Magnetic resonance imaging in spondyloarthritis: Friend or Foe?

Unmet needs in axial spondyloarthritis. Proceedings of the French spondyloarthritis taskforce workshop

The progress observed over the last 30 years in the field of axial spondyloarthritis (axSpA) has not made it possible to answer all the current questions. This manuscript represents the proceedings of the meeting of the French spondyloArthitiS Task force (FAST) in Besançon on September 28 and 29, 2023. Different points of discussion were thus individualized as unmet needs: biomarkers for early diagnosis and disease activity, a common electronic file dedicated to SpA nationwide, a better comprehension of dysbiosis in the disease, a check-list for addressing to the rheumatologist, adapt patient reported outcomes thresholds for female gender, implementation of comorbidities screening programs, new imaging tools, in research cellular and multi omics approaches, grouping, at a nationwide level, different cohorts and registries, therapeutic strategy studies, consensual definition of difficult to treat disease and management, preclinical stage of the disease, mastering AI as a tool in the various aspects of research. These elements may represent a framework for the research agenda in axSpA for the years to come.

Axial Imaging in Spondyloarthritis

Imaging plays a crucial role in diagnosing and forecasting treatment outcomes in axial spondyloarthritis. Conventional radiography may overlook patients in the initial stages of the disease, while MRI is sensitive in identifying inflammation early on. Computed tomography reliably detects structural abnormalities. Practicing rheumatologists must possess a fundamental understanding of interpreting both active inflammatory and structural lesions in axial spondyloarthritis.

The role of sacro-iliac joint magnetic resonance imaging in the diagnosis of axial spondyloarthritis: focus on differential diagnosis in women

OBJECTIVE

To review the role of sacro-iliac magnetic resonance imaging (MRI) in the diagnosis of axial spondyloarthritis (AxSpA), with a focus on gender differences.

METHODS

The experience of the authors and the results of an informal literature review are reported.

RESULTS

Inflammatory changes of the sacro-iliac joint are the hallmark of AxSpA. Early, non-radiographic sacroiliitis may be diagnosed with MRI through the assessment of bone marrow edema (BMO) as well as concomitant structural damage. The MRI protocol should include three necessary sequences, i.e., fat-saturated T2-weighted sequences on two orthogonal planes, T1-weighted semi-coronal sequence, and fat-suppressed T1-weighted semi-coronal sequence. Inflammatory changes comprise required signs (BMO and/or osteitis) and additional signs, including synovitis (better defined as joint space enhancement), enthesitis, and capsulitis. Structural changes consist of erosions, sclerosis, fat metaplasia, and ankylosis. Due to mechanical axial strain, inflammatory changes in the sacro-iliac joint can be found in healthy individuals, runners, and patients with nonspecific low back pain. The prevalence of BMO is higher in women during pregnancy and postpartum, even 12 months after childbirth, but the extent and distribution of MRI findings may help in the differential diagnosis. Other challenges in the MRI diagnosis of sacroiliitis are subchondral T2 hyperintensity during developmental age, periarticular sclerosis in healthy subjects, or osteitis condensans ilii, and several pathological conditions that may mimic AxSpA, some of which are more frequently found in women.

CONCLUSIONS

The described diagnostic challenges impose a multidisciplinary approach combining imaging findings with clinical and laboratory data.

Progressive improvement in time to diagnosis in axial spondyloarthritis through an integrated referral and education system

Objectives

To assess the delay in the diagnosis of axial SpA (axSpA) in a real-world cohort over a 16-year period and to evaluate factors associated with this delay. We implemented a service improvement project and evaluated its effectiveness in improving time to diagnosis of axSpA.

Methods

A cohort of axSpA patients newly diagnosed between January 2008 and December 2023 were studied. Surveys were carried out in 2013, 2017, 2019 and 2023 to assess time to diagnosis, which was divided into four periods from onset of inflammatory back pain to year of axSpA diagnosis. The time to diagnosis over the study period was analysed using a statistical process control chart.

Results

Over the study period, 988 referrals were received and 366 (37%) had axSpA. There was a progressive increase in the number of females with axSpA. The mean time to diagnosis significantly decreased from 9.8 years (s.d. 1.2) in 2008 to 1.0 years (s.d. 1.0) in 2023. The greatest delay was from the onset of back pain to first seeing their general practitioners (GPs; mean 3.2 years). There was a significant improvement in the mean time to diagnosis across the time periods through the service improvement interventions.

Conclusion

Structural and organizational change in triage, referral and clinic pathways has led to earlier recognition of axSpA. This is further enhanced through an integrated education program and awareness campaign for the public, GPs and healthcare professionals, including physiotherapists. With continuous quality improvement cycles, we achieved our aim of reducing the mean time to diagnosis to 1 year.