Imaging methods in polymyalgia rheumatica: a systematic review

Polymyalgia rheumatica (PMR) is an inflammatory joint disease in patients over 50 years of age with pain and prolonged morning stiffness in the shoulder and hip girdles and neck. The lack of specific clinical findings, laboratory signs, biomarker and established imaging methods makes it difficult to diagnose patients with this disease. The aim of the systematic review is to present the literature data on the use of imaging methods for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of each method are considered. A literature search was carried out in PubMed and Scopus up to June 2022. Studies were selected that met the following criteria: (1) English language publications in peer-reviewed journals, (2) cohort or case-control studies and a series of more than five clinical cases, (3) studies of newly diagnosed or suspected PMR patients according to classification criteria or expert opinion, (4) imaging evaluation of articular, extraarticular and vascular impairment in PMR. Out of a total of 1431 publications, 61 articles were selected, which differed in the imaging techniques used: radiography (5), scintigraphy (4), magnetic resonance imaging (14), PET/CT (14) and ultrasound (24). Prevalence of extraarticular involvement (tendons, entheses and bursae) was identified in patients with PMR. In a significant number of cases, subclinical vasculitis of the large vessels was found, confirming the common pathogenetic pathways of the two diseases. The diagnostic, therapeutic and prognostic potential of imaging methods in PMR has been relatively poorly studied and remains to be clarified.