Radiation Dose and Image quality of coronary CT angiography performed with whole-heart coverage CT scanner with 0.25s rotation time in patients with irregular heart rhythm

Objectives: To evaluate radiation exposure, image quality, and diagnostic performance of coronary CT angiography (CCTA) using the invasive coronary angiography (ICA) as the reference standard in patients with irregular heart rhythm on a 0.25 s rotation time, 16 cm coverage, single-beat, CT scanner with AI-assisted motion correction. Methods: CCTA data-sheets of 427 patients using a CT scanner with an ECG monitoring system and motion correction algorithm were collected retrospectively. All the patients were divided into two groups: regular heart rhythm (357 patients) and irregular heart rhythm (70 patients). 22 patients in irregular heart rhythm underwent ICA. Image quality and effective dose in both groups were evaluated and compared. Image quality was evaluated on 5-point scales. The diagnostic performance of CCTA in irregular heart rhythm group was compared with the results of ICA. Results: The image quality in both groups was similar (4.34 ± 0.47 vs 4.37 ± 0.48, p > 0.05). No significant difference was observed in effective dose between two groups (2.7 ± 0.7 vs 2.9 ± 1.3, p > 0.05). The diagnostic accuracy was 90.91% in a patient-based analysis, 96.97% in a vessel-based analysis, and 98.61% in a segment-based analysis. In irregular heart rhythm group, gender was an important factor affecting the number of CCTA scans in a single examination and the radiation dose exposed to the patient. Conclusions: For patients with irregular heart rhythm, a CT scanner with an ECG monitoring system and motion correction algorithm can not only reduce the radiation dose to the same level as patients with normal heart rhythms, but also ensure that the images with high diagnostic accuracy.