Magnetic resonance imaging and spectroscopy of the heart.

The value of magnetic resonance (MR) imaging and 31P spectroscopy is reported for evaluating the anatomy, function, and high-energy phosphate metabolism of the heart in patients with cardiovascular disease. Recent developments include the evaluation of myocardial contraction under pharmacologic stress and direct tracking of wall motion with myocardial tagging, assessment of first-pass myocardial perfusion with ultrafast MR in conjunction with MR contrast agents, and MR velocity mapping to determine flow velocity and volume in medium-sized vascular structures. The clinical significance of 31P spectroscopy is expanding, as shown in several studies in patients with ischemic heart disease and cardiomyopathy. The phosphocreatine to ATP ratio proved to be a sensitive marker for regional ischemia in patients with critical coronary artery stenoses. Changes in high-energy phosphate metabolism may be detected in patients with dilated cardiomyopathy, which may be useful to differentiate primary and secondary cardiomyopathies. MR imaging and 31P spectroscopy may be combined for a complete evaluation of patients with cardiovascular disease.