Background Neurointerventionalists do not agree about the optimal imaging protocol when evaluating patients with acute stroke for potential endovascular revascularization. Preintervention cerebrovascular blood volume (CBV) has been shown to predict outcomes in patients undergoing intra-arterial stroke therapies.

Objective To determine whether CBV can predict hemorrhagic transformation and clinical outcomes in patients selected for endovascular therapy for acute ischemic middle cerebral artery (MCA) stroke using a CT perfusion (CTP)-based imaging protocol.

Methods We retrospectively reviewed cases of acute ischemic stroke due to MCA M1 segment occlusion and correlated favorable clinical outcomes (modified Rankin scale (mRS) ≤2) and radiographic outcomes with preintervention CBV values. All patients underwent whole-brain (320-detector-row) CTP imaging, and absolute CBV values of the affected and contralateral MCA territories were obtained separately for the cortical and basal ganglia regions.

Results Relative CBV (rCBV) of the MCA cortical regions was significantly lower in patients with poor clinical outcomes than in those with favorable clinical outcomes (0.87±0.21 vs 1.02±0.09, p=0.0003), and a negative correlation was found between rCBV values and mRS score severity. rCBV of the basal ganglia region was significantly lower in patients with hemorrhagic infarction (p=0.004) and parenchymal hematoma (p=0.04) than in those without hemorrhagic transformation.

Conclusions We found that cortical CBV loss is predictive of poor clinical outcomes, whereas basal ganglia CBV loss is predictive of hemorrhagic transformation but without translation into poor clinical outcomes. Our study findings support published results of baseline preintervention CBV as a predictor of outcomes in patients undergoing intra-arterial stroke therapies.