The role of computed tomography myocardial perfusion imaging in clinical practice.

Computed tomography coronary angiography (CTCA) is a widely accepted non-invasive technique for the accurate detection of coronary artery disease (CAD), but comes with a notable limitation stemming from its limited capacity to define the physiologic significance of a given lesion This hampered ability for functional assessment of coronary stenosis may lead to additional testing in an effort to delineate whether ischemia is truly present. An important technique that can overcome this pitfall of CTCA has emerged in the form of stress CT myocardial perfusion (CTP) imaging, which provides the functional assessment necessary, thereby complementing the anatomic information provided by CTCA. The combination of CTCA and CTP permits a single exam to simultaneously detect coronary stenosis and categorize its hemodynamic significance. The accuracy of CTP is now well-described in comparison to a number of reference standards for the diagnosis of CAD, including single photon emission CT, cardiovascular magnetic resonance imaging, and invasive coronary angiography with and without fractional flow-reserve (FFR) measurements. While there is not yet a consensus for a single protocol regarding the optimal mode of acquisition and interpretation of CTP, there is a growing body of data to support its integration into clinical use with CTCA as a strategy to improve the detection and management of coronary disease. This review article is aimed to discuss the current clinical applications and methodology of CTP imaging, its strengths and weaknesses as well as some of the debated issues that remain to be resolved in the future.