Basics of cardiac MRI in the assessment of cardiac disease

The past decade has witnessed an increasingly important role for cardiac MRI in the diagnosis and management of patients with congenital and acquired heart disease. Cardiac MRI is not limited by acoustic windows or body size and offers comprehensive, noninvasive three-dimensional imaging of cardiac and extracardiac structures. In addition, cardiac MRI provides a quantitative assessment of cardiac function, flow, and myocardial perfusion and viability in a single examination while avoiding the ionizing radiation of cardiac catheterization. The benefits of cardiac MRI must be carefully evaluated against the risks of sedation or anesthesia and the procedure itself. The indications for cardiac MRI in children with heart disease include the evaluation of extracardiac vascular structures such as the great arteries, systemic and pulmonary venous systems and surgical conduits and connections, the evaluation of ventricular systolic and systolic and diastolic function, and the investigation of complex three-dimensional relationships of the heart and vascular structures. Cardiac MRI is also used to determine the effect of cardiac disease on hemodynamics and blood flow, in particular the degree of regurgitation in the setting of valvular insufficiency. Cardiac MRI is rarely used to evaluate for the presence of ischemia or infarction in childhood cardiac diseases.