Elucidation of the Efficacy of Low Tube Voltage Combined with AIIR in Suppressing Hip Prosthesis CT Artifacts

Objective: To investigate the efficacy of low tube voltage combined with artificial intelligence iterative reconstruction (AIIR) in suppressing metal artifacts during pelvic CT scans after hip arthroplasty. Methods: Data from 46 patients with hip replacements who underwent pelvic CT scans at our hospital were retrospectively collected and divided into a screening group (80 kVp) and a clinical group (120 kVp). Conventional reconstruction and AIIR reconstructions at levels 1~5 were performed. Subjective scoring of “wax-like” appearance and overall image quality was conducted. Regions of interest (ROI) were drawn to calculate ΔCT of muscle, ΔCT of fat, SD of artifacts, SD of background, MAI, and CNR. Pairwise comparisons were made within each group, and the optimal reconstruction method within the screening group was compared with all methods applied in the clinical group. Volume CT dose indices were also compared. Results: As the AIIR level increased, the overall image quality score improved (better than conventional reconstruction), and the “wax-like” appearance decreased (no significant difference between AIIR level 5 and conventional reconstruction). With increasing AIIR level, image noise displayed an upward trend in both the screening and clinical groups, while CNR decreased. MAI increased in the screening group, but no significant difference was observed in the clinical group. However, both groups performed better than that obtained from conventional reconstruction. No significant differences were found in ΔCT of muscle and ΔCT of fat between AIIR levels, but AIIR significantly reduced these values in the screening group. The volume CT dose index of the screening group is significantly lower than that of the clinical group. There was no significant difference in ΔCT of muscle or fat between optimal AIIR level 5 in the screening group and all reconstructions in the clinical group, but other objective indicators showed differences. Subjective scores showed no significant difference between the clinical group and AIIR level 5, and all were better than other reconstructions. Conclusion: In pelvic CT scans of patients after hip arthroplasty, AIIR level 5 is the optimal level, and can significantly suppress noise and metal artifacts and improve CNR. Combining 80 kVp with AIIR level 5 reduces the radiation dose below that required with 120 kVp, while maintaining comparable subjective image quality.