Low radiation dose computed tomography coronary angiography: evaluation of the variations in coronary arteries

Objective Despite attempts to decrease the radiation dose, coronary computed tomography angiography (CCTA) generally uses higher doses than computed tomography scans of other organs. The purpose of this study was to evaluate the incidence of the variations of the coronary arteries using the adaptive statistical iterative reconstruction technique to perform low-dose coronary computed tomography (CTA). Methods Diagnostic CCTA scans were performed in 3433 patients (from November 2010 to January 2015) using an Optima CT660 (GE Healthcare, USA) 64-slice and analyzed retrospectively. Results The mean effective dose was 2.1 mSv (1.2–4.9 mSv) for prospective and 4.5 mSv (3.6–9.1 mSv) for retrospective ECG-gated scans. The variations of the coronary arteries (CA) excluding myocardial bridge (MB) were detected in 76 (2.2 %) of the 3433 patients. A myocardial bridge was the most common variation ( n = 288, 8.3 %). The second most common variation ( n = 13, 17.1 %) was an absence of the left main coronary artery (LMCA) with separate starting points for the left anterior descending (LAD) and left circumflex (LCX) arteries. In addition, there was a rare variation ( n = 1, 1.3 %) consisting of the LAD artery originating from the right coronary artery (RCA). Conclusions The present retrospective study was conducted using CCTA on patients with a coronary artery variations in Turkey ( n = 3433). Our data show that low-dose CCTA can be used to detect common coronary variations.