Synopsis

Keywords: Stroke, Atherosclerosis, Calcification

Intracranial atherosclerotic plaque is a major cause of stroke. Both CTA and vessel wall magnetic resonance imaging (VW-MRI) can identify high risk plaque features. We aim to investigate the intracranial atherosclerotic plaque features associated with recurrent stroke using a multi-modality imaging approach by combining CTA and whole brain VW-MR. We found that higher calcium burden quantified by volume and Agatston score of intracranial arteries, as well as whole-brain plaque number and culprit plaque burden were independently associated with recurrent acute stroke.

Background and Purpose

Background and Purpose: Intracranial atherosclerotic plaque is a major cause of stroke. Both computed tomography angiography (CTA) and vessel wall magnetic resonance imaging (VW-MRI) can identify high risk plaque features. However, the two imaging modalities have rarely been used together. We aim to investigate the intracranial atherosclerotic plaque features associated with recurrent stroke using a multi-modality imaging approach by combining CTA and whole brain VW-MRI.

Methods

Methods: Eighty-nine patients with acute ischemic stroke caused by intracranial plaque were included, and they had CTA and VW-MRI within 1 month of stroke. Participants were divided into two group: first-time acute stroke (n=50) and recurrent acute stroke (n=39). Calcium burden was quantified semiautomatically by calculating total spotty calcium number, whole-brain Agatston scores and calcium volumes on thin-section unenhanced CT images (resolution 0.5x0.4x0.4mm3). Meanwhile, whole-brain plaque number, degree of culprit plaque luminal stenosis, culprit plaque burden, intraplaque hemorrhage were assessed on VW-MRI sequences (0.6mm isotropic resolution). Those characteristics were compared between two groups. Multivariate regression analysis was performed to assess the correlation between plaque features and recurrent acute stroke.

Results

Results: A total of 89 participants (age 61.3±8.7 years, 54[60.7%] male) were included in this study. More spotty calcium and whole-brain plaques were found in recurrent stroke patients than first-time stroke patients (p=0.041 and P=0.017). Recurrent stroke patients had larger calcium volume (p=0.031), higher calcium score (p=0.008) and greater culprit plaque burden (p=0.002). After adjustment of clinical demographic factors, in multivariate analysis, calcium volume (odds ratio, OR=7.787; p=0.044), calcium score (OR=1.421; p=0.035), whole-brain plaque number (OR=1.378; p=0.032) and culprit plaque burden (OR=3.087; P=0.002) were all independently associated with recurrent acute stroke compared to the first-time acute stroke. The AUC of MRI was 0.745 and CT was 0.723, and the combination of both CT and MRI achieved AUC of 0.803.

Conclusions

Conclusions: Higher calcium burden quantified by volume and Agatston score of intracranial arteries, as well as whole-brain plaque number and culprit plaque burden were independently associated with recurrent acute stroke. The use of both CTA and VW-MRI achieved better performance of differentiating high risk intracranial plaque than a single imaging modality.

Acknowledgements

Not applicable.