To test the hypothesis that CT hypoperfusion-hypodensity mismatch identifies patients with ischemic stroke within 4.5 hours of symptom onset.

We therefore performed the Retrospective Multicenter Hypoperfusion-Hypodensity Mismatch for The identification of Patients With Stroke Within 4.5 Hours study of patients with acute ischemic stroke and known time of symptom onset. The predictive values of hypoperfusion-hypodensity mismatch for the identification of patients with symptom onset within 4.5 hours were the main outcome measure.

Of 666 patients, 548 (82.3%) had multimodal CT within 4.5 hours and 118 (17.7%) beyond 4.5 hours. Hypoperfusion-hypodensity mismatch was visible in 516 (94.2%) patients with symptom onset within and in 30 (25.4%) patients beyond 4.5 hours. CT hypoperfusion-hypodensity mismatch identified patients within 4.5 hours of stroke onset with 94.2% (95% confidence interval [CI] 91.9%–95.8%) sensitivity, 74.6% (95% CI 66.0%–81.6%) specificity, 94.5% (95% CI 92.3%–96.1%) positive predictive value, and 73.3% (95% CI 64.8%–80.4%) negative predictive value. Interobserver agreement for hypoperfusion-hypodensity mismatch was substantial ( = 0.61, 95% CI 0.53–0.69).

Patients with acute ischemic stroke with absence of a hypodensity on native CT (NCCT) within the hypoperfused core lesion on perfusion CT (hypoperfusion-hypodensity mismatch) are likely to be within the time window of thrombolysis. Applying this method may guide the decision to use thrombolysis in patients with unknown time of stroke onset.

ClinicalTrials.gov Identifier: NCT04277728.

This study provides Class III evidence that CT hypoperfusion-hypodensity mismatch identifies patients with stroke within 4.5 hours of onset.

检验 CT 低灌注 - 低密度不匹配可在症状出现 4.5 小时内识别缺血性卒中患者的假设。

因此，我们对患有急性缺血性卒中和已知症状发作时间的患者进行了回顾性多中心低灌注 - 低密度不匹配以在 4.5 小时内识别卒中患者的研究。低灌注 - 低密度不匹配的预测值用于识别在 4.5 小时内出现症状的患者是主要的结果测量。

在 666 名患者中，548 名 (82.3%) 在 4.5 小时内进行了多模式 CT，118 名 (17.7%) 在 4.5 小时内进行了多模态 CT。在 4.5 小时内出现症状的 516 名 (94.2%) 患者和超过 4.5 小时的 30 名 (25.4%) 患者中可见低灌注 - 低密度不匹配。CT 低灌注-低密度不匹配可在卒中发作 4.5 小时内识别出患者，敏感性为 94.2%（95% 置信区间 [CI] 91.9%–95.8%），特异性为 74.6%（95% CI 66.0%–81.6%），特异性为 94.5%（95 % CI 92.3%–96.1%) 阳性预测值和 73.3% (95% CI 64.8%–80.4%) 阴性预测值。低灌注 - 低密度不匹配的观察者间一致是实质性的（= 0.61, 95% CI 0.53-0.69）。

急性缺血性卒中患者在灌注 CT 上灌注不足的核心病变（灌注不足 - 低密度不匹配）内未发现原生 CT （NCCT）低密度（低灌注 - 低密度不匹配），可能处于溶栓时间窗内。应用这种方法可以指导卒中发病时间未知的患者使用溶栓的决定。

ClinicalTrials.gov 标识符：NCT04277728。

该研究提供了 III 级证据，表明 CT 低灌注 - 低密度不匹配可在发病 4.5 小时内识别出卒中患者。