Risk factors for small cortical infarction on diffusion-weighted magnetic resonance imaging in patients with acute ischemic stroke.

Diffusion-weighted magnetic resonance imaging (MRI) is sensitive for detecting acute ischemic lesions. The present study evaluated risk factors associated with small cortical infarction (SCI) on diffusion-weighted MRI. We analyzed 123 patients with acute ischemic stroke retrospectively. We defined an SCI as a cortical lesions < 1.5 cm in diameter detected by diffusion-weighted MRI. Risk factors and comorbidities included hypertension, hypercholesterolemia, diabetes mellitus, cigarette smoking, potential cardiac sources of embolism, carotid disease, and coagulopathy. Carotid disease was defined as > 50% stenosis or occlusion in the internal carotid artery, detected by carotid ultrasonography. In addition, we analyzed plasma levels of coagulation and fibrinolysis markers. We also compared carotid disease, potential cardiac sources, and coagulopathy among localization of SCI. SCI was identified in 22.8% of patients with acute ischemic stroke. Carotid disease (odds ratio [OR] = 4.4; 95% confidence interval [CI] = 1.7-11.42; P = .002) and coagulopathy (OR = 6.8; 95% CI = 1.33-35.17; P = .02) were found to be independent risk factors for SCI. SCI with carotid disease was not associated with bilateral and multiple territorial lesions, whereas SCI with coagulopathy was associated with bilateral lesions. No borderzone lesions were found in SCI patients with cardiac sources. Our findings suggest that carotid disease and coagulopathy are independent risk factors for SCI. Localization of SCI varies depending on the underlying diseases.