The Effect of MAR Technique on Image Quality of the Anorectal Region in Pelvic CT in Patients with Metallic Hip Prostheses

Abstract

Objective:In this study, we aimed to compare the effects of using the iterative reconstruction (IR) method alone and together with metallic artifact reduction (MAR) on the image quality in computed tomography (CT) imaging of the anorectal region in patients with a metallic hip prosthesis, and to evaluate the contribution of IR+MAR approach to radiological evaluation.Method:In 22 patients carrying hip prosthesis, as subjective criteria, the degree of metal artifact visualization and critical anatomical structures as the anal canal (AC), inferior rectum (InR), mesorectum (MsR), perianal fat tissue (PFT), and levator ani muscle (LAM) were evaluated in the images of pelvic CT with IR and MAR reconstructions, using only IR technique and IR+MAR approach. As objective criteria, most pronounced hypodense artifacts obscuring the pelvic soft tissue and hyperdense artifacts were measured in the images with MAR and without MAR technique.Results:It was found that the use of the MAR technique for common metal artifacts observed after CT imaging significantly increased the diagnostic value on AC, InR, MsR, PFT, and LAM radiologically. It was determined that the method provided a significant increase in the visualization of the pelvic bone and muscle tissues and the quality of diagnosis. The differences between hypodense artifact measurements and hyperdense artifact measurements were statistically significant.Conclusion:Performing IR+MAR reconstruction on pelvic CT in patients with a metallic hip prosthesis improves image quality and the diagnostic value of CT. It can be used in the imaging of anorectal pathologies in patients who cannot undergo magnetic resonance imaging.

Keywords

• anorectal pathologies
• hip prosthesis
• iterative reconstruction
• mar technique