Pictorial essay - Using electron beam CT to evaluate conotruncal anomaliesin pediatric and adult patients

Electron beam CT has advantages over echocardiography and MR imaging in eva luating congenital cardiac malformations. These advantages include short sc anning time (50-400 msec), high temporal and spatial resolution, and compat ibility with ECG gating. Electron beam CT can clearly delineate the cardiac chambers and the vessels in the mediastinum and chest wall. The technique is particularly useful in young children without a need for deep sedation. Pressure measurement of the cardiac chambers is not possible using electron beam CT, but it is rarely a critical issue in conotruncal anomalies. The p ressures in the right and left ventricles and in the aorta are frequently e qual as a result of a commonly associated large ventricular septal defect, pulmonic stenosis, or both, and because the pulmonary blood flow is usually normal or slightly diminished in conotruncal anomalies. On the other hand, anatomic information that is obtainable by electron beam CT, such as the d imensions of the pulmonary artery and the presence of infundibular stenosis or coronary anomalies, is essential in planning surgical correction of the se anomalies [1-4]. This pictorial essay illustrates the value of electron beam CT in assessing a variety of conotruncal anomalies.