MRI for the diagnosis of myocardial ischemia and viability.

Assessment of myocardial ischemia and viability plays a crucial role in the clinical management of patients with coronary artery disease. Recently, cardiovascular MRI has emerged as an important noninvasive diagnostic modality in the assessment of coronary artery disease. MRI is able to evaluate both myocardial perfusion as well as myocardial contractile reserve. Because of its superior spatial resolution, integration of qualitative and quantitative methodology, and excellent reproducibility, MRI has advantages over conventional noninvasive modalities currently used in the evaluation of myocardial ischemia and viability, and may well emerge as the premier noninvasive technique in the assessment of patients with coronary artery disease. The authors review the rapidly expanding recent literature that has now established cardiovascular MRI (including dobutamine cine MRI and vasodilator perfusion MRI techniques) as an ideal choice in the evaluation of myocardial ischemia and delayed contrast-enhanced MRI and low-dose dobutamine cine MRI for evaluation of viability. Comparisons with more established techniques such as dobutamine stress echocardiography, single photon emission computed tomography perfusion imaging, and positron emission tomography are reviewed.