title: Effects of contrast medium injection technique on attenuation values of adrenal glands in healthy dogs during contrast-enhanced computed tomography.
abstract: OBJECTIVE
  To assess the effects of 3 contrast medium injection techniques on attenuation values for canine adrenal glands during contrast-enhanced CT.
  
  
  METHODS
  9 healthy Beagles.
  
  
  METHODS
  3 protocols were evaluated in a randomized cross-over design study: 700 mg of iodine/kg at a constant injection rate over 20 seconds (full-dose constant rate), the same dose at a rate following an exponential decay curve over 20 seconds (full-dose decelerated rate), and 350 mg of iodine/kg at a constant injection rate over 10 seconds (half-dose constant rate). Multislice CT images were obtained before and at predetermined time points after the start of contrast medium injection.
  
  
  RESULTS
  Median peak attenuation values were 129, 133, and 87 Hounsfield units with the full-dose constant rate, full-dose decelerated rate, and half-dose constant rate injection protocols, respectively. Peak attenuation differed significantly between the full-dose constant rate and half-dose constant rate injection protocols and between the full-dose decelerated rate and half-dose constant rate injection protocols. Median time to peak attenuation did not differ significantly among injection methods and was 30, 23, and 15 seconds for the full-dose constant rate, full-dose decelerated rate, and half-dose constant rate injections, respectively.
  
  
  CONCLUSIONS
  The dose of contrast medium and the timing of postinjection CT scanning were main determinants of peak attenuation for adrenal glands in healthy dogs; effects of the 3 injection protocols on attenuation were minor. The exponentially decelerated injection method was subjectively complex. A constant injection protocol delivering 700 mg of iodine/kg over 20 seconds, with scans obtained approximately 30 seconds after starting contrast medium injection, provided images with maximum adrenal gland attenuation values.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Blaser
authors.forename: Matthias
authors.initials: M
authors.lastname: Dennler
authors.forename: Martina
authors.initials: M
authors.lastname: Mosing
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Gent
authors.forename: Guido
authors.initials: G
authors.lastname: Santner
authors.forename: Sandro
authors.initials: S
authors.lastname: Imhasly
authors.forename: Felicitas S
authors.initials: FS
authors.lastname: Boretti
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Reusch
authors.forename: Patrick
authors.initials: P
authors.lastname: Kircher
authors.forename: Nadja S
authors.initials: NS
authors.lastname: Sieber-Ruckstuhl
mesh_terms: D000311:Adrenal Glands / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage* / Q000494:pharmacology; D018592:Cross-Over Studies; D004285:Dogs / Q000033:anatomy & histology*; D007455:Iodine / Q000008:administration & dosage* / Q000494:pharmacology; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary*
chemical_list: D003287:Contrast Media; D007455:Iodine