Purpose: CT perfusion predicts ischemic core volumes in acute stroke (AIS), however assumptions within the pharmacokinetic model may engender errors in the presence of tracer delay or dispersion. We aim to evaluate the impact of hemodynamic disturbance due to tandem intracranial-extracranial anterior circulation occlusions upon the accuracy of the ischemic core estimation in an automated perfusion analysis tool (RAPID) among large-vessel AIS patients.
Materials and Methods: A prospectively collected interventional database was retrospectively reviewed for all cases of endovascular treatment of AIS between September 2010-March 2015 for patients with anterior circulation occlusions with baseline CTP and full reperfusion (mTICI3). This study was IRB approved.
Results: Out of 685 treated patients, 114 fit the inclusion criteria. The comparison between tandem (n=21) vs. non-tandem groups (n=93) revealed similar baseline ischemic core (20±19vs.19±25cc; p=0.8), Tmax>6s (175±109vs.162±118cc; p=0.6), Tmax>10s (90±84vs.90±91cc; p=0.9) and final infarct volumes (45±47vs.37±45cc; p=0.5), respectively. Baseline core volumes were found to correlate with final infarct volumes for the tandem (r=0.49; p=0.02) and non-tandem (r=0.44; p=<0.01) groups. The mean absolute difference between estimated core and final infarct volume was similar between patients with and without (24±41vs.17±41cc; p=0.5) tandem lesions.
Conclusions: Optimized CTP analysis employing rigorous normalization, thresholding, and voxel-wise analysis is reliable for ischemic core prediction in AIS patients despite underlying extracranial carotid steno-occlusive disease.