Clinical Significance of Intraplaque Hemorrhage in Low- and High-Grade Basilar Artery Stenosis on High-Resolution MRI

BACKGROUND AND PURPOSE: Intraplaque hemorrhage within intracranial atherosclerotic plaques identified by high-resolution MR imaging has been studied as a potential marker of stroke risk. However, previous studies only examined intracranial arteries with high-grade stenosis (degree of stenosis, >50%). This study aimed to ascertain the clinical relevance of intraplaque hemorrhage in patients with low- and high-grade stenotic basilar artery plaques.

MATERIALS AND METHODS: Patients with basilar artery stenosis (n = 126; mean age, 62 ± 10 years; 66 symptomatic and 60 asymptomatic) underwent high-resolution MR imaging. The relationship between imaging findings (intraplaque hemorrhage, contrast enhancement, degree of stenosis, minimal lumen area, and plaque burden) and symptoms was analyzed.

RESULTS: Intraplaque hemorrhage was identified in 22 patients (17.5%), including 21 (31.8%) symptomatic patients and 1 (1.7%) asymptomatic patient. Multivariate analysis showed that intraplaque hemorrhage was the strongest independent marker of symptomatic status (odds ratio, 27.5; 95% CI, 3.4–221.5; P = .002). Contrast enhancement was also independently associated with symptomatic status (odds ratio, 9.9; 95% CI, 1.5–23.6; P = .016). Stenosis, minimal lumen area, and plaque burden were not correlated with symptoms (P > .05). Intraplaque hemorrhage was present in both low- and high-grade stenotic basilar arteries (11.3% versus 16.3%, P = .63). Diagnostic performance values of intraplaque hemorrhage for patients with acute/subacute symptomatic stroke were the following: specificity, 98.3%; sensitivity, 31.8%; positive predictive value, 95.5%; and negative predictive value, 56.7%.

CONCLUSIONS: Intraplaque hemorrhage is present in both low- and high-grade stenotic basilar artery plaques and is independently associated with symptomatic stroke status. Intraplaque hemorrhage may identify high-risk plaque and provide new insight into the management of patient with stroke without significant stenosis.