Patients with chronic back pain suspected of having axial spondyloarthritis (axSpA) should not undergo follow-up MRI of the sacroiliac joint (MRI-SI) within a year if they had a negative baseline MRI-SI, according to investigators.
It is very unlikely that a follow-up MRI-SI will yield new results, reported Pauline A. Bakker, MD, of the department of rheumatology at Leiden University Medical Centre, the Netherlands, and her colleagues.
Since gender and HLA-B27 status were closely associated with MRI-SI positivity, these factors should be considered when deciding to repeat an MRI-SI.
“Over the last decade, MRI rapidly gained ground and proved to be an important imaging technique in the diagnostic process of [nonradiographic] axial spondyloarthritis,” the investigators wrote in. “It has been shown that MRI can detect the early inflammatory stages of sacroiliitis months to years before structural damage can be detected on a conventional radiograph.”
Although MRI represents a diagnostic leap forward, questions of clinical application remain. “For example… if an MRI is completely normal and there is still a clinical suspicion of axSpA, should the MRI be repeated? And if so, after what period of follow-up? Or does this not contribute to the diagnostic process?”
To answer these questions, the investigators observed the “evolution of MRI lesions over a 3-month and 1-year time frame” in patients with early chronic back pain and suspected axSpA.
The prospective study involved 188 patients from the Spondyloarthritis Caught Early (SPACE) cohort. The authors commented that this is “an ideal cohort… since it includes a population of patients with back pain of short duration referred to rheumatologists with a suspicion of SpA [but without the mandatory presence of a single or multiple SpA features].”