Imaging for diagnosis, monitoring and outcome prediction in polymyalgia rheumatica: a systematic literature review and meta-analysis informing an international task force

Objective: To summarise evidence on imaging for the diagnosis, monitoring and outcome prediction in polymyalgia rheumatica (PMR) to inform an international task force.

Methods: Six research questions across diagnostic, monitoring, prognostic and technical aspects were defined. A systematic literature review searched Ovid MEDLINE, Ovid EMBASE, Epistemonikos and the Cochrane Library (through July 2025), including prospective and retrospective cohort studies (≥20 patients) as well as case–control and cross-sectional studies for diagnostic aspects. Test performance was summarised descriptively and meta-analysed using bivariate random-effects models when ≥2 low or some concerns on risk-of-bias (RoB) studies were available.

Results: Forty-nine studies were included: 32 on diagnosis, 6 on monitoring, 13 on outcome prediction and 8 on technical aspects (some studies covered ≥1 aspect). No study was graded as low RoB. Diagnostic studies identified useful imaging lesions (eg, extracapsular and bilateral inflammatory patterns of shoulders and hips), but few were validated in independent cohorts. Diagnostic accuracy of positron emission tomography scores was reduced in the case of prior treatment and when used to differentiate PMR from other inflammatory diseases. Glucocorticoids substantially reduced sensitivity across modalities, highlighting the value of timely imaging when indicated. Data on monitoring and outcome prediction were sparse and heterogeneous.

Conclusion: This systematic literature review serves as a basis for the formulation of international recommendations on the use of imaging in PMR. Available evidence was heterogeneous and of limited quality but revealed distinct imaging lesions and scores that can support PMR diagnosis. Well-designed prospective studies and external validations are needed.