Anomalous Coronary Arteries in Adults: Depiction at Multi–Detector Row CT Angiography

PURPOSE: To retrospectively determine the imaging features of anomalous coronary arteries depicted at multi-detector row computed tomographic (CT) angiography in 18 patients seen at four institutions. MATERIALS AND METHODS: Eighteen patients underwent imaging with a four- or 16-section multi-detector row CT unit by using retrospective electrocardiographic (ECG) gating after infusion of 120-150 mL of intravenous contrast material. Section thicknesses of 0.8-3.0 mm were achieved during breath holding, and images were reconstructed with a 50% overlap. Volumetric reconstructions were obtained for each patient. Each study was assessed retrospectively for the origin and course of the anomalous coronary artery by two thoracic radiologists; decisions were made in consensus. Institutional review board exemption and informed consent waiver was granted at each institution. The study was compliant with the Health Insurance Portability and Accountability Act. RESULTS: Seventeen patients were referred because of equivocal findings at cardiac catheterization or echocardiography; in one, the anomalous coronary artery was incidental. A total of 20 anomalous vessels were found. Twelve patients with 14 variant vessels had an anomalous origin of a left coronary artery (right cusp, 13; noncoronary cusp, one). In four patients, an anomalous right coronary artery originated from the left side; one patient had a single coronary artery arising from the right cusp. In one patient, a left coronary artery-to-vein fistula was observed. In 10 patients, the anomalous vessel passed between the aorta and the main pulmonary artery or right ventricular outflow track. In each case, the origin of the anomalous coronary artery and its course in relationship to the great vessels were unequivocally demonstrated. Volumetric images were useful for showing the three-dimensional orientation of the anomalous coronary artery with respect to the great vessels and cardiac chambers. CONCLUSION: Multi-detector row CT angiography provided accurate depiction of vessel origin and course in this review of 20 anomalous coronary arteries. The results of this study suggest that CT is a viable noninvasive modality for delineating coronary arterial anomalies, particularly if findings at coronary angiography are equivocal.