[¹⁸F]FDG-PET/CT in Polymyalgia Rheumatica: An Update and Future Aspects

Area of Science:

• Rheumatology
• Nuclear Medicine
• Medical Imaging

Background:

• Polymyalgia rheumatica (PMR) is an inflammatory disorder typically affecting individuals over 50.
• Characterized by pain and stiffness in the shoulder and/or hip girdles, sometimes with constitutional symptoms.
• PMR is associated with giant cell arteritis (GCA) in about 20% of cases, indicating a disease continuum.

Purpose of the Study:

• To explore the utility of whole-body [18F]FDG-PET/CT in diagnosing PMR, especially in atypical cases.
• To assess the role of [18F]FDG-PET/CT in confirming coexisting GCA.
• To differentiate PMR from other arthritic conditions common in the elderly population.

Main Methods:

• Review of clinical diagnosis and noninvasive imaging techniques for PMR.
• Focus on the application of whole-body [18F]FDG-PET/CT in PMR diagnosis and differential diagnosis.
• Analysis of typical [18F]FDG-PET/CT patterns, including visual and semi-quantitative assessment.

Main Results:

• [18F]FDG-PET/CT can confirm or exclude PMR diagnosis and identify concurrent GCA.
• Typical [18F]FDG-PET/CT findings include hypermetabolism in the scapular/pelvic girdle, bursae, and joints.
• Hypermetabolism in interspinous lumbar bursae shows a high post-test likelihood ratio for PMR.

Conclusions:

• [18F]FDG-PET/CT is a valuable tool for diagnosing PMR and GCA, aiding differential diagnosis in elderly patients.
• Visual and semi-quantitative analysis of [18F]FDG-PET/CT can guide accurate diagnosis.
• Future advancements in molecular imaging may further enhance the diagnosis of inflammatory rheumatic diseases in the elderly.