title: Incidental focal F-18 FDG accumulation in lung parenchyma without abnormal CT findings.
abstract: F-18 fluorodeoxyglucose (FDG) PET/CT that simultaneously offers anatomic and metabolic information is widely used and has become an effective modality in many clinical fields, especially oncology. For accurate interpretation, it is necessary to understand false-positive findings in the F-18 FDG PET image, such as physiologic conditions, findings related to patients' medical and surgical histories, normal variants, and artificial conditions. We report three cases of incidental focal F-18 FDG accumulation in lung parenchyma without abnormal CT findings in the PET/CT images. In the primary PET/CT studies, two cases showed single and one case showed multiple FDG foci in the lung without any CT abnormalities. All FDG accumulations disappeared in PET/CT studies repeated 1-3 days after the primary scannings. These artifacts are probably related to microembolisms attributable to the intravenous injection of F-18 FDG. Therefore, a cautious interpretation of the correspondence between anatomic and metabolic images is required and repeated PET/CT is helpful.
authors.affiliation: Department of Nuclear Medicine, Chonnam National University Medical School, 8 Hakdong, Gwangju 501-757, South Korea.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Ha
authors.forename: Shin-Young
authors.initials: SY
authors.lastname: Jeong
authors.forename: Young-Soon
authors.initials: YS
authors.lastname: Seo
authors.forename: Seong-Young
authors.initials: SY
authors.lastname: Kwon
authors.forename: Ari
authors.initials: A
authors.lastname: Chong
authors.forename: Jong-Ryool
authors.initials: JR
authors.lastname: Oh
authors.forename: Ho-Chun
authors.initials: HC
authors.lastname: Song
authors.forename: Hee-Seung
authors.initials: HS
authors.lastname: Bom
authors.forename: Jung-Joon
authors.initials: JJ
authors.lastname: Min
mesh_terms: D000368:Aged; D016477:Artifacts; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage / Q000378:metabolism*; D006801:Humans; D007275:Injections, Intravenous; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D049268:Positron-Emission Tomography; D011655:Pulmonary Embolism / Q000209:etiology; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18