Patterns and Implications of Intracranial Atherosclerosis in Anterior and Posterior Circulation Identified by High-Resolution Vessel Wall Imaging

Lu Zheng; Jia Li; Wenjie Yang; Ho-Ching Chloe Lam; K S Lawrence Wong; Winnie Chu; Thomas Wai Hong Leung; Xiangyan Chen

doi:10.1159/000534822

Patterns and Implications of Intracranial Atherosclerosis in Anterior and Posterior Circulation Identified by High-Resolution Vessel Wall Imaging

Cerebrovasc Dis. 2023 Nov 21:1-8. doi: 10.1159/000534822. Online ahead of print.

Authors

Lu Zheng^{1

2}, Jia Li³, Wenjie Yang⁴, Ho-Ching Chloe Lam², K S Lawrence Wong², Winnie Chu⁵, Thomas Wai Hong Leung², Xiangyan Chen⁶

Affiliations

¹ Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
² Division of Neurology, Department of Medicine and Therapeutics, The Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
³ Department of Neurology, Wuhan No.1 Hospital, Huazhong University of Science and Technology, Wuhan, China, jia-thomas.li@connect.polyu.hk.
⁴ Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Baltimore, Baltimore, Maryland, USA.
⁵ Department of Imaging and Interventional Radiology, The Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
⁶ Department of Health Technology and Informatics, the Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.

PMID: 37989118
DOI: 10.1159/000534822

Abstract

Introduction: Anterior and posterior circulation atheroscleroses differ in vascular risk factors and stroke patterns. Posterior circulation stroke has worse clinical outcomes. However, few studies described the differentiation of plaque features between anterior and posterior circulation atheroscleroses via high-resolution vessel wall imaging (HR-VWI). We aimed to compare the plaque imaging features between anterior and posterior circulations to highlight the relevance of plaque imaging features to clinical events of ischemic stroke.

Methods: Prospective data from a HR-VWI cohort of adult patients with acute ischemic stroke or transient ischemic attack were retrospectively analyzed. Quantitative and qualitative measurements of atherosclerotic plaques along the middle cerebral arteries (MCAs), the basilar artery (BA), and the vertebral arteries (VAs) were conducted on HR-VWI. Vessels with stenotic degrees over 30% were identified on the matched time-of-flight magnetic resonance angiography (TOF-MRA) and visually classified into normal, irregular, stenotic, and occluded. The sensitivity, specificity, positive and negative predictive values for TOF-MRA in detecting abnormal vessels were calculated by using quantification on the basis of HR-VWI findings as the reference standard.

Results: One hundred and one patients (median age, 64 years old; 62.4% males) were included in this study. A total of 292 plaques were identified, with 152 in the MCAs, 35 in the BA, and 105 in the VAs. The VAs possessed significantly higher enhancement index (EI) (median 38.37 vs. 18.40, p <0.001), more plaques with positive remodeling (76.2% vs. 57.2%, p = 0.002) and intraplaque hypo-intensity (43.8% vs. 12.5%, p <0.001) than the MCAs. The MCAs presented with more intraplaque hemorrhage (IPH) (20.4% vs. 8.6%, p = 0.014) than the VAs. The sensitivity and specificity of TOF-MRA for evaluating luminal stenosis were 89.0 (82.5-93.4) and 66.7 (24.1-94.0) in anterior circulation, respectively, and were 75.2 (66.7-82.2) and 27.3 (7.3-60.7) in posterior circulation, respectively.

Conclusion: Our findings might elucidate the clinical events and outcomes in anterior and posterior circulation stroke. Posterior circulation atherosclerosis had higher EI and more plaques with hypo-intensity, suggesting a heavier atherosclerosis burden. Positive remodeling pattern in posterior circulation atherosclerosis might create an impression of "wider" vascular lumen, leading to possible underestimation of atherosclerosis burden of posterior circulation on TOF-MRA as compared to HR-VWI. Besides, anterior circulation atherosclerosis with IPH might be associated with plaque rupture and artery-to-artery embolism. Future studies are needed to verify these findings.

Keywords: Anterior circulation; Intracranial atherosclerosis; Plaque imaging features; Posterior circulation.