title: Contrast between hypervascularized liver lesions and hepatic parenchyma: early dynamic PET versus contrast-enhanced CT.
abstract: OBJECTIVE
  To detect hypervascularized liver lesions, early dynamic (ED) (18)F-FDG PET may be an alternative when contrast-enhanced (CE) imaging is infeasible. This retrospective pilot analysis compared contrast between such lesions and liver parenchyma, an important objective image quality variable, in ED PET versus CE CT.
  
  
  METHODS
  Twenty-eight hypervascularized liver lesions detected by CE CT [21 (75%) hepatocellular carcinomas; mean (range) diameter 4.9 ± 3.5 (1-14) cm] in 20 patients were scanned with ED PET. Using regions of interest, maximum and mean lesional and parenchymal signals at baseline, arterial and venous phases were calculated for ED PET and CE CT.
  
  
  RESULTS
  Lesional/parenchymal signal ratio was significantly higher (P < 0.005) with ED PET versus CE CT at the arterial phase and similar between the methods at the venous phase.
  
  
  CONCLUSIONS
  In liver imaging, ED PET generates greater lesional-parenchymal contrast during the arterial phase than does CE CT; these observations should be formally, prospectively evaluated.
authors.affiliation: Clinic of Nuclear Medicine, Jena University Hospital, Bachstrasse 18, 07740, Jena, Germany, martin.freesmeyer@med.uni-jena.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Freesmeyer
authors.forename: Thomas
authors.initials: T
authors.lastname: Winkens
authors.forename: Jan-Henning
authors.initials: JH
authors.lastname: Schierz
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009389:Neovascularization, Pathologic; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media