Room: Exhibit Hall
Purpose: In 2017, our cardiac CT was updated to a new dual-source CT scanner (Siemens Force). Given the new technology available, a concerted effort was made to modify our CT coronary angiography (CCTA) practice to more aggressively pursue prospective imaging. During this transition, all studies were monitored for 17 weeks to track and analyze CCTA repeats resulting from this practice.
Methods: For every exam necessitating a repeat, the cause and success of the repeat was documented. Using our CT dose management system, we documented the dose, as well as a range of patient related factors including gender, age, patient diameter and patient water-equivalent diameter (WED).
Results: A total of 742 CCTA exams were performed over the 17 weeks. 92 repeat CCTAs were identified, resulting in an overall repeat rate of 12%. 53% of repeats were due to breathing motion, 14% due to arrhythmias, and 11% due to voluntary motion. 78% of repeats were deemed successful by the cardiac radiologist. Of those not found successful, similar causes predominated with 46% due to breathing motion, 19% due to arrhythmias, and 15% due to voluntary motion. Both male and female patients had an overall repeat rate of 12Â±0.5%. Neither patient age, patient diameter, nor patient WED were found to have a statistically significant effect on the likelihood of a repeat (p=0.10, 0.85, and 0.67 respectively). No statistically significant difference was found between the exam-level effective dose from a retrospective CCTA and that of a repeat CCTA (p=0.77).
Conclusion: Given that repeat CCTA studies did not lead to a significantly higher exam-level dose distribution than our prior standard of practice, pursuing prospective imaging does not infer greater radiation risk to our patient population. Repeats were highly influenced by breathing and voluntary motion, suggesting attention should be paid to patient compliance before investigating protocol modification.
Not Applicable / None Entered.