RESUMO
OBJECTIVES: To evaluate the feasibility of free-breathing coronary computed tomography angiography (CCTA) in adults using with a 320-detector multidetector CT (MDCT). METHODS: In 74 patients who underwent CCTA, 37 CCTA examinations were performed during free-breathing, and the remaining 37 CCTA examinations were produced with the standard breath-holding method. The quality scores for 16 segments of all coronary arteries were analysed and defined as: 1 (excellent), 2 (good), and 3 (poor). The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and effective radiation dose of each image were compared between the two methods. RESULTS: No significant differences were observed in the quality scores between the breath-holding and free-breathing methods (1.10 ± 0.31 vs. 1.12 ± 0.33; P = 0.443). The SNR and CNR were not significantly different between the two methods. The overall mean effective radiation dose revealed no significant difference between the two methods (P = 0.585). CONCLUSIONS: Free-breathing CCTA using 320-detector MDCT showed no significant difference in image quality compared with standard breath-holding CCTA. For patients with difficulties of breath-holding or non-negligible apnoea-related heart rate variability, free-breathing CCTA can be an alternative solution for coronary artery evaluation. KEY POINTS: ⢠Cardiac CT is becoming widely used and some patients are inevitably breathless. ⢠Multidetector CT (e.g. 320) offers new opportunities for the breathless patient. ⢠Free breathing images yielded similar image quality to those obtained using breath-holding. ⢠However, a possibility of higher radiation dose precludes its routine application.
