Abstract WMP19: Identifying in vivo Luminal Thrombus Within 72 Hours After Stroke Onset: Interim Results of the Stroke Imaging Package Study

Abstract

Background: The presence of luminal thrombus is associated with a high risk of stroke recurrence. Using high-resolution magnetic resonance imaging(HRMRI) and susceptibility-weighted imaging(SWI), luminal thrombus can be identified in vivo. We aimed to investigate the occurrence of luminal thrombus in patients with acute ischemic stroke. Methods: Patients with first ever stroke within 72 hours from onset, confirmed by diffusion weighted imaging, were recruited from 16 medical centers. Conventional MRI, magnetic resonance angiography, HRMRI (including 3-dimentional T1 images and 2-dimentional T2 images), and SWI were performed. Luminal thrombus was identified if isointense/hyperintense signals on 3-dimentional T1 images of HRMRI or susceptibility vessel sign on SWI were observed within the course of intracranial arteries. Results: Six hundred and one patients (70% male, mean age 61±16 years old, mean NIHSS 6± 5) were enrolled. Among them, 112 patients underwent recanalization therapies. Median time from symptom onset to MRI was 44 ± 20 hours. Luminal thrombus was identified in 138 (23%)patients. The occurrence rate of luminal thrombus was non-significantly different between the patients treated with and without recanalization therapies(16% vs.25%, p=0.054). Symptomatic luminal thrombus was more likely observed in large artery atherosclerosis stroke(121/240,50%) and cardicac stroke(11/36,31%) than other stroke subtypes (0/288 in lacunar stroke, 0/6 in stroke of undetermined etiology and 1/31 in cryptogenic stroke, P<0.001). There were five patients with asymptomatic luminal thrombus irrelevant to ischemic lesions. Conclusions: Luminal thrombus is common in patients with acute ischemic stroke within 72 hours from onset. Further studies are required to clarify whether in vivo thrombus imaging can predict early stroke recurrence.