MRI of the heart: basics for beginners

Abstract

Cardiac magnetic resonance imaging (MRI) has emerged as a highly reproducible and accurate imaging methodology for evaluating a wide variety of congenital and acquired heart diseases, including cardiac masses, myocardial ischemia or infraction, cardiomyopathies, valvular disease, coronary artery disease, pericardial disease, and complex congenital anomalies. The high soft-tissue contrast, availability of a large FOV, multiplanar acquisition capability, and lack of ionizing radiation are particularly appealing features of cardiac MRI. Of course, there are certain technical challenges unique to cardiac MRI. Most notably is the rapid and complex motion of the heart and pulsatility of the great vessels due to normal contractility. Moreover, numerous pulse sequences have been applied to cardiac MRI. To select the optimal protocol and to interpret cardiac MRI studies, the radiologist should understand the basic pulse sequences. In addition, the radiologist interpreting cardiac MRI studies should be familiar with basic cardiac anatomy and standard imaging planes. Additionally, using delayed gadolinium enhancement cardiac MRI can depict areas of overt scar or fibrosis. As a consequence, myocardial late gadolinium enhancement (LGE) imaging is an an integral part of a myocardial viability study and has already been demonstrated to provide additional insights into conditions associated with deposition of fibrosis such as myocardial infarction, hypertrophic or dilated cardiomyopathy, as well as acute inflammatory myocarditis or other rarer cardiomyopathies. Hence LGE imaging can be used as a risk-stratification tool in ischemic as well as non-ischemic cardiac diseases.