Association between carotid atherosclerosis plaque with high signal intensity on T1-weighted imaging and subsequent ipsilateral ischemic events.

BACKGROUND: An association between magnetic resonance imaging detection of intraplaque hemorrhage and the risk of cerebral ischemic events has been described. However, few studies have followed patients with intraplaque hemorrhage.
OBJECTIVE: We used 3-dimensional gradient-echo black-blood T1-weighted imaging (screening BB [S-BB]) as a magnetic resonance imaging sequence to evaluate acute cerebrovascular stroke. The association between S-BB high signal plaques and the risk of subsequent ipsilateral ischemic events was investigated.
METHODS: A total of 928 consecutive patients hospitalized for a stroke or transient ischemic attack according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification were evaluated. Recurrence was retrospectively evaluated in S-BB-positive patients and patients with severe stenosis (SS) (≥70%) by magnetic resonance angiography. Based on clinical and imaging findings, recurrence was defined as a carotid artery stroke or transient ischemic attack that developed after hospital discharge as an initial event.
RESULTS: Sixty-six patients were S-BB positive and 62 patients had severe stenosis (S-BB positive with SS, 32 patients; S-BB negative with SS, 30 patients; S-BB positive without SS, 34 patients). During a mean follow-up period of 9.1 months, 7 S-BB-positive patients with SS (18.7%) and 1 S-BB-negative patient with SS (3%) had a recurrent event (P = .051). In the S-BB-positive group, in 34 patients without SS, the recurrence rate was 14.7% (5/34); the difference in the recurrence rate between S-BB-positive group with and without SS was not significant (P = .34).
CONCLUSION: Patients with carotid artery lesions and intraplaque hemorrhage tend to be at higher risk of a subsequent ipsilateral ischemic event. Risk evaluation of carotid artery disease should include plaque characteristics.