Myocardial Blood Flow Assessment and Reporting for Ischemic Heart Disease: Cardiac PET, MR, CT, and Echocardiography

Positron emission tomographic myocardial perfusion imaging in conjunction with tracer-kinetic modeling affords the concurrent assessment of myocardial blood flow (MBF) in mL/min/g of tissue. Cardiac magnetic resonance, computed tomography, and echocardiography are emerging technologies capable of MBF quantification. The noninvasive evaluation and quantification of MBF during hyperemia and at rest and corresponding myocardial flow reserve expand the realm of conventional myocardial perfusion imaging from detection of the most advanced, and flow-limiting, epicardial lesions in multivessel coronary artery disease (CAD) to less severe intermediate epicardial lesions, accurate delineation of the extent and severity of ischemic burden in multivessel CAD, detection of diffuse ischemia attributable to CAD or at coronary arteriolar level such as in hypertrophic cardiomyopathy, transplantation vasculopathy, and coronary microvascular dysfunction in its classical and/or endogen forms. Apart from improving the diagnostic scope in ischemic heart disease, the additional quantitation of MBF also affords the contingency to follow-up on treatment success of therapeutic interventions, risk factor modifications, and/or lifestyle changes likely to improve long-term cardiovascular outcomes. Standardized algorithms for each imaging modality in the diagnosis and reporting of ischemia heart disease appear critical for optimized diagnosis and treatment decisions in such patients. In this respect, the convened expert panel strives to provide a concise overview of the pathophysiology of ischemic heart disease and its noninvasive assessment with different imaging modalities that may be pivotal for the diagnosis of various pattern types of ischemic heart disease, as well as individualized and image-guided patient care likely to further optimize cardiovascular outcome.