Brain tissue perfusion assessment without using a CT system

Real-time perfusion imaging is highly desirable for effectively using endovascular thrombectomy in treating ischemic stroke; the current standard of care is hindered by the lack of intra-operative perfusion imaging. We propose an Intra-intervention perfusion with no C-arm rotation (IPEN)-based method using X-ray angiographic images in the interventional suite. This approach aims to provide a volumetric brain perfusion assessment. IPEN is built on tomographic theory; wherein if an object consists of homogenous regions-of-interest (ROIs) with known shapes then N x-ray beams in a single projection are sufficient to estimate values of the N ROIs. IPEN for brain perfusion assessment aims to estimate the dynamic time-enhancement curve of each homogeneous ROI in the brain. The proposed algorithm was evaluated using XCAT phantoms updated for dynamic CT perfusion. Eight ischemic stroke cases were simulated. Using intra-arterial contrast-enhanced bi-plane XA images for each case, IPEN was performed to estimate the TEC values. Quantitatively, the estimated TECs had an excellent agreement with the true TECs. The normalized weighted root mean square error was 14.5% ± 1.7%, and the linear correlation coefficient values (R) ranged 0.85–0.95 (P < 0.01) for 8 cases.