proposed absorber configuration is analyzed numerically, applying first the open-source ray-tracing software Tonatiuh in order to obtain the solar flux distribution on the absorber's surfaces. Next, a Computational Fluid Dynamic (CFD) analysis of a representative single channel of the innovative receiver is performed, using the commercial CFD software ANSYS Fluent. The solution of the conjugate heat transfer problem shows that the behavior of the new absorber concept is promising, however further optimization of the geometry will be necessary in order to exceed the performance of the classical absorber designs.

  1. Neuroimaging schizophrenia: a picture is worth a thousand words, but is it saying anything important?

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    Ahmed, Anthony O; Buckley, Peter F; Hanna, Mona

    2013-03-01

    Schizophrenia is characterized by neurostructural and neurofunctional aberrations that have now been demonstrated through neuroimaging research. The article reviews recent studies that have attempted to use neuroimaging to understand the relation between neurological abnormalities and aspects of the phenomenology of schizophrenia. Neuroimaging studies show that neurostructural and neurofunctional abnormalities are present in people with schizophrenia and their close relatives and may represent putative endophenotypes. Neuroimaging phenotypes predict the emergence of psychosis in individuals classified as high-risk. Neuroimaging studies have linked structural and functional abnormalities to symptoms; and progressive structural changes to clinical course and functional outcome. Neuroimaging has successfully indexed the neurotoxic and neuroprotective effects of schizophrenia treatments. Pictures can inform about aspects of the phenomenology of schizophrenia including etiology, onset, symptoms, clinical course, and treatment effects but this assertion is tempered by the scientific and practical limitations of neuroimaging.

  2. Disorders of Consciousness: Painless or Painful Conditions?—Evidence from Neuroimaging Studies

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    Francesca Pistoia

    2016-10-01

    Full Text Available The experience of pain in disorders of consciousness is still debated. Neuroimaging studies, using functional Magnetic Resonance Imaging (fMRI, Positron Emission Tomography (PET, multichannel electroencephalography (EEG and laser-evoked potentials, suggest that the perception of pain increases with the level of consciousness. Brain activation in response to noxious stimuli has been observed in patients with unresponsive wakefulness syndrome (UWS, which is also referred to as a vegetative state (VS, as well as those in a minimally conscious state (MCS. However, all of these techniques suggest that pain-related brain activation patterns of patients in MCS more closely resemble those of healthy subjects. This is further supported by fMRI findings showing a much greater functional connectivity within the structures of the so-called pain matrix in MCS as compared to UWS/VS patients. Nonetheless, when interpreting the results, a distinction is necessary between autonomic responses to potentially harmful stimuli and conscious experience of the unpleasantness of pain. Even more so if we consider that the degree of residual functioning and cortical connectivity necessary for the somatosensory, affective and cognitive-evaluative components of pain processing are not yet clear. Although procedurally challenging, the particular value of the aforementioned techniques in the assessment of pain in disorders of consciousness has been clearly demonstrated. The study of pain-related brain activation and functioning can contribute to a better understanding of the networks underlying pain perception while addressing clinical and ethical questions concerning patient care. Further development of technology and methods should aim to increase the availability of neuroimaging, objective assessment of functional connectivity and analysis at the level of individual cases as well as group comparisons. This will enable neuroimaging to truly become a clinical tool to