Recommendations for acquisition and interpretation of MRI of the spine and sacroiliac joints in the diagnosis of axial spondyloarthritis in the UK

Abstract

Objectives To develop evidence-based recommendations on the use of MRI in the diagnosis of axial SpA (axSpA). Methods A working group comprising nine rheumatologists and nine musculoskeletal radiologists with an interest in axSpA was established, with support from the British Society of Spondyloarthritis (BRITSpA). Two meetings were held. In the first meeting, research questions were formulated. In the second meeting, the results of a systematic literature review designed to inform the recommendations were reviewed. An anonymized Delphi process was used to formulate the final set of recommendations. For each recommendation, the level of evidence and strength of recommendation was determined. The level of agreement was assessed using a 0–10 numerical rating scale. Results Two overarching principles were formulated, as follows: The diagnosis of axSpA is based on clinical, laboratory and imaging features (overarching principle 1), and patients with axSpA can have isolated inflammation of either the sacroiliac joints or the spine (overarching principle 2). Seven recommendations addressing the use of MRI in the assessment of patients with suspected axSpA were formulated, covering topics including recommended sequences, anatomical coverage, acquisition parameters and interpretation of active and structural MRI lesions. The level of agreement for each recommendation was very high (range 8.8–9.8). Conclusion A joint rheumatology and radiology consensus on the acquisition and interpretation of MRI in axSpA diagnosis was achieved, and a research agenda formulated. This consensus should help standardize practice around MRI and ensure a more informed, consistent approach to the diagnosis of axSpA.

Do Microinjury Mechanisms Complement Inflammation in Sacroiliac Joint Ankylosis on Magnetic Resonance Imaging of Young Spondyloarthritis Patients? Comment on the Article by Bray et al

“…The novel findings of a distinct trend of decreasing inflammation and increasing fusion following TNFi treatment (1) are consistent with the proposed complementary role of mechanical stress and inflammation in the pathogenesis of axial SpA (4,5). New bone formation with ankylosis of the sacroiliac joints and the spine is the main type of structural damage to the skeleton that is observed in SpA (4) and used in the diagnosis of ankylosing spondylitis (AS) (6,7).…”

“…New bone formation with ankylosis of the sacroiliac joints and the spine is the main type of structural damage to the skeleton that is observed in SpA (4) and used in the diagnosis of ankylosing spondylitis (AS) (6,7). A priority research agenda for interpreting MRI of the spine and sacroiliac joints in the diagnosis of axial SpA is to differentiate which structural MRI lesions may be stress-or biomechanically induced, as opposed to other active or inflammation-related lesions (5).…”

“…Additionally, age-tailored disease activity scores for adolescent population have only recently been validated (4). Looking forward, MRI has the potential to be more specific for the detection of inflammation than either clinical assessment of disease or serum biomarkers of inflammation, especially as new MRI methods (quantitative MRI in particular) come into practice (5)(6)(7)(8). In addition to supporting clinical studies of new therapies, we agree with Masi that MRI can contribute to better understanding the role of inflammation in the evolution of new bone formation and disease progression.…”

Histographic analysis of oedema and fat in inflamed bone marrow based on quantitative MRI

“…Our results showed that PDFF 90 enabled separation of patients with and without fat metaplasia. Fat metaplasia can contribute to diagnosis [6,7] and is also a prognostic factor, since patients with fat metaplasia are more likely to fuse their sacroiliac joints [29][30][31].…”

“…Diagnosis of SpA is often difficult due to the complex nature of pain in young patients [2], and delays in diagnosis and treatment are common [3]. Identification of bone marrow oedema on MRI is of importance for showing inflammation of the sacroiliac joints and supports diagnosis of axial SpA [4][5][6][7]. This directly influences the decision to treat patients with diseasemodifying or biologic drugs [5].…”