From the Department of Clinical Neurosciences (W.Q., H.K., M.D.H., A.M.D., M.G., B.K.M.), University of Calgary.
Lawson Health Research Institute and Robarts Research Institute (T.Y.L.).
Stroke. 2019 Nov;50(11):3269-3273. doi: 10.1161/STROKEAHA.119.026281. Epub 2019 Sep 4.
Background and Purpose- Computed tomographic perfusion (CTP) thresholds associated with follow-up brain infarction may differ by time from symptom onset to imaging and reperfusion. We confirm CTP thresholds over time to imaging and reperfusion in patients with acute ischemic stroke from the HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) data. Methods- Patients with occlusion on CT angiography were acutely imaged with CTP. Noncontrast CT and magnetic resonance-diffusion weighted imaging at 24 to 48 hours defined follow-up infarction. Reperfusion was assessed on conventional angiogram. Tmax, cerebral blood flow (CBF), and cerebral blood volume maps were derived from delay-insensitive CTP postprocessing. These parameters were analyzed using receiver operator characteristics to derive optimal thresholds based on time from stroke onset-to-CTP or to reperfusion. ANOVA and linear regression were used to test whether the derived CTP thresholds were different by time. Results- One hundred thirty-seven patients were included. Tmax thresholds of >15.7 s and >15.8 s and absolute CBF thresholds of <8.9 and <7.5 mL·min·100 g for gray matter and white matter respectively were associated with infarct if reperfusion was achieved <90 minutes from CTP with stroke onset-to-CTP <180 minutes. The discriminative ability of cerebral blood volume was modest. There were no statistically significant relationships between stroke onset-to-CTP time and Tmax, CBF, and cerebral blood volume thresholds (all >0.05). A statistically significant relationship was observed between CTP-to-reperfusion time and the optimal thresholds for Tmax (<0.001) and CBF (<0.001). Similar but more modest relationship was noted for onset-to-reperfusion time and optimal thresholds for CBF (≤0.01). Conclusions- CTP thresholds based on stroke onset and imaging time and taking into account time needed for reperfusion may improve infarct prediction in patients with acute ischemic stroke.
背景与目的- 与随访脑梗死相关的计算机断层灌注（CTP）阈值可能因症状发作到成像和再灌注的时间而有所不同。我们通过 HERMES 协作（多血管内卒中介入试验中的高效再灌注评估）的数据，对急性缺血性脑卒中患者的随时间变化的 CTP 阈值进行了确认。方法- 对 CT 血管造影上有闭塞的患者进行急性 CTP 成像。24 至 48 小时的非对比 CT 和磁共振弥散加权成像定义为随访性梗死。在常规血管造影上评估再灌注。从延迟不敏感的 CTP 后处理中得出 Tmax、脑血流（CBF）和脑血容量图。使用受试者工作特征曲线分析这些参数，以基于从卒中发作到 CTP 或再灌注的时间来得出最佳阈值。使用方差分析和线性回归来测试是否基于从卒中发作到 CTP 的时间不同，推导的 CTP 阈值也不同。结果- 共纳入 137 例患者。如果在 CTP 后 90 分钟内实现再灌注，且从卒中发作到 CTP 的时间<180 分钟，则 Tmax 阈值>15.7s 和>15.8s，以及灰质和白质的绝对 CBF 阈值<8.9 和<7.5mL·min·100g，与梗死相关。脑血容量的判别能力适中。从卒中发作到 CTP 的时间与 Tmax、CBF 和脑血容量阈值之间没有统计学上的显著关系（均>0.05）。在 CTP 到再灌注的时间与 Tmax（<0.001）和 CBF（<0.001）的最佳阈值之间观察到了统计学上显著的关系。在从卒中发作到再灌注的时间与 CBF 的最佳阈值之间也注意到了类似但更适中的关系（≤0.01）。结论- 基于卒中发作和成像时间并考虑到再灌注所需时间的 CTP 阈值可能会提高急性缺血性脑卒中患者的梗死预测能力。
