Department of Medical Sciences, University of Calgary, Calgary, Canada.
Calgary Stroke Program, Department of Clinical Neurosciences, University of Calgary, 3330 Hospital Drive NW, AB T2N 4N1, Calgary, Canada.
Clin Neuroradiol. 2019 Sep;29(3):543-552. doi: 10.1007/s00062-018-0717-x. Epub 2018 Aug 21.
Acute stroke treatment requires simple, quick and accurate detection of early ischemic changes to facilitate treatment decisions guided by published selection criteria. The aim of this study was to determine the accuracy and reliability of multiphase computed tomography angiography (mCTA) perfusion hypoattenuation for detecting early severe ischemia.
Non-contrast CT (NCCT), mCTA for regional leptomeningeal score (mCTA-rLMC), and mCTA perfusion lesion visibility (mCTA-arterial and mCTA-venous) were assessed blinded to clinical information in patients treated with endovascular therapy (EVT). The extent of early ischemia defined by regions of hypoattenuation was evaluated by the Alberta Stroke Program Early CT Score (ASPECTS). The ASPECTS scores were dichotomized based on the American Heart Association (AHA) guidelines for EVT selection, ASPECTS ≥6 vs. <6. The diagnostic accuracy was calculated by comparison to 24-h magnetic resonance imaging (MRI) or CT ASPECTS. Inter-observer reliability of NCCT and mCTA ASPECTS was evaluated. Machine learning models were used to predict the clinical follow-up outcome, e.g. National Institutes of Health Stroke scale (NIHSS) and modified Rankin scale (mRS) from baseline imaging data and patient information.
A total of 89 acute stroke patients (68 ± 15 years of age) were analyzed (33 TICI-0, 56 TICI-2b or 3). Median baseline NIHSS was 17. The mCTA-venous had a large effect on accurately identifying early ischemia when dichotomized for ASPECTS ≥6 vs <6 (likelihood ratio [LR+] > 10 vs. [LR-] < 0.29) compared to the moderate effect of NCCT ([LR+] = 6.7; [LR-] = 0.56) and mCTA-rLMC [(LR+ = 8.0; (LR-) = 0.83)]. The inter-observer reliability in mCTA-venous was almost perfect for all ASPECTS regions except the internal capsule. The machine learning support factor regression model identified mCTA-venous as the most important imaging covariate for predicting 24-h NIHSS and 90-day mRS.
The assessment of mCTA-venous permits a more accurate detection of early ischemia than NCCT and mCTA-rLMC score and is predictive of clinical outcome. We would recommend the inclusion of mCTA perfusion lesion in future endovascular trials aiming at extending current AHA guidelines for EVT in stroke patients with low ASPECTS.
急性脑卒中的治疗需要快速、准确地检测早期缺血性改变，以便根据已发表的选择标准做出治疗决策。本研究旨在确定多期 CT 血管造影（mCTA）灌注低信号对早期严重缺血的检测的准确性和可靠性。
对接受血管内治疗（EVT）的患者进行了非对比 CT（NCCT）、mCTA 区域软脑膜评分（mCTA-rLMC）和 mCTA 灌注病变显影（mCTA-动脉和 mCTA-静脉）的盲法评估。通过 Alberta 卒中计划早期 CT 评分（ASPECTS）评估由低信号区域定义的早期缺血程度。根据美国心脏协会（AHA）EVT 选择指南将 ASPECTS 评分分为二分类，即 ASPECTS≥6 与<6。通过与 24 小时 MRI 或 CT ASPECTS 比较，计算诊断准确性。评估 NCCT 和 mCTA ASPECTS 的观察者间可靠性。使用机器学习模型从基线成像数据和患者信息预测临床随访结果，例如 NIH 卒中量表（NIHSS）和改良 Rankin 量表（mRS）。
共分析了 89 例急性脑卒中患者（68±15 岁）（33 例 TICI-0，56 例 TICI-2b 或 3）。中位基线 NIHSS 为 17。与 NCCT（LR+>6.7；LR-<0.56）和 mCTA-rLMC（LR+>8.0；LR-<0.83）相比，mCTA-静脉对准确识别 ASPECTS≥6 与<6 之间的早期缺血具有较大影响（LR+>10 与 LR-<0.29）。mCTA-静脉在除内囊外的所有 ASPECTS 区域的观察者间可靠性几乎为完美。机器学习支持因子回归模型确定 mCTA-静脉是预测 24 小时 NIHSS 和 90 天 mRS 的最重要的影像学协变量。
与 NCCT 和 mCTA-rLMC 评分相比，mCTA-静脉评估可更准确地检测早期缺血，并可预测临床结果。我们建议在未来旨在扩大当前 AHA 对低 ASPECTS 脑卒中患者 EVT 指南的血管内试验中纳入 mCTA 灌注病变。
