Trained readers of radiographs and magnetic resonance imaging (MRI) scans of the spine are able to differentiate between lesions associated with axial spondyloarthritis (axSpA) and lesions associated with degenerative changes, according to the results of the DESIR (Devenir des Spondylarthropathies Indifférenciées Récentes) cohort study, which were published in RMD Open.
The investigators sought to explore the prevalence of degenerative changes on MRI and conventional radiographs of the spine in a group of young patients with suspected axSpA and to evaluate whether it is possible to distinguish between degenerative changes and lesions that are associated with axSpA.
Whole-spine MRIs and cervical and lumbar radiographs of patients ≥18 years with chronic back pain were evaluated for degeneration by 2 readers and for SpA lesions by 2 additional readers. Readers were blinded for clinical information and results of the other 2 readers. Images from patients who met the Assessment of SpondyloArthritis international Society (ASAS) axSpA criteria were compared with those of patients who did not meet the criteria for the incidence of degenerative lesions. The scores for SpA and degenerative lesions were compared, with overlap defined as the presence of both types of lesions in a single vertebral unit (VU).
A total of 648 participants with complete radiographs and MRIs at baseline were enrolled in the study. Overall, 46.8% of the patients were men, and mean participant age was 33.6±8.6 years. ASAS classification criteria were met in 63.1% of patients.
Degenerative lesions were detected in similar percentages of patients with no axSpA and those with axSpA (72.4% vs 69.2%, respectively; P =.45). Moreover, modic changes were observed more frequently in participants with no axSpA (12.1%) vs those with axSpA (4.6%; P= .01). Other lesions were similar among the participants in both groups.
Both teams of readers evaluated a total of 638 patients with 14,674 VUs on MRI and 7656 VUs on radiographs. AxSpA lesions on MRI scans are more evenly distributed in the spine, with a slightly higher prevalence observed in the lower thoracic spine. Overlap was minimal in 3.0% (n=19) of patients and 0.2% (32 of 14,674) of VUs for SpA reader 1 and in 3.6% (n=23) and 0.2% (34 of 14,674) of VUs for SpA reader 2.
The investigators concluded that prevalence of degeneration is high in the early inflammatory back pain cohort, with no differences between patients who fulfilled and those who did not fulfill ASAS axSpA critera. Therefore, distinguishing between degeneration and axSpA lesions by trained readers is possible with little overlap reported between axSpA and degenerative readings.
de Bruin F, Treyvaud MO, Feydy A, et al. Prevalence of degenerative changes and overlap with spondyloarthritis-associated lesions in the spine of patients from the DESIR cohort. RMD Open. 2018;4(1):e000657.