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.

中文翻译：

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高分辨率血管壁成像识别的前后循环颅内动脉粥样硬化的模式和意义。

引言 前循环和后循环动脉粥样硬化在血管危险因素和卒中模式方面有所不同。后循环卒中的临床结果更差。然而，很少有研究通过高分辨率血管壁成像（HR-VWI）描述前循环动脉粥样硬化和后循环动脉粥样硬化斑块特征的区分。我们的目的是比较前循环和后循环之间的斑块成像特征，以强调斑块成像特征与缺血性卒中临床事件的相关性。方法 对急性缺血性卒中或短暂性脑缺血发作成人患者 HR-VWI 队列的前瞻性数据进行回顾性分析。在 HR-VWI 上对大脑中动脉 (MCA)、基底动脉 (BA) 和椎动脉 (VA) 的动脉粥样硬化斑块进行定量和定性测量。狭窄程度超过30%的血管通过匹配的飞行时间磁共振血管造影（TOF-MRA）进行识别，并目视分类为正常、不规则、狭窄和闭塞。以HR-VWI结果为参考标准，通过定量计算TOF-MRA检测异常血管的敏感性、特异性、阳性和阴性预测值。结果 本研究纳入 101 名患者（中位年龄 64 岁；62.4% 为男性）。总共鉴定出 292 个斑块，其中 152 个位于 MCA，35 个位于 BA，105 个位于 VA。VA 具有显着更高的增强指数 (EI)（中位数 38.37 vs. 18.40，p <0.001）、更多的正重塑斑块（76.2% vs. 57.2%，p = 0.002）和斑块内低强度（43.8% vs. 12.5） %, p <0.001) 高于 MCA。MCA 比 VA 出现更多斑块内出血 (IPH)（20.4% vs. 8.6%，p = 0.014）。TOF-MRA评估管腔狭窄的敏感性和特异性在前循环中分别为89.0（82.5-93.4）和66.7（24.1-94.0），在后循环中分别为75.2（66.7-82.2）和27.3（7.3-60.7） ， 分别。结论 我们的研究结果可能阐明前循环和后循环卒中的临床事件和结果。后循环动脉粥样硬化的EI较高，低信号斑块较多，提示动脉粥样硬化负担较重。后循环动脉粥样硬化的正向重塑模式可能会产生“更宽”血管腔的印象，导致与 HR-VWI 相比，TOF-MRA 可能低估后循环的动脉粥样硬化负担。此外，前循环动脉粥样硬化伴IPH可能与斑块破裂和动脉间栓塞有关。需要未来的研究来验证这些发现。