Marco Muccio¹, Lillian Walton Masters², Giuseppina Pilloni², Lauren Krupp², Abhishek Datta³, Marom Bikson⁴, Leigh Charvet², and Yulin Ge^1
1Radiology, NYU Grossman School of Medicine, New York City, NY, United States, ²Neurology, NYU Grossman School of Medicine, New York City, NY, United States, ³Soterix Medical Inc., New York City, NY, United States, ⁴Department of Biomedical Engineering, City College of New York, New York City, NY, United States

Transcranial direct current stimulation (tDCS) represents an innovative therapeutic tool for neurological diseases such as multiple sclerosis (MS). In this study, MRI measurements of cerebral blood flow (CBF), venous oxygenation (Yv) and cerebral metabolic rate of oxygen (CMRO2) of MS patients and healthy controls (HCs) were acquired pre-, during- and post-tDCS to investigate its simultaneous effects. Whilst HCs showed an immediate increase (~5%) in CMRO2 (during- versus pre-tDCS, p<0.001), MS patients showed a delayed response to tDCS (7.7% CMRO2 increase pre- versus post-tDCS; p=0.007). We suggest that neuronal response to tDCS represents a potential biomarker of neuronal plasticity.

Xiufeng Li¹, Gregory J. Metzger¹, and Anne M. Murray^2,3,4
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, ²Hennepin HealthCare Research Institute, Hennepin Healthcare, Minneapolis, MN, United States, ³Department of Medicine, University of Minnesota, Minneapolis, MN, United States, ⁴Geriatrics Division, Department of Medicine, Hennepin Healthcare, Minneapolis, MN, United States

Repeated conventional hemodialysis may result in permanent cerebrovascular dysfunction that can initiate and exacerbate other cerebral structural abnormalities. Until today, the longitudinal WMH burden changes in old end-stage renal disease (ESRD) patients following the initiation of hemodialysis treatment have not been specifically studied. We performed a prospective pilot study with a hypothesis that WMH burden increases following the initiation of hemodialysis in old ESRD patient. Our study results suggested that WMH burdens increased significantly after the initiation of hemodialysis treatment.

Junghun Cho¹, Thanh D Nguyen¹, Lily Zexter¹, Elizabeth M Sweeney², Pascal Spincemaille¹, Ajay Gupta¹, Susan A Gauthier¹, and Yi Wang^1,3
1Radiology, Weill Cornell Medicine, New York, NY, United States, ²Population Health Sciences, Weill Cornell Medicine, New York, NY, United States, ³Biomedical Engineering, Cornell University, Ithaca, NY, United States

Understanding the cause and progress of remyelination in MS is critical for developing potential therapeutic targets of remyelination to restore neural connectivity and brain functions. In this study, we utilized a novel MRI-based oxygen extraction fraction (OEF) mapping method, namely “QQ”, and found that early lesion oxygen metabolism increase, as measured by QQ-based OEF, is positively associated with lesion myelin recovery, as measured by myelin water fraction. This study suggests that QQ-based OEF mapping may be a useful tool readily and widely available for studying MS lesion oxygen metabolism and its association with MS lesion remyelination.

Hyeong-Geol Shin¹, Riccardo Galbusera^2,3, Jincheol Seo⁴, Sooyeon Ji¹, Erik Bahn⁵, Jonas Franz⁵, Christine Stadelmann-Nessler⁵, Po-Jui Lu², Jinhee Jang⁶, Youngjeon Lee⁴, Cristina Granziera², and Jongho Lee^1
1Department of Electrical and Computer engineering, Seoul National University, Seoul, Korea, Republic of, ²Department of Biomedical Engineering, Faculty of Medicine, University Hospital Basel and University of Basel, Basel, Switzerland, ³MS Center and Research Center for Clinical Neuroimmunology and Neuroscience Basel (RC2NB), University Hospital Basel and University of Basel, Basel, Switzerland, ⁴National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, Korea, Republic of, ⁵Institute of Neuropathology, University Medical Center, Göttingen, Germany, ⁶Seoul St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea, Republic of

The pathology of multiple sclerosis (MS) is highly correlated with the dynamics of two susceptibility sources, paramagnetic iron and diamagnetic myelin. Various MRI methods sensitive to the substances have been developed for MS pathology. However, the collective effects of iron and myelin to an MRI signal have hampered monitoring individual changes of the substances. Here, we evaluated the effectiveness of 𝜒-separation, which estimates individual contributions of para-/dia-magnetic susceptibility, for visualizing MS pathology-related iron/myelin changes. The resulting paramagnetic and diamagnetic susceptibility conform to the histopathological features of MS lesion (iron-rim in Perls staining, and re-/de-myelinated lesions in myelin basic protein staining).

Simon Blyau¹, Ismail Koubiyr¹, Pierrick Coupé², Manoj Saranathan³, Julie Charré-Morin⁴, Aurore Saubusse⁴, Valentin Prevost⁵, Bei Zhang⁶, Mathilde Deloire⁴, Bruno Brochet¹, Aurélie Ruet¹, and Thomas Tourdias^1
1Neurocentre Magendie, Bordeaux, France, ²Laboratoire Bordelais de Recherche en Informatique, TALENCE, France, ³University of Arizona, Tucson, AZ, United States, ⁴Neurology Department, Hopital Pellegrin, Bordeaux, France, Metropolitan, ⁵Canon Medical System Corporation, Tochigi, Japan, ⁶Canon Medical System Europe, Paris, France

Thalamus is one of the first grey matter structure affected in multiple sclerosis (MS). It could undergo a differential vulnerability predominating on nuclei closer to the third ventricle due to pro-inflammatory factors brought by cerebrospinal fluid.First, we validated an atlas-based segmentation method that enables thalamic segmentation over conventional T1 weighted images. Then, using this segmentation method, we brought evidence for a medio-lateral gradient of thalamic atrophy in MS. While less affected, the anterior group was found useful to distinguish cognitively preserved from cognitively impaired patients. This paves the way toward more thalamic nuclei analyses in MS as new biomarkers.

Alexandra Lipka¹, Eva Heckova¹, Assunta Dal-Bianco², Gilbert Hangel^1,3, Paulus S. Rommer², Bernhard Strasser¹, Stanislav Motyka¹, Lukas Hingerl¹, Thomas Berger², Petra Hnilicová⁴, Ema Kantorová⁵, Fritz Leutmezer², Egon Kurča⁵, Stephan Gruber¹, Siegfried Trattnig^1,6, and Wolfgang Bogner^1
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Neurology, Medical University of Vienna, Vienna, Austria, Vienna, Austria, ³Department of Neurosurgery, Medical University of Vienna, Vienna, Austria, Vienna, Austria, ⁴Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia, ⁵Clinic of Neurology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia, ⁶Karl Landsteiner Institute for Clinical Molecular MRI in Musculoskeletal System, Vienna, Austria

Conventional T1/T2-weighted magnetic resonance imaging (cMRI) is the method of choice for diagnosis and treatment monitoring of multiple sclerosis (MS), though not being able to explain underlying pathological processes. In contrast to cMRI-lesions, which only reflect the severity of irreversible tissue damage, MR Spectroscopic Imaging (MRSI)  can detect pathologies on a biochemical level. In 51 relapsing-remitting (RRMS) patients, we investigate - enabled through ultra-high resolution FID-MRSI at 7T - the metabolic distribution within lesions and their vicinity as well as their location dependency and correlation to T1-hypointensity.