Spatial Dispersion of Lesions as a Surrogate Biomarker for Disability in Multiple Sclerosis

Many previous studies in multiple sclerosis (MS) have focused on the relationship between white matter lesion volume and clinical parameters, but few have investigated the independent contribution of the spatial dispersion of lesions to patient disability. In this study, we examine the ability of four different measures of lesion dispersion including one connectedness-based measure (compactness), one regionbased measure (ratio of lesion convex hull to brain volume) and two distance-based measures (Euclidean distance from a fixed point and pair-wise Euclidean distances) to act as potential surrogate markers of disability. We use a set of T2-weighted and proton density-weighted MRIs of 24 MS patients, collected from a single selected scanning site participating in an MS clinical trial. For each patient, clinica