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Musall BC, Gabr RE, Yang Y, Kamali A, Lincoln JA, Jacobs MA, Ly V, Luo X, Wolinsky JS, Narayana PA, Hasan KM. Detection of diffusely abnormal white matter in multiple sclerosis on multiparametric brain MRI using semi-supervised deep learning. Sci Rep 2024; 14:17157. [PMID: 39060426 PMCID: PMC11282266 DOI: 10.1038/s41598-024-67722-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 07/15/2024] [Indexed: 07/28/2024] Open
Abstract
In addition to focal lesions, diffusely abnormal white matter (DAWM) is seen on brain MRI of multiple sclerosis (MS) patients and may represent early or distinct disease processes. The role of MRI-observed DAWM is understudied due to a lack of automated assessment methods. Supervised deep learning (DL) methods are highly capable in this domain, but require large sets of labeled data. To overcome this challenge, a DL-based network (DAWM-Net) was trained using semi-supervised learning on a limited set of labeled data for segmentation of DAWM, focal lesions, and normal-appearing brain tissues on multiparametric MRI. DAWM-Net segmentation performance was compared to a previous intensity thresholding-based method on an independent test set from expert consensus (N = 25). Segmentation overlap by Dice Similarity Coefficient (DSC) and Spearman correlation of DAWM volumes were assessed. DAWM-Net showed DSC > 0.93 for normal-appearing brain tissues and DSC > 0.81 for focal lesions. For DAWM-Net, the DAWM DSC was 0.49 ± 0.12 with a moderate volume correlation (ρ = 0.52, p < 0.01). The previous method showed lower DAWM DSC of 0.26 ± 0.08 and lacked a significant volume correlation (ρ = 0.23, p = 0.27). These results demonstrate the feasibility of DL-based DAWM auto-segmentation with semi-supervised learning. This tool may facilitate future investigation of the role of DAWM in MS.
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Affiliation(s)
- Benjamin C Musall
- Department of Diagnostic and Interventional Imaging, University of Texas McGovern Medical School, 6431 Fannin St., MSE 168, Houston, TX, 77030, USA
| | - Refaat E Gabr
- Department of Diagnostic and Interventional Imaging, University of Texas McGovern Medical School, 6431 Fannin St., MSE 168, Houston, TX, 77030, USA
| | - Yanyu Yang
- Department of Biostatistics and Data Science, University of Texas School of Public Health, Houston, TX, USA
| | - Arash Kamali
- Department of Diagnostic and Interventional Imaging, University of Texas McGovern Medical School, 6431 Fannin St., MSE 168, Houston, TX, 77030, USA
| | - John A Lincoln
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX, USA
| | - Michael A Jacobs
- Department of Diagnostic and Interventional Imaging, University of Texas McGovern Medical School, 6431 Fannin St., MSE 168, Houston, TX, 77030, USA
- The Russell H. Morgan Department of Radiology and Radiological Science and Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins School of Medicine, Baltimore, MD, USA
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Vi Ly
- Department of Biostatistics and Data Science, University of Texas School of Public Health, Houston, TX, USA
| | - Xi Luo
- Department of Biostatistics and Data Science, University of Texas School of Public Health, Houston, TX, USA
| | - Jerry S Wolinsky
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX, USA
| | - Ponnada A Narayana
- Department of Diagnostic and Interventional Imaging, University of Texas McGovern Medical School, 6431 Fannin St., MSE 168, Houston, TX, 77030, USA
| | - Khader M Hasan
- Department of Diagnostic and Interventional Imaging, University of Texas McGovern Medical School, 6431 Fannin St., MSE 168, Houston, TX, 77030, USA.
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Lee CH, Holloman M, Salzer JL, Zhang J. Multi-parametric MRI can detect enhanced myelination in the Gli1 -/- mouse brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.20.567957. [PMID: 38045415 PMCID: PMC10690149 DOI: 10.1101/2023.11.20.567957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
This study investigated the potential of combining multiple MR parameters to enhance the characterization of myelin in the mouse brain. We collected ex vivo multi-parametric MR data at 7 Tesla from control and Gli1 -/- mice; the latter exhibit enhanced myelination at postnatal day 10 (P10) in the corpus callosum and cortex. The MR data included relaxivity, magnetization transfer, and diffusion measurements, each targeting distinct myelin properties. This analysis was followed by and compared to myelin basic protein (MBP) staining of the same samples. Although a majority of the MR parameters included in this study showed significant differences in the corpus callosum between the control and Gli1 -/- mice, only T 2 , T 1 /T 2, and radial diffusivity (RD) demonstrated a significant correlation with MBP values. Based on data from the corpus callosum, partial least square regression suggested that combining T 2 , T 1 /T 2 , and inhomogeneous magnetization transfer ratio could explain approximately 80% of the variance in the MBP values. Myelin predictions based on these three parameters yielded stronger correlations with the MBP values in the P10 mouse brain corpus callosum than any single MR parameter. In the motor cortex, combining T 2 , T 1 /T 2, and radial kurtosis could explain over 90% of the variance in the MBP values at P10. This study demonstrates the utility of multi-parametric MRI in improving the detection of myelin changes in the mouse brain.
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Morris S, Swift-LaPointe T, Yung A, Prevost V, George S, Bauman A, Kozlowski P, Samadi-Bahrami Z, Fournier C, Mattu PS, Parker L, Streijger F, Hirsch-Reinshagen V, Moore GRW, Kwon BK, Laule C. Advanced Magnetic Resonance Imaging Biomarkers of the Injured Spinal Cord: A Comparative Study of Imaging and Histology in Human Traumatic Spinal Cord Injury. J Neurotrauma 2024; 41:1223-1239. [PMID: 38318802 DOI: 10.1089/neu.2023.0208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024] Open
Abstract
A significant problem in the diagnosis and management of traumatic spinal cord injury (tSCI) is the heterogeneity of secondary injury and the prediction of neurological outcome. Imaging biomarkers specific to myelin loss and inflammation after tSCI would enable detailed assessment of the pathophysiological processes underpinning secondary damage to the cord. Such biomarkers could be used to biologically stratify injury severity and better inform prognosis for neurological recovery. While much work has been done to establish magnetic resonance imaging (MRI) biomarkers for SCI in animal models, the relationship between imaging findings and the underlying pathology has been difficult to discern in human tSCI because of the paucity of human spinal cord tissue. We utilized post-mortem spinal cords from individuals who had a tSCI to examine this relationship by performing ex vivo MRI scans before histological analysis. We investigated the correlation between the histological distribution of myelin loss and inflammatory cells in the injured spinal cord and a number of myelin and inflammation-sensitive MRI measures: myelin water fraction (MWF), inhomogeneous magnetization transfer ratio (ihMTR), and diffusion tensor and diffusion kurtosis imaging-derived fractional anisotropy (FA) and axial, radial, and mean diffusivity (AD, RD, MD). The histological features were analyzed by staining with Luxol Fast Blue (LFB) for myelin lipids and Class II major histocompatibility complex (Class II MHC) and CD68 for microglia and macrophages. Both MWF and ihMTR were strongly correlated with LFB staining for myelin, supporting the use of both as biomarkers for myelin loss after SCI. A decrease in ihMTR was also correlated with the presence of Class II MHC positive immune cells. FA and RD correlated with both Class II MHC and CD68 and may therefore be useful biomarkers for inflammation after tSCI. Our work demonstrates the utility of advanced MRI techniques sensitive to biological tissue damage after tSCI, which is an important step toward using these MRI techniques in the clinic to aid in decision-making.
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Affiliation(s)
- Sarah Morris
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Physics and Astronomy, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Radiology, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Taylor Swift-LaPointe
- Physics and Astronomy, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Andrew Yung
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Radiology, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- UBC MRI Research Centre, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Valentin Prevost
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Radiology, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- UBC MRI Research Centre, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Shana George
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Andrew Bauman
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Radiology, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- UBC MRI Research Centre, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Physics and Astronomy, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Radiology, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- UBC MRI Research Centre, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Zahra Samadi-Bahrami
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Caron Fournier
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | | | - Lisa Parker
- Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Femke Streijger
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Veronica Hirsch-Reinshagen
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - G R Wayne Moore
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Vancouver Spine Surgery Institute, Vancouver, British Columbia, Canada
- Orthopaedics, University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Cornelia Laule
- International Collaboration on Repair Discoveries (ICORD), Departments of University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Physics and Astronomy, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Radiology, University of British Columbia (UBC), Vancouver, British Columbia, Canada
- Pathology and Laboratory Medicine, University of British Columbia (UBC), Vancouver, British Columbia, Canada
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Luchicchi A, Muñoz‐Gonzalez G, Halperin ST, Strijbis E, van Dijk LHM, Foutiadou C, Uriac F, Bouman PM, Schouten MAN, Plemel J, 't Hart BA, Geurts JJG, Schenk GJ. Micro-diffusely abnormal white matter: An early multiple sclerosis lesion phase with intensified myelin blistering. Ann Clin Transl Neurol 2024; 11:973-988. [PMID: 38425098 PMCID: PMC11021636 DOI: 10.1002/acn3.52015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/03/2024] [Accepted: 01/25/2024] [Indexed: 03/02/2024] Open
Abstract
OBJECTIVE Multiple sclerosis (MS) is a chronic central nervous system disease whose white matter lesion origin remains debated. Recently, we reported subtle changes in the MS normal appearing white matter (NAWM), presenting with an increase in myelin blisters and myelin protein citrullination, which may recapitulate some of the prodromal degenerative processes involved in MS pathogenesis. Here, to clarify the relevance of these changes for subsequent MS myelin degeneration we explored their prevalence in WM regions characterized by subtly reduced myelination (dubbed as micro-diffusely abnormal white matter, mDAWM). METHODS We used an in-depth (immuno)histochemistry approach in 27 MS donors with histological presence of mDAWM and 5 controls. An antibody panel against degenerative markers was combined and the presence of myelin/axonal aberrations was analyzed and compared with the NAWM from the same cases/slices/regions. RESULTS mDAWM-defined areas exhibit ill-defined borders, no signs of Wallerian degeneration, and they associate with visible veins. Remarkably, such areas present with augmented myelin blister frequency, enhanced prevalence of polar myelin phospholipids, citrullination, and degradation of myelin basic protein (MBP) when compared with the NAWM. Furthermore, enhanced reactivity of microglia/macrophages against citrullinated MBP was also observed in this tissue. INTERPRETATION We report a new histologically defined early phase in MS lesion formation, namely mDAWM, which lacks signs of Wallerian pathology. These results support the prelesional nature of the mDAWM. We conceptualize that evolution to pathologically evident lesions comprises the previously documented imbalance of axo-myelinic units (myelin blistering) leading to their degeneration and immune system activation by released myelin components.
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Affiliation(s)
- Antonio Luchicchi
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Gema Muñoz‐Gonzalez
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Saar T. Halperin
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Eva Strijbis
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
- Department of NeurologyAmsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Laura H. M. van Dijk
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
| | - Chrisa Foutiadou
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
| | - Florence Uriac
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
| | - Piet M. Bouman
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Maxime A. N. Schouten
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Jason Plemel
- Department of NeuroscienceUniversity of AlbertaEdmontonAlbertaCanada
| | - Bert A. 't Hart
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Jeroen J. G. Geurts
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Geert J. Schenk
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
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5
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Khormi I, Al-Iedani O, Alshehri A, Ramadan S, Lechner-Scott J. MR myelin imaging in multiple sclerosis: A scoping review. J Neurol Sci 2023; 455:122807. [PMID: 38035651 DOI: 10.1016/j.jns.2023.122807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/20/2023] [Accepted: 11/19/2023] [Indexed: 12/02/2023]
Abstract
The inability of disease-modifying therapies to stop the progression of multiple sclerosis (MS), has led to the development of a new therapeutic strategy focussing on myelin repair. While conventional MRI lacks sensitivity for quantifying myelin damage, advanced MRI techniques are proving effective. The development of targeted therapeutics requires histological validation of myelin imaging results, alongside the crucial task of establishing correlations between myelin imaging results and clinical assessments, so that the effectiveness of therapeutic interventions can be evaluated. The aims of this scoping review were to identify myelin imaging methods - some of which have been histologically validated, and to determine how these approaches correlate with clinical assessments of people with MS (pwMS), thus allowing for effective therapeutic evaluation. A search of two databases was undertaken for publications relating to studies on adults MS using either MRI/MR-histology of the MS brain in the range 1990-to-2022. The myelin imaging methods specified were relaxometry, magnetization transfer, and quantitative susceptibility. Relaxometry was used most frequently, with myelin water fraction (MWF) being the primary metric. Studies conducted on tissue from various regions of the brain showed that MWF was significantly lower in pwMS than in healthy controls. Magnetization transfer ratio indicated that the macromolecular content of lesions was lower than that of normal-appearing tissue. Higher magnetic susceptibility of lesions were indicative of myelin breakdown and iron accumulation. Several myelin imaging metrics were correlated with disability, disease severity and duration. Many studies showed a good correlation between myelin measured histologically and by MR myelin imaging techniques.
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Affiliation(s)
- Ibrahim Khormi
- School of Health Sciences, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, Australia; Hunter Medical Research Institute, New Lambton Heights, Australia; College of Applied Medical Sciences, University of Jeddah, Jeddah, Saudi Arabia
| | - Oun Al-Iedani
- Hunter Medical Research Institute, New Lambton Heights, Australia; School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, Australia
| | - Abdulaziz Alshehri
- School of Health Sciences, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, Australia; Hunter Medical Research Institute, New Lambton Heights, Australia; Department of Radiology, King Fahd Hospital of the University, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Saadallah Ramadan
- School of Health Sciences, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, Australia; Hunter Medical Research Institute, New Lambton Heights, Australia.
| | - Jeannette Lechner-Scott
- Hunter Medical Research Institute, New Lambton Heights, Australia; Department of Neurology, John Hunter Hospital, New Lambton Heights, Australia; School of Medicine and Public Health, College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, Australia
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Dvorak AV, Kumar D, Zhang J, Gilbert G, Balaji S, Wiley N, Laule C, Moore GW, MacKay AL, Kolind SH. The CALIPR framework for highly accelerated myelin water imaging with improved precision and sensitivity. SCIENCE ADVANCES 2023; 9:eadh9853. [PMID: 37910622 PMCID: PMC10619933 DOI: 10.1126/sciadv.adh9853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023]
Abstract
Quantitative magnetic resonance imaging (MRI) techniques are powerful tools for the study of human tissue, but, in practice, their utility has been limited by lengthy acquisition times. Here, we introduce the Constrained, Adaptive, Low-dimensional, Intrinsically Precise Reconstruction (CALIPR) framework in the context of myelin water imaging (MWI); a quantitative MRI technique generally regarded as the most rigorous approach for noninvasive, in vivo measurement of myelin content. The CALIPR framework exploits data redundancy to recover high-quality images from a small fraction of an imaging dataset, which allowed MWI to be acquired with a previously unattainable sequence (fully sampled acquisition 2 hours:57 min:20 s) in 7 min:26 s (4.2% of the dataset, acceleration factor 23.9). CALIPR quantitative metrics had excellent precision (myelin water fraction mean coefficient of variation 3.2% for the brain and 3.0% for the spinal cord) and markedly increased sensitivity to demyelinating disease pathology compared to a current, widely used technique. The CALIPR framework facilitates drastically improved MWI and could be similarly transformative for other quantitative MRI applications.
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Affiliation(s)
- Adam V. Dvorak
- Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Dushyant Kumar
- Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jing Zhang
- Global MR Applications & Workflow, GE HealthCare Canada, Mississauga, ON, Canada
| | | | - Sharada Balaji
- Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Neale Wiley
- Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Cornelia Laule
- Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Radiology, University of British Columbia, Vancouver, BC, Canada
- Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - G.R. Wayne Moore
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Alex L. MacKay
- Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- Radiology, University of British Columbia, Vancouver, BC, Canada
- Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Shannon H. Kolind
- Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Radiology, University of British Columbia, Vancouver, BC, Canada
- Medicine (Neurology), University of British Columbia, Vancouver, BC, Canada
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Brier MR, Taha F. Measuring Pathology in Patients with Multiple Sclerosis Using Positron Emission Tomography. Curr Neurol Neurosci Rep 2023; 23:479-488. [PMID: 37418219 DOI: 10.1007/s11910-023-01285-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2023] [Indexed: 07/08/2023]
Abstract
PURPOSE OF REVIEW Multiple sclerosis is characterized by a diverse and complex pathology. Clinical relapses, the hallmark of the disease, are accompanied by focal white matter lesions with intense inflammatory and demyelinating activity. Prevention of these relapses has been the major focus of pharmaceutical development, and it is now possible to dramatically reduce this inflammatory activity. Unfortunately, disability accumulation persists for many people living with multiple sclerosis owing to ongoing damage within existing lesions, pathology outside of discrete lesions, and other yet unknown factors. Understanding this complex pathological cascade will be critical to stopping progressive multiple sclerosis. Positron emission tomography uses biochemically specific radioligands to quantitatively measure pathological processes with molecular specificity. This review examines recent advances in the understanding of multiple sclerosis facilitated by positron emission tomography and identifies future avenues to expand understanding and treatment options. RECENT FINDINGS An increasing number of radiotracers allow for the quantitative measurement of inflammatory abnormalities, de- and re-myelination, and metabolic disruption associated with multiple sclerosis. The studies have identified contributions of ongoing, smoldering inflammation to accumulating tissue injury and clinical worsening. Myelin studies have quantified the dynamics of myelin loss and recovery. Lastly, metabolic changes have been found to contribute to symptom worsening. The molecular specificity facilitated by positron emission tomography in people living with multiple sclerosis will critically inform efforts to modulate the pathology leading to progressive disability accumulation. Existing studies show the power of this approach applied to multiple sclerosis. This armamentarium of radioligands allows for new understanding of how the brain and spinal cord of people is impacted by multiple sclerosis.
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Affiliation(s)
- Matthew R Brier
- Department of Neurology, John L Trotter MS Center, Washington University in St. Louis, St. Louis, USA.
| | - Farris Taha
- Department of Neurology, Medical University of South Carolina, Charleston, USA
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8
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Jhelum P, Zandee S, Ryan F, Zarruk JG, Michalke B, Venkataramani V, Curran L, Klement W, Prat A, David S. Ferroptosis induces detrimental effects in chronic EAE and its implications for progressive MS. Acta Neuropathol Commun 2023; 11:121. [PMID: 37491291 PMCID: PMC10369714 DOI: 10.1186/s40478-023-01617-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/27/2023] Open
Abstract
Ferroptosis is a form of lipid peroxidation-mediated cell death and damage triggered by excess iron and insufficiency in the glutathione antioxidant pathway. Oxidative stress is thought to play a crucial role in progressive forms of multiple sclerosis (MS) in which iron deposition occurs. In this study we assessed if ferroptosis plays a role in a chronic form of experimental autoimmune encephalomyelitis (CH-EAE), a mouse model used to study MS. Changes were detected in the mRNA levels of several ferroptosis genes in CH-EAE but not in relapsing-remitting EAE. At the protein level, expression of iron importers is increased in the earlier stages of CH-EAE (onset and peak). While expression of hemoxygenase-1, which mobilizes iron from heme, likely from phagocytosed material, is increased in macrophages at the peak and progressive stages. Excess iron in cells is stored safely in ferritin, which increases with disease progression. Harmful, redox active iron is released from ferritin when shuttled to autophagosomes by 'nuclear receptor coactivator 4' (NCOA4). NCOA4 expression increases at the peak and progressive stages of CH-EAE and accompanied by increase in redox active ferrous iron. These changes occur in parallel with reduction in the antioxidant pathway (system xCT, glutathione peroxidase 4 and glutathione), and accompanied by increased lipid peroxidation. Mice treated with a ferroptosis inhibitor for 2 weeks starting at the peak of CH-EAE paralysis, show significant improvements in function and pathology. Autopsy samples of tissue sections of secondary progressive MS (SPMS) showed NCOA4 expression in macrophages and oligodendrocytes along the rim of mixed active/inactive lesions, where ferritin+ and iron containing cells are located. Cells expressing NCOA4 express less ferritin, suggesting ferritin degradation and release of redox active iron, as indicated by increased lipid peroxidation. These data suggest that ferroptosis is likely to contribute to pathogenesis in CH-EAE and SPMS.
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Affiliation(s)
- Priya Jhelum
- Centre for Research in Neuroscience and BRaIN Program, Research Institute of the McGill University Health Centre (RI-MUHC), Livingston Hall, Room L7-210, 1650 Cedar Ave., Montreal, QC, H3G 1A4, Canada
| | - Stephanie Zandee
- Neuroimmunology Research Laboratory, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, H2X 0A9, Canada
- Department of Neuroscience, Faculty of Medicine, Université de Montréal, Montreal, Canada
| | - Fari Ryan
- Centre for Research in Neuroscience and BRaIN Program, Research Institute of the McGill University Health Centre (RI-MUHC), Livingston Hall, Room L7-210, 1650 Cedar Ave., Montreal, QC, H3G 1A4, Canada
| | - Juan G Zarruk
- Centre for Research in Neuroscience and BRaIN Program, Research Institute of the McGill University Health Centre (RI-MUHC), Livingston Hall, Room L7-210, 1650 Cedar Ave., Montreal, QC, H3G 1A4, Canada
| | - Bernhard Michalke
- Research Unit Analytical BioGeoChemistry, Helmholz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Vivek Venkataramani
- Comprehensive Cancer Center Mainfranken, University Hospital Würzburg, 97080, Würzburg, Germany
| | - Laura Curran
- Centre for Research in Neuroscience and BRaIN Program, Research Institute of the McGill University Health Centre (RI-MUHC), Livingston Hall, Room L7-210, 1650 Cedar Ave., Montreal, QC, H3G 1A4, Canada
| | - Wendy Klement
- Neuroimmunology Research Laboratory, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, H2X 0A9, Canada
- Department of Neuroscience, Faculty of Medicine, Université de Montréal, Montreal, Canada
| | - Alexandre Prat
- Neuroimmunology Research Laboratory, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, H2X 0A9, Canada
- Department of Neuroscience, Faculty of Medicine, Université de Montréal, Montreal, Canada
| | - Samuel David
- Centre for Research in Neuroscience and BRaIN Program, Research Institute of the McGill University Health Centre (RI-MUHC), Livingston Hall, Room L7-210, 1650 Cedar Ave., Montreal, QC, H3G 1A4, Canada.
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9
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Myelinodegeneration vs. Neurodegeneration in MS Progressive Forms. Int J Mol Sci 2023; 24:ijms24021596. [PMID: 36675111 PMCID: PMC9864662 DOI: 10.3390/ijms24021596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 01/15/2023] Open
Abstract
In MS patients with a progressive form of the disease, the slow deterioration of neurological functions is thought to result from a combination of neuronal cell death, axonal damages and synaptic dysfunctions [...].
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10
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David S, Jhelum P, Ryan F, Jeong SY, Kroner A. Dysregulation of Iron Homeostasis in the Central Nervous System and the Role of Ferroptosis in Neurodegenerative Disorders. Antioxid Redox Signal 2022; 37:150-170. [PMID: 34569265 DOI: 10.1089/ars.2021.0218] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Significance: Iron accumulation occurs in the central nervous system (CNS) in a variety of neurological conditions as diverse as spinal cord injury, stroke, multiple sclerosis, Parkinson's disease, and others. Iron is a redox-active metal that gives rise to damaging free radicals if its intracellular levels are not controlled or if it is not properly sequestered within cells. The accumulation of iron occurs due to dysregulation of mechanisms that control cellular iron homeostasis. Recent Advances: The molecular mechanisms that regulate cellular iron homeostasis have been revealed in much detail in the past three decades, and new advances continue to be made. Understanding which aspects of iron homeostasis are dysregulated in different conditions will provide insights into the causes of iron accumulation and iron-mediated tissue damage. Recent advances in iron-dependent lipid peroxidation leading to cell death, called ferroptosis, has provided useful insights that are highly relevant for the lipid-rich environment of the CNS. Critical Issues: This review examines the mechanisms that control normal cellular iron homeostasis, the dysregulation of these mechanisms in neurological disorders, and more recent work on how iron can induce tissue damage via ferroptosis. Future Directions: Quick and reliable tests are needed to determine if and when ferroptosis contributes to the pathogenesis of neurological disorders. In addition, there is need to develop better druggable agents to scavenge lipid radicals and reduce CNS damage for neurological conditions for which there are currently few effective treatments. Antioxid. Redox Signal. 37, 150-170.
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Affiliation(s)
- Samuel David
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Priya Jhelum
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Fari Ryan
- Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Suh Young Jeong
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Antje Kroner
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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11
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York EN, Thrippleton MJ, Meijboom R, Hunt DPJ, Waldman AD. Quantitative magnetization transfer imaging in relapsing-remitting multiple sclerosis: a systematic review and meta-analysis. Brain Commun 2022; 4:fcac088. [PMID: 35652121 PMCID: PMC9149789 DOI: 10.1093/braincomms/fcac088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 12/17/2021] [Accepted: 03/31/2022] [Indexed: 11/28/2022] Open
Abstract
Myelin-sensitive MRI such as magnetization transfer imaging has been widely used in multiple sclerosis. The influence of methodology and differences in disease subtype on imaging findings is, however, not well established. Here, we systematically review magnetization transfer brain imaging findings in relapsing-remitting multiple sclerosis. We examine how methodological differences, disease effects and their interaction influence magnetization transfer imaging measures. Articles published before 06/01/2021 were retrieved from online databases (PubMed, EMBASE and Web of Science) with search terms including 'magnetization transfer' and 'brain' for systematic review, according to a pre-defined protocol. Only studies that used human in vivo quantitative magnetization transfer imaging in adults with relapsing-remitting multiple sclerosis (with or without healthy controls) were included. Additional data from relapsing-remitting multiple sclerosis subjects acquired in other studies comprising mixed disease subtypes were included in meta-analyses. Data including sample size, MRI acquisition protocol parameters, treatments and clinical findings were extracted and qualitatively synthesized. Where possible, effect sizes were calculated for meta-analyses to determine magnetization transfer (i) differences between patients and healthy controls; (ii) longitudinal change and (iii) relationships with clinical disability in relapsing-remitting multiple sclerosis. Eighty-six studies met inclusion criteria. MRI acquisition parameters varied widely, and were also underreported. The majority of studies examined the magnetization transfer ratio in white matter, but magnetization transfer metrics, brain regions examined and results were heterogeneous. The analysis demonstrated a risk of bias due to selective reporting and small sample sizes. The pooled random-effects meta-analysis across all brain compartments revealed magnetization transfer ratio was 1.17 per cent units (95% CI -1.42 to -0.91) lower in relapsing-remitting multiple sclerosis than healthy controls (z-value: -8.99, P < 0.001, 46 studies). Linear mixed-model analysis did not show a significant longitudinal change in magnetization transfer ratio across all brain regions [β = 0.12 (-0.56 to 0.80), t-value = 0.35, P = 0.724, 14 studies] or normal-appearing white matter alone [β = 0.037 (-0.14 to 0.22), t-value = 0.41, P = 0.68, eight studies]. There was a significant negative association between the magnetization transfer ratio and clinical disability, as assessed by the Expanded Disability Status Scale [r = -0.32 (95% CI -0.46 to -0.17); z-value = -4.33, P < 0.001, 13 studies]. Evidence suggests that magnetization transfer imaging metrics are sensitive to pathological brain changes in relapsing-remitting multiple sclerosis, although effect sizes were small in comparison to inter-study variability. Recommendations include: better harmonized magnetization transfer acquisition protocols with detailed methodological reporting standards; larger, well-phenotyped cohorts, including healthy controls; and, further exploration of techniques such as magnetization transfer saturation or inhomogeneous magnetization transfer ratio.
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Affiliation(s)
- Elizabeth N. York
- Centre for Clinical Brain Sciences, University of
Edinburgh, Edinburgh, UK
| | | | - Rozanna Meijboom
- Centre for Clinical Brain Sciences, University of
Edinburgh, Edinburgh, UK
| | - David P. J. Hunt
- Centre for Clinical Brain Sciences, University of
Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of
Edinburgh, Edinburgh, UK
- Anne Rowling Regenerative Neurology Clinic,
University of Edinburgh, Edinburgh, UK
| | - Adam D. Waldman
- Centre for Clinical Brain Sciences, University of
Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of
Edinburgh, Edinburgh, UK
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12
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Dadar M, Mahmoud S, Narayanan S, Collins LD, Arnold DL, Maranzano J. Diffusely abnormal white matter converts to T2 lesion volume in the absence of MRI-detectable acute inflammation. Brain 2021; 145:2008-2017. [DOI: 10.1093/brain/awab448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/28/2021] [Accepted: 11/12/2021] [Indexed: 01/18/2023] Open
Abstract
Abstract
Diffusely abnormal white matter (DAWM), characterised by biochemical changes of myelin in the absence of frank demyelination, has been associated with clinical progression in secondary progressive MS (SPMS). However, little is known about changes of DAWM over time and their relation to focal white matter lesions (FWML).
The objectives of this work were: 1) To characterize the longitudinal evolution of FWML, DAWM, and DAWM that transforms into FWML, and 2) To determine whether gadolinium enhancement, known to be associated with the development of new FWML, is also related to DAWM voxels that transform into FWML.
Our data included 4220 MRI scans of 689 SPMS participants, followed for 156 weeks and 2677 scans of 686 RRMS participants, followed for 96 weeks. FWML and DAWM were segmented using a previously validated, automatic thresholding technique based on normalized T2 intensity values. Using longitudinally registered images, DAWM voxels at each visit that transformed into FWML on the last MRI scan as well as their overlap with gadolinium enhancing lesion masks were identified.
Our results showed that the average yearly rate of conversion of DAWM-to-FWML was 1.27 cc for SPMS and 0.80 cc for RRMS. FWML in SPMS participants significantly increased (t = 3.9; p = 0.0001) while DAWM significantly decreased (t = −4.3 p < 0.0001) and the ratio FWML:DAWM increased (t = 12.7; p < 0.00001). RRMS participants also showed an increase in the FWML:DAWM Ratio (t = 6.9; p < 0.00001) but without a significant change of the individual volumes. Gadolinium enhancement was associated with 7.3% and 18.7% of focal New T2 lesion formation in the infrequent scans of the RRMS and SPMS cohorts, respectively. In comparison, only 0.1% and 0.0% of DAWM-to-FWML voxels overlapped with gadolinium enhancement.
We conclude that DAWM transforms into FWML over time, in both RRMS and SPMS. DAWM appears to represent a form of pre-lesional pathology that contributes to T2 lesion volume increase over time, independent of new focal inflammation and gadolinium enhancement.
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Affiliation(s)
- Mahsa Dadar
- Radiology Department, Faculty of Medicine, Laval University, Quebec, Canada
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Sawsan Mahmoud
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, Quebec, Canada
| | - Sridar Narayanan
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Louis D. Collins
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Douglas L. Arnold
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Josefina Maranzano
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, Quebec, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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13
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Cairns J, Vavasour IM, Traboulsee A, Carruthers R, Kolind SH, Li DKB, Moore GRW, Laule C. Diffusely abnormal white matter in multiple sclerosis. J Neuroimaging 2021; 32:5-16. [PMID: 34752664 DOI: 10.1111/jon.12945] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 10/17/2021] [Accepted: 10/18/2021] [Indexed: 02/06/2023] Open
Abstract
MRI enables detailed in vivo depiction of multiple sclerosis (MS) pathology. Localized areas of MS damage, commonly referred to as lesions, or plaques, have been a focus of clinical and research MRI studies for over four decades. A nonplaque MRI abnormality which is present in at least 25% of MS patients but has received far less attention is diffusely abnormal white matter (DAWM). DAWM has poorly defined boundaries and a signal intensity that is between normal-appearing white matter and classic lesions on proton density and T2 -weighted images. All clinical phenotypes of MS demonstrate DAWM, including clinically isolated syndrome, where DAWM is associated with higher lesion volume, reduced brain volume, and earlier conversion to MS. Advanced MRI metric abnormalities in DAWM tend to be greater than those in NAWM, but not as severe as focal lesions, with myelin, axons, and water-related changes commonly reported. Histological studies demonstrate a primary lipid abnormality in DAWM, with some axonal damage and lesser involvement of myelin proteins. This review provides an overview of DAWM identification, summarizes in vivo and postmortem observations, and comments on potential pathophysiological mechanisms, which may underlie DAWM in MS. Given the prevalence and potential clinical impact of DAWM, the number of imaging studies focusing on DAWM is insufficient. Characterization of DAWM significance and microstructure would benefit from larger longitudinal and additional quantitative imaging efforts. Revisiting data from previous studies that included proton density and T2 imaging would enable retrospective DAWM identification and analysis.
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Affiliation(s)
- James Cairns
- Department of Medicine (Neurology), University of British Columbia, British Columbia, Vancouver, Canada.,Department of Radiology, University of British Columbia, British Columbia, Vancouver, Canada
| | - Irene M Vavasour
- Department of Radiology, University of British Columbia, British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, Blusson Spinal Cord Centre, University of British Columbia, British Columbia, Vancouver, Canada
| | - Anthony Traboulsee
- Department of Medicine (Neurology), University of British Columbia, British Columbia, Vancouver, Canada
| | - Robert Carruthers
- Department of Medicine (Neurology), University of British Columbia, British Columbia, Vancouver, Canada
| | - Shannon H Kolind
- Department of Medicine (Neurology), University of British Columbia, British Columbia, Vancouver, Canada.,Department of Radiology, University of British Columbia, British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, Blusson Spinal Cord Centre, University of British Columbia, British Columbia, Vancouver, Canada.,Department of Physics & Astronomy, University of British Columbia, British Columbia, Vancouver, Canada
| | - David K B Li
- Department of Medicine (Neurology), University of British Columbia, British Columbia, Vancouver, Canada.,Department of Radiology, University of British Columbia, British Columbia, Vancouver, Canada
| | - G R Wayne Moore
- Department of Medicine (Neurology), University of British Columbia, British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, Blusson Spinal Cord Centre, University of British Columbia, British Columbia, Vancouver, Canada.,Department of Pathology & Laboratory Medicine, University of British Columbia, British Columbia, Vancouver, Canada
| | - Cornelia Laule
- Department of Radiology, University of British Columbia, British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, Blusson Spinal Cord Centre, University of British Columbia, British Columbia, Vancouver, Canada.,Department of Physics & Astronomy, University of British Columbia, British Columbia, Vancouver, Canada.,Department of Pathology & Laboratory Medicine, University of British Columbia, British Columbia, Vancouver, Canada
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14
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Holmes RD, Vavasour IM, Greenfield J, Zhao G, Lee JS, Moore GRW, Tam R, Metz LM, Trablousee A, Li DKB, Laule C. Nonlesional diffusely abnormal appearing white matter in clinically isolated syndrome: Prevalence, association with clinical and MRI features, and risk for conversion to multiple sclerosis. J Neuroimaging 2021; 31:981-994. [PMID: 34128576 DOI: 10.1111/jon.12900] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND AND PURPOSE While diffusely abnormal white matter (DAWM) is a nonlesional MRI abnormality identified in ∼25% of patients with multiple sclerosis (MS), it has yet to be investigated in patients at an earlier disease stage, namely clinically isolated syndrome (CIS). The goals of this study were to (1) determine the prevalence of DAWM in patients with a CIS suggestive of MS, (2) evaluate the association between DAWM and demographic, clinical, and MRI features, and (3) evaluate the prognostic significance of DAWM on conversion from CIS to MS. METHODS One hundred and forty-two CIS participants were categorized into DAWM and non-DAWM groups at baseline and followed for up to 24 months or until MS diagnosis. The primary outcome was conversion to MS (2005 McDonald criteria) within 6 months. RESULTS DAWM was present in 27.5% of participants, and was positively associated with brainstem symptom onset, receiving corticosteroids, dissemination in space, and T2 lesion volume. DAWM was associated with an increased risk of conversion to MS over 6 months after adjustment for age and disability (hazard ratio [HR] = 2.24, p = 0.004). This association remained at a trend-level after adjustment for high-risk imaging features (HR = 1.68, p = 0.10). CONCLUSIONS DAWM is present in a similar proportion of patients with CIS and clinically definite MS, and it is associated with increased risk of conversion to MS over 6 months.
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Affiliation(s)
- R Davis Holmes
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Irene M Vavasour
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jamie Greenfield
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Guojun Zhao
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MS/MRI Research Group, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jimmy S Lee
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - G R Wayne Moore
- Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Roger Tam
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MS/MRI Research Group, University of British Columbia, Vancouver, British Columbia, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Luanne M Metz
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Anthony Trablousee
- UBC MS/MRI Research Group, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medicine (Neurology), University of British Columbia, Vancouver, British Columbia, Canada
| | - David K B Li
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MS/MRI Research Group, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medicine (Neurology), University of British Columbia, Vancouver, British Columbia, Canada
| | - Cornelia Laule
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.,Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
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15
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Papadaki E, Mastorodemos V, Panou T, Pouli S, Spyridaki E, Kavroulakis E, Kalaitzakis G, Maris TG, Simos P. T2 Relaxometry Evidence of Microstructural Changes in Diffusely Abnormal White Matter in Relapsing-Remitting Multiple Sclerosis and Clinically Isolated Syndrome: Impact on Visuomotor Performance. J Magn Reson Imaging 2021; 54:1077-1087. [PMID: 33960066 DOI: 10.1002/jmri.27661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Although diffusely abnormal white matter (DAWM) is commonly seen in multiple sclerosis (MS), it is rarely considered in clinical/imaging studies. PURPOSE To evaluate quantitative markers of microstructural changes in DAWM of patients with clinically isolated syndrome (CIS) and relapsing-remitting MS (RR-MS) in relation to MS lesions and degree of neurocognitive impairment, by using a multi-echo spin echo (MESE) Proton Density PD-to-T2 sequence. STUDY TYPE Prospective, cross-sectional. POPULATION Thirty-seven RR-MS patients, 33 CIS patients, and 52 healthy controls. FIELD STRENGTH/SEQUENCE 1.5 T/T1-, T2-weighted, fluid-attenuated inversion recovery, and MESE sequences. ASSESSMENT Long T2, short T2, and myelin water fraction (MWF) values were estimated as indices of intra/extracellular water content and myelin content, respectively, in DAWM, posterior periventricular normal appearing white matter (NAWM), and focal MS lesions, classified according to their signal intensity on T1 sequences. Patients were, also, administered a battery of neuropsychological tests. STATISTICAL TESTS Comparisons of T2 and MWF values in DAWM, NAWM, and MS lesions were examined, using two-way mixed analyses of variance. Associations of Grooved Pegboard performance with T2 and MWF values in DAWM and NAWM were assessed using Pearson correlation coefficients. RESULTS T2 and MWF values of DAWM were intermediate between the respective values of NAWM and T1 hypointense focal lesions, while there was no difference between the respective values of DAWM and T1-isointense lesions. T2 values in DAWM were strongly associated with visuomotor performance in CIS patients. DATA CONCLUSION Intra/extracellular water and myelin water content of DAWM are similar to those of T1-isointense lesions and predict visuomotor performance in CIS patients. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Efrosini Papadaki
- Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
- Institute of Computer Science, Foundation of Research and Technology-Hellas, Heraklion, Greece
| | - Vasileios Mastorodemos
- Department of Neurology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Theodora Panou
- Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Styliani Pouli
- Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Eirini Spyridaki
- Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Eleftherios Kavroulakis
- Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Georgios Kalaitzakis
- Department of Medical Physics, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Thomas G Maris
- Institute of Computer Science, Foundation of Research and Technology-Hellas, Heraklion, Greece
- Department of Medical Physics, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Panagiotis Simos
- Institute of Computer Science, Foundation of Research and Technology-Hellas, Heraklion, Greece
- Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
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16
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Brier MR, Snyder AZ, Tanenbaum A, Rudick RA, Fisher E, Jones S, Shimony JS, Cross AH, Benzinger TLS, Naismith RT. Quantitative signal properties from standardized MRIs correlate with multiple sclerosis disability. Ann Clin Transl Neurol 2021; 8:1096-1109. [PMID: 33943045 PMCID: PMC8108425 DOI: 10.1002/acn3.51354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/11/2021] [Accepted: 03/16/2021] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE To enable use of clinical magnetic resonance images (MRIs) to quantify abnormalities in normal appearing (NA) white matter (WM) and gray matter (GM) in multiple sclerosis (MS) and to determine associations with MS-related disability. Identification of these abnormalities heretofore has required specialized scans not routinely available in clinical practice. METHODS We developed an analytic technique which normalizes image intensities based on an intensity atlas for quantification of WM and GM abnormalities in standardized MRIs obtained with clinical sequences. Gaussian mixture modeling is applied to summarize image intensity distributions from T1-weighted and 3D-FLAIR (T2-weighted) images from 5010 participants enrolled in a multinational database of MS patients which collected imaging, neuroperformance and disability measures. RESULTS Intensity distribution metrics distinguished MS patients from control participants based on normalized non-lesional signal differences. This analysis revealed non-lesional differences between relapsing MS versus progressive MS subtypes. Further, the correlation between our non-lesional measures and disability was approximately three times greater than that between total lesion volume and disability, measured using the patient derived disease steps. Multivariate modeling revealed that measures of extra-lesional tissue integrity and atrophy contribute uniquely, and approximately equally, to the prediction of MS-related disability. INTERPRETATION These results support the notion that non-lesional abnormalities correlate more strongly with MS-related disability than lesion burden and provide new insight into the basis of abnormalities in NA WM. Non-lesional abnormalities distinguish relapsing from progressive MS but do not distinguish between progressive subtypes suggesting a common progressive pathophysiology. Image intensity parameters and existing biomarkers each independently correlate with MS-related disability.
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Affiliation(s)
- Matthew R. Brier
- Department of NeurologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Abraham Z. Snyder
- Malinckrodt Institute of RadiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Aaron Tanenbaum
- Department of NeurologyWashington University in St. LouisSt. LouisMissouriUSA
| | | | | | | | - Joshua S. Shimony
- Malinckrodt Institute of RadiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Anne H. Cross
- Department of NeurologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Tammie L. S. Benzinger
- Malinckrodt Institute of RadiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Robert T. Naismith
- Department of NeurologyWashington University in St. LouisSt. LouisMissouriUSA
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17
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Lazari A, Lipp I. Can MRI measure myelin? Systematic review, qualitative assessment, and meta-analysis of studies validating microstructural imaging with myelin histology. Neuroimage 2021; 230:117744. [PMID: 33524576 PMCID: PMC8063174 DOI: 10.1016/j.neuroimage.2021.117744] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/05/2021] [Accepted: 01/09/2021] [Indexed: 12/16/2022] Open
Abstract
Recent years have seen an increased understanding of the importance of myelination in healthy brain function and neuropsychiatric diseases. Non-invasive microstructural magnetic resonance imaging (MRI) holds the potential to expand and translate these insights to basic and clinical human research, but the sensitivity and specificity of different MR markers to myelination is a subject of debate. To consolidate current knowledge on the topic, we perform a systematic review and meta-analysis of studies that validate microstructural imaging by combining it with myelin histology. We find meta-analytic evidence for correlations between various myelin histology metrics and markers from different MRI modalities, including fractional anisotropy, radial diffusivity, macromolecular pool, magnetization transfer ratio, susceptibility and longitudinal relaxation rate, but not mean diffusivity. Meta-analytic correlation effect sizes range widely, between R2 = 0.26 and R2 = 0.82. However, formal comparisons between MRI-based myelin markers are limited by methodological variability, inconsistent reporting and potential for publication bias, thus preventing the establishment of a single most sensitive strategy to measure myelin with MRI. To facilitate further progress, we provide a detailed characterisation of the evaluated studies as an online resource. We also share a set of 12 recommendations for future studies validating putative MR-based myelin markers and deploying them in vivo in humans.
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Affiliation(s)
- Alberto Lazari
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Ilona Lipp
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
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18
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Filippi M, Preziosa P, Barkhof F, Chard DT, De Stefano N, Fox RJ, Gasperini C, Kappos L, Montalban X, Moraal B, Reich DS, Rovira À, Toosy AT, Traboulsee A, Weinshenker BG, Zeydan B, Banwell BL, Rocca MA. Diagnosis of Progressive Multiple Sclerosis From the Imaging Perspective: A Review. JAMA Neurol 2021; 78:351-364. [PMID: 33315071 DOI: 10.1001/jamaneurol.2020.4689] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Importance Although magnetic resonance imaging (MRI) is useful for monitoring disease dissemination in space and over time and excluding multiple sclerosis (MS) mimics, there has been less application of MRI to progressive MS, including diagnosing primary progressive (PP) MS and identifying patients with relapsing-remitting (RR) MS who are at risk of developing secondary progressive (SP) MS. This review addresses clinical application of MRI for both diagnosis and prognosis of progressive MS. Observations Although nonspecific, some spinal cord imaging features (diffuse abnormalities and lesions involving gray matter [GM] and ≥2 white matter columns) are typical of PPMS. In patients with PPMS and those with relapse-onset MS, location of lesions in critical central nervous system regions (spinal cord, infratentorial regions, and GM) and MRI-detected high inflammatory activity in the first years after diagnosis are risk factors for long-term disability and future progressive disease course. These measures are evaluable in clinical practice. In patients with established MS, GM involvement and neurodegeneration are associated with accelerated clinical worsening. Subpial demyelination and slowly expanding lesions are novel indicators of progressive MS. Conclusions and Relevance Diagnosis of PPMS is more challenging than diagnosis of RRMS. No qualitative clinical, immunological, histopathological, or neuroimaging features differentiate PPMS and SPMS; both are characterized by imaging findings reflecting neurodegeneration and are also impacted by aging and comorbidities. Unmet diagnostic needs include identification of MRI markers capable of distinguishing PPMS from RRMS and predicting the evolution of RRMS to SPMS. Integration of multiple parameters will likely be essential to achieve these aims.
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Affiliation(s)
- Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Istituto di Ricovero e di Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurophysiology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Paolo Preziosa
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Istituto di Ricovero e di Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Frederik Barkhof
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, Location VU University Medical Center (VUmc), Multiple Sclerosis Center Amsterdam, Amsterdam, the Netherlands
- Institutes of Neurology and Healthcare Engineering, University College London, London, United Kingdom
| | - Declan T Chard
- Nuclear Magnetic Resonance (NMR) Research Unit, Queen Square Multiple Sclerosis Centre, University College London Institute of Neurology, London, United Kingdom
- National Institute for Health Research, University College London Hospitals, Biomedical Research Centre, London, United Kingdom
| | - Nicola De Stefano
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Robert J Fox
- Mellen Center for Multiple Sclerosis, Cleveland Clinic, Cleveland, Ohio
| | - Claudio Gasperini
- Department of Neurology, San Camillo-Forlanini Hospital, Rome, Italy
| | - Ludwig Kappos
- Neurologic Clinic and Policlinic, Departments of Medicine, Clinical Research, Biomedicine and Biomedical Engineering, University Hospital and University of Basel, Basel, Switzerland
| | - Xavier Montalban
- Department of Neurology, Centre d'Esclerosi Múltiple de Catalunya (Cemcat), Hospital Vall d'Hebron, Autonomous University of Barcelona, Barcelona, Spain
- Division of Neurology, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Bastiaan Moraal
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, Location VU University Medical Center (VUmc), Multiple Sclerosis Center Amsterdam, Amsterdam, the Netherlands
| | - Daniel S Reich
- Translational Neuroradiology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Àlex Rovira
- Neuroradiology Section, Department of Radiology (IDI), Vall d'Hebron University Hospital and Research Institute (VHIR), Autonomous University of Barcelona, Barcelona, Spain
| | - Ahmed T Toosy
- Nuclear Magnetic Resonance (NMR) Research Unit, Queen Square Multiple Sclerosis Centre, University College London Institute of Neurology, London, United Kingdom
| | - Anthony Traboulsee
- MS/Magnetic Resonance Imaging (MRI) Research Group, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Burcu Zeydan
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
- Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Brenda L Banwell
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Neurology and Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Maria A Rocca
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Istituto di Ricovero e di Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
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19
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Diffusely appearing white matter in multiple sclerosis: Insights from sodium ( 23Na) MRI. Mult Scler Relat Disord 2021; 49:102752. [PMID: 33486402 DOI: 10.1016/j.msard.2021.102752] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/04/2021] [Accepted: 01/11/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND In multiple sclerosis (MS), magnetic resonance imaging (MRI) frequently shows ill-defined areas with intermediate signal intensity between the normal appearing white matter (NAWM) and focal T2-hyperintense lesions, termed "diffusely appearing white matter" (DAWM). Even though several advanced MRI techniques have shown the potential to detect and quantify subtle commonly not visible microscopic tissue changes, to date only a few advanced MRI studies investigated DAWM changes in a quantitative manner. The aim of this study was to detect and quantify tissue abnormalities in the DAWM in comparison to focal lesions and the NAWM in MS patients by sodium (23Na) MRI. METHODS 23Na and conventional MRI were performed in 25 MS patients with DAWM (DAWM+) and in 25 sex- and age matched MS patients without DAWM (DAWM-), as well as in ten healthy controls (HC). Mean total sodium concentrations (TSC) were quantified in the DAWM, NAWM, normal appearing grey matter (NAGM) and in focal MS lesions. RESULTS In MS DAWM+and DAWM-, TSC values were increased in the NAGM (DAWM+: 44.61 ± 4.09 mM; DAWM-: 45.37 ± 3.8 mM) and in the NAWM (DAWM+: 39.85 ± 3.89 mM; DAWM-: 39.82 ± 4.25 mM) compared to normal grey and white matter in HC (GM 40.87 ± 3.25 mM, WM 35.9 ± 1.81 mM; p < 0.05 for all comparisons). Interestingly, the DAWM showed similar sodium concentrations (39.32 ± 4.59 mM) to the NAWM (39.85 ± 3.89 mM), whereas TSC values in T1 hypointense (46.53 ± 7.87 mM) and T1 isointense (41.99 ± 6.10 mM) lesions were significantly higher than in the DAWM (p < 0.001 and 0.017 respectively). CONCLUSION 23Na MRI is confirmed as a sensitive marker of even subtle tissue abnormalities. DAWM sodium levels are increased and comparable to the abnormalities in NAWM, suggesting pathological changes less severe than in focal lesions comparable to what is expected in the NAWM.
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20
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Mancini M, Karakuzu A, Cohen-Adad J, Cercignani M, Nichols TE, Stikov N. An interactive meta-analysis of MRI biomarkers of myelin. eLife 2020; 9:e61523. [PMID: 33084576 PMCID: PMC7647401 DOI: 10.7554/elife.61523] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022] Open
Abstract
Several MRI measures have been proposed as in vivo biomarkers of myelin, each with applications ranging from plasticity to pathology. Despite the availability of these myelin-sensitive modalities, specificity and sensitivity have been a matter of discussion. Debate about which MRI measure is the most suitable for quantifying myelin is still ongoing. In this study, we performed a systematic review of published quantitative validation studies to clarify how different these measures are when compared to the underlying histology. We analyzed the results from 43 studies applying meta-analysis tools, controlling for study sample size and using interactive visualization (https://neurolibre.github.io/myelin-meta-analysis). We report the overall estimates and the prediction intervals for the coefficient of determination and find that MT and relaxometry-based measures exhibit the highest correlations with myelin content. We also show which measures are, and which measures are not statistically different regarding their relationship with histology.
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Affiliation(s)
- Matteo Mancini
- Department of Neuroscience, Brighton and Sussex Medical School, University of SussexBrightonUnited Kingdom
- NeuroPoly Lab, Polytechnique MontrealMontrealCanada
- CUBRIC, Cardiff UniversityCardiffUnited Kingdom
| | | | - Julien Cohen-Adad
- NeuroPoly Lab, Polytechnique MontrealMontrealCanada
- Functional Neuroimaging Unit, CRIUGM, Université de MontréalMontrealCanada
| | - Mara Cercignani
- Department of Neuroscience, Brighton and Sussex Medical School, University of SussexBrightonUnited Kingdom
- Neuroimaging Laboratory, Fondazione Santa LuciaRomeItaly
| | - Thomas E Nichols
- Wellcome Centre for Integrative Neuroimaging (WIN FMRIB), University of OxfordOxfordUnited Kingdom
- Big Data Institute, University of OxfordOxfordUnited Kingdom
| | - Nikola Stikov
- NeuroPoly Lab, Polytechnique MontrealMontrealCanada
- Montreal Heart Institute, Université de MontréalMontrealCanada
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21
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Ma YJ, Searleman AC, Jang H, Fan SJ, Wong J, Xue Y, Cai Z, Chang EY, Corey-Bloom J, Du J. Volumetric imaging of myelin in vivo using 3D inversion recovery-prepared ultrashort echo time cones magnetic resonance imaging. NMR IN BIOMEDICINE 2020; 33:e4326. [PMID: 32691472 PMCID: PMC7952008 DOI: 10.1002/nbm.4326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/19/2020] [Accepted: 05/02/2020] [Indexed: 05/28/2023]
Abstract
Direct myelin imaging is promising for characterization of multiple sclerosis (MS) brains at diagnosis and in response to therapy. In this study, a 3D inversion recovery-prepared ultrashort echo time cones (IR-UTE-Cones) sequence was used for both morphological and quantitative imaging of myelin on a clinical 3 T scanner. Myelin powder phantoms with different myelin concentrations were imaged with the 3D UTE-Cones sequence and it showed a strong correlation between concentrations and UTE-Cones signals, demonstrating the ability of the UTE-Cones sequence to directly image myelin in the brain. Quantitative myelin imaging with multi-echo IR-UTE-Cones sequences show similar T2 * values for a D2 O-exchanged myelin phantom (T2 * = 0.33 ± 0.04 ms), ex vivo brain specimens (T2 * = 0.20 ± 0.04 ms) and in vivo healthy volunteers (T2 * = 0.254 ± 0.023 ms), further confirming the feasibility of 3D IR-UTE-Cones sequences for direct myelin imaging in vivo. In ex vivo MS brain study, signal loss is observed in MS lesions, which was confirmed with histology. For the in vivo study, the lesions in MS patients also show myelin signal loss using the proposed direct myelin imaging method, demonstrating the clinical potential for MS diagnosis. Furthermore, the measured IR-UTE-Cones signal intensities show a significant difference between normal-appearing white matter in MS patients and normal white matter in volunteers, which cannot be found in clinical used T2 -FLAIR sequences. Thus, the proposed 3D IR-UTE-Cones sequence showed clinical potential for MS diagnosis with the capability of direct myelin detection of the whole brain.
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Affiliation(s)
- Ya-Jun Ma
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - Adam C. Searleman
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - Hyungseok Jang
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - Shu-Juan Fan
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - Jonathan Wong
- Department of Radiology, University of California San Diego, San Diego, CA, USA
- Radiology Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Yanping Xue
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - Zhenyu Cai
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - Eric Y. Chang
- Department of Radiology, University of California San Diego, San Diego, CA, USA
- Radiology Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Jody Corey-Bloom
- Department of Neurosciences, University of California San Diego, San Diego, CA, USA
| | - Jiang Du
- Department of Radiology, University of California San Diego, San Diego, CA, USA
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22
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Maranzano J, Dadar M, Bertrand-Grenier A, Frigon EM, Pellerin J, Plante S, Duchesne S, Tardif CL, Boire D, Bronchti G. A novel ex vivo, in situ method to study the human brain through MRI and histology. J Neurosci Methods 2020; 345:108903. [PMID: 32777310 DOI: 10.1016/j.jneumeth.2020.108903] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND MRI-histology correlation studies of the ex vivo brain mostly employ fresh, extracted (ex situ) specimens, aldehyde fixed by immersion, which has several disadvantages for MRI scanning (e.g. deformation of the organ). A minority of studies are done ex vivo-in situ (unfixed brain), requiring an MRI scanner readily available within a few hours of the time of death. NEW METHOD We propose a new technique, exploited by anatomists, for scanning the ex vivo brain: fixation by whole body perfusion, which implies fixation of the brain in situ. This allows scanning the brain surrounded by fluids, meninges, and skull, preserving the structural relationships of the brain in vivo. To evaluate the proposed method, five heads perfused-fixed with a saturated sodium chloride solution were employed. Three sequences were acquired on a 1.5 T MRI scanner: T1weighted, T2weighted-FLAIR, and Gradient-echo. Histology analysis included immunofluorescence for myelin basic protein and neuronal nuclei. RESULTS All MRIs were successfully processed through a validated pipeline used with in vivo MRIs. All cases exhibited positive antigenicity for myelin and neuronal nuclei. COMPARISON WITH EXISTING METHODS All scans registered to a standard neuroanatomical template in pseudo-Talairach space more accurately than an ex vivo-ex situ scan. The time interval to scan the ex vivo brain in situ was increased to at least 10 months. CONCLUSIONS MRI and histology study of the ex vivo-in situ brain fixed by perfusion is an alternative approach that has important procedural and practical advantages over the two standard methods to study the ex vivo brain.
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Affiliation(s)
- Josefina Maranzano
- Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, Québec, Canada(2); McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada.
| | - Mahsa Dadar
- Department of Biomedical Engineering, McGill University, Montréal, Québec, Canada; Department of Radiology and Nuclear Medicine, Faculty of Medicine, Université Laval, Québec, Québec, Canada
| | - Antony Bertrand-Grenier
- Department of Chemistry, Biochemistry and Physics, UQTR, Trois-Rivières, Québec, Canada; Centre intégré universitaire de santé et de services sociaux de la Mauricie-et-du-Centre-du-Québec (CIUSSS MCQ), Canada
| | - Eve-Marie Frigon
- Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, Québec, Canada(2)
| | - Johanne Pellerin
- Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, Québec, Canada(2)
| | - Sophie Plante
- Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, Québec, Canada(2)
| | - Simon Duchesne
- Department of Radiology and Nuclear Medicine, Faculty of Medicine, Université Laval, Québec, Québec, Canada; CERVO Brain Research Center, Québec, Québec, Canada
| | - Christine L Tardif
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montréal, Québec, Canada; Department of Biomedical Engineering, McGill University, Montréal, Québec, Canada
| | - Denis Boire
- Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, Québec, Canada(2)
| | - Gilles Bronchti
- Department of Anatomy, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, Québec, Canada(2)
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23
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Dadar M, Narayanan S, Arnold DL, Collins DL, Maranzano J. Conversion of diffusely abnormal white matter to focal lesions is linked to progression in secondary progressive multiple sclerosis. Mult Scler 2020; 27:208-219. [DOI: 10.1177/1352458520912172] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Background: Diffusely abnormal white matter (DAWM) regions are observed in magnetic resonance images of secondary progressive multiple sclerosis (SPMS) patients. However, their role in clinical progression is still not established. Objectives: To characterize the longitudinal volumetric and intensity evolution of DAWM and focal white matter lesions (FWML) and assess their associations with clinical outcomes and progression in SPMS. Methods: Data include 589 SPMS participants followed up for 3 years (3951 time points). FWML and DAWM were automatically segmented. Screening DAWM volumes that transformed into FWML at the last visit (DAWM-to-FWML) and normalized T1-weighted intensities (indicating severity of damage) in those voxels were calculated. Results: FWML volume increased and DAWM volume decreased with an increase in disease duration ( p < 0.001). The Expanded Disability Status Scale (EDSS) was positively associated with FWML volumes ( p = 0.002), but not with DAWM. DAWM-to-FWML volume was higher in patients who progressed (2.75 cm3 vs. 1.70 cm3; p < 0.0001). Normalized T1-weighted intensity of DAWM-to-FWML was negatively associated with progression ( p < 0.00001). Conclusion: DAWM transformed into FWML over time, and this transformation was associated with clinical progression. DAWM-to-FWML voxels had greater normalized T1-weighted intensity decrease over time, in keeping with relatively greater tissue damage. Evaluation of DAWM in progressive multiple sclerosis provides a useful measure for therapies aiming to protect this at-risk tissue with the potential to slow progression.
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Affiliation(s)
- Mahsa Dadar
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada/Department of Biomedical Engineering, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Sridar Narayanan
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Douglas L Arnold
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - D Louis Collins
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada/Department of Biomedical Engineering, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Josefina Maranzano
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada/Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, QC, Canada
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24
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Maranzano J, Dadar M, Zhernovaia M, Arnold DL, Collins DL, Narayanan S. Automated separation of diffusely abnormal white matter from focal white matter lesions on MRI in multiple sclerosis. Neuroimage 2020; 213:116690. [PMID: 32119987 DOI: 10.1016/j.neuroimage.2020.116690] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/21/2020] [Accepted: 02/26/2020] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Previous histopathology and MRI studies have addressed the differences between focal white matter lesions (FWML) and diffusely abnormal white matter (DAWM) in multiple sclerosis (MS). These two categories of white matter T2-weighted (T2w) hyperintensity show different degrees of demyelination, axonal loss and immune cell density on histopathology, potentially offering distinct correlations with symptoms. OBJECTIVES 1) To automate the separation of FWML and DAWM using T2w MRI intensity thresholds and to investigate their differences in magnetization transfer ratios (MTR), which are sensitive to myelin content; 2) to correlate MTR values in FWML and DAWM with normalized signal intensity values on fluid attenuated inversion recovery (FLAIR), T2w, and T1-weighted (T1w) contrasts, as well as with the ratio of T2w/T1w normalized values, in order to determine whether these normalized intensities can be used when MTR is not available. METHODS We used three MRI datasets: datasets 1 and 2 had 20 MS participants each, scanned with similar 3T MRI protocols in 2 centers, including: 3D T1w (MP2RAGE), 3D FLAIR, 2D T2w, and 3D magnetization-transfer (MT) contrasts. Dataset 3 consisted of 67 scans of participants enrolled in a multisite study and had T1w and T2w contrasts. We used the first dataset to develop an automated technique to separate FWML from DAWM and the second and third to validate the automation of the technique. We applied the automatic thresholds to all datasets to assess the overlap of the manual and the automated masks using Dice kappa. We also assessed differences in mean MTR values between NAWM, DAWM and FWML, using manually and automatically derived masks in datasets 1 and 2. Finally, we used the mean intensity of manually-traced areas of NAWM on T2w images as the normalization factor for each MRI contrast, and compared these with the normalized-intensity values obtained using automated NAWM (A-NAWM) masks as the normalization factor. ANOVA assessed the MTR differences across tissue types. Paired t-test or Wilcoxon signed-ranked test assessed FWML and DAWM differences between manual and automatically derived volumes. Pearson correlations assessed the relationship between MTR and normalized intensity values in the manual and automatically derived masks. RESULTS The mean Dice-kappa values for dataset 1 were: 0.79 for DAWM masks and 0.90 for FWML masks. In dataset 2, mean Dice-kappa values were: 0.78 for DAWM and 0.87 for FWML. In dataset 3, mean Dice-kappa values were 0.72 for DAWM, and 0.87 for FWML. Manual and automated DAWM and FWML volumes were not significantly different in all datasets. MTR values were significantly lower in manually and automatically derived FWML compared with DAWM in both datasets (dataset 1 manual: F = 111,08, p < 0.0001; automated: F = 153.90, p < 0.0001; dataset 2 manual: F = 31.25, p < 0.0001; automated: F = 74.04, p < 0.0001). In both datasets, manually derived FWML and DAWM MTR values showed significant correlations with normalized T1w (r = 0.77 to 0.94) intensities. CONCLUSIONS The separation of FWML and DAWM on MRI scans of MS patients using automated intensity thresholds on T2w images is feasible. MTR values are significantly lower in FWML than DAWM, and DAWM values are significantly lower than NAWM, reflecting potentially greater demyelination within focal lesions. T1w normalized intensity values exhibit a significant correlation with MTR values in both tissues of interest and could be used as a proxy to assess demyelination when MTR or other myelin-sensitive images are not available.
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Affiliation(s)
- Josefina Maranzano
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, Quebec, Canada; McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
| | - Mahsa Dadar
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Maryna Zhernovaia
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, Quebec, Canada
| | - Douglas L Arnold
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - D Louis Collins
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Sridar Narayanan
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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25
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Dvorak AV, Wiggermann V, Gilbert G, Vavasour IM, MacMillan EL, Barlow L, Wiley N, Kozlowski P, MacKay AL, Rauscher A, Kolind SH. Multi-spin echo T 2 relaxation imaging with compressed sensing (METRICS) for rapid myelin water imaging. Magn Reson Med 2020; 84:1264-1279. [PMID: 32065474 DOI: 10.1002/mrm.28199] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/20/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE Myelin water imaging (MWI) provides a valuable biomarker for myelin, but clinical application has been restricted by long acquisition times. Accelerating the standard multi-echo T2 acquisition with gradient echoes (GRASE) or by 2D multi-slice data collection results in image blurring, contrast changes, and other issues. Compressed sensing (CS) can vastly accelerate conventional MRI. In this work, we assessed the use of CS for in vivo human MWI, using a 3D multi spin-echo sequence. METHODS We implemented multi-echo T2 relaxation imaging with compressed sensing (METRICS) and METRICS with partial Fourier acceleration (METRICS-PF). Scan-rescan data were acquired from 12 healthy controls for assessment of repeatability. MWI data were acquired for METRICS in 9 m:58 s and for METRICS-PF in 7 m:25 s, both with 1.5 × 2 × 3 mm3 voxels, 56 echoes, 7 ms ΔTE, and 240 × 240 × 170 mm3 FOV. METRICS was compared with a novel multi-echo spin-echo gold-standard (MSE-GS) MWI acquisition, acquired for a single additional subject in 2 h:2 m:40 s. RESULTS METRICS/METRICS-PF myelin water fraction had mean: repeatability coefficient 1.5/1.1, coefficient of variation 6.2/4.5%, and intra-class correlation coefficient 0.79/0.84. Repeatability metrics comparing METRICS with METRICS-PF were similar, and both sequences agreed with reference values from literature. METRICS images and quantitative maps showed excellent qualitative agreement with those of MSE-GS. CONCLUSION METRICS and METRICS-PF provided highly repeatable MWI data without the inherent disadvantages of GRASE or 2D multi-slice acquisition. CS acceleration allows MWI data to be acquired rapidly with larger FOV, higher estimated SNR, more isotropic voxels and more echoes than with previous techniques. The approach introduced here generalizes to any multi-component T2 mapping application.
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Affiliation(s)
- Adam V Dvorak
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vanessa Wiggermann
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Irene M Vavasour
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Erin L MacMillan
- UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,MR Clinical Science, Philips Canada, Markham, Ontario, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Laura Barlow
- UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Neale Wiley
- UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alex L MacKay
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexander Rauscher
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shannon H Kolind
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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26
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Lee J, Hyun JW, Lee J, Choi EJ, Shin HG, Min K, Nam Y, Kim HJ, Oh SH. So You Want to Image Myelin Using MRI: An Overview and Practical Guide for Myelin Water Imaging. J Magn Reson Imaging 2020; 53:360-373. [PMID: 32009271 DOI: 10.1002/jmri.27059] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/01/2020] [Accepted: 01/02/2020] [Indexed: 12/22/2022] Open
Abstract
Myelin water imaging (MWI) is an MRI imaging biomarker for myelin. This method can generate an in vivo whole-brain myelin water fraction map in approximately 10 minutes. It has been applied in various applications including neurodegenerative disease, neurodevelopmental, and neuroplasticity studies. In this review we start with a brief introduction of myelin biology and discuss the contributions of myelin in conventional MRI contrasts. Then the MRI properties of myelin water and four different MWI methods, which are categorized as T2 -, T2 *-, T1 -, and steady-state-based MWI, are summarized. After that, we cover more practical issues such as availability, interpretation, and validation of these methods. To illustrate the utility of MWI as a clinical research tool, MWI studies for two diseases, multiple sclerosis and neuromyelitis optica, are introduced. Additional topics about imaging myelin in gray matter and non-MWI methods for myelin imaging are also included. Although technical and physiological limitations exist, MWI is a potent surrogate biomarker of myelin that carries valuable and useful information of myelin. Evidence Level: 5 Technical Efficacy: 1 J. MAGN. RESON. IMAGING 2021;53:360-373.
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Affiliation(s)
- Jongho Lee
- Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea
| | - Jae-Won Hyun
- Department of Neurology, Research Institute and Hospital, National Cancer Center, Goyang-si, Korea
| | - Jieun Lee
- Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea
| | - Eun-Jung Choi
- Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea
| | - Hyeong-Geol Shin
- Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea
| | - Kyeongseon Min
- Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea
| | - Yoonho Nam
- Department of Radiology, Seoul Saint Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea
| | - Ho Jin Kim
- Department of Neurology, Research Institute and Hospital, National Cancer Center, Goyang-si, Korea
| | - Se-Hong Oh
- Division of Biomedical Engineering, Hankuk University of Foreign Studies, Gyeonggi-do, Korea.,Imaging Institute, Cleveland Clinic, Cleveland, OH, USA
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27
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Liu H, Ljungberg E, Dvorak AV, Lee LE, Yik JT, MacMillan EL, Barlow L, Li DKB, Traboulsee A, Kolind SH, Kramer JLK, Laule C. Myelin Water Fraction and Intra/Extracellular Water Geometric Mean T 2 Normative Atlases for the Cervical Spinal Cord from 3T MRI. J Neuroimaging 2019; 30:50-57. [PMID: 31407400 DOI: 10.1111/jon.12659] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Acquiring and interpreting quantitative myelin-specific MRI data at an individual level is challenging because of technical difficulties and natural myelin variation in the population. To overcome these challenges, we used multiecho T2 myelin water imaging (MWI) to create T2 metric healthy population atlases that depict the mean and variation of myelin water fraction (MWF), and intra- and extracellular water mobility as described by geometric mean T2 (IEGMT2 ). METHODS Cervical cord MWI was performed at 3T on 20 healthy individuals (10M/10F, mean age: 36 years) and 3 relapsing remitting multiple sclerosis (RRMS) participants (1M/2F, age: 39/42/37 years). Anatomical data were collected for the purpose of image segmentation and registration. Atlases were created by coregistering and averaging T2 metrics from all controls. Voxel-wise z-score maps from 3 RRMS participants were produced to demonstrate the preliminary utility of the MWF and IEGMT2 atlases. RESULTS The average MWF atlas provides a representation of myelin in the spinal cord consistent with well-known spinal cord anatomical characteristics. The IEGMT2 atlas also depicted structural variations in the spinal cord. Z-score analysis illustrated distinct abnormalities in MWF and IEGMT2 in the 3 RRMS cases. CONCLUSIONS Our findings highlight the potential for using a quantitative T2 relaxation metric atlas to visualize and detect pathology in spinal cord. Our MWF and IEGMT2 atlases (URL: https://sourceforge.net/projects/mwi-spinal-cord-atlases/) can serve as normative references in the cervical spinal cord for other studies.
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Affiliation(s)
- Hanwen Liu
- Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Emil Ljungberg
- Department of Neuroimaging, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK
| | - Adam V Dvorak
- Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Lisa Eunyoung Lee
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Jackie T Yik
- Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Erin L MacMillan
- Philips, Markham, Canada.,School of Mechatronic Systems Engineering, Simon Fraser University, Canada.,Department of Radiology, University of British Columbia, Vancouver, Canada
| | | | - David K B Li
- Department of Medicine, University of British Columbia, Vancouver, Canada.,Department of Radiology, University of British Columbia, Vancouver, Canada
| | - Anthony Traboulsee
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Shannon H Kolind
- Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Department of Medicine, University of British Columbia, Vancouver, Canada.,Department of Radiology, University of British Columbia, Vancouver, Canada
| | - John L K Kramer
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,School of Kinesiology, University of British Columbia, Vancouver, Canada
| | - Cornelia Laule
- Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Department of Radiology, University of British Columbia, Vancouver, Canada.,Pathology & Laboratory Medicine, University of British Columbia, Vancouver, Canada
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28
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Lassmann H. Pathogenic Mechanisms Associated With Different Clinical Courses of Multiple Sclerosis. Front Immunol 2019; 9:3116. [PMID: 30687321 PMCID: PMC6335289 DOI: 10.3389/fimmu.2018.03116] [Citation(s) in RCA: 364] [Impact Index Per Article: 72.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/17/2018] [Indexed: 01/02/2023] Open
Abstract
In the majority of patients multiple sclerosis starts with a relapsing remitting course (RRMS), which may at later times transform into secondary progressive disease (SPMS). In a minority of patients the relapsing remitting disease is skipped and the patients show progression from the onset (primary progressive MS, PPMS). Evidence obtained so far indicate major differences between RRMS and progressive MS, but no essential differences between SPMS and PPMS, with the exception of a lower incidence in the global load of focal white matter lesions and in particular in the presence of classical active plaques in PPMS. We suggest that in MS patients two types of inflammation occur, which develop in parallel but partially independent from each other. The first is the focal bulk invasion of T- and B-lymphocytes with profound blood brain barrier leakage, which predominately affects the white matter, and which gives rise to classical active demyelinated plaques. The other type of inflammation is a slow accumulation of T-cells and B-cells in the absence of major blood brain barrier damage in the connective tissue spaces of the brain, such as the meninges and the large perivascular Virchow Robin spaces, where they may form aggregates or in most severe cases structures in part resembling tertiary lymph follicles. This type of inflammation is associated with the formation of subpial demyelinated lesions in the cerebral and cerebellar cortex, with slow expansion of pre-existing lesions in the white matter and with diffuse neurodegeneration in the normal appearing white or gray matter. The first type of inflammation dominates in acute and relapsing MS. The second type of inflammation is already present in early stages of MS, but gradually increases with disease duration and patient age. It is suggested that CD8+ T-lymphocytes remain in the brain and spinal cord as tissue resident cells, which may focally propagate neuroinflammation, when they re-encounter their cognate antigen. B-lymphocytes may propagate demyelination and neurodegeneration, most likely by producing soluble neurotoxic factors. Whether lymphocytes within the brain tissue of MS lesions have also regulatory functions is presently unknown. Key open questions in MS research are the identification of the target antigen recognized by tissue resident CD8+ T-cells and B-cells and the molecular nature of the soluble inflammatory mediators, which may trigger tissue damage.
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Affiliation(s)
- Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
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29
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Vertinsky AT, Li DK, Vavasour IM, Miropolsky V, Zhao G, Zhao Y, Riddehough A, Moore GW, Traboulsee A, Laule C. Diffusely Abnormal White Matter, T2
Burden of Disease, and Brain Volume in Relapsing-Remitting Multiple Sclerosis. J Neuroimaging 2018; 29:151-159. [DOI: 10.1111/jon.12574] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/09/2018] [Indexed: 11/27/2022] Open
Affiliation(s)
- Alexandra T. Vertinsky
- Department of Radiology; University of British Columbia; Vancouver British Columbia Canada
| | - David K.B. Li
- Department of Radiology; University of British Columbia; Vancouver British Columbia Canada
- UBC MS/MRI Research Group; University of British Columbia; Vancouver British Columbia Canada
- Department of Medicine (Neurology); University of British Columbia; Vancouver British Columbia Canada
| | - Irene M. Vavasour
- Department of Radiology; University of British Columbia; Vancouver British Columbia Canada
| | - Vladislav Miropolsky
- Department of Radiology; University of British Columbia; Vancouver British Columbia Canada
| | - Guojun Zhao
- Department of Radiology; University of British Columbia; Vancouver British Columbia Canada
- UBC MS/MRI Research Group; University of British Columbia; Vancouver British Columbia Canada
| | - Yinshan Zhao
- Department of Medicine (Neurology); University of British Columbia; Vancouver British Columbia Canada
| | - Andrew Riddehough
- UBC MS/MRI Research Group; University of British Columbia; Vancouver British Columbia Canada
| | - G.R. Wayne Moore
- Department of Medicine (Neurology); University of British Columbia; Vancouver British Columbia Canada
- Department of Pathology and Laboratory Medicine; University of British Columbia; Vancouver British Columbia Canada
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; Vancouver British Columbia Canada
| | - Anthony Traboulsee
- UBC MS/MRI Research Group; University of British Columbia; Vancouver British Columbia Canada
- Department of Medicine (Neurology); University of British Columbia; Vancouver British Columbia Canada
| | - Cornelia Laule
- Department of Radiology; University of British Columbia; Vancouver British Columbia Canada
- Department of Pathology and Laboratory Medicine; University of British Columbia; Vancouver British Columbia Canada
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; Vancouver British Columbia Canada
- Department of Physics and Astronomy; University of British Columbia; Vancouver British Columbia Canada
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30
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Laule C, Moore GW. Myelin water imaging to detect demyelination and remyelination and its validation in pathology. Brain Pathol 2018; 28:750-764. [PMID: 30375119 PMCID: PMC8028667 DOI: 10.1111/bpa.12645] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 07/09/2018] [Indexed: 12/11/2022] Open
Abstract
Damage to myelin is a key feature of multiple sclerosis (MS) pathology. Magnetic resonance imaging (MRI) has revolutionized our ability to detect and monitor MS pathology in vivo. Proton density, T1 and T2 can provide qualitative contrast weightings that yield superb in vivo visualization of central nervous system tissue and have proved invaluable as diagnostic and patient management tools in MS. However, standard clinical MR methods are not specific to the types of tissue damage they visualize, and they cannot detect subtle abnormalities in tissue that appears otherwise normal on conventional MRIs. Myelin water imaging is an MR method that provides in vivo measurement of myelin. Histological validation work in both human brain and spinal cord tissue demonstrates a strong correlation between myelin water and staining for myelin, validating myelin water as a marker for myelin. Myelin water varies throughout the brain and spinal cord in healthy controls, and shows good intra- and inter-site reproducibility. MS plaques show variably decreased myelin water fraction, with older lesions demonstrating the greatest myelin loss. Longitudinal study of myelin water can provide insights into the dynamics of demyelination and remyelination in plaques. Normal appearing brain and spinal cord tissues show reduced myelin water, an abnormality which becomes progressively more evident over a timescale of years. Diffusely abnormal white matter, which is evident in 20%-25% of MS patients, also shows reduced myelin water both in vivo and postmortem, and appears to originate from a primary lipid abnormality with relative preservation of myelin proteins. Active research is ongoing in the quest to refine our ability to image myelin and its perturbations in MS and other disorders of the myelin sheath.
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Affiliation(s)
- Cornelia Laule
- RadiologyUniversity of British ColumbiaVancouverBCCanada
- Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Physics & AstronomyUniversity of British ColumbiaVancouverBCCanada
- International Collaboration on Repair Discoveries (ICORD)University of British ColumbiaVancouverBCCanada
| | - G.R. Wayne Moore
- Pathology & Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- International Collaboration on Repair Discoveries (ICORD)University of British ColumbiaVancouverBCCanada
- Medicine (Neurology)University of British ColumbiaVancouverBCCanada
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31
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Mainero C, Louapre C. Unraveling cortical pathology in multiple sclerosis using the T1-/T2-weighted ratio? Ann Neurol 2017; 82:516-518. [PMID: 28976603 DOI: 10.1002/ana.25063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 09/29/2017] [Accepted: 10/02/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Caterina Mainero
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA.,Harvard Medical School, Cambridge, MA
| | - Céline Louapre
- UPMC University Paris 06, UMR S 1127, and CNRS UMR 7225, and ICM, Paris, France.,APHP, Hôpital Pitié-Salpêtriere, Neurology Department, Paris, France
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32
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Warntjes JBM, Persson A, Berge J, Zech W. Myelin Detection Using Rapid Quantitative MR Imaging Correlated to Macroscopically Registered Luxol Fast Blue-Stained Brain Specimens. AJNR Am J Neuroradiol 2017; 38:1096-1102. [PMID: 28428209 DOI: 10.3174/ajnr.a5168] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/03/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Myelin detection is of great value in monitoring diseases such as multiple sclerosis and dementia. However, most MR imaging methods to measure myelin are challenging for routine clinical use. Recently, a novel method was published, in which the presence of myelin is inferred by using its effect on the intra- and extracellular water relaxation rates and proton density, observable by rapid quantitative MR imaging. The purpose of this work was to validate this method further on the brains of 12 fresh, intact cadavers. MATERIALS AND METHODS The 12 brains were scanned with a quantification sequence to determine the longitudinal and transverse relaxation rates and proton density as input for the myelin estimations. Subsequently, the brains were excised at postmortem examination, and brain slices were stained with Luxol fast blue to verify the presence of myelin. The optical density values of photographs of the stained brain slices were registered with the MR images and correlated with the myelin estimation performed by quantitative MR imaging. RESULTS A correlation was found between the 2 methods with a mean Spearman ρ for all subjects of 0.74 ± 0.11. Linear regression showed a mean intercept of 1.50% ± 2.84% and a mean slope of 4.37% ± 1.73%/%. A lower correlation was found for the separate longitudinal relaxation rates and proton density (ρ = 0.63 ± 0.12 and -0.73 ± 0.09, respectively). For transverse relaxation rates, the ρ was very low (0.11 ± 0.28). CONCLUSIONS The observed correlation supports the validity of myelin measurement by using the MR imaging quantification method.
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Affiliation(s)
- J B M Warntjes
- From the Center for Medical Image Science and Visualization (J.B.M.W., A.P., W.Z.)
- Division of Cardiovascular Medicine, Department of Medical and Health Sciences (J.B.M.W.), Linköping University, Linköping, Sweden
- SyntheticMR AB (J.B.M.W.), Linköping, Sweden
| | - A Persson
- From the Center for Medical Image Science and Visualization (J.B.M.W., A.P., W.Z.)
| | - J Berge
- Institute of Forensic Medicine (J.B., W.Z.), Linköping, Sweden
| | - W Zech
- From the Center for Medical Image Science and Visualization (J.B.M.W., A.P., W.Z.)
- Institute of Forensic Medicine (J.B., W.Z.), Linköping, Sweden
- Institute of Forensic Medicine (W.Z.), University of Bern, Bern, Switzerland
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33
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Dayan M, Hurtado Rúa SM, Monohan E, Fujimoto K, Pandya S, LoCastro EM, Vartanian T, Nguyen TD, Raj A, Gauthier SA. MRI Analysis of White Matter Myelin Water Content in Multiple Sclerosis: A Novel Approach Applied to Finding Correlates of Cortical Thinning. Front Neurosci 2017; 11:284. [PMID: 28603479 PMCID: PMC5445177 DOI: 10.3389/fnins.2017.00284] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 05/02/2017] [Indexed: 12/13/2022] Open
Abstract
A novel lesion-mask free method based on a gamma mixture model was applied to myelin water fraction (MWF) maps to estimate the association between cortical thickness and myelin content, and how it differs between relapsing-remitting (RRMS) and secondary-progressive multiple sclerosis (SPMS) groups (135 and 23 patients, respectively). It was compared to an approach based on lesion masks. The gamma mixture distribution of whole brain, white matter (WM) MWF was characterized with three variables: the mode (most frequent value) m1 of the gamma component shown to relate to lesion, the mode m2 of the component shown to be associated with normal appearing (NA) WM, and the mixing ratio (λ) between the two distributions. The lesion-mask approach relied on the mean MWF within lesion and within NAWM. A multivariate regression analysis was carried out to find the best predictors of cortical thickness for each group and for each approach. The gamma-mixture method was shown to outperform the lesion-mask approach in terms of adjusted R2, both for the RRMS and SPMS groups. The predictors of the final gamma-mixture models were found to be m1 (β = 1.56, p < 0.005), λ (β = −0.30, p < 0.0005) and age (β = −0.0031, p < 0.005) for the RRMS group (adjusted R2 = 0.16), and m2 (β = 4.72, p < 0.0005) for the SPMS group (adjusted R2 = 0.45). Further, a DICE coefficient analysis demonstrated that the lesion mask had more overlap to an ROI associated with m1, than to an ROI associated with m2 (p < 0.00001), and vice versa for the NAWM mask (p < 0.00001). These results suggest that during the relapsing phase, focal WM damage is associated with cortical thinning, yet in SPMS patients, global WM deterioration has a much stronger influence on secondary degeneration. Through these findings, we demonstrate the potential contribution of myelin loss on neuronal degeneration at different disease stages and the usefulness of our statistical reduction technique which is not affected by the typical bias associated with approaches based on lesion masks.
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Affiliation(s)
- Michael Dayan
- Department of Radiology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States.,Pattern Analysis and Computer Vision, Istituto Italiano di TecnologiaGenova, Italy
| | - Sandra M Hurtado Rúa
- Department of Mathematics, Cleveland State UniversityCleveland, OH, United States
| | - Elizabeth Monohan
- Department of Neurology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Kyoko Fujimoto
- Department of Neurology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Sneha Pandya
- Department of Radiology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Eve M LoCastro
- Department of Radiology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Tim Vartanian
- Department of Neurology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States.,Brain and Mind Institute, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Thanh D Nguyen
- Department of Radiology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Ashish Raj
- Department of Radiology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
| | - Susan A Gauthier
- Department of Neurology, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States.,Brain and Mind Institute, Weill Cornell Graduate School of Medical SciencesNew York, NY, United States
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34
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New rapid, accurate T 2 quantification detects pathology in normal-appearing brain regions of relapsing-remitting MS patients. NEUROIMAGE-CLINICAL 2017; 14:363-370. [PMID: 28239545 PMCID: PMC5318543 DOI: 10.1016/j.nicl.2017.01.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/18/2017] [Accepted: 01/25/2017] [Indexed: 01/22/2023]
Abstract
Introduction Quantitative T2 mapping may provide an objective biomarker for occult nervous tissue pathology in relapsing-remitting multiple sclerosis (RRMS). We applied a novel echo modulation curve (EMC) algorithm to identify T2 changes in normal-appearing brain regions of subjects with RRMS (N = 27) compared to age-matched controls (N = 38). Methods The EMC algorithm uses Bloch simulations to model T2 decay curves in multi-spin-echo MRI sequences, independent of scanner, and scan-settings. T2 values were extracted from normal-appearing white and gray matter brain regions using both expert manual regions-of-interest and user-independent FreeSurfer segmentation. Results Compared to conventional exponential T2 modeling, EMC fitting provided more accurate estimations of T2 with less variance across scans, MRI systems, and healthy individuals. Thalamic T2 was increased 8.5% in RRMS subjects (p < 0.001) and could be used to discriminate RRMS from healthy controls well (AUC = 0.913). Manual segmentation detected both statistically significant increases (corpus callosum & temporal stem) and decreases (posterior limb internal capsule) in T2 associated with RRMS diagnosis (all p < 0.05). In healthy controls, we also observed statistically significant T2 differences for different white and gray matter structures. Conclusions The EMC algorithm precisely characterizes T2 values, and is able to detect subtle T2 changes in normal-appearing brain regions of RRMS patients. These presumably capture both axon and myelin changes from inflammation and neurodegeneration. Further, T2 variations between different brain regions of healthy controls may correlate with distinct nervous tissue environments that differ from one another at a mesoscopic length-scale. EMC technique provides accurate and scanner-invariant T2 mapping in MS subjects. Thalamus T2 differences distinguish relapsing-remitting MS subjects from controls. Normal-appearing brain regions demonstrate T2 changes in MS patients compared to controls. T2 values reflect anatomic and function-specific differences in healthy controls.
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Key Words
- AUC, area under the curve
- B1 +, transmit field
- Biomarkers
- Demyelination
- EMC, echo modulation curve
- FLAIR, fluid-attenuated inversion recovery
- GM, gray matter
- MPRAGE, magnetization-prepared rapid gradient-echo
- MSE, multi-spin echo
- MWF, myelin water fraction
- Mesoscopic
- Neurodegeneration
- ROI, Region of Interest
- RRMS, relapsing-remitting multiple sclerosis
- Relaxation
- SPACE, sampling perfection with application-optimized contrasts using different flip angle evolution
- SSE, single spin echo
- WM, white matter
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35
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Abstract
Myelin is critical for healthy brain function. An accurate in vivo measure of myelin content has important implications for understanding brain plasticity and neurodegenerative diseases. Myelin water imaging is a magnetic resonance imaging method which can be used to visualize myelination in the brain and spinal cord in vivo. This review presents an overview of myelin water imaging data acquisition and analysis, post-mortem validation work, findings in both animal and human studies and a brief discussion about other MR techniques purported to provide in vivo myelin content. Multi-echo T2 relaxation approaches continue to undergo development and whole-brain imaging time now takes less than 10 minutes; the standard analysis method for this type of data acquisition is a non-negative least squares approach. Alternate methods including the multi-flip angle gradient echo mcDESPOT are also being used for myelin water imaging. Histological validation studies in animal and human brain and spinal cord tissue demonstrate high specificity of myelin water imaging for myelin. Potential confounding factors for in vivo myelin water fraction measurement include the presence of myelin debris and magnetization exchange processes. Myelin water imaging has successfully been used to study animal models of injury, applied in healthy human controls and can be used to assess damage and injury in conditions such as multiple sclerosis, neuromyelitis optica, schizophrenia, phenylketonuria, neurofibromatosis, niemann pick’s disease, stroke and concussion. Other quantitative magnetic resonance approaches that are sensitive to, but not specific for, myelin exist including magnetization transfer, diffusion tensor imaging and T1 weighted imaging.
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Affiliation(s)
- Alex L MacKay
- Department of Radiology, University of British Columbia, Vancouver, Canada.,Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
| | - Cornelia Laule
- Department of Radiology, University of British Columbia, Vancouver, Canada.,Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
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De Leener B, Lévy S, Dupont SM, Fonov VS, Stikov N, Louis Collins D, Callot V, Cohen-Adad J. SCT: Spinal Cord Toolbox, an open-source software for processing spinal cord MRI data. Neuroimage 2016; 145:24-43. [PMID: 27720818 DOI: 10.1016/j.neuroimage.2016.10.009] [Citation(s) in RCA: 338] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 10/03/2016] [Accepted: 10/04/2016] [Indexed: 11/17/2022] Open
Abstract
For the past 25 years, the field of neuroimaging has witnessed the development of several software packages for processing multi-parametric magnetic resonance imaging (mpMRI) to study the brain. These software packages are now routinely used by researchers and clinicians, and have contributed to important breakthroughs for the understanding of brain anatomy and function. However, no software package exists to process mpMRI data of the spinal cord. Despite the numerous clinical needs for such advanced mpMRI protocols (multiple sclerosis, spinal cord injury, cervical spondylotic myelopathy, etc.), researchers have been developing specific tools that, while necessary, do not provide an integrative framework that is compatible with most usages and that is capable of reaching the community at large. This hinders cross-validation and the possibility to perform multi-center studies. In this study we introduce the Spinal Cord Toolbox (SCT), a comprehensive software dedicated to the processing of spinal cord MRI data. SCT builds on previously-validated methods and includes state-of-the-art MRI templates and atlases of the spinal cord, algorithms to segment and register new data to the templates, and motion correction methods for diffusion and functional time series. SCT is tailored towards standardization and automation of the processing pipeline, versatility, modularity, and it follows guidelines of software development and distribution. Preliminary applications of SCT cover a variety of studies, from cross-sectional area measures in large databases of patients, to the precise quantification of mpMRI metrics in specific spinal pathways. We anticipate that SCT will bring together the spinal cord neuroimaging community by establishing standard templates and analysis procedures.
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Affiliation(s)
- Benjamin De Leener
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Simon Lévy
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada
| | - Sara M Dupont
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Vladimir S Fonov
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Nikola Stikov
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Montreal Heart Institute, Montreal, QC, Canada
| | - D Louis Collins
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Virginie Callot
- Aix-Marseille Université, CNRS, CRMBM UMR 7339, Marseille, France; AP-HM, Hopital de la Timone, Pôle d'imagerie médicale, CEMEREM, Marseille, France
| | - Julien Cohen-Adad
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada.
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37
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Turcotte R, Rutledge DJ, Bélanger E, Dill D, Macklin WB, Côté DC. Intravital assessment of myelin molecular order with polarimetric multiphoton microscopy. Sci Rep 2016; 6:31685. [PMID: 27538357 PMCID: PMC4990840 DOI: 10.1038/srep31685] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 07/25/2016] [Indexed: 11/22/2022] Open
Abstract
Myelin plays an essential role in the nervous system and its disruption in diseases such as multiple sclerosis may lead to neuronal death, thus causing irreversible functional impairments. Understanding myelin biology is therefore of fundamental and clinical importance, but no tools currently exist to describe the fine spatial organization of myelin sheaths in vivo. Here we demonstrate intravital quantification of the myelin molecular structure using a microscopy method based on polarization-resolved coherent Raman scattering. Developmental myelination was imaged noninvasively in live zebrafish. Longitudinal imaging of individual axons revealed changes in myelin organization beyond the diffraction limit. Applied to promyelination drug screening, the method uniquely enabled the identification of focal myelin regions with differential architectures. These observations indicate that the study of myelin biology and the identification of therapeutic compounds will largely benefit from a method to quantify the myelin molecular organization in vivo.
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Affiliation(s)
- Raphaël Turcotte
- Centre de recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, QC G1J 2G3, Canada
| | - Danette J Rutledge
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Erik Bélanger
- Centre de recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, QC G1J 2G3, Canada
| | - Dorothy Dill
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Daniel C Côté
- Centre de recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, QC G1J 2G3, Canada.,Centre d'Optique, Photonique et Laser, Université Laval, Québec, QC G1V 0A6, Canada
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Heterogeneity of Multiple Sclerosis Lesions in Multislice Myelin Water Imaging. PLoS One 2016; 11:e0151496. [PMID: 26990645 PMCID: PMC4798764 DOI: 10.1371/journal.pone.0151496] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/29/2016] [Indexed: 11/19/2022] Open
Abstract
Purpose To assess neuroprotection and remyelination in Multiple Sclerosis (MS), we applied a more robust myelin water imaging (MWI) processing technique, including spatial priors into image reconstruction, which allows for lower SNR, less averages and shorter acquisition times. We sought to evaluate this technique in MS-patients and healthy controls (HC). Materials and Methods Seventeen MS-patients and 14 age-matched HCs received a 3T Magnetic Resonance Imaging (MRI) examination including MWI (8 slices, 12 minutes acquisition time), T2w and T1mprage pre and post gadolinium (GD) administration. Black holes (BH), contrast enhancing lesions (CEL) and T2 lesions were marked and registered to MWI. Additionally, regions of interest (ROI) were defined in the frontal, parietal and occipital normal appearing white matter (NAWM)/white matter (WM), the corticospinal tract (CST), the splenium (SCC) and genu (GCC) of the corpus callosum in patients and HCs. Mean values of myelin water fraction (MWF) were determined for each ROI. Results Significant differences (p≤0.05) of the MWF were found in all three different MS-lesion types (BH, CEL, T2 lesions), compared to the WM of HCs. The mean MWF values among the different lesion types were significantly differing from each other. Comparing MS-patients vs. HCs, we found a significant (p≤0.05) difference of the MWF in all measured ROIs except of GCC and SCC. The mean reduction of MWF in the NAWM of MS-patients compared to HCs was 37%. No age, sex, disability score and disease duration dependency was found for the NAWM MWF. Conclusion MWF measures were in line with previous studies and lesions were clearly visible in MWI. MWI allows for quantitative assessment of NAWM and lesions in MS, which could be used as an additional sensitive imaging endpoint for larger MS studies. Measurements of the MWF also differ between patients and healthy controls.
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Beggs CB, Magnano C, Shepherd SJ, Belov P, Ramasamy DP, Hagemeier J, Zivadinov R. Dirty-Appearing White Matter in the Brain is Associated with Altered Cerebrospinal Fluid Pulsatility and Hypertension in Individuals without Neurologic Disease. J Neuroimaging 2015; 26:136-43. [DOI: 10.1111/jon.12249] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/04/2015] [Indexed: 11/30/2022] Open
Affiliation(s)
- Clive B. Beggs
- Centre for Infection Control and Biophysics; University of Bradford; Bradford UK
- Department of Neurology, Buffalo Neuroimaging Analysis Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
| | - Christopher Magnano
- Department of Neurology, Buffalo Neuroimaging Analysis Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
- MRI Clinical Translational Research Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
| | - Simon J. Shepherd
- Centre for Infection Control and Biophysics; University of Bradford; Bradford UK
| | - Pavel Belov
- Department of Neurology, Buffalo Neuroimaging Analysis Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
| | - Deepa P. Ramasamy
- Department of Neurology, Buffalo Neuroimaging Analysis Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
- MRI Clinical Translational Research Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
| | - Jesper Hagemeier
- Department of Neurology, Buffalo Neuroimaging Analysis Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
| | - Robert Zivadinov
- Department of Neurology, Buffalo Neuroimaging Analysis Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
- MRI Clinical Translational Research Center, School of Medicine and Biomedical Sciences; University at Buffalo; Buffalo NY
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Fjær S, Bø L, Myhr KM, Torkildsen Ø, Wergeland S. Magnetization transfer ratio does not correlate to myelin content in the brain in the MOG-EAE mouse model. Neurochem Int 2015; 83-84:28-40. [PMID: 25744931 DOI: 10.1016/j.neuint.2015.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 01/29/2015] [Accepted: 02/24/2015] [Indexed: 12/27/2022]
Abstract
Magnetization transfer ratio (MTR) is a magnetic resonance imaging (MRI) method which may detect demyelination not detected by conventional MRI in the central nervous system of patients with multiple sclerosis (MS). A decrease in MTR value has previously been shown to correlate to myelin loss in the mouse cuprizone model for demyelination. In this study, we investigated the sensitivity of MTR for demyelination in the myelin oligodendrocyte (MOG) 1-125 induced experimental autoimmune encephalomyelitis (EAE) mouse model. A total of 24 female c57Bl/6 mice were randomized to a control group (N = 6) or EAE (N = 18). MTR images were obtained at a preclinical 7 Tesla Bruker MR-scanner before EAE induction (baseline), 17-19 days (midpoint) and 31-32 days (endpoint) after EAE induction. Mean MTR values were calculated in five regions of the brain and compared to weight, EAE severity score and myelin content assessed by immunostaining for proteolipid protein and luxol fast blue, lymphocyte and monocyte infiltration and iron deposition. Contrary to what was expected, MTR values in the EAE mice were higher than in the control mice at the midpoint and endpoint. No significant difference in myelin content was found according to histo- or immunohistochemistry. Changes in MTR values did not correlate to myelin content, iron content, lymphocyte or monocyte infiltration, weight or EAE severity scores. This suggest that MTR measures of brain tissue can give significant differences between control mice and EAE mice not caused by demyelination, inflammation or iron deposition, and may not be useful surrogate markers for demyelination in the MOG1-125 mouse model.
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Affiliation(s)
- Sveinung Fjær
- KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Bergen, Norway; The Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway.
| | - Lars Bø
- KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Bergen, Norway; The Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Kjell-Morten Myhr
- KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Bergen, Norway; The Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Øivind Torkildsen
- KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Bergen, Norway; The Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Stig Wergeland
- KG Jebsen Centre for MS-Research, Department of Clinical Medicine, University of Bergen, Bergen, Norway; The Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway
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Brana C, Frossard MJ, Pescini Gobert R, Martinier N, Boschert U, Seabrook TJ. Immunohistochemical detection of sphingosine-1-phosphate receptor 1 and 5 in human multiple sclerosis lesions. Neuropathol Appl Neurobiol 2015; 40:564-78. [PMID: 23551178 DOI: 10.1111/nan.12048] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 03/08/2013] [Indexed: 01/18/2023]
Abstract
AIMS Sphingosine-1-phosphate receptor (S1PR) modulating therapies are currently in the clinic or undergoing investigation for multiple sclerosis (MS) treatment. However, the expression of S1PRs is still unclear in the central nervous system under normal conditions and during neuroinflammation. METHODS Using immunohistochemistry we examined tissues from both grey and white matter MS lesions for sphingosine-1-phosphate receptor 1 (S1P1 ) and 5 (S1P5 ) expression. Tissues from Alzheimer's disease (AD) cases were also examined. RESULTS S1P1 expression was restricted to astrocytes and endothelial cells in control tissues and a decrease in endothelial cell expression was found in white matter MS lesions. In grey matter MS lesions, astrocyte expression was lost in active lesions, while in quiescent lesions it was restored to normal expression levels. CNPase colocalization studies demonstrated S1P5 expression on myelin and both were reduced in demyelinated lesions. In AD tissues we found no difference in S1P1 expression. CONCLUSION These data demonstrate a differential modulation of S1PRs in MS lesions, which may have an impact on S1PR-directed therapies.
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Affiliation(s)
- Corinne Brana
- Merck Serono, Multiple Sclerosis Platform, Geneva, Switzerland
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DeLuca GC, Yates RL, Beale H, Morrow SA. Cognitive impairment in multiple sclerosis: clinical, radiologic and pathologic insights. Brain Pathol 2015; 25:79-98. [PMID: 25521179 PMCID: PMC8029470 DOI: 10.1111/bpa.12220] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/15/2014] [Indexed: 01/18/2023] Open
Abstract
Cognitive impairment is a common and debilitating feature of multiple sclerosis (MS) that has only recent gained considerable attention. Clinical neuropsychological studies have made apparent the multifaceted nature of cognitive troubles often encountered in MS and continue to broaden our understanding of its complexity. Radiographic studies have started to decipher the neuroanatomic substrate of MS-related cognitive impairment and have shed light onto its pathogenesis. Where radiographic studies have been limited by inadequate resolution or non-specificity, pathological studies have come to the fore. This review aims to provide an overview of the nature of cognitive impairment typically seen in MS and to explore the literature on imaging and pathological studies relevant to its evolution. In particular, the relative contributions of gray (i.e., cerebral cortex, hippocampus, thalamus and basal ganglia) and white matter to MS-related cognitive impairment will be discussed and the importance of interconnectivity between structures highlighted. The pressing need for longitudinal studies combining standardized neuropsychometric, paraclinical and radiographic outcomes obtained during life with post-mortem tissue analysis after death is presented.
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Affiliation(s)
- Gabriele C. DeLuca
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Richard L. Yates
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Harry Beale
- Oxford Medical SchoolUniversity of OxfordOxfordUK
| | - Sarah A. Morrow
- Department of Clinical Neurological SciencesThe University of Western OntarioLondonCanada
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Pathology of multiple sclerosis and related inflammatory demyelinating diseases. HANDBOOK OF CLINICAL NEUROLOGY 2014; 122:15-58. [PMID: 24507512 DOI: 10.1016/b978-0-444-52001-2.00002-9] [Citation(s) in RCA: 202] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This article provides a comprehensive overview of the pathology of multiple sclerosis (MS), including recent insights into its molecular neuropathology and immunology. It shows that all clinical manifestations of relapsing and progressive MS display the same basic features of pathology, such as chronic inflammation, demyelination in the white and gray matter, and diffuse neurodegeneration within the entire central nervous system. However, the individual components of the pathological spectrum vary quantitatively between early relapsing and late progressive MS. Widespread confluent and plaque-like demyelination with oligodendrocyte destruction is the unique pathological hallmark of the disease, but axonal injury and neurodegeneration are additionally present and in part extensive. Remyelination of existing lesions may occur in MS brains; it is extensive in a subset of patients, while it fails in others. Active tissue injury in MS is always associated with inflammation, consistent with T-cell and macrophage infiltration and microglia activation. Recent data suggest that oxidative injury and subsequent mitochondrial damage play a major pathogenetic role in neurodegeneration. Finally we discuss similarities and differences of the pathology between classical MS and other inflammatory demyelinating diseases, such as neuromyelitis optica, concentric sclerosis, or acute disseminated encephalomyelitis.
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Pouwels PJW, Vanderver A, Bernard G, Wolf NI, Dreha-Kulczewksi SF, Deoni SCL, Bertini E, Kohlschütter A, Richardson W, Ffrench-Constant C, Köhler W, Rowitch D, Barkovich AJ. Hypomyelinating leukodystrophies: translational research progress and prospects. Ann Neurol 2014; 76:5-19. [PMID: 24916848 DOI: 10.1002/ana.24194] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/05/2014] [Accepted: 06/05/2014] [Indexed: 12/11/2022]
Abstract
Hypomyelinating leukodystrophies represent a genetically heterogeneous but clinically overlapping group of heritable disorders. Current management approaches in the care of the patient with a hypomyelinating leukodystrophy include use of serial magnetic resonance imaging (MRI) to establish and monitor hypomyelination, molecular diagnostics to determine a specific etiology, and equally importantly, careful attention to neurologic complications over time. Emerging research in oligodendrocyte biology and neuroradiology with bedside applications may result in the possibility of clinical trials in the near term, yet there are significant gaps in knowledge in disease classification, characterization, and outcome measures in this group of disorders. Here we review the biological background of myelination, the clinical and genetic variability in hypomyelinating leukodystrophies, and the insights that can be obtained from current MRI techniques. In addition, we discuss ongoing research approaches to define potential outcome markers for future clinical trials.
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Affiliation(s)
- Petra J W Pouwels
- Department of Physics and Medical Technology, VU University Medical Center and Neuroscience Campus Amsterdam, Amsterdam, the Netherlands
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Rudko DA, Solovey I, Gati JS, Kremenchutzky M, Menon RS. Multiple sclerosis: improved identification of disease-relevant changes in gray and white matter by using susceptibility-based MR imaging. Radiology 2014; 272:851-64. [PMID: 24828000 DOI: 10.1148/radiol.14132475] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE To evaluate the potential of quantitative susceptibility (QS) and R2* mapping as surrogate biomarkers of clinically relevant, age-adjusted demyelination and iron deposition in multiple sclerosis (MS). MATERIALS AND METHODS All study participants gave written informed consent, and the study was approved by the institutional review board. Quantitative maps of the magnetic resonance imaging susceptibility parameters (R2* and QS) were computed for 25 patients with either clinically isolated syndrome (CIS) or relapsing-remitting MS, as well as for 15 age- and sex-matched control subjects imaged at 7 T. The candidate MR imaging biomarkers were correlated with Extended Disability Status Scale (EDSS), time since CIS diagnosis, time since MS diagnosis, and age. RESULTS QS maps aided identification of significant, voxel-level increases in iron deposition in subcortical gray matter (GM) of patients with MS compared with control subjects. These voxel-level increases were not observed on R2* maps. Region-of-interest analysis of mean R2* and QS in subcortical GM demonstrated that R2* (R ≥ 0.39, P < .01) and QS (R ≥ 0.44, P < .01) were strongly correlated with EDSS. In white matter (WM), the volume of total WM damage (defined by a z score of less than -2.0 criterion, indicating demyelination) on QS maps correlated significantly with EDSS (R = 0.46, P = .02). Voxelwise QS also supported a significant contribution of age to demyelination in patients with MS, suggesting that age-adjusted clinical scores may provide more robust measures of MS disease severity compared with non-age-adjusted scores. CONCLUSION Using QS and R2* mapping, evidence of both significant increases in iron deposition in subcortical GM and myelin degeneration along the WM skeleton of patients with MS was identified. Both effects correlated strongly with EDSS.
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Affiliation(s)
- David A Rudko
- From the Department of Physics (D.A.R., R.S.M.), Center for Functional and Metabolic Mapping, Robarts Research Institute (D.A.R., I.S., J.S.G., R.S.M.), and Department of Neurology, University Hospital (M.K.), University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5B7
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Nathoo N, Yong VW, Dunn JF. Using magnetic resonance imaging in animal models to guide drug development in multiple sclerosis. Mult Scler 2013; 20:3-11. [PMID: 24263386 DOI: 10.1177/1352458513512709] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Major advances are taking place in the development of therapeutics for multiple sclerosis (MS), with a move past traditional immunomodulatory/immunosuppressive therapies toward medications aimed at promoting remyelination or neuroprotection. With an increase in diversity of MS therapies comes the need to assess the effectiveness of such therapies. Magnetic resonance imaging (MRI) is one of the main tools used to evaluate the effectiveness of MS therapeutics in clinical trials. As all new therapeutics for MS are tested in animal models first, it is logical that MRI be incorporated into preclinical studies assessing therapeutics. Here, we review key papers showing how MR imaging has been combined with a range of animal models to evaluate potential therapeutics for MS. We also advise on how to maximize the potential for incorporating MRI into preclinical studies evaluating possible therapeutics for MS, which should improve the likelihood of discovering new medications for the condition.
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Affiliation(s)
- Nabeela Nathoo
- Hotchkiss Brain Institute, University of Calgary, Canada
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Aung WY, Mar S, Benzinger TL. Diffusion tensor MRI as a biomarker in axonal and myelin damage. ACTA ACUST UNITED AC 2013; 5:427-440. [PMID: 24795779 DOI: 10.2217/iim.13.49] [Citation(s) in RCA: 217] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diffusion tensor imaging has been used extensively as a research tool to understand the structural changes associated with white matter pathology. Using water diffusion as the basis to construct anatomic details, diffusion tensor imaging offers the potential to identify structural and functional adaptations before gross anatomical changes, such as lesions and tumors, become apparent on conventional MRI. Over the past 10 years, further parameters, such as axial and radial diffusivity, have been developed to characterize white matter changes specific to axons and myelin. In this paper, the potential application and outstanding issues on the use of diffusion tensor imaging directional diffusivity as a biomarker in axonal and myelin damage in neurological disorders will be reviewed.
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Affiliation(s)
- Wint Yan Aung
- Department of Radiology, Washington University, School of Medicine, 510 South Kingshighway Boulevard, St Louis, MO 63110, USA
| | - Soe Mar
- Department of Pediatric & Developmental Neurology, Washington University School of Medicine, St Louis, MO, USA
| | - Tammie Ls Benzinger
- Department of Radiology, Washington University, School of Medicine, 510 South Kingshighway Boulevard, St Louis, MO 63110, USA ; Department of Neurological Surgery, Washington University School of Medicine, St Louis, MO, USA
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Zhang Y, Moore GRW, Laule C, Bjarnason TA, Kozlowski P, Traboulsee A, Li DKB. Pathological correlates of magnetic resonance imaging texture heterogeneity in multiple sclerosis. Ann Neurol 2013; 74:91-9. [PMID: 23939554 DOI: 10.1002/ana.23867] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 01/18/2013] [Accepted: 02/01/2013] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To analyze the texture of T2-weighted magnetic resonance imaging (MRI) of postmortem multiple sclerosis (MS) brain, and to determine whether and how MRI texture correlates with tissue pathology. METHODS Ten brain samples from 3 subjects with MS were examined. Areas of complete, partial, or no loss of Luxol fast blue (myelin) and Bielschowsky (axons) staining were marked on histological images, and matched on corresponding MRI as lesions, diffusely abnormal white matter (DAWM), and normal-appearing white matter (NAWM). The number of CD45(+) cells (inflammation) was also counted. MRI texture was computed using polar Stockwell transform and compared to histology. RESULTS Thirty-four lesions, 17 DAWM regions, and 36 NAWM regions were identified. After mixed effects modeling, MRI texture heterogeneity was greater in lesions than in DAWM (p < 0.001) and NAWM (p < 0.001), and was greater in DAWM than in NAWM (p < 0.001); the number of CD45+ cells was greater in both lesions (p < 0.001) and DAWM (p = 0.005) than in NAWM. In MRI, a gradient of texture heterogeneity was detected in lesions, with gradual tapering toward perilesional NAWM. Moreover, besides univariate correlation with histological markers, texture heterogeneity correlated independently with normalized myelin density (p < 0.01) when random effects were considered. Within sample, MRI texture correlated with myelin and axonal density in 7 of 10 samples (p < 0.01). INTERPRETATION Texture analysis performed on routine clinical magnetic resonance images may be a potential measure of tissue integrity. Tissues with more severe myelin and axonal pathology are associated with greater texture heterogeneity.
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Affiliation(s)
- Yunyan Zhang
- Department of Radiology, University of Calgary, Calgary, Alberta; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta
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Borich M, MacKay A, Vavasour I, Rauscher A, Boyd L. Evaluation of white matter myelin water fraction in chronic stroke. Neuroimage Clin 2013; 2:569-80. [PMID: 24179808 PMCID: PMC3777839 DOI: 10.1016/j.nicl.2013.04.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 04/11/2013] [Accepted: 04/11/2013] [Indexed: 12/15/2022]
Abstract
Multi-component T2 relaxation imaging (MCRI) provides specific in vivo measurement of myelin water content and tissue water environments through myelin water fraction (MWF), intra/extra-cellular water fraction (I/EWF) and intra/extracellular and global geometric mean T2 (GMT2) times. Quantitative MCRI assessment of tissue water environments has provided new insights into the progression and underlying white matter pathology in neural disorders such as multiple sclerosis. It has not previously been applied to investigate changes in white matter in the stroke-affected brain. Thus, the purposes of this study were to 1) use MCRI to index myelin water content and tissue water environments in the brain after stroke 2) evaluate relationships between MWF and diffusion behavior indexed by diffusion tensor imaging-based metrics and 3) examine the relationship between white matter status (MWF and fractional anisotropy) and motor behavior in the chronic phase of stroke recovery. Twenty individuals with ischemic stroke and 12 matched healthy controls participated. Excellent to good test/re-test and inter-rater reliability was observed for region of interest-based voxelwise MWF data. Reduced MWF was observed in whole-cerebrum white matter (p < 0.001) and in the ipsilesional (p = 0.017) and contralesional (p = 0.037) posterior limb of internal capsule (PLIC) after stroke compared to whole-cerebrum and bilateral PLIC MWF in healthy controls. The stroke group also demonstrated increased I/EWF, I/E GMT2 and global GMT2 times for whole-cerebrum white matter. Measures of diffusion behavior were also significantly different in the stroke group across each region investigated (p < 0.001). MWF was not significantly correlated with specific tensor-based measures of diffusion in the PLIC for either group. Fractional anisotropy in the ipsilesional PLIC correlated with motor behavior in chronic stroke. These results provide novel insights into tissue-specific changes within white matter after stroke that may have important applications for the understanding of the neuropathology of stroke.
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Affiliation(s)
- M.R. Borich
- Department of Physical Therapy, University of British Columbia, Canada
| | - A.L. MacKay
- Department of Radiology, University of British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Canada
| | - I.M. Vavasour
- Department of Radiology, University of British Columbia, Canada
| | - A. Rauscher
- Department of Radiology, University of British Columbia, Canada
- UBC MRI Research Centre, University of British Columbia, Canada
- Brain Research Centre, University of British Columbia, Canada
| | - L.A. Boyd
- Department of Physical Therapy, University of British Columbia, Canada
- Brain Research Centre, University of British Columbia, Canada
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Diffusely abnormal white matter in multiple sclerosis: further histologic studies provide evidence for a primary lipid abnormality with neurodegeneration. J Neuropathol Exp Neurol 2013; 72:42-52. [PMID: 23242281 DOI: 10.1097/nen.0b013e31827bced3] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Although multiple sclerosis (MS) lesions have been studied extensively using histology and magnetic resonance imaging (MRI), little is known about diffusely abnormal white matter (DAWM). Diffusely abnormal white matter, regions with reduced mild MRI hyperintensity and ill-defined boundaries, show reduced myelin water fraction, and decreased Luxol fast blue staining of myelin phospholipids, with relative preservation of myelin basic protein and 2',3'-cyclic-nucleotide 3'-phosphohydrolase. Because DAWM may be important in MS disability and progression, further histologic characterization is warranted. The MRI data were collected on 14 formalin-fixed MS brain samples that were then stained for myelin phospholipids, myelin proteins, astrocytes and axons. Diffusely abnormal white matter showed reduced myelin water fraction (-30%, p < 0.05 for 13 samples). Myelin phospholipids showed the most dramatic and consistent histologic reductions in staining optical density (-29% Luxol fast blue and -24% Weil's, p < 0.05 for 13 and 14 samples,respectively) with lesser myelin protein involvement (-11% myelin-associated glycoprotein, -10% myelin basic protein, -8% myelin-oligodendrocyte glycoprotein, -7% proteolipid protein, -5% 2',3'-cyclic-nucleotide 3'-phosphohydrolase, p < 0.05 for 3, 3, 1, 2, and 3 samples, respectively). Axonal involvement was intermediate. Diffusely abnormal white matter lipid and protein reductions occurred independently. These findings suggest a primary lipid abnormality in DAWM that exceeds protein loss and is accompanied by axonal degeneration. These phenomena may be important in MS pathogenesis and disease progression, which is prominent in individuals with DAWM.
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