Single energy metal artifact reduction technique in the evaluation of postoperative tumor endoprostheses in the knee joint

Abstract

Objective To evaluate the effect of the single energy metal artifact reduction (SEMAR) algorithm with a 320 multi-slice computed tomography (MSCT) volume scanner in patients with knee tumor prostheses. Methods From November 2015 to March 2016, 23 consecutive patients with knee tumor prostheses who underwent a 320-MSCT scan were collected. And the raw data were reconstructed using two different methods: conventional iterative reconstruction (IR) alone and IR associated with SEMAR. The ROI were objectively and subjectively assessed at osteotomy level and articular level, and the Wilcoxon signed rank test was used for them. Results Compared with IR, objectively, artifact index (AI) values of the osteotomy level decreased 44.8% to 74.1% and that of the articular level decreased 73.2% to 93.2%; subjectively, the scores of image quality of two levels were increased 0.5 to 2.0 scores and 1.0 to 4.0 scores by SEMAR respectively. The objective and subject image quality of periprosthetic structures were all significantly improved by the SEMAR algorithm (P<0.05). Conclusion The SEMAR algorithm significantly reduced the metal artifact of knee tumor prostheses, improved the image quality of periprosthetic structures and may increase diagnostic confidence of prosthetic complications in patients with modular knee tumor prostheses, especially at the osteotomy level. Key words: Knee prosthesis; Tomography,X-ray computed