Figure 3d. RCA. (a) Axial CT image shows origin of the RCA (arrow) from the aorta and extension into the right atrioventricular groove. The artery is minimally calcified. (b) Coronal oblique volume-rendered image shows the caudal course of the proximal RCA (arrow). (c) Coronal oblique volume-rendered image shows the RCA (arrow) coursing in the groove between the right atrium (RA) and right ventricle (RV). (d) Coronal oblique volume-rendered image shows the course of the RCA (arrow) posterior to the pulmonary trunk. (e) Posterior coronal oblique volume-rendered image shows the RCA (long arrow), PDA branch (short arrow), and posterolateral left ventricular branch (arrowhead).