Abstract WP136: Perfusion and Plaque Evaluation in Symptomatic Middle Cerebral Arterial Athrosclerotic Stenosis: Characterization With Multimodel MRI

Abstract

Objevtive: We investigated the baseline demographics of patients with severe unilateral middle cerebral artery(MCA) athrosclerotic stenosis using multimodel MRI and tired to find out the hemodynamic and plaque features of patients who had recurrent stroke. Methods: This retrospective study had recruited consecutive patients with severe unilateral MCA athrosclerotic stenosis at 2 centers. All patients were performed arterial spin labeling(ASL) with post labeling delay(PLD) of 1.5s and 2.5s, MR angiography and high-resolution MRI. Hypoerfusion volume ratio (HVR) was calculated as [hypoperfusion volume at 2.5s / hypoperfusion volume at 1.5s X 100%]. Plaques enhancement at maximal lumen narrowing were graded from 0(none enhancement) to 3(signal intensity as high as post-contrast pituitary). In patients who had conducted conventional angiography, Spearman correlation was analyzed between collateral grades and HVR. Baseline characteristics were compared between patients with 1 year follow up ischemic events(event+) and without(event-), then multivariable logistic analysis was performed. Results: Thirty-seven patients (47.1±11.8 years; 25 men) were included in this study. HVR was with a mean of 24.9±23.6% and ranged from 0% to 93%. In 17 patients (50.47±7.23 years; 12 men) who had underwent conventional angiography, HVR was significantly correlated with collateral grading (r=-0.40, p=0.0493). In 1 year follow up, 7 patients had recurrent events in the same territory. NIHSS, HVR was significantly higher in Event+ group(p<0.05) and no significantly difference was detected in plaque enhancement grade as well as age, risk factors, qualifying event and time from symptom onset to imaging. In multivariable analysis, HVR >50% was significantly associated with recurrent stroke(OR=13.714, 95% confidence interval: 1.061-177.320, p=0.045) after adjusted by NIHSS and plaque enhancement grade. Conclusion: Multimodel MRI may be a promising approach to explore the mechanism of ischemic stroke in patients with intracranial artery stenosis. HVR obtained from 2 PLD ASL is associated with collateral circulation and may be predictable for recurrent stroke.This work was supported by the National Natural Science Foundation of China (Grant number: 81471390).