title: Metformin discontinuation less than 72 h is suboptimal for F-18 FDG PET/CT interpretation of the bowel.
abstract: OBJECTIVE
  Metformin-induced [F-18] fluorodeoxyglucose (FDG) bowel uptake can hinder positron emission tomography/computed tomography (PET/CT) evaluation of the bowel. This study aimed to investigate the segmental bowel uptake of FDG according to metformin discontinuation times up to 72 h.
  
  
  METHODS
  We retrospectively divided 240 diabetic patients into four groups: metformin discontinuation <24 h (group A; n = 86), 24-48 h (group B; n = 40), 48-72 h (group C; n = 12), and no metformin (control group; n = 102). Segmental FDG bowel uptakes were measured visually (four-point scale) and semi-quantitatively (maximum standardized uptake value).
  
  
  RESULTS
  Compared with the control group, FDG uptake increased significantly from the ileum to the rectosigmoid colon in group A, from the transverse to the rectosigmoid colon in group B, and from the descending colon to the rectosigmoid colon in group C in both visual and semi-quantitative analyses.
  
  
  CONCLUSIONS
  Metformin discontinuation for <72 h is likely suboptimal for PET/CT image interpretation, especially with respect to the distal segments of the colon.
authors.affiliation: Department of Nuclear Medicine, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43 gil, Songpa-gu, Seoul, 05505, Korea.
authors.forename: Suk Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Eulgi Medical Center, 68 Hangeulbiseok-ro, Nowon-gu, Seoul, 01830, Korea.
authors.forename: Soyoung
authors.initials: S
authors.lastname: Jin
authors.affiliation: Department of Nuclear Medicine, Gangneng Asan Medical Center, 38 Bangdong-gil, Gangneng, 25440, Korea.
authors.forename: Hyo Sang
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43 gil, Songpa-gu, Seoul, 05505, Korea.
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Ryu
authors.affiliation: Department of Nuclear Medicine, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43 gil, Songpa-gu, Seoul, 05505, Korea. jongjin@gmail.com.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Lee
mesh_terms: D016477:Artifacts; D001692:Biological Transport / Q000187:drug effects; D003920:Diabetes Mellitus / Q000188:drug therapy; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000000981:diagnostic imaging* / Q000187:drug effects; D008297:Male; D008687:Metformin / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D012189:Retrospective Studies; D013997:Time Factors; D028761:Withholding Treatment
chemical_list: D019788:Fluorodeoxyglucose F18; D008687:Metformin
keywords: Bowel uptake; Diabetes; FDG PET/CT; Metformin