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Dual-Energy Computed Tomography in Loosening of Revision Hip Prosthesis

A Comparison Between MARS and non-MARS Images

Guziński, Maciej, PhD*; Kubicki, Konrad, MD*; Waszczuk, Łukasz, MD*; Morawska-Kochman, Monika, PhD; Kochman, Andrzej, PhD; Sąsiadek, Marek, PhD*

Journal of Computer Assisted Tomography: May/June 2019 - Volume 43 - Issue 3 - p 379–385
doi: 10.1097/RCT.0000000000000850
Musculoskeletal Imaging

Purpose The aim of the study was to assess potential endoprosthesis loosening in patients after revision total hip arthroplasty, based on monochromatic dual-energy computed tomography (DECT) images obtained with and without metal artifact reduction software (MARS) and comparison with the clinical examination and hip function.

Materials and Methods Twenty-five consecutive patients underwent DECT examinations. Two monochromatic data sets were generated: with MARS (75-keV MARS) and without MARS (140-keV non-MARS) and evaluated for signs of loosening, using a dedicated radiological score. The Harris Hip Score (HHS) was used to evaluate patients' hip function.

Results The mean radiological score for loosening in the non-MARS group was 16.2, in the MARS group 17.0 and was significantly higher (P < 0.001). Radiological loosening evaluation in non-MARS images correlated with the HHS score (ρ = 0.43, P = 0.03), whereas there was no correlation between MARS images and HHS (ρ = 0.15, P = 0.47). New MARS-related artifacts, which hinder implant-bone interface evaluation, were found in 75-keV MARS images (“pseudo-loosening” in 33 of 34 prostheses, “ground-glass blurring” in 20 of 32).

Conclusions High-energy monochromatic DECT images are superior to low-energy DECT MARS images in assessment of the potential loosening and correlate better with the clinical examination outcomes. For revision total hip arthroplasty evaluation, 2 data sets should be assessed inseparably because of extra artifacts in MARS images.

From the *Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University; and

Department of Orthopedic and Traumatology, The Ministry of Internal Affairs Hospital, Wrocław, Poland.

Received for publication October 15, 2018; accepted December 14, 2018.

Correspondence to: Maciej Guziński, Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University, 213 Borowska St, 50-556 Wrocław, Poland (e-mail:

The authors declare no conflict of interest.

Written informed consent was obtained from all patients in this study. Institutional review board approval was obtained.

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