Usefulness of cardiac magnetic resonance imaging for coronary artery disease detection

Cardiac magnetic resonance imaging (cMRI) is a promising non-invasive technique to assess the presence of coronary artery disease (CAD), which is free of ionizing radiation and iodine contrast. cMRI can detect CAD by angiographic methods or indirectly by perfusion stress techniques. While coronary angiography by cMRI remains limited to research protocols, stress perfusion cMRI is currently being applied worldwide in the clinical setting. Studies have shown good correlation between adenosine-induced stress myocardial perfusion cMRI and single-photon-emission computed tomography or positron emission tomography to detect CAD. Quantitative methods to analyze cMRI perfusion data have been developed in an attempt to provide a more objective imaging interpretation. Standardization of such quantitative methods, with minimal operator dependency, would be useful for clinical and research applications. Myocardial perfusion reserve (MPR), calculated using Fermi deconvolution technique, has been compared with well established anatomical and physiological CAD detection techniques. MPR appears to be the most accurate quantitative index to detect anatomical and hemodynamically significant CAD. Beyond physiological assessment of CAD, cMRI provides information regarding regional and global left ventricular function and morphology, myocardial infarction size, transmurality and viability. Such comprehensive information would require the performance of multiple tests if other modalities were used. This article describes current applications of cMRI for evaluation of patients with CAD.