A 49-year-old male patient, with an unremarkable medical history, had begun experiencing exertional chest tightness and shortness of breath, that could be relieved by rest, four years ago. He was referred for a coronary angiography, which failed to catheterize the left coronary artery (LCA). Recently, coronary CT angiography (cCTA) was established in the hospital with the installation of a dual source CT (DSCT), SOMATOM Drive. The patient was then asked to return for a follow-up evaluation.
cCTA images revealed an ectatic left main (LM) coronary artery, originating off the main pulmonary artery (MPA) and branching into both the left anterior descending artery (LAD) and the circumflex artery (Cx). The right coronary artery (RCA), with a normal origin, was dominant and significantly dilated and tortuous. It extended posteriorly along the inferior wall of the left ventricle (LV) and connected distally, through collaterals, with the Cx and the first diagonal branch (D1) of the LAD. A small fistula, coursing behind the proximal LAD and passing in front of the MPA, joined the proximal Cx and the ascending aorta near the origin of the RCA. A diagnosis of a Bland-White-Garland (BWG) syndrome was suggested.
Fig. 1: VRT images show an ectatic LM, originating off the MPA (arrows), and branching into the LAD and the Cx. The RCA (dotted arrows), with a normal origin, is dominant and significantly dilated and tortuous, extending posteriorly along the inferior wall of the LV. A small fistula (arrowhead), coursing in front of the MPA, is also seen.
Fig. 2: A MIP image shows the small collaterals connecting the RCA and the LCA distally (dotted arrows).
Fig. 3: cVRT images show an ectatic LM, originating off the MPA (Fig. 3a, arrow). A small fistula, coursing behind the proximal LAD and passing in front of the MPA, joined the proximal Cx (Fig. 3a, arrowhead), and the ascending aorta (Fig. 3b, arrowhead) near the normal origin of the RCA (Fig. 3b, dotted arrow).
BWG syndrome, also referred to as anomalous left coronary artery originating from the pulmonary artery (ALCAPA), is a very rare congenital coronary artery anomaly. Up to 90% of the patients with this condition die within their first year of life. The probability of survival to adulthood, without surgical correction, is very low.  This case presents a rare extended adult survival with a relatively asymptomatic patient. The ALCAPA, missed during the previous coronary angiography, is directly visualized in cCTA. Image demonstration using cinematic volume rendered technique (cVRT) provides improved depth and shape perceptions in three dimensions. The visualization of vascular details, such as the small collaterals between the RCA and the LCA, is possible owing to the high spatial and temporal resolution granted by DSCT.
ECG retrospectively gated Spiral Scan
128 x 0.6 mm
66 – 71 bpm
40 mL + 40 mL saline
Bolus tracking with 100 HU at ascending aorta + 5 s