title: Pulmonary FDG uptake without a CT counterpart - a pitfall in interpreting PET/CT images.
abstract: Abnormal pulmonary 18F-FDG foci may occur with benign lesions like pneumonia but seldomly without any pathological CT findings. We report the case of a focal pulmonary 18F-FDG uptake without CT correlate in an initial staging examination of a patient with squamous cell carcinoma of the base of the tongue. A follow-up study did not show any suspicious lesion in this area, but pneumonia with 18F-FDG uptake in another region of the lung. 18F-FDG foci without pathological CT are a rare finding and have been associated with emboli. In the literature two main mechanisms underlying focal 18F-FDG uptake in pulmonary embolism are mentioned: an inflammatory reaction of a pre-existing vascular thrombus and an iatrogenic microembolism caused during injection. In our case the 18F-FDG accumulation was assessed as an iatrogenic pulmonary microembolism.
authors.affiliation: Charité, Klinik für Nuklearmedizin, Berlin, Germany. nils.schreiter@charite.de
authors.forename: Nils
authors.initials: N
authors.lastname: Schreiter
authors.forename: Munenobu
authors.initials: M
authors.lastname: Nogami
authors.forename: Ralph
authors.initials: R
authors.lastname: Buchert
authors.forename: Vera
authors.initials: V
authors.lastname: Froeling
authors.forename: Winfried
authors.initials: W
authors.lastname: Brenner
authors.forename: Felix
authors.initials: F
authors.lastname: Diekmann
mesh_terms: D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011014:Pneumonia / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014057:Tomography, X-Ray Computed; D014062:Tongue Neoplasms / Q000000981:diagnostic imaging*; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18