ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Advanced MRI in Multiple Sclerosis
Monday 22 April 2013
Room 355 BC  10:45 - 12:45 Moderators: Maria A. Rocca, Alex Rovira

10:45 0042.   Functional and Structural Disruption of the Precuneus Contributes to Cognitive Impairment in Pediatric Multiple Sclerosis
Maria A. Rocca1, Martina Absinta1, Maria Pia Amato2, Angelo Ghezzi3, Lucia Moiola4, Agnese Fiorino4, Pierangelo Veggiotti5, Giancarlo Comi4, Massimo Filippi1, and and the MS and Neuroimaging Study Groups of the Italian Neurological Society6
1Neuroimaging Research Unit, Institute of Experimental Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy, 2Department of Neurology, University of Florence, Florence, FI, Italy, 3MS Centre, Ospedale di Gallarate, Gallarate, VA, Italy, 4Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy, 5Child Neurology Unit, National Neurological Institute C. Mondino, Pavia, PV, Italy, 6SIN, Siena, SI, Italy

We combined structural and functional MRI techniques to improve our understanding of the mechanisms responsible for the presence and severity of cognitive impairment in 35 patients with pediatric multiple sclerosis (MS). We found that in pediatric MS patients, cognitive dysfunction is associated to structural and functional abnormalities of core regions of the default mode network located in the posterior brain, particularly the precuneus. Increased resting state functional connectivity of regions located in the frontal lobe might compensate for such a dysfunction and contribute to cognitive preservation.

10:57 0043.   Impaired Regulation of the Blood Supply to the Brain in Multiple Sclerosis Measured with Hypercapnia BOLD MRI
Yulin Ge1, Hanzhang Lu2, Yongxia Zhou3, Feng Xu2, Ilya Kister4, Hina Jaggi3, Joseph Herbert5, and Robert I. Grossman6
1Radiology, New York University Langone Medical Center, New York, New York, United States, 2Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States, 3Radiology, NYU Langone Medical Center, New York, New York, United States, 4Neurology, NYU Langone Medical Center, New York, New York, United States, 5Neurology, New York University, New York, New York, United States, 6Radiology, New York University, New York, New York, United States

Normal neuronal activity is tightly linked to and critically depends on the increase of blood flow for instantaneous supply of oxygen and glucose. This study is to evaluate whether there is cerebrovascular reactivity (CVR) impairment in patients with multiple sclerosis (MS) using hypercapnia BOLD MRI. Our findings of significant decrease of CVR in MS patients suggest an impaired vascular regulation of blood flow supply or defect neurocoupling mechanism, which may affect effective oxygen delivery particularly to the previously healthy and normal neurons and lead to neurodegeneration over time.

11:09 0044.   Regional Hippocampal Involvement Differs Across Multiple Sclerosis Clinical Phenotypes: A Radial Mapping MR-Based Study
Elisabetta Pagani1, Maria A. Rocca1, Giulia Longoni1, Vittorio Martinelli2, Bruno Colombo2, Andrea Falini3, Giancarlo Comi2, and Massimo Filippi1
1Neuroimaging Research Unit, Institute of Experimental Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy, 3Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, MI, Italy

The use of a regional approach for the study of hippocampal atrophy in a large cohort of patients with multiple sclerosis (MS) allowed us to detect differences in the regional pattern of damage distribution across the main disease clinical phenotypes. We found a selective and progressive CA1 atrophy in patients with MS as well as a substantial involvement of the subiculum, the major efferent of hippocampal pathways, even in the early phases of the disease. Primary progressive MS MS patients, in whom inflammation is relatively modest, showed a relative sparing of hippocampal formation.

11:21 0045.   Macromolecular Proton Fraction as a New Clinical Biomarker of Demyelination in Multiple Sclerosis
Vasily L. Yarnykh1, James D. Bowen2, Alexey A. Samsonov3, Pavle Repovic2, Angeli Mayadev2, Bart P. Keogh2, Beena Gangadharan2, Hunter R. Underhill1, Kenneth R. Maravilla1, and Lily K. Jung Henson2
1Radiology, University of Washington, Seattle, WA, United States, 2Swedish Medical Center, Seattle, WA, United States, 3Radiology, University of Wisconsin, Madison, WI, United States

Macromolecular proton fraction (MPF) is a key parameter determining magnetization transfer in tissues. Recent studies demonstrated close associations between MPF and myelin content in neural tissues. We present the first clinical evaluation of a recently published fast whole-brain MPF mapping method in multiple sclerosis (MS). MPF in both white and gray matter in MS demonstrated highly significant decrease compared to controls and strong correlations with disability. Notably, gray matter MPF showed the strongest correlations with clinical status, thus emphasizing a critical role of gray matter demyelination in MS. This study establishes MPF as a new quantitative imaging biomarker of demyelination.

11:33 0046.   Spatial Patterns of Cortical Thinning in Neuromyelitis Optica: A Comparative Study with Multiple Sclerosis
Yaou Liu1, Teng Xie2, Ni Shu2, Kuncheng Li1, and Yong He2
1Department of Radiology, Xuanwu hospital, Capital Medical University, Beijing, China, 2State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China

We analyzed the global and regional cortical thickness (CTh) in patients with neuromyelitis optica (NMO), and directly compared with multiple sclerosis (MS) and healthy controls (HCs). Different patterns of cortical thinning between MS and NMO were observed. MS showed a widespread cortical thinning in many brain regions predominantly in frontal and temporary lobes, while subtle cortical thinning in occipital lobe was observed compared with HCs. When directly compare MS and NMO, several brain regions in temporary lobe was found significantly thinner in MS. Furthermore a significant correlation was found between CTh in several brain regions and clinical variables. This study.

11:45 0047.   
Hippocampal Magnetization Transfer Ratio and Not Hippocampal Atrophy Best Explains Memory Dysfunction in Patients with Multiple Sclerosis
Mishkin Derakhshan1, Gabriel Leonard1, Daviad Araujo1, D. Louis Collins1, Douglas L. Arnold1, and Sridar Narayanan1
1Montreal Neurological Institute, McGill University, Montreal, QC, Canada

The hippocampi (HC) have been found to be demyelinated in postmortem studies of patients with multiple sclerosis (MS), and HC pathology has been shown to be responsible for memory impairment. Using magnetization transfer ratio (MTR) as a marker of demyelination, we examined HC demyelination and HC atrophy in 26 patients with MS and 15 controls matched for age, sex, and education level. We found that focal HC MTR values best explained memory performance, specifically working and visual immediate memory, better than volumetric measures.

11:57 0048.   Regional Cortical Thickness in Relapsing Remitting Multiple Sclerosis: A Multi-Center Study
Ponnada A. Narayana1, Koushik Govindarajan1, Priya Goel1, Sushmita Datta2, John A. Lincoln3, Stacy S. Cofield4, Gary R. Cutter4, Fred D. Lublin5, and Jerry S. Wolinsky3
1Diagnostic and Interventional Imaging, University of Texas Hlth Sci Cntr Houston, Houston, Texas, United States, 2Diagnostic and Interventional Imaging, Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, United States, 3Neurology, University of Texas Hlth Sci Cntr Houston, Houston, Texas, United States,43Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, United States, 5The Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Mount Sinai School of Medicine, New York, New York, United States

Changes in regional and global cortical thickness and age- and gender dependence of these measures on a large MS cohort that is a part of a multi-center clinical trial were investigated. Changes in regional cortical thicknesses were larger in the left hemisphere compared to the right. Males showed stronger age dependent cortical thickness than females. Strongest reductions in the thickness were observed in the entorhinal cortex and temporal poles in MS, the structures implicated in several neurodegenerative diseases. Weaker age dependent changes in both global and regional cortical thicknesses were observed in MS patients compared to controls.

12:09 0049.   Magnetisation Transfer Imaging of Subpial Cortical Abnormalities in Multiple Sclerosis
Rebecca S. Samson1, Manuel Jorge Cardoso2,3, Nils Muhlert4, Varun Sethi4, Claudia Angela M. Wheeler-Kingshott4, Maria A. Ron4, Sebastian Ourselin2,3, David H. Miller4, and Declan T. Chard4
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, England, United Kingdom, 2Centre for Medical Image Computing, UCL Department of Computer Sciences, London, United Kingdom, 3Dementia Research Centre, UCL Institute of Neurology, London, United Kingdom, 4NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom

Histopathology has demonstrated extensive cortical demyelination in multiple sclerosis (MS), often in a subpial location. We subdivided the cortex into inner and outer ‘bands’, and investigated the relationship between inner and outer cortical abnormality (as measured by the magnetisation transfer ratio (MTR)) and clinical course in a large cohort of MS patients. Outer was lower than inner MTR in people with MS and controls, as expected due to the lower myelin content in the outer cortex. Outer cortical MTR reductions (consistent with subpial demyelination) were observed in relapse-onset MS and were most marked in people with secondary progressive MS.

12:21 0050.   Impact of Macrophagic Activity on Tissue Structure in Patients Suffering from Clinically Isolated Syndrome Suggestive of Multiple Sclerosis: A Multicentric USPIO Enhancement Study at 3T
Adil Maarouf1,2, Jean Christophe Ferré3,4, Wafaa Zaaraoui1, Elise Bannier5, Christian Barillot4, Isabelle Berry6, Gilles Edan7, Damien Galanaud8, Jean Pelletier1,9, Christophe Portefaix10, Ayman Tourbah11, Jean-Philippe Ranjava1, and Bertrand Audoin1,9
1CRMBM, CNRS UMR 7339, Marseille, France, 2Dept. of Neurology, CHU REIMS, Reims, France, 3Dept. of Neuroradiology, CHU Rennes, RENNES cedex 9, France, 4Visages U746, INSERM INRIA IRISA, Rennes, France, 5Neurinfo, INSERM INRIA IRISA, Rennes, France, 6Dept. of Biophysics, CHU Toulouse, Toulouse, France, 7Dept. of Neurology, CHU Rennes, Rennes, France, 8Dept of Neuroradiology, Pitié Salpêtrière Hospital, Paris, France, 9Dept. of Neurology, CHU Marseille, Marseille, France, 10Dept. Radiology, CHU Reims, Reims, France, 11Dept. of Neurology, CHU Reims, Reims, France

Macrophage infiltration is an important pattern in inflammatory processes associated to multiple sclerosis. The aim of this longitudinal and multicentric study was to determine the prevalence of USPIO enhancement in patients with early MS and the impact of macrophage activity at early and medium term on tissue integrity assessed by MTR. From the earliest stage of MS, we highlighted the presence in vivo of activated macrophages. Destructuration was higher and persistent in lesions with significant macrophages burden. The total T2-w lesion was significantly higher in the group of patient that had at baseline at least one USPIO-positive lesion.

12:33 0051.   Correlations Between Corpus Callosal Myelin Water Fraction and Measures of Transcallosal Inhibition in Multiple Sclerosis Patients on Glatiramer Acetate Treatment
Eric Y. Zhao1, Irene Vavasour2, Marjan Zakeri3, Michael Borich3, Cornelia Laule4, Anthony L. Traboulsee5, David K.B. Li2, Lara Boyd3, and Alex L. Mackay2,6
1Department of Cellular & Physiological Sciences, The University of British Columbia, Vancouver, BC, Canada, 2Department of Radiology, The University of British Columbia, Vancouver, BC, Canada, 3Brain Behavior Lab, Department of Physical Therapy, The University of British Columbia, Vancouver, BC, Canada, 4Department of Pathology & Laboratory Medicine, The University of British Columbia, Vancouver, BC, Canada, 5Division of Neurology, Department of Medicine, The University of British Columbia, Vancouver, BC, Canada, 6Department of Physics & Astronomy, The University of British Columbia, Vancouver, BC, Canada

Myelin water fraction (MWF) measured via the signal fraction of the short T2 relaxation time can be used to monitor demyelination in MS over time. Transcallosal inhibition (TCI), measured via transcranial magnetic stimulation, is also indicative of neuronal health. This study aims to uncover correlations between callosal MWF and TCI parameters to better characterize MWF as a predictor of neurophysiologic function. We found that decreased MWF in the callosal region shown to carry motor information is correlated with delayed onset as well as decreased duration and magnitude of TCI. We attribute this to loss of spatiotemporal summation due to demyelination.