Image quality and required radiation dose for coronary computed tomography angiography using an automatic tube potential selection technique

To investigate the image quality and the mini- mum required radiation dose for automatic tube potential selection (ATPS) in dual-source computed tomography (DSCT) coronary computed tomography angiography (CCTA). Three hundred twenty-five consecutive patients (153 men and 172 women) undergoing CCTA were assigned to either the ATPS group (n = 172) or the control group (n = 153); the control group underwent imaging at a con- stant current of 120 kV. All patients were scanned in either prospectively ECG-triggered high-pitch helical mode or sequential mode. The subjective image quality score, attenuation, image noise, signal-to-noise ratio (SNR), con- trast-to-noise ratio (CNR), volume CT dose index (CTDIvol), and effective dose (ED) were compared between the two groups with the Student t test or Mann-Whitney U test. The subjective image quality score was not signifi- cantly different between the two groups. Imaging noise and attenuation were both significantly higher in the ATPS group than in the control group (imaging noise: 25.6 ± 7.6 versus 15.8 ± 4.0 HU, P 0.001; attenuation: 559.6 ± 142.0 versus 412.5 ± 64.3 HU, P 0.001). SNR and CNR were significantly lower in the ATPS group than in the control group (SNR: 23.21 ± 7.40 versus 27.71 ± 8.25, P 0.001; CNR: 27.81 ± 8.44 versus 33.94 ± 9.69, P 0.001). ED was significantly lower in the ATPS group than in the control group (ED: 1.25 ± 1.24 versus 2.19 ± 1.77 mSv, P 0.001). For both groups, ED was significantly lower in the high-pitch mode than in the sequential mode. The use of ATPS for CCTA significantly reduced the radiation dose while maintaining image quality.