ACR Meeting Abstracts

ACR Meeting Abstracts

  • Meetings
    • ACR Convergence 2024
    • ACR Convergence 2023
    • 2023 ACR/ARP PRSYM
    • ACR Convergence 2022
    • ACR Convergence 2021
    • ACR Convergence 2020
    • 2020 ACR/ARP PRSYM
    • 2019 ACR/ARP Annual Meeting
    • 2018-2009 Meetings
    • Download Abstracts
  • Keyword Index
  • Advanced Search
  • Your Favorites
    • Favorites
    • Login
    • View and print all favorites
    • Clear all your favorites
  • ACR Meetings

Abstract Number: 1024

What Constitutes the Characteristic Fat Lesion On MRI of the Sacroiliac Joints in Early Spondyloarthritis?

Ulrich Weber1, Susanne Juhl Pedersen2, Veronika Zubler3, Kaspar Rufibach4, Stanley Chan5, Robert GW Lambert6, Mikkel Ostergaard7 and Walter P. Maksymowych8, 1Rheumatology, Balgrist University Hospital, Zurich, Switzerland, 2Department of Rheumatology, Copenhagen University Hospital Glostrup, Copenhagen, Denmark, 3Radiology, Balgrist University Hospital, Zurich, Switzerland, 4Institute for Social and Preventive Medicine, Division of Biostatistics, University of Zurich, Zurich, Switzerland, 5Division of Ophthalmology, University of Alberta, Edmonton, AB, Canada, 6Radiology, University of Alberta, Edmonton, AB, Canada, 7Dept of Rheumatology RM, Copenhagen University Hospital, Glostrup, Denmark, 8Department of Medicine, University of Alberta, Edmonton, AB, Canada

Meeting: 2012 ACR/ARHP Annual Meeting

Keywords: Magnetic resonance imaging (MRI) and spondylarthropathy

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print
Session Information

Title: Imaging of Rheumatic Diseases: Magnetic Resonance Imaging, Computed Tomography and X-ray

Session Type: Abstract Submissions (ACR)

Background/Purpose: It is well known that fat infiltration (FI) of bone marrow may be observed on T1-weighted MRI in the sacroiliac joints (SIJ) of healthy individuals and patients with mechanical back pain and with spondyloarthritis (SpA). But it is unclear whether the MRI features of FI allow characterization of FI as pathological rather than physiological. Moreover, it is unclear if this might have diagnostic utility in early SpA. We aimed to assess which MRI features of fat contribute to diagnostic utility of SIJ MRI in 2 inception cohorts of early SpA.

Methods: Cohort A comprised 69 consecutive patients ≤50 years referred from rheumatology and primary care practices for assessment of clinically suspected SpA, cohort B comprised 88 consecutive patients ≤50 years with acute anterior uveitis and back pain. They were classified according to clinical examination and pelvic X-ray as having non-radiographic axial SpA (nr-axSpA) (n=20 and 31 for cohorts A and B, respectively), ankylosing spondylitis (AS) (n=10 and 24), or mechanical back pain (MBP) (n=39 and 33). Cohort A also comprised 20 healthy volunteers (HV). SIJ MRI were assessed independently in random order by 4 blinded readers for the following morphological features of FI: distinct border around the region of FI, homogeneity of the T1-weighted signal, proximity to subchondral bone, and association with other SIJ lesions (bone marrow edema (BME), erosion (ER)).

Results: In cohort A and B, FI in ≥2 SIJ quadrants was recorded by any 2 readers in AS in 90% and 100%, in nr-axSpA in 45% and 48%, in MBP in 36% and 24%, respectively, and in HV in 10%. Inter-reader agreement for FI expressed as intraclass correlation coefficient over all 4 readers was 0.59 and 0.75 for cohort A and B.
 
Diagnostic utility (mean of 4 readers for cohort A/B) of SIJ FI in nr-axSpA vs MBP patients
Feature Sensitivity Specificity Positive LR Negative LR
FI per se 0.44/0.42 0.73/0.78 1.62/1.91 0.77/0.74
FI with distinct border 0.21/0.21 0.97/0.90 8.29/2.13 0.81/0.88
Homogeneous FI 0.20/0.26 0.97/0.93 6.24/3.78 0.83/0.80
Subchondral FI 0.36/0.35 0.85/0.83 2.36/2.04 0.75/0.78
FI with any 2 features 0.24/0.30 0.97/0.92 9.26/3.58 0.78/0.77
FI+BME 0.19/0.18 0.99/0.92 14.63/2.13 0.82/0.90
FI+ER 0.21/0.24 0.99/0.93 33.15/3.55 0.79/0.81

BME: Bone marrow edema. ER: Erosion. FI: Fat infiltration. LR: Likelihood ratio. FI with any 2 features: ≥2 features out of FI with distinct border/Homogeneous FI/Subchondral FI

Conclusion: SIJ FI characterized by a distinct border or homogeneity on MRI had substantial diagnostic utility in early SpA. FI in combination with BME or ER also showed high diagnostic utility.


Disclosure:

U. Weber,
None;

S. J. Pedersen,
None;

V. Zubler,
None;

K. Rufibach,
None;

S. Chan,
None;

R. G. Lambert,
None;

M. Ostergaard,
None;

W. P. Maksymowych,
None.

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/what-constitutes-the-characteristic-fat-lesion-on-mri-of-the-sacroiliac-joints-in-early-spondyloarthritis/

Advanced Search

Your Favorites

You can save and print a list of your favorite abstracts during your browser session by clicking the “Favorite” button at the bottom of any abstract. View your favorites »

All abstracts accepted to ACR Convergence are under media embargo once the ACR has notified presenters of their abstract’s acceptance. They may be presented at other meetings or published as manuscripts after this time but should not be discussed in non-scholarly venues or outlets. The following embargo policies are strictly enforced by the ACR.

Accepted abstracts are made available to the public online in advance of the meeting and are published in a special online supplement of our scientific journal, Arthritis & Rheumatology. Information contained in those abstracts may not be released until the abstracts appear online. In an exception to the media embargo, academic institutions, private organizations, and companies with products whose value may be influenced by information contained in an abstract may issue a press release to coincide with the availability of an ACR abstract on the ACR website. However, the ACR continues to require that information that goes beyond that contained in the abstract (e.g., discussion of the abstract done as part of editorial news coverage) is under media embargo until 10:00 AM ET on November 14, 2024. Journalists with access to embargoed information cannot release articles or editorial news coverage before this time. Editorial news coverage is considered original articles/videos developed by employed journalists to report facts, commentary, and subject matter expert quotes in a narrative form using a variety of sources (e.g., research, announcements, press releases, events, etc.).

Violation of this policy may result in the abstract being withdrawn from the meeting and other measures deemed appropriate. Authors are responsible for notifying colleagues, institutions, communications firms, and all other stakeholders related to the development or promotion of the abstract about this policy. If you have questions about the ACR abstract embargo policy, please contact ACR abstracts staff at [email protected].

Wiley

  • Online Journal
  • Privacy Policy
  • Permissions Policies
  • Cookie Preferences

© Copyright 2025 American College of Rheumatology