Analysis of geometrical relations between multiple sclerosis lesions and brain vasculature

Abstract

Due to histological evidence of the fundamental role of the cerebral vessels in white matter abnormalities, recently there has been an increased interest in analyzing the relationship between brain white matter lesions in multiple sclerosis (MS) and brain vasculature. We developed a method for visualization and measurement of geometrical relationships between MS lesions and the brain vessels imaged with magnetic resonance (MR) imaging techniques. Using MR images we create surface models of lesions and vessels that constitute a base for quantitative analysis. In this work we analyze correlation between basic lesion geometrical characteristics and two features: 1) distances to vessels, and 2) vessel caliber. For the former, we compute a distance map from the vessel structure, such that each voxel stores its distance vector to the closest vessel. This allows the measurements of Euclidean distances to the closest vessels. For the latter, we compute a radius map in which each voxel stores the radius of its closest vessel. It is used to measure distribution of lesions with respect to the vessel caliber. We compute and analyze relations between the basic geometrical characteristics of lesions and the closest vessels locations and calibers. To demonstrate the feasibility of the developed technique we present results from the study of 3 MS cases.