Prevalence and anatomical distribution of MRI lesions in axSpA and differences between patients with and without
Bayram Farisogullari1,2,3, Stephanie Wichuk4, Xenofon Baraliakos5
1Division of Rheumatology, Department of Internal Medicine, Hacettepe University, Ankara, Turkey.
Objective:
To evaluate the prevalence and anatomical distribution of inflammatory and structural MRI lesions in axial spondyloarthritis (axSpA) and compare these between patients with isolated axial involvement and those with peripheral manifestations.
Methods:
Data from the Assessment of SpondyloArthritis International Society (ASAS) Classification Cohort were analysed. Peripheral involvement was defined as past or current arthritis/dactylitis/enthesitis. Sacroiliac joint (SIJ) and spinal MRI lesions typical of axSpA were classified per ASAS lesion definitions and centrally read with multi-reader majority agreement (lesion present if called by the majority; SIJ ≥4/7, spine ≥5/9 readers). Comparisons between patients with and without peripheral manifestations were made.
Results:
Among 199 axSpA patients with SIJ MRI, 67 also had spinal MRI. Subchondral SIJ bone marrow oedema (BMO) was observed in 49%, without quadrant preference or subgroup differences. Other SIJ inflammatory lesions ranged from 4%-18%. Erosions (35%) and fat lesions (22%) were the most frequent structural lesions. In the spine, BMO, fat lesions and syndesmophytes/ankylosis were detected in 38%, 25% and 5%, respectively, with similar subgroup frequencies. Among 40 patients with both SIJ and whole spine MRI, inflammatory lesions were observed in both sites in 18%, SIJ only in 38%, and spine only in 20%. Structural lesions occurred in both sites in 19%, SIJ only in 30%, and spine only in 5%, with no subgroup differences.
Conclusion:
The prevalence and anatomical distribution of ASAS-defined MRI lesions was similar across axSpA subgroups. Notably, 20% exhibited spine-only inflammation, suggesting potential added diagnostic and monitoring value of spinal MRI, warranting further study.
Insights
Inflammatory and structural MRI lesions in axial spondyloarthritis (axSpA) are similarly distributed across patient subgroups. However, spinal MRI may offer added diagnostic value, as 20% of patients showed spine-only inflammation.
Area of Science:
- Rheumatology
- Radiology
- Medical Imaging
Background:
- Axial spondyloarthritis (axSpA) is a spectrum of inflammatory diseases.
- Magnetic Resonance Imaging (MRI) is crucial for diagnosing axSpA.
- Understanding lesion distribution is key for accurate diagnosis and monitoring.
Purpose of the Study:
- To determine the prevalence and location of inflammatory and structural MRI lesions in axSpA.
- To compare lesion patterns between axSpA patients with and without peripheral manifestations.
- To assess the diagnostic utility of spinal MRI in axSpA.
Main Methods:
- Analysis of data from the Assessment of SpondyloArthritis International Society (ASAS) Classification Cohort.
- Classification of sacroiliac joint (SIJ) and spinal MRI lesions according to ASAS definitions.
- Centralized MRI reading with multi-reader majority agreement.
Main Results:
- Subchondral bone marrow oedema (BMO) in SIJs was seen in 49% of patients.
- Erosions (35%) and fat lesions (22%) were common structural SIJ lesions.
- Spinal BMO (38%), fat lesions (25%), and syndesmophytes (5%) were observed; 20% had spine-only inflammation.
Conclusions:
- The prevalence and distribution of ASAS-defined MRI lesions were consistent across axSpA subgroups.
- Spinal MRI may detect inflammation not evident in SIJ imaging.
- Further research into the diagnostic and monitoring value of spinal MRI in axSpA is warranted.
