Metal-on-metal hip replacement: MRI signal intensities of different body tissues and their relations to blood metal ion levels

Einat Slonimsky, Tammar Kushnir, Assaf Kadar, Aharon Menahem, Alon Grundshtein, Steven Velekes, Merav Lidar, Shmuel Dekel, Iris Eshed*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Background: Metal-on-metal total hip prostheses (MoM-THR) have been shown to produce hypersensitivity reactions and fluid collection (pseudotumor) by the hip as well as high blood metal ions levels (BMILs). Objectives: To evaluate the magnetic resonance imaging (MRI) signal-to-noise ratio (S/N) in selected body tissues around the hip of patients who underwent MoM hip replacement and to correlate to BMILs. Methods: Sixty-one MRI hip examinations in 54 post-MoMTHR patients (18 males, 36 females, mean age 65 years) were retrospectively evaluated independently by two readers. The mean S/N ratio in a region of interest was calculated for periprosthetic pseudotumor collection (PPC), the bladder, fat, and muscle on axial T1w, FSE-T2w, and short tau inversion recovery (STIR) sequences on the same location. BMILs were retrieved from patient files. Results: PPC was detected in 32 patients (52%) with an average volume of 82.48 mm3. BMIL did not correlate with the presence of PPCs but positively correlated with the PPC’s volume. A trend for positive correlation was found between BMILs and S/N levels of STIR images for muscle and bladder as well as for PPC and cobalt levels. A trend for correlation was also seen between BMIL with PPC’s T1 w S/N. Conclusions: Alteration of MRI S/N for different hip tissues showed a tendency for correlation with BMILs, possibly suggesting that metal deposition occurs in the PPC as well as in the surrounding tissues and bladder.

Original languageEnglish
Pages (from-to)674-678
Number of pages5
JournalIsrael Medical Association Journal
Issue number11
StatePublished - Nov 2017


  • Blood metal ions
  • Metal-on-metal total hip replacement (MoM-THR)
  • Pseudotumor
  • Signal intensity
  • Signal-to-noise ratio (S/N)


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