title: Optimal Pancreatic Phase Delay with 64-Detector CT Scanner and Bolus-tracking Technique.
abstract: OBJECTIVE
  To assess the optimal pancreatic phase delay in terms of parenchymal enhancement and tumor-to-pancreas contrast with a bolus-tracking method.
  
  
  METHODS
  Patients referred for suspicion of pancreatic tumor and undergoing 64-detector computed tomography scanner were randomized to an individualized scan delay of 10, 20, or 30 seconds of nonionic contrast material (370 mg I/mL) after aortic enhancement above 150 Hounsfield units. The volume of contrast was adjusted to patient weight. Pancreatic and tumor enhancements were measured. Statistical analysis included analysis of variance and post hoc Tukey tests.
  
  
  RESULTS
  One hundred and fifty patients were randomized to individualized scan delays of 10, 20, or 30 seconds. Pancreatic parenchymal enhancement in all patients (n = 150) was significantly higher with a delay of 20 or 30 seconds than that with 10 seconds (P < .001 for both). Tumor-to-pancreas contrast for solid tumors (n = 59) was significantly higher with a delay of 30 seconds than that with 10 seconds (P = .015). Adenocarcinoma-to-pancreas contrast during pancreatic phase was significantly higher for a 20- or 30-second delay than for a 10-second delay (P = .027 and .011, respectively) for one reader.
  
  
  CONCLUSIONS
  With a flow rate of 4 mL/s and weight-adjusted contrast volume, an individualized scan delay of 30 seconds after aortic transit time revealed higher pancreatic enhancement and tumor-to-pancreas contrast than that with a delay of 10 seconds.
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, 1058 Rue Saint-Denis, Montréal, Québec, Canada H2X 3J4; Research Center CHUM, Hôpital Saint-Luc, Montréal, Québec, Canada.
authors.forename: An
authors.initials: A
authors.lastname: Tang
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, 1058 Rue Saint-Denis, Montréal, Québec, Canada H2X 3J4.
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Billiard
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, 1058 Rue Saint-Denis, Montréal, Québec, Canada H2X 3J4.
authors.forename: David-Olivier
authors.initials: DO
authors.lastname: Chagnon
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, 1058 Rue Saint-Denis, Montréal, Québec, Canada H2X 3J4.
authors.forename: Fadi
authors.initials: F
authors.lastname: Rizk
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, 1058 Rue Saint-Denis, Montréal, Québec, Canada H2X 3J4.
authors.forename: Damien
authors.initials: D
authors.lastname: Olivié
authors.affiliation: Research Center CHUM, Hôpital Saint-Luc, Montréal, Québec, Canada; Department of Surgery, University of Montreal, Hepatopancreatobiliary Surgery, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, Montréal, Québec, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Turcotte
authors.affiliation: Department of Mathematics and Statistics, Pavillon André-Aisenstadt, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Miguel
authors.initials: M
authors.lastname: Chagnon
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, 1058 Rue Saint-Denis, Montréal, Québec, Canada H2X 3J4; Health Technology Assessment Unit, Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Saint-Luc, Montréal, Québec, Canada. Electronic address: luigi.lepanto.chum@ssss.gouv.qc.ca.
authors.forename: Luigi
authors.initials: L
authors.lastname: Lepanto
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007479:Iopamidol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D008954:Models, Biological; D061330:Multidetector Computed Tomography / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007479:Iopamidol
keywords: Pancreas; bolus tracking; computed tomography; contrast media; injection; pancreatic tumor