title: Application of pharmacokinetics to electron-beam tomography of the abdomen.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the pharmacokinetics of abdominal time-attenuation curves obtained at electron-beam tomography.
  
  
  METHODS
  Computed tomographic enhancement data of the aorta, portal vein, vena cava, liver, spleen, and pancreas were obtained in 25 patients after injection of 50 mL of contrast medium. These data were used to calculate pharmacokinetic parameters such as half-lives, mean residence times, and areas under the curve with a computer program.
  
  
  RESULTS
  Maximal enhancement was observed in the aorta 24 seconds +/- 5 (mean +/- standard deviation) after starting the injection of contrast medium (178 HU +/- 56), in the portal vein after 42 seconds +/- 14 (60 HU +/- 17), in the vena cava after 35 seconds +/- 7 (66 HU +/- 23), in the liver after 58 seconds +/- 15 (24 HU +/- 6), in the spleen after 35 seconds +/- 12 (42 HU +/- 16), and in the pancreas after 39 seconds +/- 15 (42 HU +/- 10). Half-lives of the last phase observed were 108 seconds +/- 123 in the aorta, 33 seconds +/- 30 in the portal vein, 49 seconds +/- 40 in the vena cava, 50 seconds +/- 54 in the liver, 62 seconds +/- 33 in the spleen, and 22 seconds +/- 27 in the pancreas. The computer program allowed for excellent fitting curves to the measured attenuation values and for subsequent calculation of pharmacokinetic parameters. New dosage regimens also could be simulated successfully.
  
  
  CONCLUSIONS
  The pharmacokinetic parameters evaluated might be useful in the optimization of dosing and scanning parameters of the abdomen for ultrafast and helical CT.
authors.affiliation: Research Laboratories of Schering AG, Berlin, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Krause
authors.forename: R
authors.initials: R
authors.lastname: Gröll
authors.forename: R
authors.initials: R
authors.lastname: Kern
authors.forename: C
authors.initials: C
authors.lastname: Baumgartner
authors.forename: R
authors.initials: R
authors.lastname: Rienmüller
mesh_terms: D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D019540:Area Under Curve; D003198:Computer Simulation; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006207:Half-Life; D006801:Humans; D007262:Infusions, Intravenous; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D008099:Liver / Q000000981:diagnostic imaging; D008956:Models, Chemical; D010179:Pancreas / Q000000981:diagnostic imaging; D011172:Portography / Q000379:methods; D011856:Radiographic Image Enhancement / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D012984:Software; D013154:Spleen / Q000000981:diagnostic imaging; D013997:Time Factors; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000008:administration & dosage / Q000493:pharmacokinetics; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; C038192:iopromide; C044834:iodixanol