Evaluation of time-resolved whole brain flat panel detector perfusion imaging using RAPID ANGIO in patients with acute stroke: comparison with CT perfusion imaging.

Abstract

In contrast to conventional CT perfusion (CTP) imaging, flat panel detector CT perfusion (FD-CTP) imaging can be acquired directly in the angiosuite. To evaluate time-resolved whole brain FD-CTP imaging and assess clinically important qualitative and quantitative perfusion parameters in correlation with previously acquired conventional CTP using the new RAPID for ANGIO software. We included patients with internal carotid artery occlusions and M1 or M2 occlusions from six centers. All patients underwent mechanical thrombectomy (MT) with preinterventional conventional CTP and FD-CTP imaging. Quantitative performance was determined by comparing volumes of infarct core, penumbral tissue, and mismatch. Eligibility for MT according to the perfusion imaging criteria of DEFUSE 3 was determined for each case from both conventional CTP and FD-CTP imaging. A total of 20 patients were included in the final analysis. Conventional relative cerebral blood flow (rCBF) <30% and FD-CTP rCBF <45% showed good correlation (R²=0.84). Comparisons of conventional CTP Tmax >6 s versus FD-CTP Tmax >6 s and CTP mismatch versus FD-CTP mismatch showed more variability (R²=0.57, and R²=0.33, respectively). Based on FD-CTP, 16/20 (80%) patients met the inclusion criteria for MT according to the DEFUSE 3 perfusion criteria, in contrast to 18/20 (90%) patients based on conventional CTP. The vessel occlusion could be correctly extrapolated from the hypoperfusion in 18/20 cases (90%). In our multicenter study, time-resolved whole brain FD-CTP was technically feasible, and qualitative and quantitative perfusion results correlated with those obtained with conventional CTP.