From the Division of Neurology (J.C.K, B.B., R.W., N.A.L., K.B.), University of Alberta, Edmonton, Canada.
Department of Neurology, Christian Medical College, Ludhiana, Punjab, India (M.K.).
Stroke. 2019 Sep;50(9):2389-2395. doi: 10.1161/STROKEAHA.119.025537. Epub 2019 Aug 1.
Background and Purpose- Cerebral perfusion in acute ischemic stroke patients is often assessed before endovascular thrombectomy (EVT), but rarely after. Perfusion data obtained following EVT may provide additional prognostic information. We developed a tool to quantitatively derive perfusion measurements from digital subtraction angiography (DSA) data and examined perfusion in patients following EVT. Methods- Source DSA images from acute anterior circulation stroke patients undergoing EVT were retrospectively assessed. Following deconvolution, maps of mean transit time (MTT) were generated from post-EVT DSA source data. Thrombolysis in Cerebral Infarction grades and MTT in patients with and without hemorrhagic transformation (HT) at 24 hours were compared. Receiver operating characteristic modeling was used to classify the presence/absence of HT at 24 hours by MTT. Results- Perfusion maps were generated in 50 patients using DSA acquisitions that were a median (interquartile range) of 9 (8-10) seconds in duration. The median post-EVT MTT within the affected territory was 2.6 (2.2-3.3) seconds. HT was observed on follow-up computed tomography in 16 (32%) patients. Thrombolysis in Cerebral Infarction grades did not differ in patients with HT from those without (P=0.575). Post-EVT MTT maps demonstrated focal areas of hyperperfusion (n=8) or persisting hypoperfusion (n=3) corresponding to the regions where HT later developed. The relationship between MTT and HT was U-shaped; HT occurred in patients at both the lowest and highest extremes of MTT. An MTT threshold <2 or >4 seconds was 81% sensitive and 94% specific for classifying the presence of HT at follow-up. Conclusions- Perfusion measurements can be obtained using DSA perfusion with minimal changes to current stroke protocols. Perfusion imaging post-recanalization may have additional clinical utility beyond visual assessment of source angiographic images alone.
背景与目的-急性缺血性脑卒中患者的脑灌注通常在血管内血栓切除术（EVT）前进行评估，但很少在术后进行。EVT 后获得的灌注数据可能提供额外的预后信息。我们开发了一种工具，用于从数字减影血管造影（DSA）数据中定量获取灌注测量值，并检查 EVT 后患者的灌注情况。方法-回顾性评估接受 EVT 的急性前循环卒中患者的源 DSA 图像。去卷积后，从术后 DSA 源数据生成平均通过时间（MTT）图。比较 24 小时时血栓溶解分级和有无出血转化（HT）患者的 MTT。使用受试者工作特征模型通过 MTT 对 24 小时时 HT 的存在/不存在进行分类。结果-使用 DSA 采集生成了 50 例患者的灌注图，采集持续时间中位数（四分位距）为 9（8-10）秒。受影响区域内的中位术后 MTT 为 2.6（2.2-3.3）秒。16 例（32%）患者在随访 CT 上观察到 HT。HT 患者与无 HT 患者的血栓溶解分级无差异（P=0.575）。MTT 图显示与随后发生 HT 的区域相对应的局部高灌注区（n=8）或持续低灌注区（n=3）。MTT 与 HT 之间的关系呈 U 形；MTT 值最低和最高的患者均发生 HT。MTT<2 或>4 秒的阈值对预测随访时 HT 的存在具有 81%的敏感性和 94%的特异性。结论-使用 DSA 灌注可以在不改变当前卒中方案的情况下获得灌注测量值。再通后灌注成像除了对源血管造影图像的单独视觉评估外，可能具有额外的临床效用。
