51
|
Zhang Y, Mao Z, Cui Z, Ling Z, Pan L, Liu X, Zhang J, Yu X. Diffusion Tensor Imaging of Axonal and Myelin Changes in Classical Trigeminal Neuralgia. World Neurosurg 2018; 112:e597-e607. [PMID: 29410338 DOI: 10.1016/j.wneu.2018.01.095] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/11/2018] [Accepted: 01/12/2018] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Trigeminal neuralgia (TN) is commonly associated with pathologic factors of axonopathy and demyelination resulting from neurovascular compression at the trigeminal root entry zone (REZ). Decompression surgery can relieve TN pain, likely by resolving such structural abnormalities. To test this hypothesis, we used diffusion tensor imaging (DTI) to capture the full extent of trigeminal microarchitecture changes in vivo in patients with TN. METHODS Twenty-four patients with TN were compared with 28 controls. DTI metrics of fractional anisotropy (FA) and mean, parallel, and perpendicular diffusivities (MD, λ||, and λ⊥, respectively) were calculated in isolation at each trigeminal REZ. In 6 patients with pain relief following decompression surgery, repeated studies were performed 2 times (1 week and 4-6 months) after surgery to detect dynamic changes in FA, MD, λ||, and λ⊥. RESULTS We observed significant FA reductions and increased diffusivity at the affected trigeminal REZ, corresponding to known underlying pathologic changes, including axonal edema and demyelination. Specifically, our results showed that these DTI-derived metrics are discriminating features for patients with TN according to the support vector machine approach. After effective treatment, diffusion recovery at 1 week was mainly due to the decrease in λ|| (consistent with axonal membrane stabilization), whereas at 4-6 months it was due to the predominant reduction in λ⊥ (consistent with remyelination). CONCLUSIONS Together, these results support that DTI permits the noninvasive detection of the trigeminal microstructural abnormalities underlying TN in vivo, and DTI-derived metrics could be considered surrogate markers of the axonal and myelin states for monitoring patients.
Collapse
Affiliation(s)
- Yanyang Zhang
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Zhiqi Mao
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Zhiqiang Cui
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Zhipei Ling
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Longsheng Pan
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Xinyun Liu
- Department of Radiology, PLA General Hospital, Beijing, China
| | - Jun Zhang
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Xinguang Yu
- Department of Neurosurgery, PLA General Hospital, Beijing, China.
| |
Collapse
|
52
|
Schneider T, Brownlee W, Zhang H, Ciccarelli O, Miller DH, Wheeler-Kingshott CG. Sensitivity of multi-shell NODDI to multiple sclerosis white matter changes: a pilot study. FUNCTIONAL NEUROLOGY 2018; 32:97-101. [PMID: 28676143 DOI: 10.11138/fneur/2017.32.2.097] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Diffusion tensor imaging (DTI) is sensitive to white matter (WM) damage in multiple sclerosis (MS), not only in focal lesions but also in the normal-appearing WM (NAWM). However, DTI indices can also be affected by natural spatial variation in WM, as seen in crossing and dispersing white matter fibers. Neurite orientation dispersion and density imaging (NODDI) is an advanced diffusion-weighted imaging technique that provides distinct indices of fiber density and dispersion. We performed NODDI of lesion tissue and NAWM in five MS patients and five controls, comparing the technique with traditional DTI. Both DTI and NODDI identified tissue damage in NAWM and in lesions. NODDI was able to detect additional changes and it provided better contrast in MS-NAWM microstructure, because it distinguished orientation dispersion and fiber density better than DTI. We showed that NODDI is viable in MS patients and that it offers, compared with DTI parameters, improved sensitivity and possibly greater specificity to microstructure features such as neurite orientation.
Collapse
|
53
|
López-Sánchez EJ, Romero JM, Yépez-Martínez H. Fractional cable equation for general geometry: A model of axons with swellings and anomalous diffusion. Phys Rev E 2018; 96:032411. [PMID: 29346980 DOI: 10.1103/physreve.96.032411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Indexed: 11/07/2022]
Abstract
Different experimental studies have reported anomalous diffusion in brain tissues and notably this anomalous diffusion is expressed through fractional derivatives. Axons are important to understand neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, and Parkinson's disease. Indeed, abnormal accumulation of proteins and organelles in axons is a hallmark of these diseases. The diffusion in the axons can become anomalous as a result of this abnormality. In this case the voltage propagation in axons is affected. Another hallmark of different neurodegenerative diseases is given by discrete swellings along the axon. In order to model the voltage propagation in axons with anomalous diffusion and swellings, in this paper we propose a fractional cable equation for a general geometry. This generalized equation depends on fractional parameters and geometric quantities such as the curvature and torsion of the cable. For a cable with a constant radius we show that the voltage decreases when the fractional effect increases. In cables with swellings we find that when the fractional effect or the swelling radius increases, the voltage decreases. Similar behavior is obtained when the number of swellings and the fractional effect increase. Moreover, we find that when the radius swelling (or the number of swellings) and the fractional effect increase at the same time, the voltage dramatically decreases.
Collapse
Affiliation(s)
- Erick J López-Sánchez
- Posgrado en Ciencias Naturales e Ingeniería, Universidad Autónoma Metropolitana, Cuajimalpa and Vasco de Quiroga 4871, Santa Fe Cuajimalpa, Ciudad de México 05300, Mexico
| | - Juan M Romero
- Departamento de Matemáticas Aplicadas y Sistemas, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Santa Fe Cuajimalpa, Ciudad de México 05300, Mexico
| | - Huitzilin Yépez-Martínez
- Universidad Autónoma de la Ciudad de México, Prolongación San Isidro 151, San Lorenzo Tezonco, Iztapalapa, Ciudad de México 09790, Mexico
| |
Collapse
|
54
|
Alcaide-Leon P, Cybulsky K, Sankar S, Casserly C, Leung G, Hohol M, Selchen D, Montalban X, Bharatha A, Oh J. Quantitative spinal cord MRI in radiologically isolated syndrome. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2018; 5:e436. [PMID: 29359174 PMCID: PMC5773843 DOI: 10.1212/nxi.0000000000000436] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 11/06/2017] [Indexed: 01/20/2023]
Abstract
Objectives To assess whether quantitative spinal cord MRI (SC-MRI) measures, including atrophy, and diffusion tensor imaging (DTI) and magnetization transfer imaging metrics were different in radiologically isolated syndrome (RIS) vs healthy controls (HCs). Methods Twenty-four participants with RIS and 14 HCs underwent cervical SC-MRI on a 3T magnet. Manually segmented regions of interest circumscribing the spinal cord cross-sectional area (SC-CSA) between C3 and C4 were used to extract SC-CSA, fractional anisotropy, mean, perpendicular, and parallel diffusivity (MD, λ⊥, and λ||) and magnetization transfer ratio (MTR). Spinal cord (SC) lesions, SC gray matter (GM), and SC white matter (WM) areas were also manually segmented. Multivariable linear regression was performed to evaluate differences in SC-MRI measures in RIS vs HCs, while controlling for age and sex. Results In this cross-sectional study of participants with RIS, 71% had lesions in the cervical SC. Of quantitative SC-MRI metrics, spinal cord MTR showed a trend toward being lower in RIS vs HCs (p = 0.06), and there was already evidence of brain atrophy (p = 0.05). There were no significant differences in SC-DTI metrics, GM, WM, or CSA between RIS and HCs. Conclusion The SC demonstrates minimal microstructural changes suggestive of demyelination and inflammation in RIS. These findings are in contrast to established MS and raise the possibility that the SC may play an important role in triggering clinical symptomatology in MS. Prospective follow-up of this cohort will provide additional insights into the role the SC plays in the complex sequence of events related to MS disease initiation and progression.
Collapse
Affiliation(s)
- Paula Alcaide-Leon
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Kateryna Cybulsky
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Stephanie Sankar
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Courtney Casserly
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - General Leung
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Marika Hohol
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Daniel Selchen
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Xavier Montalban
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Aditya Bharatha
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| | - Jiwon Oh
- Division of Neurology (P.A.-L., K.C., S.S., C.C., M.H., D.S., X.M., J.O.), Department of Medicine; Division of Neuroradiology (P.A.-L., G.L., A.B.), Department of Medical Imaging; Division of Neurosurgery (A.B.), Department of Surgery, St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Neurology-Neuroimmunology Neurorehabilitation Unit (X.M.), Multiple Sclerosis Center of Catalonia (Cemcat), Barcelona, Spain; and Department of Neurology (J.O.), Johns Hopkins University, Baltimore, MD
| |
Collapse
|
55
|
Gurevich M, Waknin R, Stone E, Achiron A. Fingolimod-improved axonal and myelin integrity of white matter tracts associated with multiple sclerosis-related functional impairments. CNS Neurosci Ther 2018; 24:412-419. [PMID: 29316271 DOI: 10.1111/cns.12796] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/10/2017] [Accepted: 12/12/2017] [Indexed: 01/26/2023] Open
Abstract
AIMS Fingolimod hydrochloride is an effective immunomodulatory drug in improving relapsing-remitting multiple sclerosis (RRMS). However, data on the neuroradiologic effects on white matter (WM) have not been demonstrated. In this study, we aimed elucidating the impact of 1-year fingolimod treatment on WM integrity in patients with RRMS. METHODS Diffusion tensor imaging (DTI) was applied to assess axonal and myelin integrity in specific WM tracts of patients with RRMS prior to and 1 year postfingolimod treatment (n = 30). The fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity, and mean diffusivity were analyzed using tract-based spatial statistics on specific regions of interest associated with impaired Expanded Disability Status Scale functional scores before treatment. RESULTS In patients with impaired pyramidal function at baseline (average score 2.3 ± 0.2, n = 25), fingolimod induced a significant increase in FA (P = 0.002) and decrease in RD (P = 0.03) in the corticospinal tract. In patients with impaired cerebellar function at baseline (average score 2.0 ± 0.1, n = 19), significant increases in FA and decreases in RD were observed in the superior (P = 0.02, P = 0.01, respectively) and inferior (P = 0.03, P = 0.05, respectively) cerebellar peduncles. CONCLUSION The observed results suggest increased microstructural integrity and decreased demyelination of damaged WM tracts and support the possible direct mechanism of fingolimod action.
Collapse
Affiliation(s)
- Michael Gurevich
- Multiple Sclerosis Center, Sheba Medical Center, Ramat-Gan, Israel
| | - Roy Waknin
- Multiple Sclerosis Center, Sheba Medical Center, Ramat-Gan, Israel
| | - Evan Stone
- Multiple Sclerosis Center, Sheba Medical Center, Ramat-Gan, Israel
| | - Anat Achiron
- Multiple Sclerosis Center, Sheba Medical Center, Ramat-Gan, Israel.,Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| |
Collapse
|
56
|
Ammitzbøll C, Dyrby TB, Lyksborg M, Schreiber K, Ratzer R, Romme Christensen J, Iversen P, Magyari M, Garde E, Sørensen PS, Siebner HR, Sellebjerg F. Disability in progressive MS is associated with T2 lesion changes. Mult Scler Relat Disord 2017; 20:73-77. [PMID: 29324249 DOI: 10.1016/j.msard.2017.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/17/2017] [Accepted: 12/15/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND Progressive multiple sclerosis (MS) is characterised by diffuse changes on brain magnetic resonance imaging (MRI), which complicates the use of MRI as a diagnostic and prognostic marker. The relationship between MRI measures (conventional and non-conventional) and clinical disability in progressive MS therefore warrants further investigation. OBJECTIVE To investigate the relationship between clinical disability and MRI measures in patients with progressive MS. METHODS Data from 93 primary and secondary progressive MS patients who had participated in 3 phase 2 clinical trials were included in this cross-sectional study. From 3T MRI baseline scans we calculated total T2 lesion volume and analysed magnetisation transfer ratio (MTR) and the diffusion tensor imaging indices fractional anisotropy (FA) and mean diffusivity (MD) in T2 lesions, normal-appearing white matter (NAWM) and cortical grey matter. Disability was assessed by the Expanded Disability Status Scale (EDSS) and the MS functional composite. RESULTS T2 lesion volume was associated with impairment by all clinical measures. MD and MTR in T2 lesions were significantly related to disability, and lower FA values correlated with worse hand function in NAWM. In multivariable analyses, increasing clinical disability was independently correlated with increasing T2 lesion volumes and MTR in T2 lesions. CONCLUSION In progressive MS, clinical disability is related to lesion volume and microstructure.
Collapse
Affiliation(s)
- C Ammitzbøll
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
| | - T B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Lyngby, Denmark
| | - M Lyksborg
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Lyngby, Denmark
| | - K Schreiber
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - R Ratzer
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - J Romme Christensen
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - P Iversen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - M Magyari
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - E Garde
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Faculty of Health and Medical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Demark
| | - P S Sørensen
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - H R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, University of Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark
| | - F Sellebjerg
- Danish Multiple Sclerosis Center, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
57
|
Thaler C, Faizy TD, Sedlacik J, Bester M, Stellmann JP, Heesen C, Fiehler J, Siemonsen S. The use of multiparametric quantitative magnetic resonance imaging for evaluating visually assigned lesion groups in patients with multiple sclerosis. J Neurol 2017; 265:127-133. [PMID: 29159467 DOI: 10.1007/s00415-017-8683-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/13/2017] [Accepted: 11/14/2017] [Indexed: 12/19/2022]
Abstract
In multiple sclerosis (MS), inflammatory lesions present a broad spectrum of histopathologic processes. For a better discrimination, lesions are visually defined into different lesion groups according to their appearance on conventional magnetic resonance imaging (MRI). The aim of this study was to investigate the properties of different MS lesion groups using multiparametric quantitative MRI. 35 patients diagnosed with relapsing-remitting MS received 3 Tesla MRI including magnetization-prepared 2 rapid acquisition gradient echo, diffusion tensor imaging and magnetization transfer imaging. Lesion segmentation was performed for T2 lesions, black holes and contrast-enhancing lesions. A subtraction mask was created including only T2 lesions that did not correspond to a black hole or contrast-enhancing lesion. T1 relaxation time (T1-RT), magnetization transfer ratio (MTR), mean diffusivity (MD) and fractional anisotropy (FA) were determined for every lesion and in normal-appearing white matter. Only MD differed significantly between all lesion groups and NAWM (p < 0.05), while FA differed between all lesion groups but not NAWM. T1-RT and MTR were not useful imaging biomarkers to distinguish between lesion groups. A lack of sensitivity and specificity and unproportional alterations of quantitative MRI measures, due to heterogenous histopathologic processes within lesions, may be a possible explanation for missing discrimination. Thus, not only interpretation of visually defined MS lesion but also interpretation of quantitative MRI measures remains challenging and should be conducted carefully.
Collapse
Affiliation(s)
- Christian Thaler
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
| | - Tobias D Faizy
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Jan Sedlacik
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Maxim Bester
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Jan-Patrick Stellmann
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute for Neuroimmunology and Clinical MS Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Heesen
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute for Neuroimmunology and Clinical MS Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jens Fiehler
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Susanne Siemonsen
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| |
Collapse
|
58
|
A probabilistic atlas of fiber crossings for variability reduction of anisotropy measures. Brain Struct Funct 2017; 223:635-651. [PMID: 28905121 DOI: 10.1007/s00429-017-1508-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 08/31/2017] [Indexed: 12/13/2022]
Abstract
Diffusion imaging enables assessment of human brain white matter (WM) in vivo. WM microstructural integrity is routinely quantified via fractional anisotropy (FA). However, FA is also influenced by the number of differentially oriented fiber populations per voxel. To date, the precise statistical relationship between FA and fiber populations has not been characterized, complicating microstructural integrity assessment. Here, we used 630 state-of-the-art diffusion datasets from the Human Connectome Project, which allowed us to infer the number of fiber populations per voxel in a model-free fashion. Beyond the known impact on mean FA, variance of anisotropy distributions was drastically impacted, not only for FA, but also the more recent anisotropy indices generalized FA and multidimensional anisotropy. To ameliorate this bias, we introduce a probabilistic WM atlas delineating the number of distinctly oriented fiber populations per voxel. Our atlas shows that the majority of WM voxels features two differentially directed fiber populations (44.7%) rather than unidirectional fibers (32.9%) and identified WM regions with high numbers of crossing fibers, referred to as crossing pockets. Compartmentalizing anisotropy drastically reduced variance in group comparisons ranging from the whole brain to a few voxels in a single slice. In summary, we demonstrate a systematic effect of intra-voxel diffusion inhomogeneity on anisotropy. Moreover, we introduce a potential solution: The provided probabilistic WM atlas can easily be used with any given diffusion dataset to enhance the statistical robustness of anisotropy measures and increase their neurobiological utility.
Collapse
|
59
|
Chiou SY, Hellyer PJ, Sharp DJ, Newbould RD, Patel MC, Strutton PH. Relationships between the integrity and function of lumbar nerve roots as assessed by diffusion tensor imaging and neurophysiology. Neuroradiology 2017; 59:893-903. [PMID: 28744730 PMCID: PMC5559579 DOI: 10.1007/s00234-017-1869-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/14/2017] [Indexed: 01/02/2023]
Abstract
Purpose Diffusion tensor imaging (DTI) has shown promise in the measurement of peripheral nerve integrity, although the optimal way to apply the technique for the study of lumbar spinal nerves is unclear. The aims of this study are to use an improved DTI acquisition to investigate lumbar nerve root integrity and correlate this with functional measures using neurophysiology. Methods Twenty healthy volunteers underwent 3 T DTI of the L5/S1 area. Regions of interest were applied to L5 and S1 nerve roots, and DTI metrics (fractional anisotropy, mean, axial and radial diffusivity) were derived. Neurophysiological measures were obtained from muscles innervated by L5/S1 nerves; these included the slope of motor-evoked potential input-output curves, F-wave latency, maximal motor response, and central and peripheral motor conduction times. Results DTI metrics were similar between the left and right sides and between vertebral levels. Conversely, significant differences in DTI measures were seen along the course of the nerves. Regression analyses revealed that DTI metrics of the L5 nerve correlated with neurophysiological measures from the muscle innervated by it. Conclusion The current findings suggest that DTI has the potential to be used for assessing lumbar spinal nerve integrity and that parameters derived from DTI provide quantitative information which reflects their function.
Collapse
Affiliation(s)
- S Y Chiou
- The Nick Davey Laboratory, Division of Surgery, Human Performance Group, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK
| | - P J Hellyer
- Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, London, UK.,Department of Bioengineering, Imperial College London, London, UK
| | - D J Sharp
- Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Imperial College London, London, UK
| | | | - M C Patel
- Imaging Department, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, UK
| | - P H Strutton
- The Nick Davey Laboratory, Division of Surgery, Human Performance Group, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK.
| |
Collapse
|
60
|
Filippi M, Rovaris M, Rocca MA. Imaging primary progressive multiple sclerosis: the contribution of structural, metabolic, and functional MRI techniques. Mult Scler 2017; 10 Suppl 1:S36-44; discussion S44-5. [PMID: 15218808 DOI: 10.1191/1352458504ms1029oa] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Patients with primary progressive multiple sclerosis (PPMS) typically experience a progressive disease course from onset, leading to the accumulation of severe neurological disability. This is in contrast with the observation that the burden and activity of lesions on conventional magnetic resonance imaging (MRI) scans of the brain are much lower in patients with PPMS than in those with other less disabling forms of the disease. Studies with structural and functional MRI techniques are providing relevant contributions to the understanding of the mechanisms underlying the accumulatio n of irreversible neurological deficits in patients with PPMS. The results of these studies underpin that the main factors possibly explaining the clinical/MRI discrepancy observed in patients with PPMS include the presence of a diffuse tissue damage that is beyond the resolution of conventional imaging, the extent of cervical cord damage, and the impairment of the adaptive capacity of the cortex to limit the functional consequences of subcortical pathology.
Collapse
Affiliation(s)
- Massimo Filippi
- Department of Neurology, Neuroimaging Research Unit, Scientific Institute and University Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy.
| | | | | |
Collapse
|
61
|
Baker LM, Laidlaw DH, Cabeen R, Akbudak E, Conturo TE, Correia S, Tate DF, Heaps-Woodruff JM, Brier MR, Bolzenius J, Salminen LE, Lane EM, McMichael AR, Paul RH. Cognitive reserve moderates the relationship between neuropsychological performance and white matter fiber bundle length in healthy older adults. Brain Imaging Behav 2017; 11:632-639. [PMID: 26961092 PMCID: PMC7083104 DOI: 10.1007/s11682-016-9540-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Recent work using novel neuroimaging methods has revealed shorter white matter fiber bundle length (FBL) in older compared to younger adults. Shorter FBL also corresponds to poorer performance on cognitive measures sensitive to advanced age. However, it is unclear if individual factors such as cognitive reserve (CR) effectively moderate the relationship between FBL and cognitive performance. This study examined CR as a potential moderator of cognitive performance and brain integrity as defined by FBL. Sixty-three healthy adults underwent neuropsychological evaluation and 3T brain magnetic resonance imaging. Cognitive performance was measured using the Repeatable Battery of Assessment of Neuropsychological Status (RBANS). FBL was quantified from tractography tracings of white matter fiber bundles, derived from the diffusion tensor imaging. CR was determined by estimated premorbid IQ. Analyses revealed that lower scores on the RBANS were associated with shorter whole brain FBL (p = 0.04) and lower CR (p = 0.01) CR moderated the relationship between whole brain FBL and RBANS score (p < 0.01). Tract-specific analyses revealed that CR also moderated the association between FBL in the hippocampal segment of the cingulum and RBANS performance (p = 0.03). These results demonstrate that lower cognitive performance on the RBANS is more common with low CR and short FBL. On the contrary, when individuals have high CR, the relationship between FBL and cognitive performance is attenuated. Overall, CR protects older adults against lower cognitive performance despite age-associated reductions in FBL.
Collapse
Affiliation(s)
- Laurie M Baker
- Department of Psychological Sciences, University of Missouri - Saint Louis, One University Boulevard, Stadler Hall 327, Saint Louis, MO, 63121, USA.
| | - David H Laidlaw
- Computer Science Department, Brown University, Providence, RI, 02912, USA
| | - Ryan Cabeen
- Computer Science Department, Brown University, Providence, RI, 02912, USA
| | - Erbil Akbudak
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Thomas E Conturo
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Stephen Correia
- Division of Biology and Medicine, Brown Medical School, Providence, RI, 02912, USA
| | - David F Tate
- Missouri Institute of Mental Health, St. Louis, MO, 63134, USA
| | | | - Matthew R Brier
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jacob Bolzenius
- Missouri Institute of Mental Health, St. Louis, MO, 63134, USA
| | - Lauren E Salminen
- Department of Psychological Sciences, University of Missouri - Saint Louis, One University Boulevard, Stadler Hall 327, Saint Louis, MO, 63121, USA
| | - Elizabeth M Lane
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Amanda R McMichael
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Robert H Paul
- Department of Psychological Sciences, University of Missouri - Saint Louis, One University Boulevard, Stadler Hall 327, Saint Louis, MO, 63121, USA
- Missouri Institute of Mental Health, St. Louis, MO, 63134, USA
| |
Collapse
|
62
|
Correale J, Gaitán MI, Ysrraelit MC, Fiol MP. Progressive multiple sclerosis: from pathogenic mechanisms to treatment. Brain 2017; 140:527-546. [PMID: 27794524 DOI: 10.1093/brain/aww258] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 08/18/2016] [Indexed: 12/30/2022] Open
Abstract
During the past decades, better understanding of relapsing-remitting multiple sclerosis disease mechanisms have led to the development of several disease-modifying therapies, reducing relapse rates and severity, through immune system modulation or suppression. In contrast, current therapeutic options for progressive multiple sclerosis remain comparatively disappointing and challenging. One possible explanation is a lack of understanding of pathogenic mechanisms driving progressive multiple sclerosis. Furthermore, diagnosis is usually retrospective, based on history of gradual neurological worsening with or without occasional relapses, minor remissions or plateaus. In addition, imaging methods as well as biomarkers are not well established. Magnetic resonance imaging studies in progressive multiple sclerosis show decreased blood-brain barrier permeability, probably reflecting compartmentalization of inflammation behind a relatively intact blood-brain barrier. Interestingly, a spectrum of inflammatory cell types infiltrates the leptomeninges during subpial cortical demyelination. Indeed, recent magnetic resonance imaging studies show leptomeningeal contrast enhancement in subjects with progressive multiple sclerosis, possibly representing an in vivo marker of inflammation associated to subpial demyelination. Treatments for progressive disease depend on underlying mechanisms causing central nervous system damage. Immunity sheltered behind an intact blood-brain barrier, energy failure, and membrane channel dysfunction may be key processes in progressive disease. Interfering with these mechanisms may provide neuroprotection and prevent disability progression, while potentially restoring activity and conduction along damaged axons by repairing myelin. Although most previous clinical trials in progressive multiple sclerosis have yielded disappointing results, important lessons have been learnt, improving the design of novel ones. This review discusses mechanisms involved in progressive multiple sclerosis, correlations between histopathology and magnetic resonance imaging studies, along with possible new therapeutic approaches.
Collapse
|
63
|
Gupta A, Al-Dasuqi K, Xia F, Askin G, Zhao Y, Delgado D, Wang Y. The Use of Noncontrast Quantitative MRI to Detect Gadolinium-Enhancing Multiple Sclerosis Brain Lesions: A Systematic Review and Meta-Analysis. AJNR Am J Neuroradiol 2017; 38:1317-1322. [PMID: 28522663 DOI: 10.3174/ajnr.a5209] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/22/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND Concerns have arisen about the long-term health effects of repeat gadolinium injections in patients with multiple sclerosis and the incomplete characterization of MS lesion pathophysiology that results from relying on enhancement characteristics alone. PURPOSE Our aim was to perform a systematic review and meta-analysis analyzing whether noncontrast MR imaging biomarkers can distinguish enhancing and nonenhancing brain MS lesions. DATA SOURCES Our sources were Ovid MEDLINE, Ovid Embase, and the Cochrane data base from inception to August 2016. STUDY SELECTION We included 37 journal articles on 985 patients with MS who had MR imaging in which T1-weighted postcontrast sequences were compared with noncontrast sequences obtained during the same MR imaging examination by using ROI analysis of individual MS lesions. DATA ANALYSIS We performed random-effects meta-analyses comparing the standard mean difference of each MR imaging metric taken from enhancing-versus-nonenhancing lesions. DATA SYNTHESIS DTI-based fractional anisotropy values are significantly different between enhancing and nonenhancing lesions (P = .02), with enhancing lesions showing decreased fractional anisotropy compared with nonenhancing lesions. Of the other most frequently studied MR imaging biomarkers (mean diffusivity, magnetization transfer ratio, or ADC), none were significantly different (P values of 0.30, 0.47, and 0.19. respectively) between enhancing and nonenhancing lesions. Of the limited studies providing diagnostic accuracy measures, gradient-echo-based quantitative susceptibility mapping had the best performance in discriminating enhancing and nonenhancing MS lesions. LIMITATIONS MR imaging techniques and patient characteristics were variable across studies. Most studies did not provide diagnostic accuracy measures. All imaging metrics were not studied in all 37 studies. CONCLUSIONS Noncontrast MR imaging techniques, such as DTI-based FA, can assess MS lesion acuity without gadolinium.
Collapse
Affiliation(s)
- A Gupta
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.) .,Clinical and Translational Neuroscience Unit (A.G.), Feil Family Brain and Mind Research Institute
| | - K Al-Dasuqi
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.)
| | - F Xia
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.).,Department of Biomedical Engineering (F.X., Y.W.), Cornell University, Ithaca, New York
| | - G Askin
- Department of Healthcare Policy and Research (G.A., Y.Z.)
| | - Y Zhao
- Department of Healthcare Policy and Research (G.A., Y.Z.)
| | - D Delgado
- Samuel J. Wood Library and C.V. Starr Biomedical Information Center (D.D.), Weill Cornell Medicine, New York, New York
| | - Y Wang
- From the Department of Radiology (A.G., K.A.-D., F.X., Y.W.).,Department of Biomedical Engineering (F.X., Y.W.), Cornell University, Ithaca, New York
| |
Collapse
|
64
|
|
65
|
Milad P, Elbegiermy M, Shokry T, Mahmoud H, Kamal I, Taha MS, Keriakos N. The added value of pretreatment DW MRI in characterization of salivary glands pathologies. Am J Otolaryngol 2017; 38:13-20. [PMID: 27806890 DOI: 10.1016/j.amjoto.2016.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 09/06/2016] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To evaluate the added value of diffusion weighted magnetic resonance imaging (DW-MRI) in characterization of salivary gland lesions. STUDY DESIGN A prospective study was carried out between January 2013, and March 2015. METHODS The study included 46 patients. The consultant radiologist, who reviewed the scans to comment on the apparent diffusion coefficient (ADC) value and ADC histogram was blind to the suspected pathology. Radiological findings were then compared to clinical and histological findings. RESULTS The diagnostic performance of DW-MRI for identification of malignant lesions showed that the sensitivity, specificity, and positive and negative prediction value were 100%, 92%, 91.3%, and 100%, respectively. CONCLUSION The specific ability of DW-MRI to probe tissue microstructures is an interesting complement to the currently used imaging procedures in the characterization, and even grading of malignancies. ADC mapping is an easy, cost effective promising tool that has neither radiation exposure, nor amalgam artifacts and can be used in helping characterization of salivary glands lesions. LEVEL OF EVIDENCE 1B.
Collapse
Affiliation(s)
- Peter Milad
- ENT Department, Ain Shams University Hospitals.
| | | | | | | | - Ihab Kamal
- ENT Department, Ain Shams University Hospitals
| | | | | |
Collapse
|
66
|
Jin Y, Huang C, Daianu M, Zhan L, Dennis EL, Reid RI, Jack CR, Zhu H, Thompson PM. 3D tract-specific local and global analysis of white matter integrity in Alzheimer's disease. Hum Brain Mapp 2016; 38:1191-1207. [PMID: 27883250 PMCID: PMC5299040 DOI: 10.1002/hbm.23448] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 10/13/2016] [Accepted: 10/13/2016] [Indexed: 12/04/2022] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by progressive decline in memory and other aspects of cognitive function. Diffusion‐weighted imaging (DWI) offers a non‐invasive approach to delineate the effects of AD on white matter (WM) integrity. Previous studies calculated either some summary statistics over regions of interest (ROI analysis) or some statistics along mean skeleton lines (Tract Based Spatial Statistic [TBSS]), so they cannot quantify subtle local WM alterations along major tracts. Here, a comprehensive WM analysis framework to map disease effects on 3D tracts both locally and globally, based on a study of 200 subjects: 49 healthy elderly normal controls, 110 with mild cognitive impairment, and 41 AD patients has been presented. 18 major WM tracts were extracted with our automated clustering algorithm—autoMATE (automated Multi‐Atlas Tract Extraction); we then extracted multiple DWI‐derived parameters of WM integrity along the WM tracts across all subjects. A novel statistical functional analysis method—FADTTS (Functional Analysis for Diffusion Tensor Tract Statistics) was applied to quantify degenerative patterns along WM tracts across different stages of AD. Gradually increasing WM alterations were found in all tracts in successive stages of AD. Among all 18 WM tracts, the fornix was most adversely affected. Among all the parameters, mean diffusivity (MD) was the most sensitive to WM alterations in AD. This study provides a systematic workflow to examine WM integrity across automatically computed 3D tracts in AD and may be useful in studying other neurological and psychiatric disorders. Hum Brain Mapp 38:1191–1207, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yan Jin
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, California.,Department of Biostatistics and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Chao Huang
- Department of Biostatistics and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Madelaine Daianu
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, California
| | - Liang Zhan
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, California.,Computer Engineering Program, University of Wisconsin-Stout, Menomonie, Wisconsin
| | - Emily L Dennis
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, California
| | - Robert I Reid
- Department of Information Technology, Mayo Clinic, Rochester, Minnesota
| | | | - Hongtu Zhu
- Department of Biostatistics and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Paul M Thompson
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, California.,Departments of Neurology, Psychiatry, Pediatrics, Radiology, and Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California.,Viterbi School of Engineering, University of Southern California, Los Angeles, California
| | | |
Collapse
|
67
|
Schilling K, Gao Y, Stepniewska I, Choe AS, Landman BA, Anderson AW. Reproducibility and variation of diffusion measures in the squirrel monkey brain, in vivo and ex vivo. Magn Reson Imaging 2016; 35:29-38. [PMID: 27587226 DOI: 10.1016/j.mri.2016.08.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/11/2016] [Accepted: 08/20/2016] [Indexed: 01/07/2023]
Abstract
PURPOSE Animal models are needed to better understand the relationship between diffusion MRI (dMRI) and the underlying tissue microstructure. One promising model for validation studies is the common squirrel monkey, Saimiri sciureus. This study aims to determine (1) the reproducibility of in vivo diffusion measures both within and between subjects; (2) the agreement between in vivo and ex vivo data acquired from the same specimen and (3) normal diffusion values and their variation across brain regions. METHODS Data were acquired from three healthy squirrel monkeys, each imaged twice in vivo and once ex vivo. Reproducibility of fractional anisotropy (FA), mean diffusivity (MD), and principal eigenvector (PEV) was assessed, and normal values were determined both in vivo and ex vivo. RESULTS The calculated coefficients of variation (CVs) for both intra-subject and inter-subject MD were below 10% (low variability) while FA had a wider range of CVs, 2-14% intra-subject (moderate variability), and 3-31% inter-subject (high variability). MD in ex vivo tissue was lower than in vivo (30%-50% decrease), while FA values increased in all regions (30-39% increase). The mode of angular differences between in vivo and ex vivo PEVs was 12 degrees. CONCLUSION This study characterizes the diffusion properties of the squirrel monkey brain and serves as the groundwork for using the squirrel monkey, both in vivo and ex vivo, as a model for diffusion MRI studies.
Collapse
Affiliation(s)
- Kurt Schilling
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
| | - Yurui Gao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | | | - Ann S Choe
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Bennett A Landman
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Department of Electrical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Adam W Anderson
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
68
|
Thomas B, Sunaert S. Diffusion Tensor Imaging: Technique, Clinical and Research Applications. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/197140090501800403] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- B. Thomas
- Department of Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum; Kerala, India
| | - S. Sunaert
- Department of Radiology, University Hospitals, KUL; Leuven, Belgium
| |
Collapse
|
69
|
Dworkin JD, Sweeney EM, Schindler MK, Chahin S, Reich DS, Shinohara RT. PREVAIL: Predicting Recovery through Estimation and Visualization of Active and Incident Lesions. NEUROIMAGE-CLINICAL 2016; 12:293-9. [PMID: 27551666 PMCID: PMC4983640 DOI: 10.1016/j.nicl.2016.07.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/21/2016] [Accepted: 07/30/2016] [Indexed: 12/02/2022]
Abstract
Objective The goal of this study was to develop a model that integrates imaging and clinical information observed at lesion incidence for predicting the recovery of white matter lesions in multiple sclerosis (MS) patients. Methods Demographic, clinical, and magnetic resonance imaging (MRI) data were obtained from 60 subjects with MS as part of a natural history study at the National Institute of Neurological Disorders and Stroke. A total of 401 lesions met the inclusion criteria and were used in the study. Imaging features were extracted from the intensity-normalized T1-weighted (T1w) and T2-weighted sequences as well as magnetization transfer ratio (MTR) sequence acquired at lesion incidence. T1w and MTR signatures were also extracted from images acquired one-year post-incidence. Imaging features were integrated with clinical and demographic data observed at lesion incidence to create statistical prediction models for long-term damage within the lesion. Validation The performance of the T1w and MTR predictions was assessed in two ways: first, the predictive accuracy was measured quantitatively using leave-one-lesion-out cross-validated (CV) mean-squared predictive error. Then, to assess the prediction performance from the perspective of expert clinicians, three board-certified MS clinicians were asked to individually score how similar the CV model-predicted one-year appearance was to the true one-year appearance for a random sample of 100 lesions. Results The cross-validated root-mean-square predictive error was 0.95 for normalized T1w and 0.064 for MTR, compared to the estimated measurement errors of 0.48 and 0.078 respectively. The three expert raters agreed that T1w and MTR predictions closely resembled the true one-year follow-up appearance of the lesions in both degree and pattern of recovery within lesions. Conclusion This study demonstrates that by using only information from a single visit at incidence, we can predict how a new lesion will recover using relatively simple statistical techniques. The potential to visualize the likely course of recovery has implications for clinical decision-making, as well as trial enrichment. A model for predicting degree and pattern of MS lesion tissue recovery is proposed. The model relies solely on MR images at lesion incidence and patient information. Predictions performed well when rated for accuracy by expert MS clinicians.
Collapse
Affiliation(s)
- Jordan D Dworkin
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Elizabeth M Sweeney
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States
| | - Matthew K Schindler
- Translational Neuroradiology Unit, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disease and Stroke, National Institute of Health, Bethesda, MD 20892, United States
| | - Salim Chahin
- Multiple Sclerosis Division of the Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Daniel S Reich
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States; Translational Neuroradiology Unit, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disease and Stroke, National Institute of Health, Bethesda, MD 20892, United States
| | - Russell T Shinohara
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| |
Collapse
|
70
|
Klistorner A, Wang C, Fofanova V, Barnett MH, Yiannikas C, Parratt J, You Y, Graham SL. Diffusivity in multiple sclerosis lesions: At the cutting edge? NEUROIMAGE-CLINICAL 2016; 12:219-26. [PMID: 27489769 PMCID: PMC4950592 DOI: 10.1016/j.nicl.2016.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/04/2016] [Accepted: 07/04/2016] [Indexed: 12/22/2022]
Abstract
Background Radial Diffusivity (RD) has been suggested as a promising biomarker associated with the level of myelination in MS lesions. However, the level of RD within the lesion is affected not only by loss of myelin sheaths, but also by the degree of tissue destruction. This may lead to exaggeration of diffusivity measures, potentially masking the effect of remyelination. Objective To test the hypothesis that the T2 hyperintense lesion edge that extends beyond the T1 hypointense lesion core is less affected by tissue loss, and therefore a more appropriate target for imaging biomarker development targeting de- and re-myelination. Method Pre- and post-gadolinium (Gd) enhanced T1, T2 and DTI images were acquired from 75 consecutive RRMS patients. The optic radiation (OR) was identified in individual patients using a template-based method. T2 lesions were segmented into T1-hypointense and T1-isointense areas and lesion masks intersected with the OR. Average Radial, Axial and Mean diffusivity (RD, AD and MD) and fractional anisotropy (FA) were calculated for lesions of the entire brain and the OR. In addition, Gd enhancing lesions were excluded from the analysis. Results 86% of chronic T2 lesions demonstrated hypointense areas on T1-weighted images, which typically occupied the central part of each T2 lesion, taking about 40% of lesional volume. The T1-isointense component of the T2 lesion was most commonly seen as a peripheral ring of relatively constant thickness (“T2-rim”). While changes of diffusivity between adjacent normal appearing white matter and the “T2-rim” demonstrated a disproportionally high elevation of RD compare to AD, the increase of water diffusion was largely isointense between the “T2-rim” and T1-hypointense parts of the lesion. Conclusion Distinct patterns of diffusivity within the central and peripheral components of MS lesions suggest that axonal loss dominates in the T1 hypointense core. The effects of de/remyelination may be more readily detected in the “T2-rim”, where there is relative preservation of structural integrity. Identifying and separating those patterns has an important implication for clinical trials of both neuroprotective and, in particular, remyelinating agents. Distinct patterns of diffusivity within the central and peripheral components of MS lesions were identified. Axonal loss is likely to dominate the T1 hypointense core. The effects of de/remyelination may be more readily detected in the “T2-rim”.
Collapse
Affiliation(s)
- Alexander Klistorner
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
- Corresponding author at: Save Sight Institute, University of Sydney, 8 Macquarie St. Sydney, NSW 2000, Australia.Save Sight InstituteUniversity of Sydney8 Macquarie St. SydneyNSW2000Australia
| | - Chenyu Wang
- Brain and Mind Research Institute, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Vera Fofanova
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Michael H. Barnett
- Brain and Mind Research Institute, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | | | - John Parratt
- Royal North Shore Hospital, Sydney, NSW, Australia
| | - Yuyi You
- Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Stuart L. Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| |
Collapse
|
71
|
Cassol E, Ranjeva JP, Ibarrola D, Mékies C, Manelfe C, Clanet M, Berry I. Diffusion tensor imaging in multiple sclerosis: a tool for monitoring changes in normal-appearing white matter. Mult Scler 2016; 10:188-96. [PMID: 15124766 DOI: 10.1191/1352458504ms997oa] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Our objectives were to determine the reproducibility of diffusion tensor imaging (DTI) in volunteers and to evaluate the ability of the method to monitor longitudinal changes occurring in the normal-appearing white matter (NAWM) of patients with multiple sclerosis (MS). DTI was performed three-mo nthly for one year in seven MS patients: three relapsing-remitting (RRMS), three secondary progressive (SPMS) and one relapsing SP. They were selected with a limited cerebral lesion load. Seven age- and sex-matched controls also underwent monthly examinations for three months. Diffusivity and anisotropy were quantified over the segmented whole supratentorial white matter, with the indices of trace (Tr) and fractional anisotropy (FA). Results obtained in volunteers show the reproducibility of the method. Patients had higher trace and lower anisotropy than matched controls (P B-0.0001). O ver the follow-up, both Tr and FA indicated a recovery after the acute phase in RRMS and a progressive shift towards abnormal values in SPMS. A lthough this result is not statistically significant, it suggests that DTI is sensitive to microscopic changes occurring in tissue of normal appearance in conventional images and could be useful for monitoring the course of the disease, even though it was unable to clearly distinguish between the various physiopathological processes involved.
Collapse
Affiliation(s)
- Emmanuelle Cassol
- Department of Biophysics and Multimodality Imaging, University Paul Sabatier, Toulouse-Rangueil, France
| | | | | | | | | | | | | |
Collapse
|
72
|
Rashid W, Hadjiprocopis A, Griffin CM, Chard DT, Davies GR, Barker GJ, Tofts PS, Thompson AJ, Miller DH. Diffusion tensor imaging of early relapsing-remitting multiple sclerosis with histogram analysis using automated segmentation and brain volume correction. Mult Scler 2016; 10:9-15. [PMID: 14760947 DOI: 10.1191/1352458504ms985oa] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Diffusion tensor magnetic resonance imaging (DTI) reveals measurable abnormalities in normal-appear ing brain tissue (NA BT) in established multiple sclerosis (MS). However, it is unclear how early this occurs. Recent studies have employed whole brain histogram analysis to improve sensitivity, but concern exists regarding reliability of tissue/cerebrospinal fluid segmentation and possible intersubject brain volume differences, which can introduce partial volume error. To address this, 28 early relapsing-remitting MS subjects [median disease duration 1.6 years; median Expanded Disability Status Scale (EDSS) score 1.5] and 20 controls were compared with whole brain histogram analysis using an automated segmentation algorithm to improve reproducibility. Brain parenchymal volumes (BPV) were estimated for each subject in the analysis. The mean, peak height and peak location were calculated for DTI parameters [fractional anisotropy (FA), mean diffusivity and volume ratio]. A n increased FA peak height in MS subject NA BT was observed (P =0.02) accounting for age, gender and BPV. Removing BPV revealed additional abnormalities in NABT. The main conclusions are i) FA peak height is increased in NA BT in early MS, ii) partial volume edge effects may contribute to apparent NA BT histogram abnormalities, and iii) correction for brain volume differences should reduce potential partial volume edge effects.
Collapse
Affiliation(s)
- W Rashid
- MS NMR Research Unit, Department of Neuroinflammation, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
73
|
Parizel PM, Van Rompaey V, Van Loock R, Van Hecke W, Van Goethem JW, Leemans A, Sijbers J. Influence of User-Defined Parameters on Diffusion Tensor Tractography of the Corticospinal Tract. Neuroradiol J 2016; 20:139-47. [PMID: 24299634 DOI: 10.1177/197140090702000202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 03/19/2007] [Indexed: 11/16/2022] Open
Abstract
This study discusses the influence of user-defined parameters on fiber tracking results obtained from a standard deterministic streamline tractography algorithm. Diffusion tensor imaging with fiber tractography was performed in five healthy volunteers. A region of interest was highlighted in the ventral part of the pons at the level of the middle cerebellar peduncle. The parameters studied were angle threshold, fractional anisotropy threshold, step length and number of seed samples per voxel. Changes in fiber tracts were described for increasing values per parameter. Increasing the angle threshold resulted in more and longer fibers. A higher fractional anisotropy threshold resulted in decreased length and fiber tracts that were not representative. Increasing the step length decreased the fiber continuity and altered its position. A higher number of seed samples per voxel resulted in a higher fiber tract density. When interpreting diffusion tensor images, the reader should understand the influence of user-defined settings on the results, and should be aware of the inter-dependency of fiber tracking parameters.
Collapse
Affiliation(s)
- P M Parizel
- Department of Radiology and Medical Imaging, University Hospital Antwerp; Edegem, Belgium -
| | | | | | | | | | | | | |
Collapse
|
74
|
Bai Z, Ma X, Tian J, Dong J, He J, Zhan W, Xu L, Xu Y, Jiang G. Brain Microstructural Abnormalities Are Related to Physiological Alterations in End-Stage Renal Disease. PLoS One 2016; 11:e0155902. [PMID: 27227649 PMCID: PMC4881995 DOI: 10.1371/journal.pone.0155902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 05/05/2016] [Indexed: 01/14/2023] Open
Abstract
PURPOSE To study whole-brain microstructural alterations in patients with end-stage renal disease (ESRD) and examine the relationship between brain microstructure and physiological indictors in the disease. MATERIALS AND METHODS Diffusion tensor imaging data were collected from 35 patients with ESRD (28 men, 18-61 years) and 40 age- and gender-matched healthy controls (HCs, 32 men, 22-58 years). A voxel-wise analysis was then used to identify microstructural alterations over the whole brain in the ESRD patients compared with the HCs. Multiple biochemical measures of renal metabolin, vascular risk factors, general cognitive ability and dialysis duration were correlated with microstructural integrity for the patients. RESULTS Compared to the HCs, the ESRD patients exhibited disrupted microstructural integrity in not only white matter (WM) but also gray matter (GM) regions, as characterized by decreased fractional anisotropy (FA) and increased mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). Further correlation analyses revealed that the in MD, AD and RD values showed significantly positive correlations with the blood urea nitrogen in the left superior temporal gyrus and significantly negative correlations with the calcium levels in the left superior frontal gyrus (orbital part) in the patients. CONCLUSION Our findings suggest that ESRD is associated with widespread diffusion abnormalities in both WM and GM regions in the brain, and microstructural integrity of several GM regions are related to biochemical alterations in the disease.
Collapse
Affiliation(s)
- Zhigang Bai
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medial University, Guangzhou City, Guangdong province, PR China
| | - Xiaofen Ma
- Department of Medical Imaging, Guangdong No. 2 Provincial People’s Hospital, Guangzhou City, Guangdong province, PR China
| | - Junzhang Tian
- Department of Medical Imaging, Guangdong No. 2 Provincial People’s Hospital, Guangzhou City, Guangdong province, PR China
| | - Jianwei Dong
- Department of Mathematics, Guangdong Pharmaceutical University, Guangzhou City, Guangdong province, PR China
| | - Jinlong He
- Image diagnostics division, the Affiliated Hospital of Inner Mongolia Medical University, Huhehaote City, Inner Mongolia Autonomous Region, PR China
| | - Wenfeng Zhan
- Department of Medical Imaging, Guangdong No. 2 Provincial People’s Hospital, Guangzhou City, Guangdong province, PR China
| | - Lijuan Xu
- National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, PR China
| | - Yikai Xu
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medial University, Guangzhou City, Guangdong province, PR China
- * E-mail: (GJ); (YX)
| | - Guihua Jiang
- Department of Medical Imaging, Guangdong No. 2 Provincial People’s Hospital, Guangzhou City, Guangdong province, PR China
- * E-mail: (GJ); (YX)
| |
Collapse
|
75
|
Basmacı Kandemir S, Bayazıt H, Selek S, Kılıçaslan N, Kandemir H, Karababa İF, Katı M, Çeçe H. Tracking down the footprints of bad paternal relationships in dissociative disorders: A diffusion tensor imaging study. J Trauma Dissociation 2016; 17:371-81. [PMID: 26566870 DOI: 10.1080/15299732.2015.1111282] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Preclinical studies indicate that stress early in life can cause long-term alterations in brain development. Studies have shown alterations in the brain functions of patients after experiencing trauma. Our aim is to examine whether the integrity of white matter tracts might be affected in dissociative disorder (DD) patients. A total of 15 DD patients and 15 healthy controls were studied, with the groups matched by age and gender. Diffusion-weighted echoplanar brain images were obtained using a 1.5 Tesla magnetic resonance imaging scanner. Regions of interest were manually placed on directional maps based on principal anisotropy. Apparent diffusion coefficient and fractional anisotropy (FA) values of white matter were measured bilaterally in the anterior corona radiata (ACR) and by diffusion tensor imaging in the genu and splenium of the corpus callosum. Significantly lower FA values were observed in the right ACR of DD patients versus healthy individuals. We also found an association between bad paternal relationships and lower FA in the genu of the corpus callosum in female patients. Alterations in the right ACR suggest that diffusion anisotropy measurement can be used as a quantitative biomarker for DD. Paternal relationships may also affect the brain's microstructure in women with DD.
Collapse
Affiliation(s)
| | - Hüseyin Bayazıt
- b Department of Psychiatry , Siverek State Hospital , Sanliurfa , Turkey
| | - Salih Selek
- c Department of Psychiatry , McGovern Medical School, University of Texas Health Science Center at Houston , Houston , Texas , USA
| | - Nihat Kılıçaslan
- d Department of Radiology , M.Akif Inan Training and Education Hospital , Sanliurfa , Turkey
| | - Hasan Kandemir
- e Department of Child and Adolescent Psychiatry , University of Harran , Sanliurfa , Turkey
| | | | - Mahmut Katı
- f Department of Psychiatry , University of Harran , Sanliurfa , Turkey
| | - Hasan Çeçe
- f Department of Psychiatry , University of Harran , Sanliurfa , Turkey
| |
Collapse
|
76
|
Giacosa C, Karpati FJ, Foster NEV, Penhune VB, Hyde KL. Dance and music training have different effects on white matter diffusivity in sensorimotor pathways. Neuroimage 2016; 135:273-86. [PMID: 27114054 DOI: 10.1016/j.neuroimage.2016.04.048] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 04/18/2016] [Accepted: 04/20/2016] [Indexed: 12/22/2022] Open
Affiliation(s)
- Chiara Giacosa
- International Laboratory for Brain, Music and Sound Research (BRAMS), Pavillon 1420 Mont Royal, FAS, Département de psychologie, CP 6128 Succ. Centre Ville, Montreal, QC H3C 3J7, Canada; Department of Psychology, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.
| | - Falisha J Karpati
- International Laboratory for Brain, Music and Sound Research (BRAMS), Pavillon 1420 Mont Royal, FAS, Département de psychologie, CP 6128 Succ. Centre Ville, Montreal, QC H3C 3J7, Canada; Faculty of Medicine, McGill University, 3655 Sir William Osler, Montreal, Quebec H3G 1Y6, Canada
| | - Nicholas E V Foster
- International Laboratory for Brain, Music and Sound Research (BRAMS), Pavillon 1420 Mont Royal, FAS, Département de psychologie, CP 6128 Succ. Centre Ville, Montreal, QC H3C 3J7, Canada; Department of Psychology, University of Montreal, Pavillon Marie-Victorin, 90 avenue Vincent d'Indy, Montreal, Quebec H2V 2S9, Canada
| | - Virginia B Penhune
- International Laboratory for Brain, Music and Sound Research (BRAMS), Pavillon 1420 Mont Royal, FAS, Département de psychologie, CP 6128 Succ. Centre Ville, Montreal, QC H3C 3J7, Canada; Department of Psychology, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada
| | - Krista L Hyde
- International Laboratory for Brain, Music and Sound Research (BRAMS), Pavillon 1420 Mont Royal, FAS, Département de psychologie, CP 6128 Succ. Centre Ville, Montreal, QC H3C 3J7, Canada; Faculty of Medicine, McGill University, 3655 Sir William Osler, Montreal, Quebec H3G 1Y6, Canada; Department of Psychology, University of Montreal, Pavillon Marie-Victorin, 90 avenue Vincent d'Indy, Montreal, Quebec H2V 2S9, Canada
| |
Collapse
|
77
|
Morozova SN, Bryukhov VV, Trifonova OV, Kremneva EI, Krotenkova MV. [A DTI study of the spinal cord lesion in patients with multiple sclerosis during the follow-up after relapse]. Zh Nevrol Psikhiatr Im S S Korsakova 2016; 116:21-26. [PMID: 27070357 DOI: 10.17116/jnevro20161162221-26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED Spinal cord involvement is frequent in multiple sclerosis (MS) but the correlation between spinal cord damage on conventional MRI and clinical symptoms is not always obvious. Diffusion tensor imaging (DTI) is a sensitive technique for revealing tissue damage. OBJECTIVE to investigate spinal cord DTI changes in MS patients during the relapse and in the follow-up. MATERIAL AND METHODS Data were acquired from 25 patients with relapsing-remitting MS during the relapse characterized by unilateral light hand palsy, in three and twelve months after it. All patients underwent full neurological examination and MRI including conventional head and neck MRI and DTI of the brain and upper spinal cord in the sagittal plane. Twelve healthy subjects entered the control group. RESULTS AND CONCLUSION Spinal cord sagittal DTI provides a reliable information about significant changes in MS patients compared tothe control group both inside demyelinating lesions and in the normal appearing spinal cord. These differences are preserved both in 3 and 12 months after the relapse and together with clinical recovery create evidence of functional compensatory mechanisms development. A tendency towards DTI parameters normalization together with faster fine motor skills recovery in patients without the asymmetrical decrease in vibration sense shows an important role that afferentation plays in recovery after the relapse.
Collapse
|
78
|
Durhan G, Diker S, Has AC, Karakaya J, Tuncer Kurne A, Oguz KK. Influence of cigarette smoking on white matter in patients with clinically isolated syndrome as detected by diffusion tensor imaging. Diagn Interv Radiol 2016; 22:291-6. [PMID: 27015443 DOI: 10.5152/dir.2015.15415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE Cigarette smoking has been associated with increased occurrence of multiple sclerosis (MS), as well as clinical disability and disease progression in MS. We aimed to assess the effects of smoking on the white matter (WM) in patients with clinically isolated syndrome (CIS) using diffusion tensor imaging. METHODS Smoker patients with CIS (n=16), smoker healthy controls (n=13), nonsmoker patients with CIS (n=17) and nonsmoker healthy controls (n=14) were included. Thirteen regions-of-interest including nonenhancing T1 hypointense lesion and perilesional WM, and 11 normal-appearing white matter (NAWM) regions were drawn on color-coded fractional anisotropy (FA) maps. Lesion load was determined in terms of number and volume of WM hyperintensities. RESULTS A tendency towards greater lesion load was found in smoker patients. T1 hypointense lesions and perilesional WM had reduced FA and increased mean diffusivity to a similar degree in smoker and nonsmoker CIS patients. Compared with healthy smokers, smoker CIS patients had more extensive NAWM changes shown by increased mean diffusivity. There was no relationship between diffusion metrics and clinical disability scores, duration of the disease and degree of smoking exposure. CONCLUSION Smoker patients showed a tendency towards having greater number of WM lesions and displayed significantly more extensive NAWM abnormalities.
Collapse
Affiliation(s)
- Gamze Durhan
- Department of Radiology, Ministry of Health Ankara Training and Research Hospital, Ankara, Turkey.
| | | | | | | | | | | |
Collapse
|
79
|
Hubbard EA, Wetter NC, Sutton BP, Pilutti LA, Motl RW. Diffusion tensor imaging of the corticospinal tract and walking performance in multiple sclerosis. J Neurol Sci 2016; 363:225-31. [PMID: 27000254 DOI: 10.1016/j.jns.2016.02.044] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/17/2016] [Accepted: 02/16/2016] [Indexed: 12/13/2022]
Abstract
Research has identified a significant relationship between DTI (Diffusion Tensor Imaging) indices in the Corticospinal Tract (CST) and disability status in persons with multiple sclerosis (MS). To date, there is little known about the association between DTI indices of the CST with walking and gait outcomes in MS. This study examined the associations among DTI indices [fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD)] of the CST with walking and gait outcomes in persons with MS. We enrolled 69 persons with MS who underwent 3T brain magnetic resonance imaging (MRI) and examined white matter structural integrity in the CST in the brain with DTI. Participants completed three walking performance assessments: 6-minute walk (6MW), timed 25-foot walk (T25FW), and gait testing. We examined associations using Spearman (r(s)) and partial Spearman correlation (pr(s)) analyses, using the entire sample and stratifying by disability status after controlling for age and sex. After controlling for age, sex, and disease duration, RD was significantly correlated (p<0.05) with step time (pr(s)=0.30). AD was significantly correlated (p<0.05) with step length (pr(s)=-0.32). MD was significantly associated (p<0.05) with 6MW (pr(s)=-0.35), T25FW (pr(s)=-0.34), gait velocity (pr(s)=-0.31), step time (pr(s)=0.29), and step length (pr(s)=-0.36). FA was not significantly correlated with any of the walking parameters (p>0.05). We provide novel evidence of possible motor pathway damage involved in walking performance in MS. There may be subtle differences in associations between MD, AD, and RD with walking outcomes, and these could be assessed in future longitudinal examinations and clinical trials of motor rehabilitation.
Collapse
Affiliation(s)
- Elizabeth A Hubbard
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, United States.
| | - Nathan C Wetter
- Department of Bioengineering, University of Illinois at Urbana-Champaign, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, United States
| | - Bradley P Sutton
- Department of Bioengineering, University of Illinois at Urbana-Champaign, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, United States
| | - Lara A Pilutti
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, United States
| | - Robert W Motl
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, United States
| |
Collapse
|
80
|
Roman CAF, Arnett PA. Structural brain indices and executive functioning in multiple sclerosis: A review. J Clin Exp Neuropsychol 2016; 38:261-74. [DOI: 10.1080/13803395.2015.1105199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
81
|
Abstract
The advances in diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and functional magnetic resonance imaging (fMRI) over the last 20 years have vastly contributed to improving the understanding of the brain structure and function in patients with many diseases of the central nervous system (CNS). DWI is commonly used, for instance, in the diagnostic workup of stroke, CNS neoplasia, and rapidly progressive dementia cases. The new DTI methods provide more specific information about the most destructive aspects of tumors, neurodegenerative dementia, and multiple sclerosis pathology and give a more complete picture of the complex pathologic mechanisms of these conditions. More recently, fMRI has provided insight to the mechanisms of brain adaptation and plasticity to damage related to many neurologic conditions and has further extended our ability to understand the functional significance of pathologic changes in these diseases. Although at present fMRI does not have a role in the diagnosis, routine assessment, and monitoring of neurologic diseases, significant efforts are under way in order to achieve harmonization of both acquisition and postprocessing procedures, which are likely to contribute to a significant change of the clinical scenario.
Collapse
Affiliation(s)
- Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
| | - Federica Agosta
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
82
|
Park YK, Kwon OH, Joo EY, Kim JH, Lee JM, Kim ST, Hong SB. White matter alterations in narcolepsy patients with cataplexy: tract-based spatial statistics. J Sleep Res 2015; 25:181-9. [PMID: 26610427 DOI: 10.1111/jsr.12366] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 10/07/2015] [Indexed: 10/22/2022]
Affiliation(s)
- Yun K. Park
- Department of Neurology; Neuroscience Center; Sungkyunkwan University School of Medicine; Seoul Korea
| | - Oh-Hun Kwon
- Computational NeuroImage Analysis Laboratory; Department of Biomedical Engineering; Hanyang University; Seoul Korea
| | - Eun Yeon Joo
- Department of Neurology; Neuroscience Center; Sungkyunkwan University School of Medicine; Seoul Korea
- Department of Health Sciences and Technology; SAIHST; Sungkyunkwan University; Seoul Korea
| | - Jae-Hun Kim
- Department of Radiology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul Korea
| | - Jong M. Lee
- Computational NeuroImage Analysis Laboratory; Department of Biomedical Engineering; Hanyang University; Seoul Korea
| | - Sung T. Kim
- Department of Radiology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul Korea
| | - Seung B. Hong
- Department of Neurology; Neuroscience Center; Sungkyunkwan University School of Medicine; Seoul Korea
- Department of Health Sciences and Technology; SAIHST; Sungkyunkwan University; Seoul Korea
| |
Collapse
|
83
|
Sweeney EM, Shinohara RT, Dewey BE, Schindler MK, Muschelli J, Reich DS, Crainiceanu CM, Eloyan A. Relating multi-sequence longitudinal intensity profiles and clinical covariates in incident multiple sclerosis lesions. NEUROIMAGE-CLINICAL 2015; 10:1-17. [PMID: 26693397 PMCID: PMC4660378 DOI: 10.1016/j.nicl.2015.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/22/2015] [Accepted: 10/25/2015] [Indexed: 11/19/2022]
Abstract
The formation of multiple sclerosis (MS) lesions is a complex process involving inflammation, tissue damage, and tissue repair - all of which are visible on structural magnetic resonance imaging (MRI) and potentially modifiable by pharmacological therapy. In this paper, we introduce two statistical models for relating voxel-level, longitudinal, multi-sequence structural MRI intensities within MS lesions to clinical information and therapeutic interventions: (1) a principal component analysis (PCA) and regression model and (2) function-on-scalar regression models. To do so, we first characterize the post-lesion incidence repair process on longitudinal, multi-sequence structural MRI from 34 MS patients as voxel-level intensity profiles. For the PCA regression model, we perform PCA on the intensity profiles to develop a voxel-level biomarker for identifying slow and persistent, long-term intensity changes within lesion tissue voxels. The proposed biomarker's ability to identify such effects is validated by two experienced clinicians (a neuroradiologist and a neurologist). On a scale of 1 to 4, with 4 being the highest quality, the neuroradiologist gave the score on the first PC a median quality rating of 4 (95% CI: [4,4]), and the neurologist gave the score a median rating of 3 (95% CI: [3,3]). We then relate the biomarker to the clinical information in a mixed model framework. Treatment with disease-modifying therapies (p < 0.01), steroids (p < 0.01), and being closer to the boundary of abnormal signal intensity (p < 0.01) are all associated with return of a voxel to an intensity value closer to that of normal-appearing tissue. The function-on-scalar regression model allows for assessment of the post-incidence time points at which the covariates are associated with the profiles. In the function-on-scalar regression, both age and distance to the boundary were found to have a statistically significant association with the lesion intensities at some time point. The two models presented in this article show promise for understanding the mechanisms of tissue damage in MS and for evaluating the impact of treatments for the disease in clinical trials.
Collapse
Key Words
- Biomarker
- CI, confidence interval
- Expert rater trial
- FLAIR, fluid-attenuated inversion recovery
- Function-on-scalar regression
- Longitudinal lesion behavior
- Longitudinal study
- MRI, magnetic resonance imaging
- MS, multiple sclerosis
- Multi-sequence imaging
- Multiple sclerosis
- NAWM, normal-appearing white matter
- NINDS, National Institute of Neurological Disease and Stroke
- PC, principal component
- PCA, principal component analysis
- PD, proton density-weighted
- Principal component analysis and regression
- RRMS, relapsing remitting MS
- SPMS, secondary progressive MS
- Structural magnetic resonance imaging
- T, Tesla
- T1, T1-weighted
- T2, T2-weighted
- sd, standard deviation
Collapse
Affiliation(s)
- Elizabeth M. Sweeney
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States
- Translational Neuroradiology Unit, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disease and Stroke, National Institute of Health, Bethesda, MD 20892, United States
- Corresponding author.
| | - Russell T. Shinohara
- Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Blake E. Dewey
- Translational Neuroradiology Unit, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disease and Stroke, National Institute of Health, Bethesda, MD 20892, United States
| | - Matthew K. Schindler
- Translational Neuroradiology Unit, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disease and Stroke, National Institute of Health, Bethesda, MD 20892, United States
| | - John Muschelli
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States
| | - Daniel S. Reich
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States
- Translational Neuroradiology Unit, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disease and Stroke, National Institute of Health, Bethesda, MD 20892, United States
| | - Ciprian M. Crainiceanu
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States
| | - Ani Eloyan
- Department of Biostatistics, Brown University School of Public Health, RI 02912, United States
| |
Collapse
|
84
|
Banaszek A, Bladowska J, Pokryszko-Dragan A, Podemski R, Sąsiadek MJ. Evaluation of the Degradation of the Selected Projectile, Commissural and Association White Matter Tracts Within Normal Appearing White Matter in Patients with Multiple Sclerosis Using Diffusion Tensor MR Imaging - a Preliminary Study. Pol J Radiol 2015; 80:457-63. [PMID: 26516389 PMCID: PMC4603607 DOI: 10.12659/pjr.894661] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/30/2015] [Indexed: 11/21/2022] Open
Abstract
Backround The aim of the study was to assess the impairment of the selected white matter tracts within normal appearing white matter (NAWM) in multiple sclerosis (MS) patients using diffusion tensor imaging (DTI). Material/Methods Thirty-six patients (mean age 33.4 yrs) with clinically definite, relapsing-remitting MS and mild disability (EDSS – Expanded Disability Status Scale 1–3.5) and 16 control subjects (mean age 34.4 yrs) were enrolled in the study. DTI examinations were performed on a 1.5T MR scanner. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained with a small ROI method in several white matter tracts within NAWM including: the middle cerebellar peduncles (MCP), the inferior longitudinal fasciculi (ILF), inferior frontooccipital fasciculi (IFOF), genu (GCC) and splenium of the corpus callosum (SCC), posterior limbs of the internal capsules (PLIC), superior longitudinal fasciculi (SLF) and posterior cingula (CG). There were no demyelinative lesions within the ROIs in any of the patients. Results A significant decrease in FA was found in MS patients in both the ILFs and IFOFs (p<0.001) and in the left MCP and right SLF (p<0.05), compared to the normal subjects. There were no significant differences in FA values in the remaining evaluated ROIs, between MS patients and the control group. A significant increase in ADC (p<0.05) was found only in the right PLIC and the right SLF in MS subjects, compared to the control group. Conclusions The FA values could be a noninvasive neuroimaging biomarker for assessing the microstructural changes within NAWM tracts in MS patients.
Collapse
Affiliation(s)
- Anna Banaszek
- Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
| | - Joanna Bladowska
- Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
| | | | - Ryszard Podemski
- Department and Clinic of Neurology, Wrocław Medical University, Wrocław, Poland
| | - Marek J Sąsiadek
- Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
| |
Collapse
|
85
|
Matsui JT, Vaidya JG, Wassermann D, Kim RE, Magnotta VA, Johnson HJ, Paulsen JS. Prefrontal cortex white matter tracts in prodromal Huntington disease. Hum Brain Mapp 2015; 36:3717-32. [PMID: 26179962 PMCID: PMC4583330 DOI: 10.1002/hbm.22835] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/20/2015] [Accepted: 04/28/2015] [Indexed: 01/23/2023] Open
Abstract
Huntington disease (HD) is most widely known for its selective degeneration of striatal neurons but there is also growing evidence for white matter (WM) deterioration. The primary objective of this research was to conduct a large-scale analysis using multisite diffusion-weighted imaging (DWI) tractography data to quantify diffusivity properties along major prefrontal cortex WM tracts in prodromal HD. Fifteen international sites participating in the PREDICT-HD study collected imaging and neuropsychological data on gene-positive HD participants without a clinical diagnosis (i.e., prodromal) and gene-negative control participants. The anatomical prefrontal WM tracts of the corpus callosum (PFCC), anterior thalamic radiations (ATRs), inferior fronto-occipital fasciculi (IFO), and uncinate fasciculi (UNC) were identified using streamline tractography of DWI. Within each of these tracts, tensor scalars for fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity coefficients were calculated. We divided prodromal HD subjects into three CAG-age product (CAP) groups having Low, Medium, or High probabilities of onset indexed by genetic exposure. We observed significant differences in WM properties for each of the four anatomical tracts for the High CAP group in comparison to controls. Additionally, the Medium CAP group presented differences in the ATR and IFO in comparison to controls. Furthermore, WM alterations in the PFCC, ATR, and IFO showed robust associations with neuropsychological measures of executive functioning. These results suggest long-range tracts essential for cross-region information transfer show early vulnerability in HD and may explain cognitive problems often present in the prodromal stage. Hum Brain Mapp 36:3717-3732, 2015. © 2015 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Joy T. Matsui
- Department of Psychiatry, Carver College of MedicineUniversity of IowaIowa CityIowa
- John A. Burns School of MedicineUniversity of HawaiiHonoluluHawaii
| | - Jatin G. Vaidya
- Department of Psychiatry, Carver College of MedicineUniversity of IowaIowa CityIowa
| | | | - Regina Eunyoung Kim
- Department of Psychiatry, Carver College of MedicineUniversity of IowaIowa CityIowa
| | - Vincent A. Magnotta
- Department of Psychiatry, Carver College of MedicineUniversity of IowaIowa CityIowa
- Department of Radiology, Carver College of MedicineUniversity of IowaIowa CityIowa
- Department of Biomedical Engineering, College of EngineeringUniversity of IowaIowa CityIowa
| | - Hans J. Johnson
- Department of Psychiatry, Carver College of MedicineUniversity of IowaIowa CityIowa
- Department of Biomedical Engineering, College of EngineeringUniversity of IowaIowa CityIowa
- Department of Electrical and Computer Engineering, College of EngineeringUniversity of IowaIowa CityIowa
| | - Jane S. Paulsen
- Department of Psychiatry, Carver College of MedicineUniversity of IowaIowa CityIowa
- Department of Neurology, Carver College of MedicineUniversity of IowaIowa CityIowa
- Department of PsychologyUniversity of IowaIowa CityIowa
| | | |
Collapse
|
86
|
Karababa IF, Bayazıt H, Kılıçaslan N, Celik M, Cece H, Karakas E, Selek S. Microstructural Changes of Anterior Corona Radiata in Bipolar Depression. Psychiatry Investig 2015; 12. [PMID: 26207131 PMCID: PMC4504920 DOI: 10.4306/pi.2015.12.3.367] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE In bipolar disorder, dysregulation of mood may result from white matter abnormalities that change fiber tract length and fiber density. There are few studies evaluating the white matter microstructural changes in bipolar I patients (BD) with depressive episodes. The present study aimed to evaluate anterior corona radiata in BD patients with depressive episode using Diffusion Tensor Imaging (DTI). METHODS Twenty-one patients with bipolar depression and 19 healthy controls were investigated and groups were matched for age and gender. Diffusion-weighted echoplanar brain images (DW-EPI) were obtained using a 1.5 T MRI scanner. Regions of interest (ROIs) were manually placed on directional maps based on principal anisotropy. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of white matter were measured in the anterior corona radiata (ACR) bilaterally by diffusion tensor imaging. RESULTS There was not a significant difference between groups of age and gender (p>0.05). Significantly lower FA was observed in bilateral ACR in bipolar patients with depression compared with healthy individuals. And there is significantly higher ADC values in the left frontal corona radiate in bipolar patients. CONCLUSION White matter abnormalities can be detected in patients with BD using DTI. The neuropathology of these abnormalities is unclear, but neuronal and axonal loss, myelin abnormalities and reduced white matter fiber density are likely to be relevant.
Collapse
Affiliation(s)
- I. Fatih Karababa
- Department of Psychiatry, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Huseyin Bayazıt
- Department of Psychiatry, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Nihat Kılıçaslan
- Department of Radiology, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Mustafa Celik
- Department of Psychiatry, Diyarbakir Training and Research Hospital, Diyarbakir, Turkey
| | - Hasan Cece
- Department of Radiology, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Ekrem Karakas
- Department of Radiology, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Salih Selek
- Department of Psychiatry, Faculty of Medicine, University of Medeniyet, Istanbul, Turkey
- Department of Psychiatry and Behavioral Sciences, Harris County Psychiatric Center, The University of Texas Health Science Center at Houston, Houston, TX, USA
| |
Collapse
|
87
|
Erichev VP, Panyushkina LA, Novikov IA, Bryukhov VV. [Diffusion tensor magnetic resonance imaging in the diagnosis of visual pathway neurodegeneration in glaucoma]. Vestn Oftalmol 2015; 131:59-63. [PMID: 26080584 DOI: 10.17116/oftalma2015131259-63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM To study the state of visual pathways in patients with glaucoma by means of diffusion tensor magnetic resonance imaging (DT-MRI). MATERIAL AND METHODS DT-MRI was performed in 16 patients: 12 patients with POAG of different stages and 4 controls. Fractional anisotropy (FA) and its longitudinal variation (FA) determined by an original software (Fractional Anisotropy Analyzer) were used to assess the state of the lateral geniculate body and optic radiation. All patients also underwent optical coherence tomography (OCT) of the retina and optic nerve head, Heindelberg retinal tomography (HRT), and Humphrey standard automated perimetry (SAP). RESULTS There was a significant decrease in FA values in glaucoma patients as compared with the control group (medians of 0.74 and 0.77 respectively, p < 0.01). Moderate and strong correlations of AFA with glaucoma stage as well as morphometric (GCC Average, GLV, FLV, and RNFL Average provided by OCT, rim area provided by HRT) and functional parameters (MD and PSD provided by SAP) of the retina and optic nerve head were also established. CONCLUSION Reduced fractional anisotropy of the lateral geniculate body and optic radiation in patients with glaucoma may be considered an indicator of axonal degeneration at the level of the visual centers. DT-MRI in vivo helps to determine whether or not the neurodegenerative process spreads to the central nervous system as glaucoma progresses.
Collapse
Affiliation(s)
- V P Erichev
- Research Institute of Eye Diseases, 11 A, B Rossolimo St., Moscow, Russian Federation, 119021
| | - L A Panyushkina
- Research Institute of Eye Diseases, 11 A, B Rossolimo St., Moscow, Russian Federation, 119021
| | - I A Novikov
- Research Institute of Eye Diseases, 11 A, B Rossolimo St., Moscow, Russian Federation, 119021
| | - V V Bryukhov
- Research Centre of Neurology, 80 Volokolamskoe Shosse, Moscow, Russian Federation, 125367
| |
Collapse
|
88
|
Chua AS, Egorova S, Anderson MC, Polgar-Turcsanyi M, Chitnis T, Weiner HL, Guttmann CRG, Bakshi R, Healy BC. Using multiple imputation to efficiently correct cerebral MRI whole brain lesion and atrophy data in patients with multiple sclerosis. Neuroimage 2015; 119:81-8. [PMID: 26093330 DOI: 10.1016/j.neuroimage.2015.06.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 05/22/2015] [Accepted: 06/11/2015] [Indexed: 11/24/2022] Open
Abstract
Automated segmentation of brain MRI scans into tissue classes is commonly used for the assessment of multiple sclerosis (MS). However, manual correction of the resulting brain tissue label maps by an expert reader remains necessary in many cases. Since automated segmentation data awaiting manual correction are "missing", we proposed to use multiple imputation (MI) to fill-in the missing manually-corrected MRI data for measures of normalized whole brain volume (brain parenchymal fraction-BPF) and T2 hyperintense lesion volume (T2LV). Automated and manually corrected MRI measures from 1300 patients enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital (CLIMB) were identified. Simulation studies were conducted to assess the performance of MI with missing data both missing completely at random and missing at random. An imputation model including the concurrent automated data as well as clinical and demographic variables explained a high proportion of the variance in the manually corrected BPF (R(2)=0.97) and T2LV (R(2)=0.89), demonstrating the potential to accurately impute the missing data. Further, our results demonstrate that MI allows for the accurate estimation of group differences with little to no bias and with similar precision compared to an analysis with no missing data. We believe that our findings provide important insights for efficient correction of automated MRI measures to obviate the need to perform manual correction on all cases.
Collapse
Affiliation(s)
- Alicia S Chua
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA
| | - Svetlana Egorova
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Mark C Anderson
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Tanuja Chitnis
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Howard L Weiner
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Charles R G Guttmann
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - Rohit Bakshi
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - Brian C Healy
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Biostatistics Center, Massachusetts General Hospital, Boston, MA, USA.
| |
Collapse
|
89
|
Taha MS, El Fiky LM, Taha TM, Sabra RM, Youssef TA, Nada IM. Utility of apparent diffusion coefficient in characterization of different sinonasal pathologies. Am J Rhinol Allergy 2015; 28:181-6. [PMID: 25198015 DOI: 10.2500/ajra.2014.28.4098] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Sinonasal lesions are a heterogeneous group of lesions that span from a tumor to tumor-like nature. Characterization of such cases preoperatively can improve the surgical control and the overall outcome of these patients. OBJECTIVE In this prospective study, we aimed at evaluation of the role of apparent diffusion coefficient (ADC) in the differentiation between benign and malignant sinonasal lesions. SUBJECTS AND METHODS All patients scheduled to have sinonasal surgical intervention at Ain Shams University Hospitals, Cairo, Egypt, were enrolled. Diffusion-weighted (DW) magnetic resonance imaging (MRI) with calculation of ADC were done for all cases. Radiologic findings were then compared with histologic findings, and the sensitivity, specificity, negative and positive predictive values (PPVs) of the conventional MRI, DW-MRI, and ADC value in differentiation of benign from malignant sinonasal lesions were then calculated. RESULTS There were 59 patients with median age of 43 years old. There were 20 cases of inflammatory lesions, 16 cases of benign tumors, and 23 cases of malignant lesions. The ADC values of all cases ranged from 0.4 × 10(-3) to 2 × 10(-3) (median = 1.5 × 10(-3)). The median ADC value for the malignant lesions was 0.6 × 10(-3), whereas that for the inflammatory conditions was 1.6 × 10(-3) and that for the benign tumors was 1.5 × 10(-3) with a highly significant difference (p < .001). Analysis of the conventional MRI and DW-MRI to differentiate between malignant and benign lesions showed that the sensitivity, specificity, PPV, and negative predictive value (NPV) were 100%, 97%, 96%, and 100% and 91%, 97%, 95%, and 95%, respectively. CONCLUSION DW-MRI did not add significantly to the information gained from conventional MRI. It should be considered complimentary only to standard MRI in uncertain cases when malignancy is still a concern.
Collapse
Affiliation(s)
- Mohamed S Taha
- Department of Otorhinolaryngology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | | | | | | | | | | |
Collapse
|
90
|
Khanna N, Altmeyer W, Zhuo J, Steven A. Functional Neuroimaging: Fundamental Principles and Clinical Applications. Neuroradiol J 2015; 28:87-96. [PMID: 25963153 DOI: 10.1177/1971400915576311] [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] [Indexed: 11/16/2022] Open
Abstract
Functional imaging modalities, such as functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), are rapidly changing the scope and practice of neuroradiology. While these modalities have long been used in research, they are increasingly being used in clinical practice to enable reliable identification of eloquent cortex and white matter tracts in order to guide treatment planning and to serve as a diagnostic supplement when traditional imaging fails. An understanding of the scientific principles underlying fMRI and DTI is necessary in current radiological practice. fMRI relies on a compensatory hemodynamic response seen in cortical activation and the intrinsic discrepant magnetic properties of deoxy- and oxyhemoglobin. Neuronal activity can be indirectly visualized based on a hemodynamic response, termed neurovascular coupling. fMRI demonstrates utility in identifying areas of cortical activation (i.e., task-based activation) and in discerning areas of neuronal connectivity when used during the resting state, termed resting state fMRI. While fMRI is limited to visualization of gray matter, DTI permits visualization of white matter tracts through diffusion restriction along different axes. We will discuss the physical, statistical and physiological principles underlying these functional imaging modalities and explore new promising clinical applications.
Collapse
Affiliation(s)
- Nishanth Khanna
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine; Baltimore, MD, USA
| | - Wilson Altmeyer
- Section of Neuroradiology, University of Texas Health Science Center San Antonio; San Antonio, TX, USA
| | - Jiachen Zhuo
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Medical Center; Baltimore MD, USA
| | - Andrew Steven
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Medical Center; Baltimore MD, USA
| |
Collapse
|
91
|
Droby A, Fleischer V, Carnini M, Zimmermann H, Siffrin V, Gawehn J, Erb M, Hildebrandt A, Baier B, Zipp F. The impact of isolated lesions on white-matter fiber tracts in multiple sclerosis patients. NEUROIMAGE-CLINICAL 2015; 8:110-6. [PMID: 26106534 PMCID: PMC4473264 DOI: 10.1016/j.nicl.2015.03.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/08/2015] [Indexed: 01/05/2023]
Abstract
Infratentorial lesions have been assigned an equivalent weighting to supratentorial plaques in the new McDonald criteria for diagnosing multiple sclerosis. Moreover, their presence has been shown to have prognostic value for disability. However, their spatial distribution and impact on network damage is not well understood. As a preliminary step in this study, we mapped the overall infratentorial lesion pattern in relapsing-remitting multiple sclerosis patients (N = 317) using MRI, finding the pons (lesion density, 14.25/cm(3)) and peduncles (13.38/cm(3)) to be predilection sites for infratentorial lesions. Based on these results, 118 fiber bundles from 15 healthy controls and a subgroup of 23 patients showing lesions unilaterally at the predilection sites were compared using diffusion tensor imaging to analyze the impact of an isolated infratentorial lesion on the affected fiber tracts. Fractional anisotropy, mean diffusion as well as axial and radial diffusivity were investigated at the lesion site and along the entire fiber tract. Infratentorial lesions were found to have an impact on the fractional anisotropy and radial diffusivity not only at the lesion site itself but also along the entire affected fiber tract. As previously found in animal experiments, inflammatory attack in the posterior fossa in multiple sclerosis impacts the whole affected fiber tract. Here, this damaging effect, reflected by changes in diffusivity measures, was detected in vivo in multiple sclerosis patients in early stages of the disease, thus demonstrating the influence of a focal immune attack on more distant networks, and emphasizing the pathophysiological role of Wallerian degeneration in multiple sclerosis.
Collapse
Affiliation(s)
- Amgad Droby
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
- Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University, Mainz, Germany
| | - Vinzenz Fleischer
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
- Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University, Mainz, Germany
| | - Marco Carnini
- Department of Computer Science, Johannes Gutenberg University, Mainz, Germany
| | - Hilga Zimmermann
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
- Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University, Mainz, Germany
| | - Volker Siffrin
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Joachim Gawehn
- Department of Neuroradiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Michael Erb
- Department of Biomedical Magnetic Resonance, University Hospital, Tübingen, Germany
| | - Andreas Hildebrandt
- Department of Computer Science, Johannes Gutenberg University, Mainz, Germany
| | - Bernhard Baier
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
- Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University, Mainz, Germany
| | - Frauke Zipp
- Department of Neurology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
- Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University, Mainz, Germany
- Corresponding author at: Department of Neurology, University Medical Center of the Johannes Gutenberg University Mainz, Neuroimage Center (NIC) of the Focus Program Translational Neuroscience (FTN), Langenbeckstr. 1, 55131 Mainz, Germany. Tel.: +49 (0)6131 17 7156; fax: +49 (0)6131 17 5697.
| |
Collapse
|
92
|
Commowick O, Maarouf A, Ferré JC, Ranjeva JP, Edan G, Barillot C. Diffusion MRI abnormalities detection with orientation distribution functions: a multiple sclerosis longitudinal study. Med Image Anal 2015; 22:114-23. [PMID: 25867549 DOI: 10.1016/j.media.2015.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 02/04/2015] [Accepted: 02/26/2015] [Indexed: 11/19/2022]
Abstract
We propose a new algorithm for the voxelwise analysis of orientation distribution functions between one image and a group of reference images. It relies on a generic framework for the comparison of diffusion probabilities on the sphere, sampled from the underlying models. We demonstrate that this method, combined to dimensionality reduction through a principal component analysis, allows for more robust detection of lesions on simulated data when compared to classical tensor-based analysis. We then demonstrate the efficiency of this pipeline on the longitudinal comparison of multiple sclerosis patients at an early stage of the disease: right after their first clinically isolated syndrome (CIS) and three months later. We demonstrate the predictive value of ODF-based scores for the early detection of lesions that will appear or heal.
Collapse
Affiliation(s)
- Olivier Commowick
- VISAGES: INSERM U746, CNRS UMR6074, INRIA, University of Rennes I, France.
| | - Adil Maarouf
- Neurology Department, University Hospital of Reims, France
| | - Jean-Christophe Ferré
- VISAGES: INSERM U746, CNRS UMR6074, INRIA, University of Rennes I, France; Radiology Department, University Hospital of Rennes, 2 Rue Henri le Guilloux, 35000 Rennes, France
| | | | - Gilles Edan
- VISAGES: INSERM U746, CNRS UMR6074, INRIA, University of Rennes I, France; Neurology Department, University Hospital of Rennes, 2 Rue Henri le Guilloux, 35000 Rennes, France
| | - Christian Barillot
- VISAGES: INSERM U746, CNRS UMR6074, INRIA, University of Rennes I, France
| |
Collapse
|
93
|
Ono SE, de Carvalho Neto A, Gasparetto EL, Coelho LODM, Escuissato DL, Bonfim CMS, Ribeiro LL. X-linked adrenoleukodystrophy: correlation between Loes score and diffusion tensor imaging parameters. Radiol Bras 2015; 47:342-9. [PMID: 25741116 PMCID: PMC4341377 DOI: 10.1590/0100-3984.2013.1886] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Accepted: 04/29/2014] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The present study was aimed at evaluating the correlation between diffusion tensor imaging parameters and Loes score as well as whether those parameters could indicate early structural alterations. MATERIALS AND METHODS Diffusion tensor imaging measurements were obtained in 30 studies of 14 patients with X-linked adrenoleukodystrophy and were correlated with Loes scores. A control group including 28 male patients was created to establish agematched diffusion tensor imaging measurements. Inter- and intraobserver statistical analyses were undertaken. RESULTS Diffusion tensor imaging measurements presented strong Pearson correlation coefficients (r) of -0.86, 0.89, 0.89 and 0.84 for fractional anisotropy and mean, radial and axial diffusivities (p < 0.01). Analysis of changes in diffusion tensor measurements at early stage of the disease indicates that mean and radial diffusivities might be useful to predict the disease progression. CONCLUSION Measurements of diffusion tensor parameters can be used as an adjunct to the Loes score, aiding in the monitoring of the disease and alerting for possible Loes score progression in the range of interest for therapeutic decisions.
Collapse
Affiliation(s)
- Sergio Eiji Ono
- Master, MD, Radiologist at Clínica DAPI - Diagnóstico Avançado por Imagem, Curitiba, PR, Brazil
| | - Arnolfo de Carvalho Neto
- PhDs, Associate Professors, Universidade Federal do Paraná (UFPR), Radiologists at Clínica DAPI - Diagnóstico Avançado por Imagem, Curitiba, PR, Brazil
| | - Emerson Leandro Gasparetto
- PhD, Research Productivity Scholar - Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Course of Post-graduation in Medicine (Radiology), Department of Radiology, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Luiz Otávio de Mattos Coelho
- Titular Member of Colégio Brasileiro de Radiologia e Diagnóstico por Imagem (CBR), MD, Radiologist at Clínica DAPI - Diagnóstico Avançado por Imagem, Curitiba, PR, Brazil
| | - Dante Luiz Escuissato
- PhDs, Associate Professors, Universidade Federal do Paraná (UFPR), Radiologists at Clínica DAPI - Diagnóstico Avançado por Imagem, Curitiba, PR, Brazil
| | - Carmem Maria Sales Bonfim
- MD, Hematologist, Coordinator for the Pediatric Bone Marrow Transplant Program at Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil
| | - Lisandro Lima Ribeiro
- MD, Hematologist, Fanconi Anemia Clinica at Service of Bone Marrow Transplant, Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil
| |
Collapse
|
94
|
Kolasa M, Hakulinen U, Helminen M, Hagman S, Raunio M, Rossi M, Brander A, Dastidar P, Elovaara I. Longitudinal assessment of clinically isolated syndrome with diffusion tensor imaging and volumetric MRI. Clin Imaging 2015; 39:207-12. [DOI: 10.1016/j.clinimag.2014.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 09/28/2014] [Accepted: 10/20/2014] [Indexed: 11/16/2022]
|
95
|
Nenonen M, Hakulinen U, Brander A, Ohman J, Dastidar P, Luoto TM. Possible confounding factors on cerebral diffusion tensor imaging measurements. Acta Radiol Open 2015; 4:2047981614546795. [PMID: 25793107 PMCID: PMC4364398 DOI: 10.1177/2047981614546795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/15/2014] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) is prone to numerous systemic confounding factors that should be acknowledged to avoid false conclusions. PURPOSE To investigate the possible effects of age, gender, smoking, alcohol consumption, and education on cerebral DTI parameters in a generally healthy homogenous sample with no neurological or psychiatric diseases. MATERIAL AND METHODS Forty (n = 40) subjects (mean age, 40.3 years; SD, 12.3) underwent brain DTI with 3 T magnetic resonance imaging (MRI). At enrolment, all the subjects were interviewed with respect to general health, education, history of smoking, and alcohol consumption. Studied DTI parameters included: (i) fractional anisotropy (FA); and (ii) apparent diffusion coefficient (ADC). Region-of-interest (ROI)-based measurements were estimated at 13 anatomical locations bilaterally on the axial images, except for the corpus callosum in which the ROIs were placed on the sagittal images. Circular ROI measurements were mainly used. Freehand ROI method was used with the forceps minor, uncinate fasciculus, and thalamus. Intra-observer variability and repeatability were assessed. RESULTS The most consistent finding was that aging decreased FA values in the frontal brain regions. Regarding the other confounding factors, the results were discontinuous and no concrete conclusions could be drawn from these findings. In general, intra-observer repeatability of the DTI measurement was considered relatively good. CONCLUSION Age should be noted as considerable confounding factors in ROI-based DTI analysis. More research on the effects of gender, smoking, alcohol consumption, and education is needed.
Collapse
Affiliation(s)
- Miina Nenonen
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Ullamari Hakulinen
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Antti Brander
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Juha Ohman
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Prasun Dastidar
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Teemu M Luoto
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| |
Collapse
|
96
|
Fabri M, Pierpaoli C, Barbaresi P, Polonara G. Functional topography of the corpus callosum investigated by DTI and fMRI. World J Radiol 2014; 6:895-906. [PMID: 25550994 PMCID: PMC4278150 DOI: 10.4329/wjr.v6.i12.895] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/02/2014] [Accepted: 10/29/2014] [Indexed: 02/06/2023] Open
Abstract
This short review examines the most recent functional studies of the topographic organization of the human corpus callosum, the main interhemispheric commissure. After a brief description of its anatomy, development, microstructure, and function, it examines and discusses the latest findings obtained using diffusion tensor imaging (DTI) and tractography (DTT) and functional magnetic resonance imaging (fMRI), three recently developed imaging techniques that have significantly expanded and refined our knowledge of the commissure. While DTI and DTT have been providing insights into its microstructure, integrity and level of myelination, fMRI has been the key technique in documenting the activation of white matter fibers, particularly in the corpus callosum. By combining DTT and fMRI it has been possible to describe the trajectory of the callosal fibers interconnecting the primary olfactory, gustatory, motor, somatic sensory, auditory and visual cortices at sites where the activation elicited by peripheral stimulation was detected by fMRI. These studies have demonstrated the presence of callosal fiber tracts that cross the commissure at the level of the genu, body, and splenium, at sites showing fMRI activation. Altogether such findings lend further support to the notion that the corpus callosum displays a functional topographic organization that can be explored with fMRI.
Collapse
|
97
|
Welton T, Kent D, Constantinescu CS, Auer DP, Dineen RA. Functionally relevant white matter degradation in multiple sclerosis: a tract-based spatial meta-analysis. Radiology 2014; 275:89-96. [PMID: 25426773 DOI: 10.1148/radiol.14140925] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE To identify statistical consensus between published studies for distribution and functional relevance of tract white matter (WM) degradation in multiple sclerosis (MS). MATERIALS AND METHODS By systematically searching online databases, tract-based spatial statistics studies were identified that compared fractional anisotropy (FA; a marker for WM integrity) in MS patients to healthy control subjects, correlated FA in MS patients with physical disability, or correlated FA in MS patients with cognitive performance. Voxelwise meta-analysis was performed by using the Signed Differential Mapping method for each comparison. Moderating effects of mean age, mean physical disability score, imager magnet strength, lesion load, and number of diffusion directions were assessed by means of meta-regression. RESULTS Meta-analysis was performed on data from 495 patients and 253 control subjects across 12 studies. MS diagnosis was significantly associated with widespread lower tract FA (nine studies; largest cluster, 4379 voxels; z = 7.1; P < .001). Greater physical disability was significantly associated with lower FA in the right posterior cingulum, left callosal splenium, right inferior fronto-occipital fasciculus, and left fornix crus (six studies; 323 voxels; z = 1.7; P = .001). Impaired cognition was significantly associated with lower FA in the callosal genu, thalamus, right posterior cingulum, and fornix crus (seven studies; largest cluster, 980 voxels; z = 2.5; P < .001). CONCLUSION WM damage is widespread in MS with differential and only minimally overlapping distributions of low FA that relates to physical disability and cognitive impairment. The higher number of clusters of lower FA in relation to cognition and their higher z scores suggest that cerebral WM damage may have a greater relevance to cognitive dysfunction than physical disability in MS, and that low anterior callosal and thalamic FA have specific importance to cognitive status.
Collapse
Affiliation(s)
- Thomas Welton
- From the Departments of Radiological Sciences (T.W., D.K., D.P.A., R.A.D.) and Clinical Neurology (C.S.C.), Division of Clinical Neurosciences, University of Nottingham, Queen's Medical Centre, Derby Rd, Nottingham NG7 2UH, England
| | | | | | | | | |
Collapse
|
98
|
Lummel N, Mehrkens JH, Linn J, Buchholz G, Stahl R, Bochmann K, Brückmann H, Lutz J. Diffusion tensor imaging of the trigeminal nerve in patients with trigeminal neuralgia due to multiple sclerosis. Neuroradiology 2014; 57:259-67. [DOI: 10.1007/s00234-014-1463-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 11/03/2014] [Indexed: 12/31/2022]
|
99
|
Anatomical likelihood estimation meta-analysis of grey and white matter anomalies in autism spectrum disorders. NEUROIMAGE-CLINICAL 2014; 7:525-36. [PMID: 25844306 PMCID: PMC4375647 DOI: 10.1016/j.nicl.2014.11.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/20/2014] [Accepted: 11/11/2014] [Indexed: 11/24/2022]
Abstract
Autism spectrum disorders (ASD) are characterized by impairments in social communication and restrictive, repetitive behaviors. While behavioral symptoms are well-documented, investigations into the neurobiological underpinnings of ASD have not resulted in firm biomarkers. Variability in findings across structural neuroimaging studies has contributed to difficulty in reliably characterizing the brain morphology of individuals with ASD. These inconsistencies may also arise from the heterogeneity of ASD, and wider age-range of participants included in MRI studies and in previous meta-analyses. To address this, the current study used coordinate-based anatomical likelihood estimation (ALE) analysis of 21 voxel-based morphometry (VBM) studies examining high-functioning individuals with ASD, resulting in a meta-analysis of 1055 participants (506 ASD, and 549 typically developing individuals). Results consisted of grey, white, and global differences in cortical matter between the groups. Modeled anatomical maps consisting of concentration, thickness, and volume metrics of grey and white matter revealed clusters suggesting age-related decreases in grey and white matter in parietal and inferior temporal regions of the brain in ASD, and age-related increases in grey matter in frontal and anterior-temporal regions. White matter alterations included fiber tracts thought to play key roles in information processing and sensory integration. Many current theories of pathobiology ASD suggest that the brains of individuals with ASD may have less-functional long-range (anterior-to-posterior) connections. Our findings of decreased cortical matter in parietal-temporal and occipital regions, and thickening in frontal cortices in older adults with ASD may entail altered cortical anatomy, and neurodevelopmental adaptations.
Collapse
|
100
|
Wang C, Paling D, Chen L, Hatton SN, Lagopoulos J, Aw ST, Kiernan MC, Barnett MH. Axonal conduction in multiple sclerosis: A combined magnetic resonance imaging and electrophysiological study of the medial longitudinal fasciculus. Mult Scler 2014; 21:905-15. [DOI: 10.1177/1352458514556301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 09/17/2014] [Indexed: 12/30/2022]
Abstract
Objective: The objective of this paper is to inform the pathophysiology of medial longitudinal fasciculus (MLF) axonal dysfunction in patients with internuclear ophthalmoplegia (INO) due to multiple sclerosis (MS), and develop a composite structural-functional biomarker of axonal and myelin integrity in this tract. Methods: Eighteen patients with definite MS and clinically suspected INO underwent electrical vestibular stimulation and search-coil eye movement recording. Components of the electrically evoked vestibulo-ocular reflex (eVOR) were analyzed to probe the latency and fidelity of MLF axonal conduction. The MLF and T2-visible brainstem lesions were defined by high-resolution MRI. White matter integrity was determined by diffusion-weighted imaging metrics. Results: eVOR onset latency was positively correlated with MLF lesion length (left: r = 0.66, p = 0.004; right: r = 0.75, p = 0.001). The mean conduction velocity (±SD) within MLF lesions was estimated at 2.72 (±0.87) m/s. eVOR onset latency correlated with normalized axial diffusivity ( r = 0.66, p < 0.001) and fractional anisotropy ( r = 0.44, p = 0.02) after exclusion of cases with ipsilateral vestibular root entry zone lesions. Conclusions: Axonal conduction velocity through lesions involving the MLF was reduced below levels predicted for natively myelinated and remyelinated axons. Composite in vivo biomarkers enable delineation of axonal from myelin processes and may provide a crucial role in assessing efficacy of novel reparative therapies in MS.
Collapse
Affiliation(s)
- Chenyu Wang
- Sydney Neuroimaging Analysis Centre, Sydney, Australia/Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - David Paling
- Royal Hallamshire Hospital, Sheffield, UK and Department of Neuroscience, University of Sheffield, Sheffield, UK
| | - Luke Chen
- Central Clinical School, University of Sydney, Sydney, Australia/Royal Prince Alfred Hospital, Sydney, Australia
| | - Sean N Hatton
- Sydney Neuroimaging Analysis Centre, Sydney, Australia/Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - Jim Lagopoulos
- Sydney Neuroimaging Analysis Centre, Sydney, Australia/Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - Swee T Aw
- Central Clinical School, University of Sydney, Sydney, Australia/Royal Prince Alfred Hospital, Sydney, Australia
| | - Matthew C Kiernan
- Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - Michael H Barnett
- Sydney Neuroimaging Analysis Centre, Sydney, Australia/Brain and Mind Research Institute, University of Sydney, Sydney, Australia/Royal Prince Alfred Hospital, Sydney, Australia
| |
Collapse
|