title: Incidental focal 18F-FDG uptake in the pituitary gland: clinical significance and differential diagnostic criteria.
abstract: The purpose of this study was to identify the incidence and clinical significance of incidental pituitary uptake on whole-body (18)F-FDG PET/CT.
  
  
  METHODS
  We evaluated 13,145 consecutive subjects who underwent (18)F-FDG PET/CT. The final diagnosis of pathologic or physiologic uptake was based on brain MRI and follow-up PET scanning. Receiver-operating-characteristic curve analysis was performed to determine an optimal cutoff for detecting pathologic uptake.
  
  
  RESULTS
  We found that 107 (0.8%) subjects showed incidental pituitary uptake. In 29 of 71 subjects with the final diagnosis, the pituitary uptake was pathologic: macroadenomas (n = 21), microadenomas (n = 5), and malignancy (n = 3). When a maximum standardized uptake value of 4.1 was used as an optimal criterion for detecting pathologic uptake, the diagnostic sensitivity, specificity, and accuracy were 96.6%, 88.1%, and 91.5%, respectively.
  
  
  CONCLUSIONS
  Although incidental pituitary uptake is an unusual finding, the degree of (18)F-FDG accumulation is helpful in identifying pathologic pituitary lesions that warrant further diagnostic evaluation.
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Hyup
authors.initials: SH
authors.lastname: Hyun
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.forename: Yearn Seong
authors.initials: YS
authors.lastname: Choe
authors.forename: Byung-Tae
authors.initials: BT
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000000981:diagnostic imaging* / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D049268:Positron-Emission Tomography; D012372:ROC Curve; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed; D014915:Whole-Body Counting
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18