title: Dynamic changes of FDG uptake and clearance in normal tissues.
abstract: OBJECTIVE
  This study aims to evaluate dynamic 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) uptake in normal tissues.
  
  
  METHODS
  Thirty male patients underwent FDG positron emission tomography (PET)/computed tomography imaging at 1, 2, and 3 h after tracer injection. Standardized uptake values (SUV) were obtained in regions of interest of normal tissues.
  
  
  RESULTS
  The aorta (blood pool), liver, and spleen FDG activity demonstrated significantly and continuously decreased activity from 1 to 2 and 2 to 3 h, while FDG uptake in the lungs, pancreas, lymph nodes, and skeletal muscle decreased from 1 to 2 h only. In contrast, the left ventricular myocardium demonstrated two patterns of dynamic changes: myocardium with higher FDG uptake (SUVmax ≥ 3.25) on the initial images had more remarkable increased activity on the delayed images, while myocardium with lower FDG uptake (SUVmax < 3.25) on the initial imaging had no increased uptake on delayed imaging. Increased FDG uptake was also observed in the bones on the delayed images. No significant changes of FDG uptake were noted in the parotid gland, thyroid gland, and prostate gland.
  
  
  CONCLUSIONS
  These findings may help nuclear medicine physicians when comparing images performed at different time points, when using FDG uptake in internal reference regions as a relative indicator of FDG uptake in a specific lesion, and when reading a delayed FDG PET imaging.
authors.affiliation: Department of Radiology, Philadelphia VA Medical Center, 3900 Woodland Avenue, Philadelphia, PA, 19104, USA. gangcheng99@yahoo.com
authors.forename: Gang
authors.initials: G
authors.lastname: Cheng
authors.forename: Abass
authors.initials: A
authors.lastname: Alavi
authors.forename: Esther
authors.initials: E
authors.lastname: Lim
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Werner
authors.forename: Catherine V
authors.initials: CV
authors.lastname: Del Bello
authors.forename: Scott R
authors.initials: SR
authors.lastname: Akers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009928:Organ Specificity; D011877:Radionuclide Imaging; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D019788:Fluorodeoxyglucose F18