Application of 80 kVp combined with deep learning reconstruction algorithm in overweight patients coronary CT angiography: reduced radiation dose and contrast agent dose

Background: Coronary CT angiography (CCTA) has become a key imaging technique for clinical screening of coronary artery disease (CAD). Overweight patients have a higher prevalence of CAD, however, they face increased risks of radiation exposure and contrast-induced nephropathy during CCTA examinations. This study aimed to explore the feasibility of an 80 kVp scanning protocol combined with deep learning image reconstruction (DLIR) algorithm to reducing radiation dose and contrast agent dose in overweight patients with CCTA. Methods: A prospective study was conducted on 100 overweight patients who underwent CCTA, randomly divided into two groups of 50 patients each. The scanning tube voltage of group A was 80 kVp, the dose of contrast agent was calculated as BMI × 0.14mL/s x 9s, and H-strength DLIR(DLIR-H) was used for image reconstruction. The voltage of group B was 100 kVp, the contrast agent dose was calculated as BMI × 0.18mL/s x 9s and the image was reconstruction by 50% adaptive statistical iterative reconstruction-Veo (ASIR-V50%). Radiation dose, contrast agent dose, injection rate, subjective and objective image quality were compared. Results: Compared to Group B, Group A exhibited significantly lower values for radiation dose (2.85 ± 0.46 vs.4.46 ± 0.69 mSv), contrast agent dose (34.62 ± 2.05 vs. 43.64 ± 1.91 mL) and injection rate (3.83 ± 0.22 vs. 4.84 ± 0.21 mL/s) (all P  < 0.001), representing reductions of 36.02%, 20.67% and 20.87%, respectively. Inter-reader agreement for subjective scores were excellent ( к between 0.89 and 1.00). Group A demonstrated significantly lower background noise compared to Group B (15.46 ± 2.82 vs. 21.60 ± 4.36 HU, P  < 0.001). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of major coronary arteries were significantly better in Group A compared to Group B (both P  < 0.05), except for the SNR of left circumflex artery. Conclusions: In overweight patients undergoing CCTA, the 80 kVp protocol combined DLIR-H effectively reduced the radiation dose, contrast agent dose and injection rate while ensuring image quality compared to the 100 kVp combined ASIR-V50% scanning protocol.