title: Fever of unknown origin.
abstract: Fever of unknown origin (FUO) often is defined as a fever greater than 38.3 degrees C on several occasions during at least 3 weeks with uncertain diagnosis after a number of obligatory tests. In general, infection accounts for approximately one-fourth of cases of FUO, followed by neoplasm and noninfectious inflammatory diseases. No diagnosis is reached in up to 50% of cases. Scintigraphic methods, such as (67)Ga-citrate, labeled leukocytes, and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET), are often used in the diagnosis of FUO. In FUO, FDG-PET appears to be of great advantage because malignancy, inflammation, and infection can be detected. FDG-PET does not seem to contribute to a final diagnosis in patients with normal erythrocyte sedimentation rate and C-reactive protein. Image fusion combining PET and computed tomography facilitates anatomical localization of increased FDG uptake and better guiding for further diagnostic tests to achieve a final diagnosis. In conclusion, the body of evidence on the utility of FDG-PET in patients with FUO is growing and FDG-PET will probably become the preferred diagnostic procedure, especially when a definite diagnosis cannot easily be achieved. Because of favorable characteristics of FDG-PET, conventional scintigraphic techniques may be replaced by FDG-PET in institutions in which PET is available.
authors.affiliation: Department of General Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands. c.bleeker-rovers@aig.umcn.nl
authors.forename: Chantal P
authors.initials: CP
authors.lastname: Bleeker-Rovers
authors.forename: Jos W M
authors.initials: JW
authors.lastname: van der Meer
authors.forename: Wim J G
authors.initials: WJ
authors.lastname: Oyen
mesh_terms: D000818:Animals; D000906:Antibodies; D002951:Citrates; D005335:Fever of Unknown Origin / Q000000981:diagnostic imaging / Q000276:immunology / Q000473:pathology; D019788:Fluorodeoxyglucose F18; D005708:Gallium; D006098:Granulocytes / Q000276:immunology / Q000378:metabolism; D006801:Humans; D049268:Positron-Emission Tomography
chemical_list: D000906:Antibodies; D002951:Citrates; D019788:Fluorodeoxyglucose F18; D005708:Gallium; C103850:gallium citrate