18F-FDG PET in Giant Cell Arteritis.

Area of Science:

• Vascular Imaging
• Nuclear Medicine
• Rheumatology

Background:

• Giant cell arteritis (GCA) is a systemic vasculitis primarily affecting large and medium-sized arteries.
• Diagnosis can be challenging, often requiring invasive procedures like temporal artery biopsy.
• Atypical presentations of GCA, particularly involving peripheral vessels, can delay diagnosis.

Observation:

• An elderly male patient presented with unexplained fever and weight loss, refractory to initial investigations.
• Conventional imaging failed to identify the cause of his symptoms.
• F-FDG PET/CT demonstrated intense tracer uptake in the peripheral arteries of the limbs, sparing larger vessels.

Findings:

• The F-FDG PET/CT findings were indicative of arteritis.
• Temporal artery biopsy confirmed the diagnosis of giant cell arteritis.
• The pattern of involvement was predominantly in the peripheral upper and lower limb vessels.

Implications:

• F-FDG PET/CT can be a valuable tool for diagnosing GCA, especially in cases with atypical peripheral vessel involvement.
• Early diagnosis and treatment with corticosteroids, such as methylprednisolone, lead to rapid clinical improvement.
• This case underscores the utility of advanced imaging in identifying inflammatory conditions affecting the vasculature.