Zhang Kesong, Han Qing, Xu Xiaolin, Jiang Hao, Ma Lin, Zhang Yong, Yang Kerong, Chen Bingpeng, Wang Jincheng
Department of Orthopedics.
Radiology Department, The Second Hospital of Jilin University, Changchun, 130000, Jilin Province, China.
Medicine (Baltimore). 2020 Mar;99(11):e19268. doi: 10.1097/MD.0000000000019268.
The purpose of this study was to investigate metal artifact reduction effect of orthopedics metal artifact reduction (O-Mar) algorithm in computer tomography (CT) image of patients who have undergone total hip arthroplasty (THA) or total knee arthroplasty (TKA).35 cases of patients who underwent TKA or THA have been recruited in this study. CT image of hip or knee joint was obtained with Philips 256-row CT scanner. Tube voltages of 120 and 140 kilovolt peak (KVP) were set. Afterwards, CT image was reconstructed by O-Mar algorithm to reduce metal artifact. Grade of image quality and severity of metal artifact would be taken into qualitative evaluation. While, quantitative evaluation mainly included measurement of metal artifact volume and 2D measurement of average CT value in region of interest (ROI). The visibility of interface between bone-prostheses was also estimated.Result of qualitative analysis indicated that score of CT quality was improved and grade of metal artifact was decreased significantly with O-Mar. Quantitative analysis illustrated that volume of beam-hardening (B-H) metal artifact decreased remarkably after reconstruction of O-Mar (P < .001). In addition, O-Mar algorithm reduced 83.3% to 83.7% volume of photon-starvation (P-S) metal artifact. As for result of 2D measurement, CT value in ROI was closer to standard value in O-Mar group CT image (P < .001). Meanwhile, error of CT value also decreased significantly after reconstruction of O-Mar algorithm. Visibility rate of bone-prosthesis interface improved from 34.3% (Non-O-Mar) to 66.7% (O-Mar).O-Mar algorithm could significantly reduce metal artifact in CT image of THA and TKA in both 2D and three-dimensional (3D) level. Therefore, better image quality and visibility of bone-prostheses interface could be presented. In this study, O-Mar was proved as an efficient metal artifact reduction method in CT image of THA and TKA.
本研究旨在探讨骨科金属伪影减少（O-Mar）算法在接受全髋关节置换术（THA）或全膝关节置换术（TKA）患者的计算机断层扫描（CT）图像中的金属伪影减少效果。本研究招募了35例接受TKA或THA的患者。使用飞利浦256排CT扫描仪获取髋关节或膝关节的CT图像。设置管电压为120和140千伏峰值（KVP）。之后，通过O-Mar算法重建CT图像以减少金属伪影。对图像质量等级和金属伪影严重程度进行定性评估。同时，定量评估主要包括金属伪影体积测量和感兴趣区域（ROI）内平均CT值的二维测量。还评估了骨-假体界面的可视性。定性分析结果表明，使用O-Mar后CT质量评分提高，金属伪影等级显著降低。定量分析表明，O-Mar重建后束硬化（B-H）金属伪影体积显著减少（P<0.001）。此外，O-Mar算法使光子饥饿（P-S）金属伪影体积减少了83.3%至83.7%。至于二维测量结果，O-Mar组CT图像中ROI内的CT值更接近标准值（P<0.001）。同时，O-Mar算法重建后CT值误差也显著降低。骨-假体界面可视率从34.3%（非O-Mar）提高到66.7%（O-Mar）。O-Mar算法可在二维和三维（3D）层面显著减少THA和TKA的CT图像中的金属伪影。因此，可以呈现更好的图像质量和骨-假体界面可视性。在本研究中，O-Mar被证明是THA和TKA的CT图像中一种有效的金属伪影减少方法。
