MRI and the distribution of bone marrow fat in hip osteoarthritis

Jennifer S Gregory, Rebecca J Barr, Victor Varela, Trevor S Ahearn, Jennifer Lee Gardiner, Fiona J Gilbert, Thomas W Redpath, James D Hutchison, Richard M Aspden

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)
11 Downloads (Pure)



To characterize the distribution of bone marrow fat in hip osteoarthritis (OA) using magnetic resonance imaging (MRI) and to assess its use as a potential biomarker.

Materials and Methods

In all, 67 subjects (39 female, 28 male) with either total hip replacement (THA) or different severities of radiographic OA, assessed by Kellgren–Lawrence grading (KLG), underwent 3T MRI of the pelvis using the IDEAL sequence to separate fat and water signals. Six regions of interest (ROIs) were identified within the proximal femur. Within each ROI the fractional-fat distribution, represented by pixel intensities, was described by its mean, standard deviation, skewness, kurtosis, and entropy.ResultsHips were graded: 12 as severe symptomatic (THA), 33 had KLG0 or 1, 9 were KLG2, 11 with KLG3, and 2 with KLG4 were analyzed together. The fractional-fat content in the whole proximal femur did not vary with severity in males (mean (SD) 91.2 (6.0)%) but reduced with severity in females from 89.1 (6.7)% (KLG0,1), 91.5 (2.9)% (KLG2), 85.8 (16.7)% (KLG3,4) to 77.5 (11.9)% (THA) (analysis of variance [ANOVA] P = 0.029). These differences were most pronounced in the femoral head, where mean values fell with OA severity in both sexes from 97.9% (2.5%) (KLG0,1) to 73.0% (25.9%) (THA, P < 0.001) with the largest difference at the final stage. The standard deviation and the entropy of the distribution both increased (P < 0.001).


Descriptors of the fractional fat distribution varied little with the severity of OA until the most severe stage, when changes appeared mainly in the femoral head, and have, therefore, limited value as biomarkers.

Original languageEnglish
Pages (from-to)42–50
Number of pages9
JournalJournal of Magnetic Resonance Imaging
Issue number1
Early online date2 Jun 2016
Publication statusPublished - 1 Jan 2017

Bibliographical note

Grant support
This study was supported by an award (Ref: WHMSB-AU119) from the Translational Medicine Research Collaboration – a consortium made up of the Universities of Aberdeen, Dundee, Edinburgh and Glasgow, the four associated NHS Health Boards (Grampian, Tayside, Lothian and Greater Glasgow & Clyde), Scottish Enterprise and Wyeth. The funder played no part in the design, execution, analysis or publication of this paper.

We are grateful to Mrs D. Younie for kindly arranging the imaging sessions and Mrs B.MacLennan (research radiographer) for acquiring the MR images. We also thank Dr S. Galea-Soler, Dr G. Waiter, Dr.Zhiqing Wu, and Dr K. Yoshida for Kellgren-Lawrence grading, help and advice, and Mr G. Buchan for his expertise making the phantoms.


  • osteoarthritis
  • hip
  • intramedullary fat
  • fractional fat content
  • imaging biomarker


Dive into the research topics of 'MRI and the distribution of bone marrow fat in hip osteoarthritis'. Together they form a unique fingerprint.

Cite this