Ischemic white matter lesions associated with medullary arteries: Classification of MRI findings based on the anatomic arterial distributions

OBJECTIVE. The purposes of this article are to describe the important role of the medullary arteries in the pathogenesis of cerebral vascular disease and to present a classification of MRI findings of ischemic white matter lesions for use in elucidating pathogenesis. CONCLUSION. From the viewpoint of the anatomy of the medullary arteries, the pattern of medullary artery-related ischemic changes and infarcts can be classified into four types: 1, ischemic leukoaraiosis; 2, infarcts involving individual medullary arteries; 3, watershed infarcts; and 4, territorial infarcts.