Classification of axial SpA based on positive imaging (radiographs and/or MRI of the sacroiliac joints) by local rheumatologists or radiologists versus central trained readers in the DESIR cohort

Abstract

In patients with recent onset IBP, trained readers and local rheumatologists/radiologists agree well on recognising a pos-MRI. While disagreeing in 28% of the patients on positive imaging (MRI-SI and/or X-SI), classification of only 7.9% of the patients changed based on a different evaluation of images, showing the ASAS axSpA criteria's robustness.

Defining active sacroiliitis on MRI for classification of axial spondyloarthritis: update by the ASAS MRI working group

“…Using the DESIR cohort of subjects with inflammatory back pain (IBP) of less than 3 years duration before the age of 50, the reliability of classification of radiographs and MRI was compared between rheumatologists and radiologists of 25 local recruiting centres and central readers 5 7. The results indicate that the existing MRI definition could be applied across multiple centres with the expectation of acceptable reliability and at least with better reliability than the X-ray definition of sacroiliitis according to the modified New York criteria.…”

Reliability of mSASSS scoring in everyday practice in DESIR-cohort study centres: cross-sectional study of agreement with trained readers

“…In earlier work, we found the same—moderate—level of agreement between local reading (LocR) and central reading (CentR) as between the two central readers regarding radiographic sacroiliitis assessment 1. However, differences between LocR and CentR resulted in misclassification of some patients (ankylosing spondylitis (AS) or axSpA meeting Assessment of SpondyloArthritis international Society (ASAS) criteria) 2. The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) is the recommended tool to assess erosions, sclerosis, squaring and (bridging) syndesmophytes at each anterior vertebral corner of the cervical and lumbar spine 3 4.…”

The term ‘non-radiographic axial spondyloarthritis’ is much more important to classify than to diagnose patients with axial spondyloarthritis

“…Local readers can take into account the clinical characteristics of individual patients when interpreting their imaging studies, especially the potentially important factors of age14 15 or of confounding diagnoses such as erosive osteochondrosis (Modic lesions) at the L4/L5 level. Disagreement in interpreting SIJ imaging, both between local rheumatologists or radiologists and central trained readers and between different central trained readers, has been reported to occur in 20–30% of cases 20 21. The experience in the first randomised controlled trials (RCTs) to study nr-axSpA10 was that the trained central readers revised the interpretation of SIJ radiographs by local readers in 185 (40%) of cases—an unfortunate, but typical, example.…”