Abstract TP76: Quantitative Comparison of Multidetector CT and Cone-Beam CT Perfusion Maps in Large Vessel Occlusion Stroke Patients Undergoing Mechanical Thrombectomy

Abstract

Cerebral perfusion evaluation using CT or MR perfusion is the gold standard modality to select large vessel occlusion (LVO) stroke patients presenting >6 hours from symptom onset. The availability of cone beam C-arm CT perfusion (CBCTP) in angiography suites could reduce time to endovascular revascularization. We aimed to evaluate the reliability of using CBCTP when compared to multidetector CT perfusion (MDCTP). In this prospective, single-arm, interventional study, 14 LVO anterior circulation thrombectomy patients underwent both a 128 slice MDCTP in the ED and a CBCTP <30 minutes apart prior to groin puncture. CBCTP was acquired using a prototype acquisition mode enabling 10 consecutive C-Arm rotations with nearly continuous data acquisition. A total of 60 cc of contrast layered with 60 cc of saline were injected covering arterial inflow, parenchymal phase and venous outflow. Image data was reconstructed into CBF, CBV, MTT and TTP maps. Three types of measurements were used to compare modalities. In measurement 1, 6 circular regions of interest (ROI) (400mm 2 ) were placed in the anterior arterial territory. In measurement 2, circular ROIs were placed in the ASPECTS regions (cortical 300mm 2 , subcortical 200mm 2 ). In measurement 3, a ROI was drawn around the entire affected area. All ROIs were placed in the basal ganglia and supraganglionic level of both brain sides. Rates (unaffected/affected area) between MDCTP and CBCTP were compared for all sequences. The intraclass correlation coefficient (ICC) was calculated using a single rater, consistency, two-way random-effects model. Measurement 1 found a moderate degree of agreement between MDCTP and CBCTP in CBF, CBV, MTT and TTP rates with ICCs of 0.58 (CI 0.42 - 0.69), 0.65 (CI 0.53 - 0.74), 0.77 (CI 0.68 - 0.83) and 0.52 (CI 0.35 - 0.65). In measurement 2, moderate agreement was found in CBF, CBV and MTT rates; with ICCs of 0.51 (CI 0.32 - 0.65), 0.57 (CI 0.4 - 0.69) and 0.62 (CI 0.47 - 0.73). The results of measurement 3 found an excellent (ICC=0.95, CI 0.88 - 0.98), good (ICC=0.83, CI 0.62 - 0.9) and moderate (ICC=0.7, CI 0.34 - 0.87), degree of agreement in the CBV, MTT and CBF rates, respectively. These results demonstrate promising accuracy of CBCTP in the evaluating ischemic tissue in patient presenting with LVO acute stroke.