Abstract
Recent advances in coronary computed tomography angiography (CCTA) increased its utilization as a tool for non-invasive detection of coronary artery disease (CAD). The aim of this analysis is to determine the impact of adopting new radiation dose-reducing techniques on the radiation exposure in consecutive patients undergoing CCTA. We included 1341 consecutive patients who underwent CCTA to rule out CAD between January 2007 and December 2013. New dose-reducing techniques were adopted in July 2010 in 1034 patients. These included high pitch scanning, 100 KVP (Kilovoltage Peak) imaging, and iterative reconstruction. The total radiation dose was calculated for each scan from the dose length product multiplied by conversion factor (0.014). The annual median radiation doses were compared over the study period. After the adoption of the new scanning techniques (n = 578), 53% of the scans were done with high pitch scanning, 46% with prospective gating, and 1% with retrospective gating. This was associated with > 90% reduction in the radiation doses with a median radiation dose of 2.7, 1.5, 1.7, and 1.5 mSv (Millisievert) in 2010, 2011, 2012, and 2013, respectively. A total of 15 and 66% of the CCTA scans had a radiation dose of < 1 and 2 mSv, respectively. There was no difference in the frequency of non-diagnostic studies or imaging quality before and after July 2010. Our analysis demonstrates that, in the current era, low-radiation CCTA can be routinely done in clinical practice.