Coronary computed tomography angiography (CCTA) quality

Abstract

Coronary computed tomography angiography (CCTA) is increasingly being utilized for assessment of coronary artery disease. New techniques for CCTA intend to reduce the radiation dose, whereas maintaining the image quality. This research was carried out in order to explore the advantages of assessing the image quality of the non-enhanced CT scan in the pre-determination of the best CCTA gating protocol, which we hypothesized to result in better image quality and lower radiation exposure. A prospective analysis of the 150 non-enhanced CT scans which were performed before 256-slice CCTA to look into the presence of artifacts affecting the coronary arteries, the scan protocol (prospective vs. Prospective with padding or retrospective gating) was selected in the light of these observations. The image quality (four-point scale) and the radiation dose were compared with 150 standard CCTA scans performed without pre-selection of the desired protocol. The median age of the patients was 49 (23–78) years and the average heart rate during the CCTA scan was 62 ± 14 beats per minute. We found that the subjective image quality obtained with the guidance of the pre-selection of the scan protocol is better compared to the standard CCTA scanning, especially when the heart rate is more than 65 per minute (3.5 ± 0.5 vs. 2.8 ± 0.8; p = 0.06) respectively. The overall radiation dose was significantly lower in the pre-selection group compared to the standard CCTA (4.9 ± 1.4 vs. 7.5 ± 1.8 mSv; p <;0.01) respectively, The use of Prospective with padding or retrospective gating was infrequent in the non-enhanced scans based pre-selection of CCTA protocol compared to the standard group (14 out of 150 versus 28 out of 150 scans) respectively. The use of 256-raw CCTA and the determination of the acquisition protocol based on the assessment of the non-enhanced CT scan, prompts better image quality and a significant radiation exposure reduction. We recommend performing this analysis to guide the selection of the CCTA scan protocol.