F-18 FDG PET Findings of Takayasu Arteritis Before and After Immunosuppressive Therapy

A 73-year-old woman with a 3-month history of fever of unknown origin underwent F-18 FDG positron emission tomography (PET). The serum C-reactive protein was 9.62 mg/dL. Her systolic blood pressure was 120 and 96 mill Hg in the right and left arms, respectively. FDG PET images demonstrated intense FDG uptake in the aorta and bilateral subclavian and brachiocephalic arteries consistent with Takayasu arteritis. After 6 weeks of immunosuppressive therapy, a follow-up PET scan showed disappearance of the large vessel uptake of FDG. She was asymptomatic, with a normal C-reactive protein (0.06 mg/dL).