1
|
Manivannan A, Foley LM, Hitchens TK, Rattray I, Bates GP, Modo M. Ex vivo 100 μm isotropic diffusion MRI-based tractography of connectivity changes in the end-stage R6/2 mouse model of Huntington's disease. NEUROPROTECTION 2023; 1:66-83. [PMID: 37745674 PMCID: PMC10516267 DOI: 10.1002/nep3.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 11/08/2022] [Indexed: 09/26/2023]
Abstract
Background Huntington's disease is a progressive neurodegenerative disorder. Brain atrophy, as measured by volumetric magnetic resonance imaging (MRI), is a downstream consequence of neurodegeneration, but microstructural changes within brain tissue are expected to precede this volumetric decline. The tissue microstructure can be assayed non-invasively using diffusion MRI, which also allows a tractographic analysis of brain connectivity. Methods We here used ex vivo diffusion MRI (11.7 T) to measure microstructural changes in different brain regions of end-stage (14 weeks of age) wild type and R6/2 mice (male and female) modeling Huntington's disease. To probe the microstructure of different brain regions, reduce partial volume effects and measure connectivity between different regions, a 100 μm isotropic voxel resolution was acquired. Results Although fractional anisotropy did not reveal any difference between wild-type controls and R6/2 mice, mean, axial, and radial diffusivity were increased in female R6/2 mice and decreased in male R6/2 mice. Whole brain streamlines were only reduced in male R6/2 mice, but streamline density was increased. Region-to-region tractography indicated reductions in connectivity between the cortex, hippocampus, and thalamus with the striatum, as well as within the basal ganglia (striatum-globus pallidus-subthalamic nucleus-substantia nigra-thalamus). Conclusions Biological sex and left/right hemisphere affected tractographic results, potentially reflecting different stages of disease progression. This proof-of-principle study indicates that diffusion MRI and tractography potentially provide novel biomarkers that connect volumetric changes across different brain regions. In a translation setting, these measurements constitute a novel tool to assess the therapeutic impact of interventions such as neuroprotective agents in transgenic models, as well as patients with Huntington's disease.
Collapse
Affiliation(s)
- Ashwinee Manivannan
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lesley M. Foley
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - T. Kevin Hitchens
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ivan Rattray
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, University College London, London, UK
| | - Gillian P. Bates
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, Huntington’s Disease Centre and UK Dementia Research Institute at UCL, University College London, London, UK
| | - Michel Modo
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
2
|
Hippocampal and non-hippocampal correlates of physically active lifestyle and their relation to episodic memory in older adults. Neurobiol Aging 2021; 109:100-112. [PMID: 34706317 DOI: 10.1016/j.neurobiolaging.2021.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 11/21/2022]
Abstract
Aging is associated with compromised neurocognition. While aerobic exercise has been linked with cognitive resilience, findings regarding its relationship with brain morphology are inconsistent. Furthermore, the biological underpinnings of the relationship between aerobic activity and memory in the aging human brain are unclear. To investigate these issues, we examined hippocampal and non-hippocampal structural correlates of aerobically active lifestyle and cardiorespiratory fitness in older adults. We then examined structural pathways which may potentially mediate the association between active lifestyle and memory. Fifty participants (aged 65-80) underwent structural and diffusion MRI, memory evaluation, were examined for active lifestyle and cardiorespiratory fitness. Morphological features of the hippocampus and fornix, white matter lesions, and brain atrophy were assessed. Active lifestyle and cardiorespiratory fitness correlated with all neurocognitive measures. An exploratory mediation analysis revealed hippocampal and white matter lesions pathways linking active lifestyle and cardiorespiratory fitness with memory. Our results support a neuroprotective role of aerobic exercise on the aging brain and suggest plausible morphological pathways that may underlie the relationship between aerobic exercise and memory.
Collapse
|
3
|
Glutamine + glutamate level predicts the magnitude of microstructural organization in the gray matter in the healthy elderly. Int Psychogeriatr 2021; 33:21-29. [PMID: 31578159 PMCID: PMC8482373 DOI: 10.1017/s1041610219001418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Diffusion tensor imaging (DTI), which is a technique for measuring the degree and direction of movement of water molecules in tissue, has been widely used to noninvasively assess white matter (WM) or gray matter (GM) microstructures in vivo. Mean diffusivity (MD), which is the average diffusion across all directions, has been considered as a marker of WM tract degeneration or extracellular space enlargement in GM. Recent lines of evidence suggest that cortical MD can better identify early-stage Alzheimer's disease than structural morphometric parameters in magnetic resonance imaging. However, knowledge of the relationships between cortical MD and other biological factors in the same cortical region, e.g. metabolites, is still limited. METHODS Thirty-three healthy elderly individuals [aged 50-77 years (mean, 63.8±7.4 years); 11 males and 22 females] were enrolled. We estimated the associations between cortical MD and neurotransmitter levels. Specifically, we measured levels of γ-aminobutyric acid (GABA) and glutamate + glutamine (Glx), which are inhibitory and excitatory neurotransmitters, respectively, in medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC) using MEGA-PRESS magnetic resonance spectroscopy, and we measured regional cortical MD using DTI. RESULTS Cortical MD was significantly negatively associated with Glx levels in both mPFC and PCC. No significant association was observed between cortical MD and GABA levels in either GM region. CONCLUSION Our findings suggest that degeneration of microstructural organization in GM, as determined on the basis of cortical MD measured by DTI, is accompanied by the decline of Glx metabolism within the same GM region.
Collapse
|
4
|
Gatto RG, Weissmann C. Diffusion Tensor Imaging in Preclinical and Human Studies of Huntington's Disease: What Have we Learned so Far? Curr Med Imaging 2020; 15:521-542. [PMID: 32008561 DOI: 10.2174/1573405614666181115113400] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 10/23/2018] [Accepted: 10/26/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Huntington's Disease is an irreversible neurodegenerative disease characterized by the progressive deterioration of specific brain nerve cells. The current evaluation of cellular and physiological events in patients with HD relies on the development of transgenic animal models. To explore such events in vivo, diffusion tensor imaging has been developed to examine the early macro and microstructural changes in brain tissue. However, the gap in diffusion tensor imaging findings between animal models and clinical studies and the lack of microstructural confirmation by histological methods has questioned the validity of this method. OBJECTIVE This review explores white and grey matter ultrastructural changes associated to diffusion tensor imaging, as well as similarities and differences between preclinical and clinical Huntington's Disease studies. METHODS A comprehensive review of the literature using online-resources was performed (Pub- Med search). RESULTS Similar changes in fractional anisotropy as well as axial, radial and mean diffusivities were observed in white matter tracts across clinical and animal studies. However, comparative diffusion alterations in different grey matter structures were inconsistent between clinical and animal studies. CONCLUSION Diffusion tensor imaging can be related to specific structural anomalies in specific cellular populations. However, some differences between animal and clinical studies could derive from the contrasting neuroanatomy or connectivity across species. Such differences should be considered before generalizing preclinical results into the clinical practice. Moreover, current limitations of this technique to accurately represent complex multicellular events at the single micro scale are real. Future work applying complex diffusion models should be considered.
Collapse
Affiliation(s)
- Rodolfo Gabriel Gatto
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607, United States
| | - Carina Weissmann
- Insituto de Fisiología Biologia Molecular y Neurociencias-IFIBYNE-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
5
|
Pieri V, Trovatelli M, Cadioli M, Zani DD, Brizzola S, Ravasio G, Acocella F, Di Giancamillo M, Malfassi L, Dolera M, Riva M, Bello L, Falini A, Castellano A. In vivo Diffusion Tensor Magnetic Resonance Tractography of the Sheep Brain: An Atlas of the Ovine White Matter Fiber Bundles. Front Vet Sci 2019; 6:345. [PMID: 31681805 PMCID: PMC6805705 DOI: 10.3389/fvets.2019.00345] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/24/2019] [Indexed: 11/30/2022] Open
Abstract
Diffusion Tensor Magnetic Resonance Imaging (DTI) allows to decode the mobility of water molecules in cerebral tissue, which is highly directional along myelinated fibers. By integrating the direction of highest water diffusion through the tissue, DTI Tractography enables a non-invasive dissection of brain fiber bundles. As such, this technique is a unique probe for in vivo characterization of white matter architecture. Unraveling the principal brain texture features of preclinical models that are advantageously exploited in experimental neuroscience is crucial to correctly evaluate investigational findings and to correlate them with real clinical scenarios. Although structurally similar to the human brain, the gyrencephalic ovine model has not yet been characterized by a systematic DTI study. Here we present the first in vivo sheep (ovis aries) tractography atlas, where the course of the main white matter fiber bundles of the ovine brain has been reconstructed. In the context of the EU's Horizon EDEN2020 project, in vivo brain MRI protocol for ovine animal models was optimized on a 1.5T scanner. High resolution conventional MRI scans and DTI sequences (b-value = 1,000 s/mm2, 15 directions) were acquired on ten anesthetized sheep o. aries, in order to define the diffusion features of normal adult ovine brain tissue. Topography of the ovine cortex was studied and DTI maps were derived, to perform DTI tractography reconstruction of the corticospinal tract, corpus callosum, fornix, visual pathway, and occipitofrontal fascicle, bilaterally for all the animals. Binary masks of the tracts were then coregistered and reported in the space of a standard stereotaxic ovine reference system, to demonstrate the consistency of the fiber bundles and the minimal inter-subject variability in a unique tractography atlas. Our results determine the feasibility of a protocol to perform in vivo DTI tractography of the sheep, providing a reliable reconstruction and 3D rendering of major ovine fiber tracts underlying different neurological functions. Estimation of fiber directions and interactions would lead to a more comprehensive understanding of the sheep's brain anatomy, potentially exploitable in preclinical experiments, thus representing a precious tool for veterinaries and researchers.
Collapse
Affiliation(s)
- Valentina Pieri
- Neuroradiology Unit and CERMAC, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Trovatelli
- Department of Health, Animal Science and Food Safety, Faculty of Veterinary Medicine, University of Milan, Milan, Italy
| | | | - Davide Danilo Zani
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Stefano Brizzola
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Giuliano Ravasio
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Fabio Acocella
- Department of Health, Animal Science and Food Safety, Faculty of Veterinary Medicine, University of Milan, Milan, Italy
| | - Mauro Di Giancamillo
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Luca Malfassi
- Fondazione La Cittadina Studi e Ricerche Veterinarie, Romanengo, Italy
| | - Mario Dolera
- Fondazione La Cittadina Studi e Ricerche Veterinarie, Romanengo, Italy
| | - Marco Riva
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy.,Neurosurgical Oncology Unit, Humanitas Clinical and Research Center - IRCCS, Rozzano, Italy
| | - Lorenzo Bello
- Neurosurgical Oncology Unit, Humanitas Clinical and Research Center - IRCCS, Rozzano, Italy.,Department of Oncology and Hemato-Oncology, Università degli Studi di Milano, Milan, Italy
| | - Andrea Falini
- Neuroradiology Unit and CERMAC, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Antonella Castellano
- Neuroradiology Unit and CERMAC, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| |
Collapse
|
6
|
Gatto RG, Ye AQ, Colon-Perez L, Mareci TH, Lysakowski A, Price SD, Brady ST, Karaman M, Morfini G, Magin RL. Detection of axonal degeneration in a mouse model of Huntington's disease: comparison between diffusion tensor imaging and anomalous diffusion metrics. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2019; 32:461-471. [PMID: 30771034 DOI: 10.1007/s10334-019-00742-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/31/2018] [Accepted: 01/29/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The goal of this work is to study the changes in white matter integrity in R6/2, a well-established animal model of Huntington's disease (HD) that are captured by ex vivo diffusion imaging (DTI) using a high field MRI (17.6 T). MATERIALS AND METHODS DTI and continuous time random walk (CTRW) models were used to fit changes in the diffusion-weighted signal intensity in the corpus callosum of controls and in R6/2 mice. RESULTS A significant 13% decrease in fractional anisotropy, a 7% increase in axial diffusion, and a 33% increase in radial diffusion were observed between R6/2 and control mice. No change was observed in the CTRW beta parameter, but a significant decrease in the alpha parameter (- 21%) was measured. Histological analysis of the corpus callosum showed a decrease in axonal organization, myelin alterations, and astrogliosis. Electron microscopy studies demonstrated ultrastructural changes in degenerating axons, such as an increase in tortuosity in the R6/2 mice. CONCLUSIONS DTI and CTRW diffusion models display quantitative changes associated with the microstructural alterations observed in the corpus callosum of the R6/2 mice. The observed increase in the diffusivity and decrease in the alpha CTRW parameter providing support for the use of these diffusion models for non-invasive detection of white matter alterations in HD.
Collapse
Affiliation(s)
- Rodolfo G Gatto
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA.,Department of Bioengineering, University of Illinois at Chicago, 851 S Morgan St, 218 SEO (MC 063), Chicago, IL, 60607, USA
| | - Allen Q Ye
- Department of Bioengineering, University of Illinois at Chicago, 851 S Morgan St, 218 SEO (MC 063), Chicago, IL, 60607, USA
| | - Luis Colon-Perez
- Department of Neurology and Behavior, University of California at Irvine, Irvine, CA, USA.,Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Thomas H Mareci
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Anna Lysakowski
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Steven D Price
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Scott T Brady
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Muge Karaman
- Department of Bioengineering, University of Illinois at Chicago, 851 S Morgan St, 218 SEO (MC 063), Chicago, IL, 60607, USA.,Center for MR Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Gerardo Morfini
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Richard L Magin
- Department of Bioengineering, University of Illinois at Chicago, 851 S Morgan St, 218 SEO (MC 063), Chicago, IL, 60607, USA.
| |
Collapse
|
7
|
Huhn S, Beyer F, Zhang R, Lampe L, Grothe J, Kratzsch J, Willenberg A, Breitfeld J, Kovacs P, Stumvoll M, Trampel R, Bazin PL, Villringer A, Witte AV. Effects of resveratrol on memory performance, hippocampus connectivity and microstructure in older adults - A randomized controlled trial. Neuroimage 2018; 174:177-190. [PMID: 29548848 DOI: 10.1016/j.neuroimage.2018.03.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/03/2018] [Accepted: 03/12/2018] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION The polyphenol resveratrol has been suggested to exert beneficial effects on memory and the aging hippocampus due to calorie-restriction mimicking effects. However, the evidence based on human interventional studies is scarce. We therefore aimed to determine the effects of resveratrol on memory performance, and to identify potential underlying mechanisms using a broad array of blood-based biomarkers as well as hippocampus connectivity and microstructure assessed with ultra-high field magnetic resonance imaging (UHF-MRI). METHODS In this double-blind, randomized controlled trial, 60 elderly participants (60-79 years) with a wide body-mass index (BMI) range of 21-37 kg/m2 were randomized to receive either resveratrol (200 mg/day) or placebo for 26 weeks (registered at ClinicalTrials.gov: NCT02621554). Baseline and follow-up assessments included the California Verbal Learning Task (CVLT, main outcome), the ModBent task, anthropometry, markers of glucose and lipid metabolism, inflammation and neurotrophins derived from fasting blood, multimodal neuroimaging at 3 and 7 T, and questionnaires to assess confounding factors. RESULTS Multivariate repeated-measures ANOVA did not detect significant time by group effects for CVLT performance. There was a trend for preserved pattern recognition memory after resveratrol, while performance decreased in the placebo group (n.s., p = 0.07). Further exploratory analyses showed increases in both groups over time in body fat, cholesterol, fasting glucose, interleukin 6, high sensitive C-reactive protein, tumor necrosis factor alpha and in mean diffusivity of the subiculum and presubiculum, as well as decreases in physical activity, brain-derived neurotrophic factor and insulin-like growth factor 1 at follow-up, which were partly more pronounced after resveratrol. DISCUSSION This interventional study failed to show significant improvements in verbal memory after 6 months of resveratrol in healthy elderly with a wide BMI range. A non-significant trend emerged for positive effects on pattern recognition memory, while possible confounding effects of unfavorable changes in lifestyle behavior, neurotrophins and inflammatory markers occurred. Our findings also indicate the feasibility to detect (un)healthy aging-related changes in measures of hippocampus microstructure after 6 months using 7T diffusion MRI. More studies incorporating a longer duration and larger sample size are needed to determine if resveratrol enhances memory performance in healthy older adults.
Collapse
Affiliation(s)
- Sebastian Huhn
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany; Collaborative Research Centre 1052 'Obesity Mechanisms', Subproject A1, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| | - Frauke Beyer
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany; Collaborative Research Centre 1052 'Obesity Mechanisms', Subproject A1, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| | - Rui Zhang
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany; Collaborative Research Centre 1052 'Obesity Mechanisms', Subproject A1, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| | - Leonie Lampe
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany.
| | - Jana Grothe
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany.
| | - Jürgen Kratzsch
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany.
| | - Anja Willenberg
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany.
| | - Jana Breitfeld
- Leipzig University Medical Center, IFB AdiposityDiseases, Leipzig, Germany.
| | - Peter Kovacs
- Leipzig University Medical Center, IFB AdiposityDiseases, Leipzig, Germany.
| | - Michael Stumvoll
- Collaborative Research Centre 1052 'Obesity Mechanisms', Subproject A1, Faculty of Medicine, University of Leipzig, Leipzig, Germany; IFB Adiposity Diseases, Medical Research Centre, University of Leipzig, Leipzig, Germany.
| | - Robert Trampel
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany.
| | - Pierre-Louis Bazin
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany; Spinoza Centre for Neuroimaging, Amsterdam, Netherlands; Netherlands Institute for Neuroscience, Amsterdam, Netherlands.
| | - Arno Villringer
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany; Collaborative Research Centre 1052 'Obesity Mechanisms', Subproject A1, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| | - A Veronica Witte
- Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurology, Stephanstr. 1A, 04103 Leipzig, Germany; Collaborative Research Centre 1052 'Obesity Mechanisms', Subproject A1, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| |
Collapse
|
8
|
Wu D, Faria AV, Younes L, Mori S, Brown T, Johnson H, Paulsen JS, Ross CA, Miller MI. Mapping the order and pattern of brain structural MRI changes using change-point analysis in premanifest Huntington's disease. Hum Brain Mapp 2017; 38:5035-5050. [PMID: 28657159 PMCID: PMC5766002 DOI: 10.1002/hbm.23713] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/12/2017] [Accepted: 06/19/2017] [Indexed: 02/02/2023] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that progressively affects motor, cognitive, and emotional functions. Structural MRI studies have demonstrated brain atrophy beginning many years prior to clinical onset ("premanifest" period), but the order and pattern of brain structural changes have not been fully characterized. In this study, we investigated brain regional volumes and diffusion tensor imaging (DTI) measurements in premanifest HD, and we aim to determine (1) the extent of MRI changes in a large number of structures across the brain by atlas-based analysis, and (2) the initiation points of structural MRI changes in these brain regions. We adopted a novel multivariate linear regression model to detect the inflection points at which the MRI changes begin (namely, "change-points"), with respect to the CAG-age product (CAP, an indicator of extent of exposure to the effects of CAG repeat expansion). We used approximately 300 T1-weighted and DTI data from premanifest HD and control subjects in the PREDICT-HD study, with atlas-based whole brain segmentation and change-point analysis. The results indicated a distinct topology of structural MRI changes: the change-points of the volumetric measurements suggested a central-to-peripheral pattern of atrophy from the striatum to the deep white matter; and the change points of DTI measurements indicated the earliest changes in mean diffusivity in the deep white matter and posterior white matter. While interpretation needs to be cautious given the cross-sectional nature of the data, these findings suggest a spatial and temporal pattern of spread of structural changes within the HD brain. Hum Brain Mapp 38:5035-5050, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Dan Wu
- The Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins University School of MedicineBaltimoreMaryland
| | - Andreia V. Faria
- The Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins University School of MedicineBaltimoreMaryland
| | - Laurent Younes
- Center for Imaging Science, Johns Hopkins UniversityBaltimoreMaryland
- Institute for Computational Medicine, Johns Hopkins UniversityBaltimoreMaryland
- Department of Applied Mathematics and StatisticsJohns Hopkins UniversityBaltimoreMaryland
| | - Susumu Mori
- The Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins University School of MedicineBaltimoreMaryland
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger InstituteBaltimoreMaryland
| | - Timothy Brown
- Center for Imaging Science, Johns Hopkins UniversityBaltimoreMaryland
| | - Hans Johnson
- Department of Electrical and Computer EngineeringUniversity of IowaIowa CityIowa
| | - Jane S. Paulsen
- Departments of Psychiatry, Neurology, Psychology and NeurosciencesUniversity of IowaIowa CityIowa
| | - Christopher A. Ross
- Division of Neurobiology, Departments of Psychiatry, Neurology, Neuroscience and Pharmacology, and Program in Cellular and Molecular MedicineJohns Hopkins University School of MedicineBaltimoreMaryland
| | - Michael I. Miller
- Center for Imaging Science, Johns Hopkins UniversityBaltimoreMaryland
- Institute for Computational Medicine, Johns Hopkins UniversityBaltimoreMaryland
- Department of Biomedical EngineeringJohns Hopkins UniversityBaltimoreMaryland
| | | |
Collapse
|
9
|
Gillespie NA, Neale MC, Hagler DJ, Eyler LT, Fennema-Notestine C, Franz CE, Lyons MJ, McEvoy LK, Dale AM, Panizzon MS, Kremen WS. Genetic and environmental influences on mean diffusivity and volume in subcortical brain regions. Hum Brain Mapp 2017; 38:2589-2598. [PMID: 28240386 DOI: 10.1002/hbm.23544] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 12/15/2022] Open
Abstract
Increased mean diffusivity (MD) is hypothesized to reflect tissue degeneration and may provide subtle indicators of neuropathology as well as age-related brain changes in the absence of volumetric differences. Our aim was to determine the degree to which genetic and environmental variation in subcortical MD is distinct from variation in subcortical volume. Data were derived from a sample of 387 male twins (83 MZ twin pairs, 55 DZ twin pairs, and 111 incomplete twin pairs) who were MRI scanned as part of the Vietnam Era Twin Study of Aging. Quantitative estimates of MD and volume for 7 subcortical regions were obtained: thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens. After adjusting for covariates, bivariate twin models were fitted to estimate the size and significance of phenotypic, genotypic, and environmental correlations between MD and volume at each subcortical region. With the exception of the amygdala, familial aggregation in MD was entirely explained by additive genetic factors across all subcortical regions with estimates ranging from 46 to 84%. Based on bivariate twin modeling, variation in subcortical MD appears to be both genetically and environmentally unrelated to individual differences in subcortical volume. Therefore, subcortical MD may be an alternative biomarker of brain morphology for complex traits worthy of future investigation. Hum Brain Mapp 38:2589-2598, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Nathan A Gillespie
- Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Virginia
| | - Michael C Neale
- Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Virginia
| | - Donald J Hagler
- Department of Radiology, University of California, San Diego, California
| | - Lisa T Eyler
- Desert-Pacific Mental Illness Research, Education, and Clinical Center, VA San Diego Healthcare System, California.,Department of Psychiatry, University of California, San Diego, California
| | - Christine Fennema-Notestine
- Department of Radiology, University of California, San Diego, California.,Department of Psychiatry, University of California, San Diego, California
| | - Carol E Franz
- Department of Psychiatry, University of California, San Diego, California
| | - Michael J Lyons
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts
| | - Linda K McEvoy
- Department of Radiology, University of California, San Diego, California
| | - Anders M Dale
- Department of Radiology, University of California, San Diego, California.,Department of Psychiatry, University of California, San Diego, California
| | - Matthew S Panizzon
- Department of Psychiatry, University of California, San Diego, California
| | - William S Kremen
- Department of Psychiatry, University of California, San Diego, California.,Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, California
| |
Collapse
|
10
|
Elman JA, Panizzon MS, Hagler DJ, Fennema-Notestine C, Eyler LT, Gillespie NA, Neale MC, Lyons MJ, Franz CE, McEvoy LK, Dale AM, Kremen WS. Genetic and environmental influences on cortical mean diffusivity. Neuroimage 2017; 146:90-99. [PMID: 27864081 PMCID: PMC5322245 DOI: 10.1016/j.neuroimage.2016.11.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 11/08/2016] [Accepted: 11/12/2016] [Indexed: 12/13/2022] Open
Abstract
Magnetic resonance imaging (MRI) has become an important tool in the early detection of age-related and neuropathological brain changes. Recent studies suggest that changes in mean diffusivity (MD) of cortical gray matter derived from diffusion MRI scans may be useful in detecting early effects of Alzheimer's disease (AD), and that these changes may be detected earlier than alterations associated with standard structural MRI measures such as cortical thickness. Thus, due to its potential clinical relevance, we examined the genetic and environmental influences on cortical MD in middle-aged men to provide support for the biological relevance of this measure and to guide future gene association studies. It is not clear whether individual differences in cortical MD reflect neuroanatomical variability similarly detected by other MRI measures, or whether unique features are captured. For instance, variability in cortical MD may reflect morphological variability more commonly measured by cortical thickness. Differences among individuals in cortical MD may also arise from breakdowns in myelinated fibers running through the cortical mantle. Thus, we investigated whether genetic influences on variation in cortical MD are the same or different from those influencing cortical thickness and MD of white matter (WM) subjacent to the cortical ribbon. Univariate twin analyses indicated that cortical MD is heritable in the majority of brain regions; the average of regional heritability estimates ranged from 0.38 in the cingulate cortex to 0.66 in the occipital cortex, consistent with the heritability of other MRI measures of the brain. Trivariate analyses found that, while there was some shared genetic variance between cortical MD and each of the other two measures, this overlap was not complete (i.e., the correlation was statistically different from 1). A significant amount of distinct genetic variance influences inter-individual variability in cortical MD; therefore, this measure could be useful for further investigation in studies of neurodegenerative diseases and gene association studies.
Collapse
Affiliation(s)
- Jeremy A Elman
- Department of Psychiatry, University of California San Diego, CA, USA; Center for Behavior Genetics of Aging, University of California San Diego, CA, USA.
| | - Matthew S Panizzon
- Department of Psychiatry, University of California San Diego, CA, USA; Center for Behavior Genetics of Aging, University of California San Diego, CA, USA
| | - Donald J Hagler
- Department of Radiology, University of California San Diego, CA, USA
| | - Christine Fennema-Notestine
- Department of Psychiatry, University of California San Diego, CA, USA; Department of Radiology, University of California San Diego, CA, USA
| | - Lisa T Eyler
- Department of Psychiatry, University of California San Diego, CA, USA; San Diego VA Health Care System, San Diego, CA 92161, USA
| | - Nathan A Gillespie
- Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, VA, USA
| | - Michael C Neale
- Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, VA, USA
| | - Michael J Lyons
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | - Carol E Franz
- Department of Psychiatry, University of California San Diego, CA, USA; Center for Behavior Genetics of Aging, University of California San Diego, CA, USA
| | - Linda K McEvoy
- Department of Radiology, University of California San Diego, CA, USA
| | - Anders M Dale
- Department of Radiology, University of California San Diego, CA, USA; Department of Neurosciences, University of California San Diego, CA, USA
| | - William S Kremen
- Department of Psychiatry, University of California San Diego, CA, USA; Center for Behavior Genetics of Aging, University of California San Diego, CA, USA; San Diego VA Health Care System, San Diego, CA 92161, USA
| |
Collapse
|
11
|
Faria AV, Ratnanather JT, Tward DJ, Lee DS, van den Noort F, Wu D, Brown T, Johnson H, Paulsen JS, Ross CA, Younes L, Miller MI. Linking white matter and deep gray matter alterations in premanifest Huntington disease. Neuroimage Clin 2016; 11:450-460. [PMID: 27104139 PMCID: PMC4827723 DOI: 10.1016/j.nicl.2016.02.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 02/17/2016] [Accepted: 02/22/2016] [Indexed: 01/07/2023]
Abstract
Huntington disease (HD) is a fatal progressive neurodegenerative disorder for which only symptomatic treatment is available. A better understanding of the pathology, and identification of biomarkers will facilitate the development of disease-modifying treatments. HD is potentially a good model of a neurodegenerative disease for development of biomarkers because it is an autosomal-dominant disease with complete penetrance, caused by a single gene mutation, in which the neurodegenerative process can be assessed many years before onset of signs and symptoms of manifest disease. Previous MRI studies have detected abnormalities in gray and white matter starting in premanifest stages. However, the understanding of how these abnormalities are related, both in time and space, is still incomplete. In this study, we combined deep gray matter shape diffeomorphometry and white matter DTI analysis in order to provide a better mapping of pathology in the deep gray matter and subcortical white matter in premanifest HD. We used 296 MRI scans from the PREDICT-HD database. Atrophy in the deep gray matter, thalamus, hippocampus, and nucleus accumbens was analyzed by surface based morphometry, and while white matter abnormalities were analyzed in (i) regions of interest surrounding these structures, using (ii) tractography-based analysis, and using (iii) whole brain atlas-based analysis. We detected atrophy in the deep gray matter, particularly in putamen, from early premanifest stages. The atrophy was greater both in extent and effect size in cases with longer exposure to the effects of the CAG expansion mutation (as assessed by greater CAP-scores), and preceded detectible abnormalities in the white matter. Near the predicted onset of manifest HD, the MD increase was widespread, with highest indices in the deep and posterior white matter. This type of in-vivo macroscopic mapping of HD brain abnormalities can potentially indicate when and where therapeutics could be targeted to delay the onset or slow the disease progression.
Collapse
Affiliation(s)
- Andreia V Faria
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - J Tilak Ratnanather
- Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, The Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, USA
| | - Daniel J Tward
- Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, The Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, USA
| | - David Soobin Lee
- Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, The Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, USA
| | - Frieda van den Noort
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Dan Wu
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Timothy Brown
- Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, USA
| | - Hans Johnson
- Department of Psychiatry, The University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Jane S Paulsen
- Department of Psychiatry, The University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry, and Departments of Neurology, Neuroscience and Pharmacology, Johns Hopkins University, Baltimore, MD, USA
| | - Laurent Younes
- Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, The Johns Hopkins University, Baltimore, MD, USA; Department of Applied Mathematics and Statistics, The Johns Hopkins University, Baltimore, MD, USA
| | - Michael I Miller
- Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, The Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
12
|
Gregory S, Cole JH, Farmer RE, Rees EM, Roos RA, Sprengelmeyer R, Durr A, Landwehrmeyer B, Zhang H, Scahill RI, Tabrizi SJ, Frost C, Hobbs NZ. Longitudinal Diffusion Tensor Imaging Shows Progressive Changes in White Matter in Huntington’s Disease. J Huntingtons Dis 2015; 4:333-46. [DOI: 10.3233/jhd-150173] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Sarah Gregory
- Wellcome Trust Centre for Neuroimaging, UCL, London, WC1N 3BG, UK
| | - James H. Cole
- UCL Institute of Neurology, University College London, UK
- Computational, Cognitive & Clinical Neuroimaging Laboratory, Department of Medicine, Imperial College London, UK
| | - Ruth E. Farmer
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine London, UK
| | - Elin M. Rees
- UCL Institute of Neurology, University College London, UK
| | - Raymund A.C. Roos
- Department of Neurology, Leiden University Medical Centre, 2300RC Leiden, The Netherlands
| | | | - Alexandra Durr
- Department of Genetics and Cytogenetics, INSERM UMR S679, APHP Hôpital de la Salpêtrière, Paris, France
| | | | - Hui Zhang
- Centre for Medical Image Computing, University College London, UK
| | | | | | - Chris Frost
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine London, UK
| | - Nicola Z. Hobbs
- UCL Institute of Neurology, University College London, UK
- IXICO Plc., London, UK
| |
Collapse
|
13
|
Wang X, Lin F, Gao Y, Lei H. Bilateral common carotid artery occlusion induced brain lesions in rats: A longitudinal diffusion tensor imaging study. Magn Reson Imaging 2015; 33:551-8. [PMID: 25708261 DOI: 10.1016/j.mri.2015.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 02/14/2015] [Accepted: 02/15/2015] [Indexed: 11/29/2022]
Abstract
Bilateral common carotid artery occlusion (BCCAO) has been widely used to reproduce the white matter (WM) and gray matter (GM) damage associated with chronic cerebral hypoperfusion (CCH). This study investigated whether diffusion tensor imaging (DTI) could be used at the early stages of disease to assess brain damage induced by BCCAO. To this end, DTI, together with histological methods, was used to evaluate the progression of WM lesions and GM neurodegeneration following BCCAO. The DTI was sufficiently sensitive to detect WM abnormalities in selected regions of the brain at 4weeks after BCCAO. These abnormalities may indicate damage to the myelin and axons in the optic nerve (ON) and optic tract (OT). Our longitudinal results showed that DTI could be used to detect abnormalities of the WM and GM in select regions of the brain as early as 2days after ligation. The DTI parameter patterns of change were region-specific throughout the detection time course. Lesions of the external capsule (EC) and periventricular hypothalamic nucleus (Pe) have not been thoroughly studied before. We found that the EC and Pe were both vulnerable to BCCAO and that the associated lesions could be detected using DTI. The current study demonstrated that in vivo DTI could potentially be used to measure WM damage evolution in a BCCAO rat model as well as early brain injury following CCH.
Collapse
Affiliation(s)
- Xuxia Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Fuchun Lin
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Yunling Gao
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Hao Lei
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
| |
Collapse
|
14
|
Odish OFF, Leemans A, Reijntjes RHAM, van den Bogaard SJA, Dumas EM, Wolterbeek R, Tax CMW, Kuijf HJ, Vincken KL, van der Grond J, Roos RAC. Microstructural brain abnormalities in Huntington's disease: A two-year follow-up. Hum Brain Mapp 2015; 36:2061-74. [PMID: 25644819 DOI: 10.1002/hbm.22756] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 12/05/2014] [Accepted: 01/26/2015] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES To investigate both cross-sectional and time-related changes of striatal and whole-brain microstructural properties in different stages of Huntington's disease (HD) using diffusion tensor imaging. EXPERIMENTAL DESIGN From the TRACK-HD study, premanifest gene carriers (preHD), early manifest HD and controls were scanned at baseline and 2-year follow-up. Stratification of the preHD group into a far (preHD-A) and near (preHD-B) to predicted disease onset was performed. Age-corrected histograms of whole-brain white matter (WM), gray matter (GM) and striatal diffusion measures were computed and normalised by the number of voxels in each subject's data set. PRINCIPLE OBSERVATIONS Higher cross-sectional mean, axial and radial diffusivities were found in both WM (P ≤ 0.001) and GM (P ≤ 0.001) of the manifest HD compared to the preHD and control groups. In preHD, only WM axial diffusivity (AD) was higher than in controls (P ≤ 0.01). This finding remained valid only in preHD-B (P ≤ 0.001). AD was also higher in the striatum of preHD-B compared to controls and preHD-A (P ≤ 0.01). Fractional anisotropy (FA) lacked sensitivity in differentiating between the groups. Histogram peak heights were generally lower in manifest HD compared to the preHD and control groups. No longitudinal differences were found in the degree of diffusivity change between the groups in the two year follow-up. There was a significant relationship between diffusivity and neurocognitive measures. CONCLUSIONS Alterations in cross-sectional diffusion profiles between manifest HD subjects and controls were evident, both in whole-brain and striatum. In the preHD stage, only AD alterations were found, a finding suggesting that this metric is a sensitive marker for early change in HD prior to disease manifestation. The individual diffusivities were superior to FA in revealing pathologic microstructural brain alterations. Diffusion measures were well related to clinical functioning and disease stage.
Collapse
Affiliation(s)
- Omar F F Odish
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
Background Spinocerebellar ataxias (SCAs) are autosomal-dominant neurodegenerative diseases that are clinically and genetically heterogeneous. SCAs are characterized by a range of neurological symptoms. SCA12 is an autosomal-dominant (AD) ataxia caused by a CAG repeat expansion mutation in a presumed promoter region of the gene PPP2R2B in a non-coding region on chromosome 5q32. This study sought to determine changes in different positions in a single Uyghur SCA12 pedigree by measuring the apparent diffusion coefficient (ADC) and fractional anisotropy (FA). Material/Methods A single Uyghur pedigree was collected and was confirmed to possess SCA12 by genetic diagnosis, among which 13 cases were patients and 54 cases were “healthy” individuals. Five patients were presymptomatic and 15 individuals selected as a control group were examination in the same time. DTI was performed on a 1.5T scanner, with b=1000 s/mm2 and 15 directions. ADC and FA were measured by regions of interest positioned in the corticospinal tract at the level of the pons (pons), superior peduncle (SCP), middle cerebellar peduncle (MCP), cerebellar cortex (CeC), cerebral cortex (CC), and cerebellar vermis (CV) white matter. Results Compared with the controls, the ADC was significantly elevated in the CeC, SCP, CC, and CV regions in SCA12 patients. The FA significantly decreased in the CC region in SCA12 patients and the CC and CV regions in SCA12 presymptomatic patients. The course of the disease, SARA score, and ADC values in CV showed highly positive correlations. Conclusions SCA12 pedigree patients exhibited microstructural damage in the brain white matter. The damage in white matter fiber may first occur in the CC and CV regions in SCA12 presymptomatic patients. The ADC values in the CV region could reflect disease severity in SCA12 patients.
Collapse
Affiliation(s)
- Haitao Li
- Department of Neurology, First Affiliated Hospital, Xinjiang Medical University, Urumuqi, China (mainland)
| | - Jingjing Ma
- Department of Neurology, First Affiliated Hospital, Xinjiang Medical University, Urumuqi, China (mainland)
| | - Xiaoning Zhang
- Department of Neurology, First Affiliated Hospital, Xinjiang Medical University, Urumuqi, China (mainland)
| |
Collapse
|
16
|
Hess CW, Ofori E, Akbar U, Okun MS, Vaillancourt DE. The evolving role of diffusion magnetic resonance imaging in movement disorders. Curr Neurol Neurosci Rep 2013; 13:400. [PMID: 24046183 PMCID: PMC3824956 DOI: 10.1007/s11910-013-0400-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Significant advances have allowed diffusion magnetic resonance imaging (MRI) to evolve into a powerful tool in the field of movement disorders that can be used to study disease states and connectivity between brain regions. Diffusion MRI is a promising potential biomarker for Parkinson's disease and other forms of parkinsonism, and may allow the distinction of different forms of parkinsonism. Techniques such as tractography have contributed to our current thinking regarding the pathophysiology of dystonia and possible mechanisms of penetrance. Diffusion MRI measures could potentially assist in monitoring disease progression in Huntington's disease, and in uncovering the nature of the processes and structures involved the development of essential tremor. The ability to represent structural connectivity in vivo also makes diffusion MRI an ideal adjunctive tool for the surgical treatment of movement disorders. We review recent studies using diffusion MRI in movement disorders research and present the current state of the science as well as future directions.
Collapse
Affiliation(s)
- Christopher W. Hess
- Laboratory for Rehabilitation Neuroscience, University of Florida, Gainesville, FL, USA
- University of Florida Center for Movement Disorders & Neurorestoration, Gainesville, FL, USA
- Neurology Service, Malcom Randall VA Medical Center, Gainesville, FL, USA
| | - Edward Ofori
- Laboratory for Rehabilitation Neuroscience, University of Florida, Gainesville, FL, USA
| | - Umer Akbar
- University of Florida Center for Movement Disorders & Neurorestoration, Gainesville, FL, USA
| | - Michael S. Okun
- University of Florida Center for Movement Disorders & Neurorestoration, Gainesville, FL, USA
| | - David E. Vaillancourt
- Laboratory for Rehabilitation Neuroscience, University of Florida, Gainesville, FL, USA
| |
Collapse
|
17
|
Keller J, Rulseh AM, Komárek A, Latnerová I, Rusina R, Brožová H, Vymazal J. New non-linear color look-up table for visualization of brain fractional anisotropy based on normative measurements - principals and first clinical use. PLoS One 2013; 8:e71431. [PMID: 23990954 PMCID: PMC3750032 DOI: 10.1371/journal.pone.0071431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 06/28/2013] [Indexed: 12/14/2022] Open
Abstract
Fractional anisotropy (FA) is the most commonly used quantitative measure of diffusion in the brain. Changes in FA have been reported in many neurological disorders, but the implementation of diffusion tensor imaging (DTI) in daily clinical practice remains challenging. We propose a novel color look-up table (LUT) based on normative data as a tool for screening FA changes. FA was calculated for 76 healthy volunteers using 12 motion-probing gradient directions (MPG), a subset of 59 subjects was additionally scanned using 30 MPG. Population means and 95% prediction intervals for FA in the corpus callosum, frontal gray matter, thalamus and basal ganglia were used to create the LUT. Unique colors were assigned to inflection points with continuous ramps between them. Clinical use was demonstrated on 17 multiple system atrophy (MSA) patients compared to 13 patients with Parkinson disease (PD) and 17 healthy subjects. Four blinded radiologists classified subjects as MSA/non-MSA. Using only the LUT, high sensitivity (80%) and specificity (84%) were achieved in differentiating MSA subjects from PD subjects and controls. The LUTs generated from 12 and 30 MPG were comparable and accentuate FA abnormalities.
Collapse
Affiliation(s)
- Jiří Keller
- Department of Neurology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
- * E-mail:
| | - Aaron M. Rulseh
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
| | - Arnošt Komárek
- Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
| | - Iva Latnerová
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
| | - Robert Rusina
- Department of Neurology, Thomayer Hospital, Prague, Czech Republic
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Brožová
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Josef Vymazal
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
| |
Collapse
|
18
|
Sánchez‐Castañeda C, Cherubini A, Elifani F, Péran P, Orobello S, Capelli G, Sabatini U, Squitieri F. Seeking Huntington disease biomarkers by multimodal, cross-sectional basal ganglia imaging. Hum Brain Mapp 2013; 34:1625-35. [PMID: 22359398 PMCID: PMC6870326 DOI: 10.1002/hbm.22019] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 11/08/2011] [Accepted: 11/21/2011] [Indexed: 11/05/2022] Open
Abstract
Neurodegeneration of the striatum in Huntington disease (HD) is characterized by loss of medium-spiny neurons, huntingtin nuclear inclusions, reactive gliosis, and iron accumulation. Neuroimaging allows in vivo detection of the macro- and micro-structural changes that occur from presymptomatic stages of the disease (preHD). The aim of our study was to evaluate the reliability of multimodal imaging as an in vivo biomarker of vulnerability and development of the disease and to characterize macro- and micro-structural changes in subcortical nuclei in HD. Macrostructure (T1-weighted images), microstructure (diffusion tensor imaging), and iron content (R 2* relaxometry) of subcortical nuclei and medial temporal lobe structures were evaluated by a 3 T scanner in 17 preHD carriers, 12 early-stage patients and 29 matched controls. We observed a volume reduction and microstructural changes in the basal ganglia (caudate, putamen, and globus pallidus) and iron accumulation in the globus pallidus in both preHD and symptomatic subjects; all these features were significantly more pronounced in patients, in whom degeneration extended to the other subcortical nuclei (i.e., thalamus and accumbens). Mean diffusivity (MD) was the most powerful predictor in models explaining more than 50% of the variability in HD development in the caudate, putamen, and thalamus. These findings suggest that the measurement of MD may further enhance the well-known predictive value of striatal volume to assess disease progression as it is highly sensitive to tissue microimpairment. Multimodal imaging may detect brain changes even in preHD stages.
Collapse
Affiliation(s)
- Cristina Sánchez‐Castañeda
- Department of Radiology, IRCCS Santa Lucia, Rome, Italy
- Department of Psychiatry and Clinical Psychobiology, University of Barcelona, IDIBAPS, Barcelona, Spain
| | | | - Francesca Elifani
- Centre for Neurogenetics and Rare Diseases, IRCCS Neuromed, Pozzilli, Italy
| | - Patrice Péran
- Department of Radiology, IRCCS Santa Lucia, Rome, Italy
- INSERM U825, Université Paul‐Sabatier, Toulouse, France
| | - Sara Orobello
- Centre for Neurogenetics and Rare Diseases, IRCCS Neuromed, Pozzilli, Italy
| | - Giovanni Capelli
- Department of Health and Sport Sciences, University of Cassino, University of Cassino, Cassino, Italy
| | | | | |
Collapse
|
19
|
Kelp A, Koeppen AH, Petrasch-Parwez E, Calaminus C, Bauer C, Portal E, Yu-Taeger L, Pichler B, Bauer P, Riess O, Nguyen HP. A novel transgenic rat model for spinocerebellar ataxia type 17 recapitulates neuropathological changes and supplies in vivo imaging biomarkers. J Neurosci 2013; 33:9068-81. [PMID: 23699518 PMCID: PMC6705027 DOI: 10.1523/jneurosci.5622-12.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/18/2013] [Accepted: 04/09/2013] [Indexed: 02/05/2023] Open
Abstract
Spinocerebellar ataxia 17 (SCA17) is an autosomal-dominant, late-onset neurodegenerative disorder caused by an expanded polyglutamine (polyQ) repeat in the TATA-box-binding protein (TBP). To further investigate this devastating disease, we sought to create a first transgenic rat model for SCA17 that carries a full human cDNA fragment of the TBP gene with 64 CAA/CAG repeats (TBPQ64). In line with previous observations in mouse models for SCA17, TBPQ64 rats show a severe neurological phenotype including ataxia, impairment of postural reflexes, and hyperactivity in early stages followed by reduced activity, loss of body weight, and early death. Neuropathologically, the severe phenotype of SCA17 rats was associated with neuronal loss, particularly in the cerebellum. Degeneration of Purkinje, basket, and stellate cells, changes in the morphology of the dendrites, nuclear TBP-positive immunoreactivity, and axonal torpedos were readily found by light and electron microscopy. While some of these changes are well recapitulated in existing mouse models for SCA17, we provide evidence that some crucial characteristics of SCA17 are better mirrored in TBPQ64 rats. Thus, this SCA17 model represents a valuable tool to pursue experimentation and therapeutic approaches that may be difficult or impossible to perform with SCA17 transgenic mice. We show for the first time positron emission tomography (PET) and diffusion tensor imaging (DTI) data of a SCA animal model that replicate recent PET studies in human SCA17 patients. Our results also confirm that DTI are potentially useful correlates of neuropathological changes in TBPQ64 rats and raise hope that DTI imaging could provide a biomarker for SCA17 patients.
Collapse
Affiliation(s)
- Alexandra Kelp
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Arnulf H. Koeppen
- Department of Neuropathology and Neurology, Albany, New York 12208, and
| | - Elisabeth Petrasch-Parwez
- Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, 44787 Bochum, Germany
| | - Carsten Calaminus
- Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, and
| | - Claudia Bauer
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Esteban Portal
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Libo Yu-Taeger
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Bernd Pichler
- Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, and
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| | - Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics
- Centre for Rare Diseases Tübingen, University of Tübingen, 72076 Tübingen, Germany
| |
Collapse
|
20
|
Duning T, Deppe M, Brand E, Stypmann J, Becht C, Heidbreder A, Young P. Brainstem involvement as a cause of central sleep apnea: pattern of microstructural cerebral damage in patients with cerebral microangiopathy. PLoS One 2013; 8:e60304. [PMID: 23637744 PMCID: PMC3634049 DOI: 10.1371/journal.pone.0060304] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/25/2013] [Indexed: 12/22/2022] Open
Abstract
Background The exact underlying pathomechanism of central sleep apnea with Cheyne-Stokes respiration (CSA-CSR) is still unclear. Recent studies have demonstrated an association between cerebral white matter changes and CSA. A dysfunction of central respiratory control centers in the brainstem was suggested by some authors. Novel MR-imaging analysis tools now allow far more subtle assessment of microstructural cerebral changes. The aim of this study was to investigate whether and what severity of subtle structural cerebral changes could lead to CSA-CSR, and whether there is a specific pattern of neurodegenerative changes that cause CSR. Therefore, we examined patients with Fabry disease (FD), an inherited, lysosomal storage disease. White matter lesions are early and frequent findings in FD. Thus, FD can serve as a "model disease" of cerebral microangiopathy to study in more detail the impact of cerebral lesions on central sleep apnea. Patients and Methods Genetically proven FD patients (n = 23) and age-matched healthy controls (n = 44) underwent a cardio-respiratory polysomnography and brain MRI at 3.0 Tesla. We applied different MR-imaging techniques, ranging from semiquantitative measurement of white matter lesion (WML) volumes and automated calculation of brain tissue volumes to VBM of gray matter and voxel-based diffusion tensor imaging (DTI) analysis. Results In 5 of 23 Fabry patients (22%) CSA-CSR was detected. Voxel-based DTI analysis revealed widespread structural changes in FD patients when compared to the healthy controls. When calculated as a separate group, DTI changes of CSA-CSR patients were most prominent in the brainstem. Voxel-based regression analysis revealed a significant association between CSR severity and microstructural DTI changes within the brainstem. Conclusion Subtle microstructural changes in the brainstem might be a neuroanatomical correlate of CSA-CSR in patients at risk of WML. DTI is more sensitive and specific than conventional structural MRI and other advanced MR analyses tools in demonstrating these abnormalities.
Collapse
Affiliation(s)
- Thomas Duning
- Department of Neurology, University Hospital of Muenster, Muenster, Germany.
| | | | | | | | | | | | | |
Collapse
|
21
|
Brain microstructure reveals early abnormalities more than two years prior to clinical progression from mild cognitive impairment to Alzheimer's disease. J Neurosci 2013; 33:2147-55. [PMID: 23365250 DOI: 10.1523/jneurosci.4437-12.2013] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Diffusion imaging is a promising marker of microstructural damage in neurodegenerative disorders, but interpretation of its relationship with underlying neuropathology can be complex. Here, we examined both volumetric and brain microstructure abnormalities in 13 amnestic patients with mild cognitive impairment (MCI), who progressed to probable Alzheimer's disease (AD) no earlier than 2 years after baseline scanning, in order to focus on early, and hence more sensitive, imaging markers. We compared them to 22 stable amnestic MCI patients with similar cognitive performance and episodic memory impairment but who did not show progression of symptoms for at least 3 years. Significant group differences were mainly found in the volume and microstructure of the left hippocampus, while white matter group differences were also found in the body of the fornix, left fimbria, and superior longitudinal fasciculus (SLF). Diffusion index abnormalities in the SLF were the sign of a subtle microstructural injury not detected by standard atrophy measures in the corresponding gray matter regions. The microstructural measure obtained in the left hippocampus using diffusion imaging showed the most substantial differences between the two groups and was the best single predictor of future progression to AD. An optimal prediction model (91% accuracy, 85% sensitivity, 96% specificity) was obtained by combining MRI measures and CSF protein biomarkers. These results highlight the benefit of using the information of brain microstructural damage, in addition to traditional gray matter volume, to detect early, subtle abnormalities in MCI prior to clinical progression to probable AD and, in combination with CSF markers, to accurately predict such progression.
Collapse
|
22
|
Blockx I, Verhoye M, Van Audekerke J, Bergwerf I, Kane JX, Delgado Y Palacios R, Veraart J, Jeurissen B, Raber K, von Hörsten S, Ponsaerts P, Sijbers J, Leergaard TB, Van der Linden A. Identification and characterization of Huntington related pathology: an in vivo DKI imaging study. Neuroimage 2012; 63:653-62. [PMID: 22743196 DOI: 10.1016/j.neuroimage.2012.06.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 06/10/2012] [Accepted: 06/15/2012] [Indexed: 12/31/2022] Open
Abstract
An important focus of Huntington Disease (HD) research is the identification of symptom-independent biomarkers of HD neuropathology. There is an urgent need for reproducible, sensitive and specific outcome measures, which can be used to track disease onset as well as progression. Neuroimaging studies, in particular diffusion-based MRI methods, are powerful probes for characterizing the effects of disease and aging on tissue microstructure. We report novel diffusional kurtosis imaging (DKI) findings in aged transgenic HD rats. We demonstrate altered diffusion metrics in the (pre)frontal cerebral cortex, external capsule and striatum. Presence of increased diffusion complexity and restriction in the striatum is confirmed by an increased fiber dispersion in this region. Immunostaining of the same specimens reveals decreased number of microglia in the (pre)frontal cortex, and increased numbers of oligodendrocytes in the striatum. We conclude that DKI allows sensitive and specific characterization of altered tissue integrity in this HD rat model, indicating a promising potential for diagnostic imaging of gray and white matter pathology.
Collapse
Affiliation(s)
- Ines Blockx
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Oguz I, McMurray MS, Styner M, Johns JM. The translational role of diffusion tensor image analysis in animal models of developmental pathologies. Dev Neurosci 2012; 34:5-19. [PMID: 22627095 DOI: 10.1159/000336825] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 01/24/2012] [Indexed: 12/31/2022] Open
Abstract
Diffusion tensor magnetic resonance imaging (DTI) has proven itself a powerful technique for clinical investigation of the neurobiological targets and mechanisms underlying developmental pathologies. The success of DTI in clinical studies has demonstrated its great potential for understanding translational animal models of clinical disorders, and preclinical animal researchers are beginning to embrace this new technology to study developmental pathologies. In animal models, genetics can be effectively controlled, drugs consistently administered, subject compliance ensured, and image acquisition times dramatically increased to reduce between-subject variability and improve image quality. When pairing these strengths with the many positive attributes of DTI, such as the ability to investigate microstructural brain organization and connectivity, it becomes possible to delve deeper into the study of both normal and abnormal development. The purpose of this review is to provide new preclinical investigators with an introductory source of information about the analysis of data resulting from small animal DTI studies to facilitate the translation of these studies to clinical data. In addition to an in-depth review of translational analysis techniques, we present a number of relevant clinical and animal studies using DTI to investigate developmental insults in order to further illustrate techniques and to highlight where small animal DTI could potentially provide a wealth of translational data to inform clinical researchers.
Collapse
Affiliation(s)
- Ipek Oguz
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | | | | |
Collapse
|
24
|
Altered diffusion tensor imaging measurements in aged transgenic Huntington disease rats. Brain Struct Funct 2012; 218:767-78. [PMID: 22618438 PMCID: PMC3586769 DOI: 10.1007/s00429-012-0427-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 04/30/2012] [Indexed: 11/12/2022]
Abstract
Rodent models of Huntington disease (HD) are valuable tools for investigating HD pathophysiology and evaluating new therapeutic approaches. Non-invasive characterization of HD-related phenotype changes is important for monitoring progression of pathological processes and possible effects of interventions. The first transgenic rat model for HD exhibits progressive late-onset affective, cognitive, and motor impairments, as well as neuropathological features reflecting observations from HD patients. In this report, we contribute to the anatomical phenotyping of this model by comparing high-resolution ex vivo DTI measurements obtained in aged transgenic HD rats and wild-type controls. By region of interest analysis supplemented by voxel-based statistics, we find little evidence of atrophy in basal ganglia regions, but demonstrate altered DTI measurements in the dorsal and ventral striatum, globus pallidus, entopeduncular nucleus, substantia nigra, and hippocampus. These changes are largely compatible with DTI findings in preclinical and clinical HD patients. We confirm earlier reports that HD rats express a moderate neuropathological phenotype, and provide evidence of altered DTI measures in specific HD-related brain regions, in the absence of pronounced morphometric changes.
Collapse
|
25
|
Magnotta VA, Matsui JT, Liu D, Johnson HJ, Long JD, Bolster BD, Mueller BA, Lim K, Mori S, Helmer KG, Turner JA, Reading S, Lowe MJ, Aylward E, Flashman LA, Bonett G, Paulsen JS. Multicenter reliability of diffusion tensor imaging. Brain Connect 2012; 2:345-55. [PMID: 23075313 PMCID: PMC3623569 DOI: 10.1089/brain.2012.0112] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A number of studies are now collecting diffusion tensor imaging (DTI) data across sites. While the reliability of anatomical images has been established by a number of groups, the reliability of DTI data has not been studied as extensively. In this study, five healthy controls were recruited and imaged at eight imaging centers. Repeated measures were obtained across two imaging protocols allowing intra-subject and inter-site variability to be assessed. Regional measures within white matter were obtained for standard rotationally invariant measures: fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity. Intra-subject coefficient of variation (CV) was typically <1% for all scalars and regions. Inter-site CV increased to ~1%-3%. Inter-vendor variation was similar to inter-site variability. This variability includes differences in the actual implementation of the sequence.
Collapse
Affiliation(s)
- Vincent A. Magnotta
- Department of Radiology, The University of Iowa, Iowa City, Iowa
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa
| | - Joy T. Matsui
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa
- John A. Burns School of Medicine, The University of Hawaii, Honolulu, Hawaii
| | - Dawei Liu
- Department of Biostatistics, The University of Iowa, Iowa City, Iowa
| | - Hans J. Johnson
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa
| | - Jeffrey D. Long
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa
| | - Bradley D. Bolster
- MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Rochester, Minnesota
| | - Bryon A. Mueller
- Department of Psychiatry, The University of Minnesota, Minneapolis, Minnesota
| | - Kelvin Lim
- Department of Psychiatry, The University of Minnesota, Minneapolis, Minnesota
| | - Susumu Mori
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland
| | - Karl G. Helmer
- Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts
| | | | - Sarah Reading
- Department of Psychiatry, Johns Hopkins University, Baltimore, Maryland
- Mental Health and Behavioral Science Service, James A. Haley Veterans' Hospital, Tampa, Florida
- Department of Psychiatry and Neurosciences, University of South Florida, Tampa, Florida
| | - Mark J. Lowe
- Department of Radiology, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Elizabeth Aylward
- Department of Radiology, Seattle Children's Hospital, Seattle, Washington
| | - Laura A. Flashman
- Department of Psychiatry, Dartmouth Medical School, Hanover, New Hampshire
| | - Greg Bonett
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa
- The University of California Los Angeles, Los Angeles, California
| | - Jane S. Paulsen
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa
| |
Collapse
|