Cardiac Magnetic Resonance Imaging - Children and Congenital Heart Disease

Children and Congenital Heart Disease

Congenital heart defects are the most common type of major birth defect. Accurate diagnosis is essential for the development of appropriate treatment plans. CMR can provide comprehensive information about the nature of congenital hearts defects in a safe fashion without using x-rays or entering the body. It is rarely used as the first or sole diagnostic test for congenital heart disease. Rather, it is typically used in concert with other diagnostic techniques. In general, the clinical reasons for a CMR examination fall into one or more of the following categories: 1) when echocardiography (cardiac ultrasound) cannot provide sufficient diagnostic information, 2) as an alternative to diagnostic cardiac catheterization which involve risks including x-ray radiation exposure, 3) to obtain diagnostic information for which CMR offers unique advantages such as blood flow measurement or identification of cardiac masses, and 4) when clinical assessment and other diagnostic tests are inconsistent. Examples of conditions in which CMR is often used include tetralogy of Fallot, transposition of the great arteries, coarctation of the aorta, single ventricle heart disease, abnormalities of the pulmonary veins, atrial septal defect, connective tissue diseases such as Marfan syndrome, vascular rings, abnormal origins of the coronary arteries, and cardiac tumors.

CMR examinations in children typically last 15 to 60 minutes. In order to avoid blurry images the child must remain very still during the examination. Different institutions have different protocols for pediatric CMR, but most children 7 years of age and older can cooperate sufficiently for a good quality examination. Providing an age-appropriate explanation of the procedure to the child in advance will increase the likelihood of a successful study. After proper safety screening, parents can be allowed into the MRI scanner room to help their child complete the examination. Some centers allow children to listen to music or watch movies through a specialized MRI-compatible audiovisual system to reduce anxiety and improve cooperation. However, the presence of a calm, encouraging, supportive parent generally produces better results in terms of pediatric cooperation than any distraction or entertainment strategy short of sedation. If the child cannot cooperate sufficiently, sedation with intravenous medications or general anesthesia may be necessary. In very young babies, it may be possible to perform the examination while they are in a natural sleep.