Protocol variation analysis of whole brain CT perfusion in acute ischemic stroke

摘要

Computed tomography perfusion (CTP) analysis is a rapidly advancing imaging modality that is improving diagnosis of brain abnormalities in patients suffering from hemorrhagic or ischemic stroke, traumatic brain injury, vascular occlusion and numerous other conditions. Through the advancements of computed tomography (CT) imaging, including the introduction of the 320-detector row CT with a 16 centimeter range in the z-axis enabling whole brain CTP, perfusion analysis now has a significantly increased clinical utility that is useful for both diagnosis and treatment of central nervous system (CNS) conditions. This study focuses on the procedural and analytical approach to the diagnostic evaluation of patients suffering from acute ischemic stroke (AIS). Through the automatic, manual ipsilateral, and manual contralateral selection of the arterial input function (AIF) and venous input function (VIF), along with the interchangeable combinations using singular value decomposition (SVD) and singular value decomposition plus (SVD+) deconvolution algorithms, CTP parametric maps are compared and analyzed for similarities and differences between each selection method. In particular, the region of interest (ROI) placements on the axial views of the perfusion maps are compared with the values derived by the SVD+ and SVD deconvolution algorithms for each AIF/VIF selection. These differences and product CTP map manipulations allow for outcomeassessments that prove which approach provides the best clinical accuracy and reproducibility for evaluating or diagnosing acute ischemic stroke with computed tomography perfusion.In this study of protocol variation analysis, SVD+ produced more consistent CTP values with less variation than the SVD deconvolution algorithm. With the use of the SVD+ deconvolution algorithm, the most consistent results were produced with the AIF manually placed in the contralateral M1 segment of the middle cerebral artery (MCA) and the venous input function (VIF) placed in the posterior portion of the superior sagittal sinus (SSS).