title: Effect of rate of contrast medium injection on hepatic enhancement at CT.
abstract: OBJECTIVE
  To determine the effect of the rate of contrast medium injection on liver enhancement at computed tomography (CT).
  
  
  METHODS
  Forty-five patients who underwent a follow-up CT examination of the liver were included in five different groups according to the compared rates of contrast material delivery: group A, 2 versus 3 mL/sec; group B, 2 versus 4.5 mL/sec; group C, 3 versus 4.5 mL/sec; group D, 3 versus 6 mL/sec; and group E, 4.5 versus 6 mL/sec.
  
  
  RESULTS
  Time to peak enhancement was shorter for the faster rates of injection. In each group, maximum enhancement was nearly identical for the paired examinations (group A, 57 vs 58 HU; group B, 48 vs 47 HU; group C, 55 vs 58 HU; group D, 55 vs 54 HU; group E, 62 vs 61 HU, respectively). Mean enhancement in each group was similar when calculated at 3-second intervals.
  
  
  CONCLUSIONS
  Higher rates of injection shorten the time to peak liver enhancement but have no effect on maximum liver enhancement.
authors.affiliation: Department of Diagnostic Radiology, Montreal General Hospital, McGill University, Quebec, Canada.
authors.forename: P A
authors.initials: PA
authors.lastname: Garcia
authors.forename: V M
authors.initials: VM
authors.lastname: Bonaldi
authors.forename: P M
authors.initials: PM
authors.lastname: Bret
authors.forename: L
authors.initials: L
authors.lastname: Liang
authors.forename: C
authors.initials: C
authors.lastname: Reinhold
authors.forename: M
authors.initials: M
authors.lastname: Atri
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous / Q000379:methods; D007472:Iohexol / Q000008:administration & dosage; D007479:Iopamidol / Q000008:administration & dosage; D007482:Iothalamate Meglumine / Q000008:administration & dosage; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; D007479:Iopamidol; C054871:ioversol; D007482:Iothalamate Meglumine