Purpose: The purpose of this study was to investigate the effectiveness of automated best R-R interval determination software for the evaluation of dual-source coronary multidetector computed tomography (MDCT) angiography.
Methods: One hundred and nine consecutive patients who underwent dual-source coronary MDCT angiography are included in the study. The indications were chest pain syndrome of low-intermediate risk and/or nonspecific electrocardiographic changes (n = 91), stenting (n = 9), and bypass grafts (n = 9). Imaging was performed using dual-source MDCT. Temporal resolution was 0.83 milliseconds and slice thickness was 0.6 mm. None of the patients received β-blockers. Best R-R interval software has determined the best intervals in diastole and systole. The visibility of coronary arteries was evaluated using 15-segment (total 1635 segments) AHA classification by 2 radiologists in consensus.
Results: The mean patient age was 55 years. The mean heart rate was 73 beats per minute (range, 47-110 beats per minute). The mean (SD) best diastole R-R interval was determined as 73 (5) (95% CI, 63-83), and the mean (SD) best systole interval as 38 (5) (95% CI, 28-48). When only best diastole, only best systole, and both best systole and diastole reconstructions were evaluated, all coronary artery segments were visualized in 65 (60%), 61 (56%), and 93 (85%) patients, respectively. In 12 patients' evaluation of additional 1(n = 11) or 2(n = 1), R-R reconstruction intervals allowed visualization of all coronary artery segments. In 4 patients with arrhythmia, all segments cannot be visualized, but after electrocardiographic editing, all segments were visible in 3 of 4 patients.
Conclusions: Automatic determination of best R-R reconstruction interval allows evaluation of all coronary artery segments in most patients (85%) without additional reconstructions. By means of this software, coronary CT angiography studies can be evaluated faster and easier. The most significant limitation of the software is patients with arrhythmia.