Simple Congenital Heart Disease

The established tests for the assessment of congenital heart disease are transthoracic (TTE) and transesophageal echocardiography (TEE), cardiac MRI, and cardiac catheterization.

Cardiac CT (CCT) is an emerging alternative because of its rapid acquisition times and post-processing robustness, but the potential radiation risks are particularly relevant for children and younger adults. Nonetheless, its use has increased prominently in the assessment of congenital heart disease.

Most intracardiac lesions can be assessed by echocardiography, and many procedures can be planned and guided with TTE, TEE, or intracardiac echocardiography, thus avoiding radiation risk and also providing Doppler assessment.

For patients with congenital heart disease, MRI is the established test for the evaluation of extracardiac surgical shunts, pulmonary vascular anomalies and complications, and aortic anomalies. This modality avoids the risk of radiation exposure and also provides flow information. Cardiac MRI also is the preferred test for quantifying right ventricular function and the degree of pulmonic insufficiency.

Clearly CCT is able to provide nonphysiologic but superb anatomic delineation of a wide range of congenital cardiac and thoracic vascular defects, and its use has increased substantially during the past decade. However, it remains unclear which lesions should be assessed by CCT, given the radiation risk-free, and widespread availability of other established modalities and the natural and proven complementarity of echocardiography and cardiac MRI.

The greatest contribution of CCT, therefore, is likely to be:

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  In patients who cannot undergo MRI or whose MRI images are insufficient in lesions such as extracardiac shunts

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  For the assessment of coronary anatomy, such as identification of an anomalous left anterior descending coronary artery in patients with tetralogy of Fallot

CT imaging is appropriate for a number of congenital pathologies. The most common of these are discussed in the following sections. It may be useful to categorize congenital lesions based on their level of simplicity rather than on physiology, as follows.