Polymyalgia rheumatica and interspinous FDG uptake on PET/CT

Area of Science:

• Rheumatology
• Nuclear Medicine Imaging

Background:

• Polymyalgia rheumatica (PMR) is an inflammatory condition affecting individuals over 50, characterized by neck, shoulder, and hip stiffness.
• PMR shares clinical similarities with giant cell arthritis (GCA) and rheumatoid arthritis.
• Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are common biomarkers in PMR.

Observation:

• (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) was utilized in four patients diagnosed with PMR.
• FDG PET/CT imaging showed abnormal tracer uptake in the shoulder and hip joints of these patients.
• Distinct focal and diffuse uptake patterns were observed in the interspinous and supraspinous regions.

Findings:

• The study observed FDG uptake in the shoulder and hip joints, consistent with inflammatory processes in PMR.
• Diffuse uptake in the interspinous and supraspinous areas suggests potential ligamentous inflammation.
• Focal uptake in these regions may indicate adjacent interspinous bursitis.

Implications:

• FDG PET/CT imaging may serve as a valuable tool for diagnosing PMR and identifying specific sites of inflammation.
• This imaging modality could help differentiate PMR from other conditions with similar symptoms.
• Understanding the imaging patterns can refine diagnostic criteria and guide targeted treatment strategies for PMR.