Computed Tomography Perfusion Core Infarct Measurement Compared to Diffusion-Weighted Magnetic Resonance Imaging in Patients with Revascularization of Anterior Circulation, Large Artery Occlusion Ischemic Stroke

Relative cerebral blood flow (CBF) < 30% has been identified as a predictor of infarct core on computed tomography perfusion (CTP). We investigated the relationship between CTP-predicted infarct core and diffusion-weighted imaging magnetic resonance imaging (DWI MRI). We conducted a retrospective analysis comparing infarct core (CBF < 30%; RAPID iSchemaView) and post-revascularization DWI MRI (ADC < 620 cc; RAPID iSchemaView) in patients with internal carotid artery (ICA) or proximal middle cerebral artery (MCA) stroke between November 2016 and May 2019. Included subjects had a modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b or better and presented within 24 h of last known well (LKW) time. Two hundred one cases were identified. Mean duration from LKW time to CTP and MRI was 4.3 and 28.6 h, respectively. Median ischemic core volume was 8 cc, and median MRI infarct volume was 17 cc. CTP core volume showed fair correlation with MRI infarct volume ( r = 0.294, p < 0.0001). There was a stronger association between CBF < 30% and DWI MRI in subjects presenting beyond 6 h ( r = 0.359, p = 0.011). In a multivariate analysis, greater volumetric difference was associated with younger age ( p = 0.001), longer duration from LKW time to revascularization time ( p < 0.020), and longer CTP to revascularization time ( p < 0.0001). Reduced relative CBF < 30% is a fair measure of infarct size within 24 h of anterior circulation, large artery occlusion (LAO) stroke when adequate reperfusion is achieved.