PURPOSE Different CT-based protocols are being used in acute ischemic stroke. We aimed to assess the added value of delayed-phase CT angiography (CTA) and CT perfusion (CTP) to a basic protocol using non-contrast computerized tomography (NCCT) with arterial-phase CTA in patient selection for mechanical thrombectomy. METHODS We retrospectively included consecutive acute ischemic stroke patients with a symptomatic intracranial arterial occlusion between January 2015 and November 2016 who underwent NCCT, arterial and delayed-phase CTA, and CTP. These imaging studies were grouped into five protocols: (1) NCCT and arterial-phase CTA; (2) NCCT, arterial-phase CTA, and CTP; (3) NCCT, arterial- and delayed-phase CTA; (4) NCCT, arterial- and delayed-phase CTA, and CTP; and (5) NCCT and delayed-phase CTA. Two interventional neuro-radiologists independently decided on mechanical thrombectomy for each patient based on the protocols. They reached consensus for discrepant decisions. We assessed the raters' confidence level, inter-rater agreement, and compared treatment decisions for the different protocols. RESULTS We included 73 patients (44% male, mean age 74). The inter-rater agreement was substantial for protocols with three or more modalities (ҡ = 0.613-0.704) and moderate for two-modality protocols (ҡ = 0.506-0.529). The highest agreement and confidence level was achieved for the combination of NCCT, arterial-phase CTA, and CTP. Adding CTP to NCCT and arterial-phase CTA resulted in a 10% increase of recommendations for mechanical thrombectomy and adding delayed-phase CTA resulted in a 4% increase. These management changes did not reach statistical significance (p = 0.07; p = 0.25, respectively). CONCLUSION Adding CTP and/or a delayed-phase CTA to NCCT with arterial-phase CTA improves the decision-maker's confidence level and creates a trend towards a lower threshold for mechanical thrombectomy.

中文翻译：

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比较用于急性缺血性卒中的机械血栓切除术决策的多模式CT扫描方案。

目的在急性缺血性卒中中使用不同的基于CT的方案。我们的目的是评估在使用机械性血栓切除术的患者选择中，使用非对比计算机断层扫描（NCCT）和动脉期CTA的基本方案，评估延迟期CT血管造影（CTA）和CT灌注（CTP）的附加价值。方法我们回顾性分析了2015年1月至2016年11月间连续有症状的颅内动脉闭塞的急性缺血性中风患者，这些患者接受了NCCT，动脉期和延迟期CTA以及CTP。这些影像学研究分为五种方案：（1）NCCT和动脉期CTA；（2）NCCT，动脉期CTA和CTP；（3）NCCT，动脉期和延迟期CTA；（4）NCCT，动脉期和延迟期CTA和CTP；（5）NCCT和延迟CTA。两名介入神经放射科医生根据协议分别为每位患者决定进行机械血栓切除术。他们就不一致的决定达成共识。我们评估了评估者的置信度，评估者之间的共识，并比较了不同方案的治疗决策。结果我们纳入了73例患者（男性44％，平均年龄74岁）。评分者之间的协议对于具有三种或三种以上模式的协议（ҡ= 0.613-0.704）至关重要，而对于两种模式的协议（moderate = 0.506-0.529）则适中。NCCT，动脉期CTA和CTP的组合达到了最高的一致性和置信度。在NCCT和动脉期CTA中增加CTP可使机械性血栓切除术的建议增加10％，而延迟期CTA的建议则增加4％。这些管理变化未达到统计学显着性（分别为p = 0.07; p = 0.25）。结论在动脉CT CTA的NCCT中增加CTP和/或延迟相CTA可以提高决策者的置信度，并有降低机械血栓切除术门槛的趋势。