title: Combined C-11 methionine and F-18 FDG PET imaging in a case of neurosarcoidosis.
abstract: OBJECTIVE
  PET scanning of the brain with F-18 FDG and C-11 methionine (MET) is useful for characterizing brain lesions discovered at MRI or CT. Most positive PET scans indicate malignancy. However, this case report demonstrates positive F-18 FDG and C-11 MET PET scans in a patient with a nonmalignant condition, neurosarcoidosis.
  
  
  METHODS
  We detail the history and evaluation of a 59-year-old woman who presented with ataxia. The patient's evaluation included a contrast-enhanced MRI followed by PET scanning of the brain with C-11 MET and of the brain and trunk with F-18 FDG. The patient subsequently underwent biopsy of a lesion as directed by MRI and PET.
  
  
  RESULTS
  The MRI demonstrated multiple enhancing leptomeningeal lesions consistent with metastatic disease. PET with F-18 FDG and C-11 MET demonstrated lesions in both cerebellar hemispheres with F-18 FDG accumulation in the mediastinum and left hilum. Biopsy of a brain lesion directed by MRI and PET revealed sarcoidosis.
  
  
  CONCLUSIONS
  In evaluating brain lesions, PET with F-18 FDG and C-11 MET can help localize the lesion best suited for biopsy. However, not all lesions that have increased uptake on C-11 MET or F-18 FDG PET are malignant. Granulomatous inflammatory diseases such as neurosarcoidosis should also be considered in the differential diagnosis.
authors.affiliation: Department of Internal Medicine, Kettering Medical Center, Dayton, Ohio 45429, USA.
authors.forename: David
authors.initials: D
authors.lastname: Ng
authors.forename: Martin
authors.initials: M
authors.lastname: Jacobs
authors.forename: Joseph
authors.initials: J
authors.lastname: Mantil
mesh_terms: D001706:Biopsy; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D002524:Cerebellar Ataxia / Q000209:etiology; D002526:Cerebellar Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000175:diagnosis / Q000556:secondary; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008482:Mediastinum / Q000000981:diagnostic imaging; D008715:Methionine / Q000493:pharmacokinetics; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012507:Sarcoidosis / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D008715:Methionine