title: Role of PET/CT in Workup of Fever without a Source.
abstract: Fever without source is a febrile illness without localizing signs or initial obvious cause. Early workup will often include chest radiography and computed tomography (CT) of the abdomen and pelvis, with or without CT of the chest. To evaluate localizing signs or symptoms or to further evaluate findings from initial studies, targeted imaging according to body part can be performed by using radiography, ultrasonography, CT, or magnetic resonance (MR) imaging. Nuclear medicine studies can provide imaging of the whole body and may be helpful when the clinical and conventional imaging workup findings are negative or equivocal in identifying a source of fever. Nuclear medicine studies can be used to detect pathologic changes early in a disease course, even in the absence of an anatomic abnormality. Gallium 67 scintigraphy, indium 111- and technetium 99m-labeled leukocyte scintigraphy, and fluorine 18 fluorodeoxyglucose positron emission tomography (PET)/CT studies are all useful in the evaluation of fever, but the radiopharmaceutical cost for PET/CT is much lower than that for radiolabeled leukocyte studies. The increased use of bundled payments for inpatient admissions requires updated cost evaluations for the preferred nuclear medicine study. For inpatients in whom the findings from the initial clinical workup and imaging studies are nondiagnostic, PET/CT examination may be preferable to radiolabeled leukocyte studies because of its high sensitivity and lower cost. Negative findings at PET/CT can be helpful in excluding a suspected site of infection, and positive findings at PET/CT can be helpful in confirming a suspected site of infection or in identifying an unexpected cause of fever. (©)RSNA, 2016.
authors.affiliation: From the Department of Diagnostic Imaging, Alpert Medical School of Brown University and Rhode Island Hospital, 593 Eddy St, Providence, RI 02903.
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Dibble
authors.affiliation: From the Department of Diagnostic Imaging, Alpert Medical School of Brown University and Rhode Island Hospital, 593 Eddy St, Providence, RI 02903.
authors.forename: Don C
authors.initials: DC
authors.lastname: Yoo
authors.affiliation: From the Department of Diagnostic Imaging, Alpert Medical School of Brown University and Rhode Island Hospital, 593 Eddy St, Providence, RI 02903.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Noto
mesh_terms: D003287:Contrast Media; D003937:Diagnosis, Differential; D005335:Fever of Unknown Origin / Q000000981:diagnostic imaging*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18