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Suspected non-radiographic axial spondyloarthritis — MSRA MCQ

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HardMRISuspected non-radiographic axial spondyloarthritisMSRA

A 32-year-old woman is reviewed in rheumatology after GP referral for 14 months of low back pain. Symptoms began at age 31 and are associated with waking in the second half of the night, alternating buttock pain and morning stiffness lasting 75 minutes. Pain improves with exercise and improved substantially within 48 hours of naproxen. She has chronic plaque psoriasis with nail pitting. There is no fever, weight loss, trauma, peripheral neurological deficit or history of malignancy. Plain radiographs of the sacroiliac joints show no sacroiliitis meeting modified New York criteria. HLA-B27 is negative and CRP is normal. She has no contraindication to MRI. What is the most appropriate next investigation?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: D — Request unenhanced MRI using an inflammatory back pain protocol of the whole spine and sacroiliac joints

Explanation lettering: C = shown as A · D = shown as B · E = shown as C · B = shown as D · A = shown as E

This presentation remains strongly suggestive of axial spondyloarthritis: onset occurred before age 45 years, and she has multiple inflammatory back pain features, a rapid NSAID response and psoriasis. Neither negative HLA-B27 nor normal CRP excludes spondyloarthritis. The sacroiliac radiographs do not meet modified New York criteria, so she cannot be diagnosed with radiographic axial spondyloarthritis from the plain films. NICE recommends unenhanced MRI using an inflammatory back pain protocol at this point. The protocol includes STIR and T1-weighted sequences of the whole spine and sacroiliac joints, allowing assessment for non-radiographic axial spondyloarthritis. A is incomplete because the NICE protocol includes the whole spine as well as the sacroiliac joints. C is not the recommended routine protocol: the specified investigation is unenhanced MRI. D may demonstrate structural bony change but is not the recommended next-line investigation for suspected non-radiographic axial spondyloarthritis after non-diagnostic radiographs. E is specifically not recommended for suspected axial spondyloarthritis. If MRI were negative, axial spondyloarthritis would still not be fully excluded when clinical suspicion remains high.

Reference: NICE NG65: Spondyloarthritis in over 16s: diagnosis and management — recommendations 1.2.2-1.2.10 (2017) — https://www.nice.org.uk/guidance/NG65/chapter/Recommendations NICE NG65: Spondyloarthritis in over 16s: diagnosis and management (2017) — https://www.nice.org.uk/guidance/ng65/resources/spondyloarthritis-in-over-16s-diagnosis-and-management-pdf-1837575441349 NICE QS170: Quality statement 2 — Diagnosis of axial spondyloarthritis using imaging (2018) — https://www.nice.org.uk/guidance/qs170/chapter/quality-statement-2-diagnosis-of-axial-spondyloarthritis-using-imaging