Can whole spine magnetic resonance imaging predict radiographic progression and inflammatory activity in axial spondyloarthritis?

Abstract

Objective: To investigate whether initial whole spine magnetic resonance imaging (MRI) predicts radiographic progression and inflammatory activity in patients with axial spondyloarthritis (axSpA).

Methods: A retrospective analysis of spine MRI and X-rays from 70 axSpA patients was conducted. The number of affected discovertebral units was determined according to the definition of pathologic lesions on spine MRI set down by the ASAS/OMERACT group. Radiographic progression was defined as an increase in the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) of≥2 compared with baseline. The association of spine MRI with radiographic progression, cumulative C-reactive protein (CRP), and cumulative erythrocyte sedimentation rate (ESR) was investigated.

Results: The axSpA-relevant lesions on spine MRI at baseline were independent predictors of radiographic progression. Arthritis of the costovertebral and costotransverse joints on MRI showed the highest odds ratio at 3years (OR [95% CI]: 2.54 [1.29-5.02]). Receiver operating characteristic curve analysis revealed that the area under the curve (AUC) for radiographic progression at 2years was 0.89 [95% CI: 0.81-0.96] for structural lesions and 0.83 [95% CI: 0.72-0.94] for inflammatory lesions. Notably, subgroup analysis of 26 patients with mSASSS=0 showed that fatty metaplasia on MRI were highly predictive of radiographic progression at 3years (AUC [95% CI]: 0.87 [0.61-1.00]). Moreover, 3-year cumulative ESR and CRP values increased in proportion to the extent of inflammatory lesions on initial MRI.

Conclusion: Initial MRI assessment of the whole spine may predict radiographic progression and subsequent systemic inflammatory burden in axSpA patients, particularly those without axSpA-relevant abnormalities on spine X-rays.

Keywords: Axial spondyloarthritis; Radiographic progression; Spine MRI.