Positron emission tomography in the diagnosis of giant cell arteritis.

This case describes how positron emission tomography (PET) led to the diagnosis of giant cell arteritis in a 50-year-old woman with fever of unknown origin. The patient presented with fever, weight loss, anemia, and headaches. She underwent multiple serologic, biopsy, and imaging tests that were inconclusive. Her sedimentation rate was 83. Giant cell arteritis was suspected clinically. PET revealed diffuse abnormal F-18 fluorodeoxyglucose (FDG) arterial uptake consistent with giant cell arteritis. After treatment with steroids, the patient showed prompt resolution of symptoms. A repeat PET scan showed near-complete resolution of the abnormal FDG uptake.