Abstract
ObjectiveTo investigate the effects of 80-kilovoltage (kV) tube voltage coronary computed tomographic angiography (CCTA) with a reduced amount of contrast agent on qualitative and quantitative image quality parameters and on radiation dose in patients with a body mass index (BMI) <23.0kg/m2. MethodsOne hundred and twenty consecutive patients with a BMI <23.0kg/m2 and a low calcium load undergoing retrospective electrocardiogram (ECG)-gated dual-source CCTA were randomized into two groups [standard-tube voltage (120-kV) vs. low-tube voltage (80-kV)]. The injection flow rate of contrast agent (350mgI/mL) was adjusted to body weight of each patient (4.5–5.5mL/s in the 120-kV group and 2.8–3.8mL/s in the 80-kV group). Radiation and contrast agent doses were evaluated. Quantitative image quality parameters and figure of merit (FOM) of coronary artery were evaluated. Each coronary segment was evaluated for image quality on a 4-point scale. ResultsCompared with the 120-kV group, effective dose and amount of contrast agent in the 80-kV group were decreased by 57.8% and 30.5% (effective dose:2.7±0.5vs. 6.4±1.3mSv; amount of contrast agent:57.1±3.2 vs. 82.1±6.1mL; both p<0.0001), respectively. Image noise was 22.7±2.1HU for 120-kV images and 33.2±5.2HU for 80-kV images (p<0.0001). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the proximal right coronary artery (RCA) and left main coronary artery (LMA) were all lower in 80-kV than 120-kV images (SNR in the proximal RCA: 16.5±1.8 vs. 19.4±2.8; SNR in the LMA: 16.3±2.0 vs.19.6±2.7; CNR in the proximal RCA: 19.4±2.3 vs.22.9±3.0; CNR in the LMA: 18.8±2.4 vs. 22.7±2.9; all p<0.0001). FOM were all significantly higher in 80-kV than 120-kV images (proximal RCA: 146.7±45.1 vs. 93.4±32.0; LMA: 139.1±47.2 vs. 91.6±31.1; all p<0.0001). There was no significant difference in image quality score between the two groups (3.3±0.8 vs. 3.3±0.8, p=0.068) despite decreased SNR and CNR of coronary artery in the 80-kV group. ConclusionThe 80-kV protocol significantly reduces radiation and contrast agent doses in CCTA in patients with a low BMI <23.0kg/m2 and a low calcium load while maintaining image quality.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
