Comparative analysis of pre-transcatheter aortic valve implantation CTA protocols: optimizing radiation dose and contrast volume

Background: To establish the most effective and safe pre-transcatheter aortic valve implantation (TAVI) CT angiography (CTA) protocol by comparing two approaches in terms of image quality, radiation and contrast dose. Methods: Consecutive patients undergoing pre-procedural CTA were prospectively enrolled from January to May 2024. Patients were randomly assigned into two different acquisition protocols: group A underwent an ECG-gated CTA of the thorax followed by a non-gated helical scan of abdomen and pelvis; group B underwent an ECG-gated CTA including only the heart and aortic root, followed by a non-gated helical scan of thorax, abdomen, and pelvis. Objective image analysis was performed by evaluating vascular attenuation, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) in multiple segments. Subjective image analysis was evaluated by two radiologists and radiation and contrast dose were compared between the groups. Results: The final population consisted of 64 patients, 37 in group A and 27 in group B (80.6 ± 5.2 years; 49 males). Group B showed lower radiation dose compared to group A (13.7 ± 1.2 vs 15.7 ± 1.4 mSv; p < 0.001) and lower contrast medium volume (82.9 ± 10.1 vs 90.3 ± 12.0 ml; p = 0.004) while achieving no differences in terms of signal-to-noise ratio, contrast-to-noise ratio and subjective image quality (all p > 0.05). Average vascular attenuation was higher in group A compared to group B (707.1 ± 120.7 vs 633.0 ± 198.6 HU; p < 0.001); however, lumen attenuation at the aortic root was consistent across the two protocols (p = 0.077). Conclusions: Optimization of pre-TAVI CTA protocol results in lower contrast medium volume and radiation dose exposure while maintaining consistent image quality.