A diminutive right coronary artery (RCA) originates from anomalous high location at the sinotubular junction, instead of the expected more inferior location at mid (aortic) sinus. There is also clockwise radial malpositioning, as the artery origin is directly superior to the right coronary/left coronary commissure.
Of note, there is short segment increased acute angulation at the most proximal segment of RCA, just beyond the origin (best appreciable on maximum intensity projection image). The vessel has a narrowed appearance near the ostia. These findings are suggestive of an interarterial course.
A dominant left coronary artery (LCA) originates from the expected location at left coronary cusp.