title: Two-phase helical CT for pancreatic tumors: pancreatic versus hepatic phase enhancement of tumor, pancreas, and vascular structures.
abstract: OBJECTIVE
  To quantitatively evaluate and validate a two-phase helical computed tomographic (CT) protocol for evaluation of pancreatic tumors.
  
  
  METHODS
  Twenty-seven patients with pathologically proved pancreatic adenocarcinomas prospectively underwent two-phase CT examination with helical acquisition during the pancreatic phase (40-70 seconds after infusion of intravenous contrast material at 3 mL/sec) and the hepatic phase (70-100 seconds after infusion). Mean CT attenuation values of tumor, bordering pancreas, and all major peripancreatic vessels were obtained for both time intervals.
  
  
  RESULTS
  Mean tumor-pancreas contrast was significantly greater during the pancreatic phase (67 HU +/- 19) than the hepatic phase (39 HU +/- 16) (P < .001) This was the result of both greater enhancement of normal pancreas and lower tumor enhancement during the pancreatic phase. Opacification of all vascular structures, including the portal vein, was also greater during the pancreatic phase (P < .001).
  
  
  CONCLUSIONS
  Two-phase helical CT with pancreatic phase acquisition provides statistically significantly better pancreatic, arterial, and portal venous enhancement than that of hepatic phase imaging, with improved tumor-pancreas contrast.
authors.affiliation: Department of Radiological Sciences, University of California Los Angeles School of Medicine 90095-1721, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Lu
authors.forename: S
authors.initials: S
authors.lastname: Vedantham
authors.forename: R M
authors.initials: RM
authors.lastname: Krasny
authors.forename: B
authors.initials: B
authors.lastname: Kadell
authors.forename: W L
authors.initials: WL
authors.lastname: Berger
authors.forename: H A
authors.initials: HA
authors.lastname: Reber
mesh_terms: D000230:Adenocarcinoma / Q000098:blood supply / Q000000981:diagnostic imaging*; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000098:blood supply / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol