How do you manage inflammatory back pain when X-rays and MRI show no evidence of sacroiliitis?

While a normal MRI makes the diagnosis of axial spondyloarthritis unlikely, it doesn’t completely rule it out. This is specifically true in patients with inflammatory back pain or other features of spondyloarthritis. While classification criteria definitely should not be used for diagnosis, it is helpful to refer to the criteria to answer the above question. In the ASAS criteria, the sensitivity for the imaging arm alone was only 66% (with a higher specificity of 97%) as compared to the overall sensitivity of 83% when both imaging and clinical arms were used. Therefore, using only MRI-positive patients could miss many patients.

We should remember that MRI only gives us cross-sectional information at a certain point in time. Like most of our ...

I would also add that negative MRI results need to be interpreted in the context of current NSAIDs' use as anti-inflammatory meds that can mask sacroiliitis.

Jones et al., British Society for Rheumatology 2023