title: Effects of blood glucose level on FDG uptake by liver: a FDG-PET/CT study.
abstract: In FDG-PET for abdominal malignancy, the liver may be assumed as an internal standard for grading abnormal FDG uptake both in early images and in delayed images. However, physiological variables of FDG uptake by the liver, especially the effects of blood glucose level, have not yet been elucidated.
  
  
  METHODS
  FDG-PET studies of 70 patients examined at 50 to 70 min after injection (60 ± 10 min: early images) and of 68 patients examined at 80 to 100 min after injection (90 ± 10 min: delayed images) were analyzed for liver FDG uptake. Patients having lesions in the liver, spleen and pancreas; patients having bulk tumor in other areas; and patients early after chemotherapy or radiotherapy were excluded; also, patients with blood glucose level over 125 mg/dl were excluded.
  
  
  RESULTS
  Mean standardized uptake value (SUV) of the liver, blood glucose level and sex showed no significant differences between early images and delayed images. However, liver SUV in the delayed image showed a larger variation than that in the early image and showed significant correlation to blood glucose level. The partial correlation coefficient between liver SUV and blood glucose level in the delayed image with adjustment for sex and age was 0.73 (P < .0001). Multivariate regression coefficient (95% confidence interval) of blood glucose was 0.017 (0.013-0.021).
  
  
  CONCLUSIONS
  Blood glucose level is an important factor affecting the normal liver FDG uptake in nondiabetic patients. In the case of higher glucose level, liver FDG uptake is elevated especially in the delayed image. This may be due to the fact that the liver is the key organ responsible for glucose metabolism through gluconeogenesis and glycogen storage.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan. kkubota@cpost.plala.or.jp
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kubota
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Watanabe
authors.forename: Yuji
authors.initials: Y
authors.lastname: Murata
authors.forename: Masashi
authors.initials: M
authors.lastname: Yukihiro
authors.forename: Kimiteru
authors.initials: K
authors.lastname: Ito
authors.forename: Miyako
authors.initials: M
authors.lastname: Morooka
authors.forename: Ryogo
authors.initials: R
authors.lastname: Minamimoto
authors.forename: Ai
authors.initials: A
authors.lastname: Hori
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shibuya
mesh_terms: D000368:Aged; D016477:Artifacts; D001692:Biological Transport; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D001786:Blood Glucose; D019788:Fluorodeoxyglucose F18