Purpose: Search for focus in patients with fever of unknown origin (FUO).
Material and methods: In four patients with the above mentioned problem, F-18-FDG-PET was performed, following the common imaging methods, which were without evidence for a focus.
Results: The origin of FUO was verified in all patients by PET: Tuberculosis, pneumocystis-carinii pneumonia, chronic inflammatory 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.