ISSN 1004-4140
CN 11-3017/P

低管电压结合AIIR抑制髋关节假体CT伪影的效果研究

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

  • 摘要: 目的:探讨低管电压结合AIIR在髋关节术后盆腔CT检查中抑制金属伪影的效果。方法:回顾性收集46例在我院接受盆腔CT扫描的髋关节置换患者数据,分为筛查组(80 kVp)和临床组(120 kVp),分别进行常规重建、1~5级AIIR的重建;对图像“蜡像感”和整体质量进行主观评分;勾画ROI并计算ΔCT肌肉、ΔCT脂肪、SD伪影、SD背景、MAI和CNR;对主观和客观指标先进行组内两两对比,再将筛查组最优重建方法与临床组所有重建方法进行对比,并比较其容积CT剂量指数。结果:随着AIIR等级提升,图像整体质量评分提升(均优于常规重建),“蜡像感”降低(AIIR 5级与常规重建差异无统计学意义)。随着AIIR等级提升,筛查组和临床组图像噪声呈上升趋势,CNR呈下降趋势,筛查组MAI呈上升趋势,临床组MAI差异无统计学意义,但均优于常规重建。AIIR等级间ΔCT肌肉、ΔCT脂肪差异无统计学意义,但AIIR使筛查组的该差值明显降低。筛查组容积CT剂量指数明显低于临床组。筛查组最优的AIIR 5级与临床组各重建相比,ΔCT肌肉、ΔCT脂肪差异无统计学意义,其他客观指标均有差异;主观评分与临床组AIIR 5级差异无统计学意义,且都优于其他重建。结论:在髋关节置换术后患者盆腔CT中,5级是最优的AIIR等级,能显著抑制噪声和金属伪影并提升CNR;80 kVp结合5级AIIR,能在辐射剂量低于120 kVp的同时,使图像主观质量达到120 kVp水平。

     

    Abstract: Objective: To investigate the efficacy of low tube voltage combined with 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.

     

/

返回文章
返回