Lesion Pattern on Magnetic Resonance Imaging and Stroke Etiology in Multi-territorial Infarctions

INTRODUCTION: Presence of ischemic lesions in multiple vascular territories is suggestive of an embolic etiology, which could therefore necessitate a detailed etiologic work-up to uncover the underlying pathology. Lesion patterns on diffusion-weighted imaging (DWI) might be used as a marker of certain stroke etiologies and guide the clinician in prioritizing diagnostic investigations. In this study, we sought to identify the relationship between certain lesion characteristics on DWI and stroke etiologies in a consecutive series of ischemic stroke patients with multi-territorial lesions. METHODS: Patients with acute and subacute ischemic lesions simultaneously present in multiple cerebral arterial territories were retrospectively identified from a departmental database. The distribution, number and size of these lesions, and their association with different stroke etiologies were assessed for all patients. RESULTS: A total of 74 patients were included into the study. Patients with ‘other’ causes of stroke more commonly had lesions distributed in all cerebral arterial territories (p=0.02), ≥10 lesions (p<0. 01) and a heterogeneous pattern composed of multiple small and large lesions (p=0.03) when compared to the remaining patients. In contrast, patients with undetermined/unclassified origin of stroke had lower number of lesions (p<0.01) that were distributed mainly in only two circulations (p=0.04) and were primarily homogenously small in nature (p