title: Late-phase enhancement of the upstream portion of pancreatic adenocarcinoma on dual-phase helical CT.
abstract: BACKGROUND
  Late-phase enhancement of pancreatic parenchyma upstream (tail side) of pancreatic adenocarcinoma is found frequently on dual-phase helical computed tomography (CT). We measured the frequency of late-phase enhancement of the upstream portion of pancreatic adenocarcinoma and normal pancreatic parenchyma using dual-phase helical CT.
  
  
  METHODS
  Twenty-one patients with pancreatic adenocarcinoma and nontumorous pancreas upstream of tumors were compared with 100 control patients without pancreatic disease. Early and late scans started at 25 and 75 s, respectively, after intravenous injection of contrast material. The attenuation values of normal and nontumorous pancreas upstream of tumors were assessed in three phases: precontrast, early, and late enhanced. Enhancement ratio (ER) was calculated as ER = (late phase - precontrast)/(early phase - precontrast).
  
  
  RESULTS
  Late-phase enhancements (ER > 1.0) were seen in 86% of upstream pancreas and 10% of normal pancreas. The mean ER of upstream pancreas was significantly higher than that of normal pancreas (p < 0.01).
  
  
  CONCLUSIONS
  Late-phase enhancement of the pancreas upstream of the tumor is frequently observed in patients with pancreatic adenocarcinoma. Late-phase enhancement and histology showed a correlation for chronic obstructing pancreatitis in five patients.
authors.affiliation: Department of Radiology, Ehime University School of Medicine, Onsen-gun, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tsuda
authors.forename: T
authors.initials: T
authors.lastname: Mochizuki
authors.forename: K
authors.initials: K
authors.lastname: Kikuchi
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Sugata
authors.forename: J
authors.initials: J
authors.lastname: Ikezoe
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000368:Aged; D016022:Case-Control Studies; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media