UNASSIGNED: We searched Medline, Embase, the Cochrane Library, and reference lists of manuscripts up to April 2022 using the following terms \"computed tomography perfusion,\" \"stroke,\" \"infarct,\" and \"penumbra.\" Studies were included if they reported perfusion thresholds and undertook co-registration of CTP to reference standards. The quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool and Standards for Reporting of Diagnostic Accuracy (STARD) guidelines.
UNASSIGNED: A total of 24 studies were included. A meta-analysis could not be performed due to insufficient data and significant heterogeneity in the study design. When reported, the mean age was 70.2 years (SD+/-3.69), and the median NIHSS on admission was 15 (IQR 13-17). The perfusion parameter identified for the core was relative cerebral blood flow (rCBF), with a median threshold of <30% (IQR 30, 40%). However, later studies reported lower thresholds in the early time window with rapid reperfusion (median 25%, IQR 20, 30%). A total of 15 studies defined a single threshold for all brain regions irrespective of collaterals and the gray and white matter.
UNASSIGNED: A single threshold and parameter may not always accurately differentiate penumbra from core and oligemia. Further refinement of parameters is needed in the current era of reperfusion therapy.
■我们搜索了Medline,Embase,Cochrane图书馆,以及截至2022年4月的手稿参考清单,使用以下术语“计算机断层扫描灌注,\"\"笔画,\"\"梗塞,“和”半影。“如果研究报告了灌注阈值,并将CTP与参考标准进行了共同注册,则包括在内。使用诊断准确性研究质量评估-2(QUADAS-2)工具和诊断准确性报告标准(STARD)指南评估研究质量。
■共纳入24项研究。由于研究设计中的数据不足和显著的异质性,无法进行荟萃分析。报告时,平均年龄为70.2岁(SD+/-3.69),入院时NIHSS中位数为15(IQR13-17)。为核心确定的灌注参数是相对脑血流量(rCBF),中位阈值<30%(IQR30,40%)。然而,后来的研究报告了在快速再灌注的早期时间窗中阈值较低(中位数25%,IQR20,30%)。总共15项研究为所有大脑区域定义了一个单一的阈值,而不考虑侧支以及灰质和白质。
■单个阈值和参数可能并不总是准确地将半暗带与核心和少血症区分开。在当前的再灌注治疗时代,需要进一步完善参数。