Purpose: Search for focus in patients with fever of unknown origin (FUO). M
aterial and methods: In four patients with the above mentioned problem, F-1
8-FDG-PET was performed, following the common imaging methods, which were w
ithout evidence for a focus. Results: The origin of FUO was verified in all
patients by PET: Tuberculosis, pneumocystis-carinii pneumonia, chronic inf
lammatory hematoma, aortitis. Conclusion: Successful implementation of F-18
-FDG-PET as additional imaging method in patients with FUO seems reasonable
. This has to be verified by further prospective studies.