CT angiography for planning transcatheter aortic valve replacement using automated tube voltage selection: Image quality and radiation exposure

Abstract

PurposeTo assess image quality and accuracy of CT angiography (CTA) for transcatheter aortic valve replacement (TAVR) planning performed with 3rd generation dual-source CT (DSCT). Material and methodsWe evaluated 125 patients who underwent TAVR-planning CTA on 3rd generation DSCT. A two-part protocol was performed including retrospectively ECG-gated coronary CTA (CCTA) and prospectively ECG-triggered aortoiliac CTA using 60mL of contrast medium. Automated tube voltage selection and advanced iterative reconstruction were applied. Effective dose (ED), signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were calculated. Five-point scales were used for subjective image quality analysis. In patients who underwent TAVR, sizing parameters were obtained. ResultsImage quality was rated good to excellent in 97.6% of CCTA and 100% of aortoiliac CTAs. CTA studies at >100kV showed decreased objective image quality compared to 70–100kV (SNR, all p≤0.0459; CNR, all p≤0.0462). Mean ED increased continuously from 70 to >100kV (CCTA: 4.5±1.7mSv–13.6±2.9mSv, all p≤0.0233; aortoiliac CTA: 2.4±0.9mSv–6.8±2.7mSv, all p≤0.0414). In 39 patients TAVR was performed and annulus diameter was within the recommended range in all patients. No severe cardiac or vascular complications were noted. Conclusion3rd generation DSCT provides diagnostic image quality in TAVR-planning CTA and facilitates reliable assessment of TAVR device and delivery option while reducing radiation dose.