Multimodality imaging for assessment of myocardial viability: nuclear, echocardiography, MR, and CT.

The assessment of myocardial viability may be an important component of the evaluation of patients with coronary artery disease and left ventricular dysfunction. The primary goal of viability assessment in such patients is to guide therapeutic decisions by determining which patients would most likely benefit from revascularization. In patients with chronic coronary artery disease, left ventricular dysfunction may be a consequence of prior myocardium infarction, which is an irreversible condition, or reversible ischemic states such as stunning and hibernation. Imaging techniques utilize several methods to assess myocardial viability: left ventricular function, morphology, perfusion, and metabolism. Each technique (echocardiography, nuclear imaging, magnetic resonance imaging, and x-ray computed tomography) has the ability to assess one or more of these parameters. This article describes how each of these imaging modalities can be used to assess myocardial viability, and reviews the relative strengths and limitations of each technique.