title: Spectrum of Benign Articular and Periarticular Findings at FDG PET/CT.
abstract: Whole-body fluorine 18 fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) is performed primarily for oncologic indications; however, FDG uptake is not specific for malignancy. Herein we focus on causes of increased FDG uptake in and around joints, as lesions in these locations are commonly benign. A combination of primary intra-articular processes and osseous processes that may occur near the joint space will be discussed. Causes of intra-articular and periarticular increased FDG activity can be broadly divided into infectious, inflammatory, degenerative, and benign neoplastic categories. A familiarity with the full range of these processes is important to avoid misinterpretation, in turn decreasing unnecessary follow-up studies, procedures, and treatments. Differentiation from malignancy is often possible on the basis of a different level of FDG activity, divergent response to therapy, or differing changes over time, in comparison with a patient's known primary cancer. Recognizing an intra-articular lesion location can also be critical, as intra-articular metastases are rare. In some cases, benign FDG-avid articular and periarticular entities have a specific appearance at FDG PET/CT and a correct diagnosis may be made without any additional workup. In most other cases, comparison with prior studies and/or additional imaging can afford an accurate diagnosis. This review is meant to introduce the reader to a spectrum of benign FDG-avid articular and periarticular processes that may be encountered at oncologic FDG PET/CT to increase confidence and diagnostic accuracy. (©)RSNA, 2016.
authors.affiliation: From the Departments of Radiology (M.L.W., G.B.J., B.M.H, P.J.P, S.M.B.) and Immunology (G.B.J.), Mayo Clinic, 200 First Street SW, Mayo 2E, Rochester, MN 55905.
authors.forename: Mariah L
authors.initials: ML
authors.lastname: White
authors.affiliation: From the Departments of Radiology (M.L.W., G.B.J., B.M.H, P.J.P, S.M.B.) and Immunology (G.B.J.), Mayo Clinic, 200 First Street SW, Mayo 2E, Rochester, MN 55905.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Johnson
authors.affiliation: From the Departments of Radiology (M.L.W., G.B.J., B.M.H, P.J.P, S.M.B.) and Immunology (G.B.J.), Mayo Clinic, 200 First Street SW, Mayo 2E, Rochester, MN 55905.
authors.forename: Benjamin Matthew
authors.initials: BM
authors.lastname: Howe
authors.affiliation: From the Departments of Radiology (M.L.W., G.B.J., B.M.H, P.J.P, S.M.B.) and Immunology (G.B.J.), Mayo Clinic, 200 First Street SW, Mayo 2E, Rochester, MN 55905.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Peller
authors.affiliation: From the Departments of Radiology (M.L.W., G.B.J., B.M.H, P.J.P, S.M.B.) and Immunology (G.B.J.), Mayo Clinic, 200 First Street SW, Mayo 2E, Rochester, MN 55905.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Broski
mesh_terms: D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging*; D009369:Neoplasms / Q000000981:diagnostic imaging; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18