Global Impairment of Cerebral Perfusion Measured using Dynamic Susceptibility Contrast Perfusion-Weighted Imaging in Out-of-Hospital Cardiac Arrest Survivors: A Prospectively Preliminary Study

Abstract

Background: Dynamic susceptibility contrast perfusion weighted imaging (DSC-PWI) is useful for measuring cerebral perfusion (CP). This study aimed to assess global impairment and the prognostic performance of CP parameters measured by DSC-PWI in out-of-hospital cardiac arrest (OHCA) survivors.Methods: This is a single-centre, prospective observational study. OHCA survivors who underwent DSC-PWI within 6 h after restoration of spontaneous circulation were enrolled. CP parameters (cerebral blood volume [CBV], cerebral blood flow [CBF], mean transit time [MTT], time to peak [TTP], and time to the maximum of the residue function [Tmax]) were quantified by normalisation + leakage correction (LC) or by arterial input function (AIF) + LC. The primary outcome was survival to discharge; subjects who died due to withdrawal of life-sustaining therapy or who were diagnosed with brain death (BD) were included in non-survival. The secondary outcome was 6-months neurological outcome. CP parameters were compared across groups, and receiver operating characteristic (ROC) curves were constructed to assess prognostic performances.Results: Thirty-one subjects (male, 20; 64.5%) participated. Relative CBV (rCBV) and CBF (rCBF) quantified by normalisation + LC were significantly higher in the non-survival group (p=0.02 and p=0.03, respectively). The area under the ROC curves (AUROCs) and 100% specific sensitivities for non-survival were 0.75/31.3% and 0.73/25.0%, respectively. MTT and Tmax quantified by AIF + LC were significantly higher in non-survival (p=0.01 and p=0.01, respectively). Their AUROCs and 100% specific sensitivities were 0.77/56.3% and 0.76/43.8%, respectively. rCBV and rCBF quantified by normalisation + LC were significantly higher in the poor neurological outcome group (p<0.01 and p=0.02, respectively). The AUROCs and 100% specific sensitivities for poor neurological outcome were 0.81/23.8% and 0.77/19.1%, respectively. Tmax quantified by AIF + LC was significantly higher in poor neurological outcome (p=0.04). Its AUROC and 100% specific sensitivity were 0.74/33.3%.Conclusion: Hyperaemia and delayed CP were present in the non-survival and poor neurological outcome groups. MTT quantified by AIF + LC could be the most powerful parameter for predicting mortality or BD in OHCA survivors at an early stage of post cardiac arrest care. AIF may be more appropriate as quantifying method for CP in OHCA survivors than normalisation.