MRI-based predictors of spinal ankylosis progression: ESSR framework for axial spondyloarthritis.

Background: Magnetic resonance imaging (MRI), utilizing fat-saturated T2-weighted and short-tau inversion recovery sequences, is essential for the early diagnosis and monitoring of axial spondyloarthritis (axSpA). Recently, the European Society of Musculoskeletal Radiology proposed recommendations for the standardization of MRI findings for axSpA. However, the predictive value of specific MRI findings for spinal ankylosis progression remains unclear. This study investigates whether baseline MRI findings correlate with the progression of spinal ankylosis observed on radiographs over a 2-year period.

Methods: Twenty-six axSpA patients who met Assessment of SpondyloArthritis International Society criteria and underwent baseline and 2-year follow-up imaging were included. MRI assessments of the lumbar spine and sacroiliac joint evaluated inflammatory and structural lesions, including Romanus and Anderson lesions. Radiographic progression was defined as a ≥2-point increase in the modified Stoke Ankylosing Spondylitis Spinal Score. Statistical analyses compared clinical and imaging parameters between progression (n = 9) and nonprogression (n = 17) groups.

Results: Patients in the progression group had significantly higher baseline modified Stoke Ankylosing Spondylitis Spinal Score (P = .04) and modified-health assessment questionnaire scores (P = .04). Positive MRI findings of anterior and posterior corner inflammatory lesions and Anderson-central lesions were significantly associated with progression (P < .05). Romanus lesions, indicative of early structural changes, were more frequent in the progression group (P = .02). However, fat lesions and sacroiliac joint inflammation showed no significant predictive value.

Conclusion: Baseline MRI findings, particularly inflammatory and Romanus lesions, are strong predictors of spinal ankylosis progression in axSpA. These results highlight the importance of incorporating MRI into personalized treatment strategies to mitigate disease progression. Further studies are needed to validate these findings in larger cohorts.