PET/CT in giant cell arteritis: High 18F-FDG uptake in the temporal, occipital and vertebral arteries.

18F-FDG PET/CT imaging is useful in patients with fever of unknown origin and can detect giant cell arteritis in extracranial large arteries. However, it is usually assumed that temporal arteries cannot be visualized with a PET/CT scanner due to their small diameter. Three patients with clinical symptoms of temporal arteritis were examined using a standard whole body PET/CT protocol (skull base - mid thighs) followed by a head PET/CT scan using the brain protocol. High 18F-FDG uptake in the aorta and some arterial branches were detected in all 3 patients with the whole body protocol. Using the brain protocol, head imaging led to detection of high 18F-FDG uptake in temporal arteries as well as in their branches (3 patients), in occipital arteries (2 patients) and also in vertebral arteries (3 patients).