Lesion homogeneity on diffusion-weighted imaging is a marker of outcome in acute ischemic stroke

Abstract

Background and purpose: MRI Diffusion-weighted imaging (DWI) lesion volume, pattern, and location have all been used to predict outcome of acute ischemic stroke. We hypothesized that homogeneity within the DWI lesion may also be associated with outcome. Methods: Brain MRI including DWI was performed for consecutive acute ischemic stroke patients within 48 h of onset. Patients were classified as having a homogenous or non-homogenous (heterogeneous) DWI lesion visually. NIHSS was recorded at baseline, 1 week and at 1 month. Modified Rankin Scale (mRS) score was assessed at 3 months. Results: Fifteen patients were recruited to each group (homogenous and non-homogenous DWI lesion). There were no significant differences at baseline (p > 0.05). Patients with a homogenous DWI lesion had significantly higher mRS score at 3 months (worse outcome) than those with a non-homogenous (heterogeneous) DWI lesion (median, IQR 4, 2–4 vs. 1, 0–2 respectively, p = 0.001). On repeated measures ANOVA, NIHSS was significantly worse at 1 week and 1 month in patients with a homogenous DWI lesion. Conclusion: Lesion homogeneity on early MR DWI is a simple and reproducible visual assessment that may be a strong marker of outcome in acute ischemic stroke.