Background and purpose CT perfusion (CTP) might support decision making in patients with acute ischemic stroke by providing perfusion maps of ischemic tissue. Currently, the reliability of CTP is hampered by varying results between different post-processing software packages. The purpose of this study is to compare ischemic core volumes estimated by IntelliSpace Portal (ISP) and syngo.via with core volumes as estimated by RAPID.
Methods Thirty-five CTP datasets from patients in the MR CLEAN trial were post-processed. Core volumes were estimated with ISP using default settings and with syngo.via using three different settings: default settings (method A); additional smoothing filter (method B); and adjusted settings (method C). The results were compared with RAPID. Agreement between methods was assessed using Bland–Altman analysis and intraclass correlation coefficient (ICC). Accuracy for detecting volumes up to 25 mL, 50 mL, and 70 mL was assessed. Final infarct volumes were determined on follow-up non-contrast CT.
Results Median core volume was 50 mL with ISP, 41 mL with syngo.via method A, 20 mL with method B, 36 mL with method C, and 11 mL with RAPID. Agreement ranged from poor (ISP: ICC 0.41; method A: ICC 0.23) to good (method B: ICC 0.83; method C: ICC 0.85). The bias (1.8 mL) and limits of agreement (−27, 31 mL) were the smallest with syngo.via with additional smoothing (method B). Agreement for detecting core volumes ≤25 mL with ISP was 54% and 57%, 85% and 74% for syngo.via methods A, B, and C, respectively.
Conclusion Best agreement with RAPID software is provided by syngo.via default settings with additional smoothing. Moreover, this method has the highest agreement in categorizing patients with small core volumes.
- brain ischemia
- CT perfusion
- post-processing software
- ischemic core
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Contributors The MR CLEAN trial was designed by WHZ, AvdL, RJvO, DWJD, YBWEMR, and CBLMM. OAB collected and prepared the data for the trial. OAB, RREGG, MAAvW, and SFJ collected the data for this study. MSK conducted the statistical analysis, interpreted the results, and drafted the paper. HAM and BJE assisted with the statistical analysis, interpretation of the results, and drafting the paper. OAB, MAAvW, SFJ, WHZ, RJvO, AvdL, DWJD, LFB, YBWEMR, and CBLMM critically revised the paper. All authors approved the version to be published.
Funding The MR CLEAN trial was partly funded by the Dutch Heart Foundation, grant no 2008T30, and by unrestricted grants from AngioCare BV, Medtronic/Covidien/EV3,MEDAC Gmbh/LAMEPRO, Penumbra, Stryker, and Top Medical/ Concentric.
Competing interests Amsterdam UMC, location AMC received funds from Stryker for consultations by CBLMM, YBWEMR, and OAB. CBLMM received research grants from CVON/Dutch Heart Foundation, European Commission and Twin Foundation. HAM, RREGG, CBLMM, and YBWEMR are shareholders of Nico.lab, a company that focuses on the use of artificial intelligence for medical image analysis. Erasmus MC received funds from Bracco Imaging for consultations by DWJD. Erasmus MC received funds from CVON/Dutch Heart Foundation, European Commission, Stryker, Penumbra, and Medtronic for the execution of stroke trials by DWJD and AvdL. Maastricht University Medical Center received funds from Stryker and Cerenovus for consultations by WHZ.
Ethics approval A central medical ethics committee and the research boards of all participating centers accepted the MR CLEAN trial.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Because of the sensitive nature of the data collected for this study, requests to access the data set may be sent to the MR CLEAN executive committee (https://www.mrclean-trial.org/).
Patient consent for publication Obtained.
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