Images of a patient in whom a solitary pulmonary nodule was being evaluated by PET. The patient received 370 MBq of 18F-FDG and was imaged 1 h after injection. The study was negative for solitary pulmonary nodule, but the images demonstrate increased uptake in brown fat (arrows). Submitted by Kastytis C. Karvelis, MD, Henry Ford Hospital, Detriot, Michigan.