Scoring magnetic resonance imaging (MRI) inflammation and structural lesions in sacroiliac joints of patients with axial spondyloarthritis: assessment of all MRI slices of the cartilaginous compartment versus standardized six or five slices

Abstract

Objectives: The Spondyloarthritis Research Consortium of Canada (SPARCC) sacroiliac joint (SIJ) scoring system assesses six or five (6/5) semicoronal magnetic resonance imaging (MRI) slices for inflammation/structural lesions in patients with axial spondyloarthritis (axSpA). However, the cartilaginous SIJ compartment may be visible in a few additional slices. The objective was to investigate interreader reliability, sensitivity to change, and classification of MRI scans as positive or negative for various lesion types using an ‘all slices’ approach versus standard SPARCC scoring of 6/5 slices.

Method: Fifty-three axSpA patients were treated with the tumour necrosis factor inhibitor golimumab and followed with serial MRI scans at weeks 0, 4, 16, and 52. The most anterior and posterior slices covering the cartilaginous compartment and the transitional slice were identified. Scores for inflammation, fat metaplasia, erosion, backfill, and ankylosis in the cartilaginous SIJ compartment were calculated for the ‘all slices’ approach and the 6/5 slices standard.

Results: By the ‘all slices’ approach, three readers scored mean 7.2, 7.7, and 7.0 slices per MRI scan. Baseline and change scores for the various lesion types closely correlated between the two approaches (Pearson’s rho ≥ 0.95). Inflammation score was median 13 (interquartile range 6–21, range 0–49) for 6/5 slices versus 14 (interquartile range 6–23, range 0–69) for all slices at baseline. Interreader reliability, sensitivity to change, and classification of MRI scans as positive or negative for various lesion types were similar.

Conclusion: The standardized 6/5 slices approach showed no relevant differences from the ‘all slices’ approach and, therefore, is equally suited for monitoring purposes.

Acknowledgements

We thank CaRE Arthritis, Edmonton, Alberta (www.carearthritis.com), for making the web-based scoring interface available.

Images for this analysis were provided from an investigator-initiated trial (MANGO) sponsored by MSD. MSD had no role in the study design or in the collection, analysis, or interpretation of the data, the writing of the manuscript, or the decision to submit the manuscript for publication, and publication of this article was not contingent upon approval by MSD. This work was supported by the Danish Rheumatism Association and Copenhagen University Hospital, Rigshospitalet.

Disclosure statement

MØ has received research support and/or consultancy/speaker fees from AbbVie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Centocor, GSK, Hospira, Janssen, Merck, Mundipharma, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Schering-Plough, Takeda, UCB, and Wyeth. SJP has received consulting fees from AbbVie and research funding from AbbVie and MSD. UW received speaking fees from AbbVie for serving as convenor on a workshop on imaging in SpA. The remaining authors declare that they have no competing interests.

Supporting information

Additional supporting Information may be found in the online version of this article.

Supplementary figure S1. Bone marrow oedema, multiple-reader agreement plots.

Supplementary figure S2. Fat metaplasia, multiple-reader agreement plots.

Supplementary figure S3. Erosion, multiple-reader agreement plots.

Supplementary figure S4. Backfill, multiple-reader agreement plots.

Supplementary figure S5. Ankylosis, multiple-reader agreement plots.

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