Background and Purpose-In contrast to platelet-rich white thrombi, red thrombi in the heart are rich in fibrin and trapped erythrocytes. The magnetic susceptibility effect of deoxygenated hemoglobin in red thrombi may result in hypointense signals on T2*-weighted gradient echo imaging (GRE). We tested the hypothesis that a GRE susceptibility vessel sign (SVS) is specific for cardioembolic stroke. Methods-This retrospective study examined data from acute ischemic stroke patients who underwent diffusion-weighted imaging, GRE and magnetic resonance angiography (MRA) within 24 hours of stroke onset and who had symptomatic occlusion of large intracranial arteries in the circle of Willis. Hypointense signals within vascular cisterns on GRE corresponding to symptomatic vascular occlusion were termed "GRE SVS." Recanalization was assessed on follow-up MRA performed within 7 days of onset. The relationships between GRE SVS and stroke subtypes and subsequent recanalization were explored. Results-Of the 95 patients who met the inclusion criteria, GRE SVS was observed in 45 (47.4%). GRE SVS was more commonly associated with cardioembolic stroke patients (31 of

Objective We seek to identify potentially modifiable determinants associated with variability in leptomeningeal collateral status in patients with acute ischemic stroke. Methods Data are from the Keimyung Stroke Registry. Consecutive patients with M1 segment middle cerebral artery (MCA) ± intracranial internal carotid artery (ICA) occlusions on baseline CT-angiography (CTA) from May 2004 to July 2009 were included. Baseline and follow-up imaging was analyzed blinded to all clinical information. Two raters assessed leptomeningeal collaterals on baseline CTA by consensus, using a previously validated regional leptomeningeal score (rLMC). Results Baseline characteristics (n=206) were: mean age 66.9±11.6 years, median baseline NIHSS 14 (IQR 11-20), and median stroke symptom onset to CTA 166 minutes (IQR 96-262), Poor collateral status at baseline (rLMC score 0-10) was seen in 73/206 (35.4%). On univariate analyses, patients with poor collateral status at baseline were older, hypertensive, had higher white blood cell count, blood glucose, D-dimer, serum uric acid levels, and were more likely to have metabolic syndrome. Multivariable modeling identified metabolic syndrome (OR 3.22 95% CI 1.69-6.15, p<0.001), hyperuricemia (per 1 mg/dl OR 1.35 95% CI 1.12-1.62, p<0.01) and older age (per 10 years, OR 1.34 95% CI 1.02-1.77, p=0.03) as independent predictors of poor leptomeningeal collateral status at baseline. Conclusion Metabolic syndrome, hyperuricemia and age are associated with poor leptomeningeal collateral status in patients with acute ischemic stroke.

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