A Case of R-II-B Type Single Coronary Artery Evaluated by Multi-Detector Computed Tomography and Coronary Angiography

Multi-Detector Computed Tomography (MDCT) has been used to detect coronary lesions in a number of earlier studies. Here, we describe a rare case of congenital anomaly of the coronary artery, i.e., the R-II-B subtype (Lipton classification) of single coronary artery (SCA). A 61 year old man with angina was referred to our hospital. Assessment by coronary angiography (CAG) suggested SCA. The R-II-B subtype was confirmed by MDCT. Coronary artery bypass grafting (CABG) was then performed, and success of the grafting was evaluated by post- CABG MDCT. This subtype of SCA has been reported to be associated with high risk of cardiac sudden death because the aberrant vessel, which passes between the aorta and the main pulmonary artery, is readily compressed by these arteries. This subtype of SCA is also very rare: there is only one previously reported case in which MDCT was used for diagnosis. Ours is the first case of this subtype in which MDCT together with CAG was used for evaluation both pre- and post-CABG. Our results show that MDCT may be useful not only prior to CABG for risk stratification in patients with anomalous coronary arteries but also after CABG for evaluation.