title: Metastatic brain lesions may demonstrate photopenia on FDG-PET.
abstract: Metastatic brain lesions generally demonstrate hypermetabolic foci on fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) images. A large area of photopenia of the brain on FDG-PET is most likely consistent with a benign etiology. The author reports 2 cases of cerebral metastases from lung cancers, which display complete photopenia on FDG-PET. The brain is a special organ with high background uptake on PET and significant cytotoxic edema surrounding the metastatic deposits. In some cases, it is a dilemma to identify malignant intracranial foci on PET. Anatomic imaging, for example, MRI or CT correlation is needed for proper interpretation of brain PET on evaluation of metastases.
authors: Department of Radiology, Nuclear Medicine Service, University Hospital, UMDNJ, Newark, New Jersey 07103, USA. liuyl@umdnj.edu
authors: Yiyan
authors: Y
authors: Liu
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18