3D pCASL不同标记后延迟时间评估急性缺血性脑卒中缺血半暗带体积时相对脑血流量阈值的选择OACSTPCD

Objective To explore the selection of relative cerebral blood flow(rCBF)threshold on 3D pseudo-con-tinuous arterial spin labeling(3D pCASL)at different post labeling delay(PLD)for assessment of ischemic penumbra vol-ume in acute ischemic stroke(AIS).Methods Forty-two patients with AIS underwent magnetic resonance imaging(MRI)conventional sequence imaging,3D pCASL imaging,and dynamic susceptibility contrast-perfusion weighted imag-ing(DSC-PWI).Image data of diffusion weighted imaging,3D pCASL and DSC-PWI were imported into F-stroke software for automatic analysis in order to generate ischemic penumbra volume of 3D pCASL and DSC-PWI.The ischemic penum-bra volume of DSC-PWI was taken as the reference standard,and intraclass correlation coefficient(ICC)was used to ana-lyze consistency between ischemic penumbra volume from rCBF<30%,40%,and 50%at PLDs of 1 525 ms and 2 525 ms.The difference between the ischemic penumbra volume from different rCBF thresholds and that from DSC-PWI was compared.Results The ischemic penumbra volume from rCBF<40%,50%at the PLD of 1 525 ms was consistent with that from DSC-PWI(ICC=0.595,0.791,all P<0.01).The ischemic penumbra volume from rCBF<50%at PLD of 2 525 ms was consistent with that from DSC-PWI(ICC=0.577,P<0.01).Ischemic penumbra volume from rCBF<40%at PLD of 1 525 ms was not significantly different from that from rCBF<50%at PLD of 2 525 ms(P>0.05).Conclusions Both PLDs of 1 525 ms and 2 525 ms based on 3D pCASL can be used for quantitative evaluation of ischemic penumbra vol-ume.The rCBF threshold of different PLD is different.The rCBF threshold should be selected as<50%at short PLD(1 525 ms),while the rCBF threshold at long PLD(2 525 ms)should be higher than that at short PLD(1 525 ms).