Figure 1.

Flowchart of the processing steps required to compare CTP-defined ischemic core to a DWI standard reference. Each processing step can impact the perfusion analysis and influence the observed performance of CTP in terms of infarct core prediction. Only studies that use equivalent implementations are directly comparable. To allow for better inter-study comparability, we have created an open-source CTP benchmarking tool in which all processes are standardized (green outline: co-registration, DWI lesion outlining, and statistical evaluation), except for the CTP algorithm used to segment the infarct core (orange outline).