Estimation of Stroke Etiology from Lesion Patterns on Diffusion-Weighted Magnetic Resonance Imaging in Patients with Carotid Artery Occlusive Disease

Abstract

Background: Various mechanisms can be considered in ischemic stroke with internal carotid artery (ICA) occlusive diseases. We clarified the etiologic mechanisms from lesion patterns on diffusion-weighted imaging (DWI). Methods: One hundred and twenty consecutive ischemic stroke patients with ipsilateral ICA occlusive diseases were enrolled and classified into 3 groups according to the size of DWI lesions: group A, massive; group B, moderate-to-large; and group C, small. Group C was divided into 3 subgroups according to the number of lesions: C1, 1–3; C2, 4–9; and C3, 10 or more. The relationship between the DWI findings and stroke subtypes according to the TOAST classification was investigated. Results: Cardioembolism was significantly more common in groups A and B than in group C, while large-artery atherosclerosis (LAA) was more frequent in group C than in groups A and B. In group A, cardioembolism accounted for 32%, while LAA was not observed. Statistical analyses showed trends toward a higher frequency of LAA in groups C2 and C3 than in group C1. Conclusions: Mechanisms of acute stroke in ICA diseases can be simply assessed from the lesion size and number, which may be useful in considering acute therapeutic strategies.

Lesion Patterns on Early Diffusion-weighted Magnetic Resonance Imaging and Ischemic Stroke Subtypes

“…We detected diffuse scattered lesions in one vascular area in the LAA group at a higher rate. Our result was concordant with previous studies (6,8,11,14,15). The presence of either "string of pearls" or "scattered pearls" on MRI was found to be associated with an independently determined mechanism of intracranial or extracranial arterial stenosis (16,17).…”