Automated tube voltage selection for radiation dose and contrast medium reduction at coronary CT angiography using 3(rd) generation dual-source CT.

Abstract

To investigate the relationship between automated tube voltage selection (ATVS) and body mass index (BMI) and its effect on image quality and radiation dose of coronary CT angiography (CCTA). We evaluated 272 patients who underwent CCTA with 3(rd) generation dual-source CT (DSCT). Prospectively ECG-triggered spiral acquisition was performed with automated tube current selection and advanced iterative reconstruction. Tube voltages were selected by ATVS (70-120kV). BMI, effective dose (ED), and vascular attenuation in the coronary arteries were recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used for subjective image quality analysis. Image quality was rated good to excellent in 98.9% of examinations without significant differences for proximal and distal attenuation (all p ≥ .0516), whereas image noise was rated significantly higher at 70kV compared to ≥100kV (all p < .0266). However, no significant differences were observed in SNR or CNR at 70-120kV (all p ≥ .0829). Mean ED at 70-120kV was 1.5 ± 1.2mSv, 2.4 ± 1.5mSv, 3.6 ± 2.7mSv, 5.9 ± 4.0mSv, 7.9 ± 4.2mSv, and 10.7 ± 4.1mSv, respectively (all p ≤ .0414). Correlation analysis showed a moderate association between tube voltage and BMI (r = .639). ATVS allows individual tube voltage adaptation for CCTA performed with 3(rd) generation DSCT, resulting in significantly decreased radiation exposure while maintaining image quality. • Automated tube voltage selection allows an individual tube voltage adaption in CCTA. • A tube voltage-based reduction of contrast medium volume is feasible. • Image quality was maintained while radiation exposure was significantly decreased. • A moderate association between tube voltage and body mass index was found.