Computed tomography perfusion or fractional flow reserve–computed tomography to assess the significance of stenosis: Literature review

Abstract

Abstract Detection of myocardial ischemia based on detection and grading of myocardial perfusion is a cornerstone of coronary artery disease (CAD) diagnosis. Coronary CT angiography (CCTA) is a recognized imaging test for exclusion of anatomically significant coronary stenosis in patients with low or moderate probability of CAD, but gives no information on its physiological significance. The two major approaches to evaluate the presence of induced myocardial ischemia using CT, static or dynamic perfusion CT (CTP) or non-invasive fractional flow reserve analysis (FFRCT), have been validated in multiple single- and multi-center studies with comparable results of high sensitivity, specificity and accuracy. Several studies with head-to-head comparison of CTP and FFRCT using invasive FFR measurement as a reference standard showed a slight superiority of CTP, especially in groups of patients with the borderline values of FFR-CT. The principle of myocardial perfusion assessment with CTP looks more physiological than computation models used in FFR-CT. However, the best results were shown by combined use of CCTA, CTP and FFRCT, providing the integrated anatomical and physiological information. Technical advances in CT technique, artificial intelligence and machine learning, together with accumulation of new clinical evidence, will result in development of the best strategy for comprehensive assessment of both coronary anatomy and myocardial perfusion with help of cardiac CT.