Abstract TP88: Optimal Detection of Plaque Hemorrhage in Acute Ischemic Stroke With Mild to Moderate Carotid Stenosis: Does Time-of-Flight Magnetic Resonance Angiography Represent Intraplaque Hemorrhage?

Background: Carotid intraplaque hemorrhage (IPH) is well known for a risk indicator for thromboembolism, but not easy to detect it rapidly in acute symptomatic carotid disease. The aim of this study was to assess usefulness of time-of-flight (TOF) MRA for the detection of IPH in patients with acute symptomatic carotid diseases. Methods: We retrospectively identified consecutive patients with acute symptomatic carotid disease who were admitted within 12 hours after stroke onset. Fifty-nine patients underwent TOF MRA at admission and were divided according to the presence of intraplaque high signal intensity (HSI). The severity of carotid stenosis and diffusion weighted imaging (DWI) MRI lesion patterns were evaluated. Results: Intraplaque HSI was detected in 28.8% of total enrolled patients (17/59). Mild to moderate symptomatic carotid stenosis was more in the intraplaque HSI positive group (70.6%) than the intraplaque HSI negative group (42.8%) (p=0.025). The patients with intraplaque HSI more frequently demonstrated disseminated small infarction pattern (76.5% in the intraplaque HSI positive, 47.6% in the negative group), and did not show border-zone infarction pattern (0% in the positive, 16.7% in the negative group). Conclusion: TOF MRA in acute symptomatic carotid disease may be noninvasive and rapid tool to detect the IPH. The IPH was common in smaller degree of carotid stenosis and demonstrated disseminated small infarction pattern. Intraplaque HSI on TOF MRA in acute symptomatic carotid disease may help determine the mechanism of stroke and establish treatment plan early.