Computed tomography imaging of a hip prosthesis using iterativemodel-based reconstruction and orthopaedicmetal artefact reduction: A quantitative analysis

Objectives: To quantify the combined use of iterative model-based reconstruction (IMR) and orthopaedic metal artefact reduction (O-MAR) in reducing metal artefacts and improving image quality in a total hip arthroplasty phantom. Methods: Scans acquired at several dose levels and kVps were reconstructed with filtered back-projection (FBP), iterative reconstruction (iDose4) and IMR, with and without O-MAR. Computed tomography (CT) numbers, noise levels, signal-to-noise-ratios and contrast-to-noise-ratios were analysed. Results: Iterative model-based reconstruction results in overall improved image quality compared to iDose4 and FBP (P < 0.001).Orthopaedicmetal artefact reduction is most effective in reducing severe metal artefacts improving CT number accuracy by 50%, 60%, and 63% (P < 0.05) and reducing noise by 1%, 62%, and 85% (P < 0.001) whereas improving signal-to-noise-ratios by 27%, 47%, and 46% (P < 0.001) and contrastto-noise-ratios by 16%, 25%, and 19% (P < 0.001) with FBP, iDose4 , and IMR, respectively. Conclusions: The combined use of IMR and O-MAR strongly improves overall image quality and strongly reduces metal artefacts in the CT imaging of a total hip arthroplasty phantom.