Utility of three-dimensional volume rendering images using electron-beam computed tomography to evaluate possible causes of ischemia from an anomalous origin of the right coronary artery from the left sinus of Valsalva

The present study evaluated the usefulness of S-dimensional volume rendering (VR) images using electron-beam computed tomography (EBCT) in determining the possible causes of ischemia resulting from the anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva, which coursed between the ascending aorta and pulmonary trunk. Such anomalies could cause ischemia or sudden death without obstructive coronary artery disease. The suggested mechanism is either compression causing closure of the slit-like orifice of the anomalous artery as the aorta dilates with exertion or compression of the anomalous artery by the aorta and pulmonary trunk as it courses between these 2 arteries, which dilate with exercise. A 17-year-old male underwent EBCT coupled with a 100-ml intravenous injection of iodinated contrast medium. Data were reconstructed into 3-dimensional images through VR to evaluate the shape of the orifice and the spatial relationship of the RCA, ascending aorta and pulmonary trunk. Perspective VR showed the shape of the orifice of the left main trunk, which was not slit-like, and cut-plane VR showed the spatial relationship of both the lumen and the surface of the RCA, ascending aorta and pulmonary trunk, providing information on whether the ascending aorta or pulmonary trunk would compress the RCA and cause ischemia.