title: Multiphase contrast-enhanced CT of the liver with a multislice CT scanner: effects of iodine concentration and delivery rate.
abstract: OBJECTIVE
  To determine whether or not high-concentration contrast material is useful in multiphase contrast-enhanced CT of the liver with a multislice CT scanner.
  
  
  METHODS
  One hundred twenty-four examinations, in which first- and second-pass acquisitions (double arterial phase imaging) were performed during a single breath-hold followed by third-pass acquisition, were randomized into three protocols: contrast injection at 0.07 mL/kg body weight/sec over 30 sec at an iodine concentration of 300 mgI/mL in group 1, contrast injection at 0.06 mL/kg body weight/sec over 30 sec at an iodine concentration of 350 mgI/mL in group 2, and contrast injection at 0.07 mL/kg body weight/sec over 25.7 sec at an iodine concentration of 350 mgI/mL in group 3. Each group received an equivalent iodine dose per kg body weight (2.1 mL/kg of contrast material of 300 mgI/mL). Contrast enhancement in each acquisition was measured in the aorta, portal vein, and liver.
  
  
  RESULTS
  No statistically significant differences were seen between groups 1 and 2 in any enhancement in any acquisition. In group 3, aortic enhancement in the first-pass acquisition was significantly more intense than in groups 1 and 2, while portal venous enhancement and hepatic enhancement were equivalent.
  
  
  CONCLUSIONS
  Shortening the injection duration for a given iodine dose with high-concentration contrast material (group 3) can achieve improved arterial enhancement on arterial phase images.
authors.affiliation: Department of Technical Radiology, Nagoya University School of Health Sciences, Aichi, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Itoh
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ikeda
authors.forename: Masataka
authors.initials: M
authors.lastname: Achiwa
authors.forename: Hiroko
authors.initials: H
authors.lastname: Satake
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Ota
authors.forename: Takeo
authors.initials: T
authors.lastname: Ishigaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007267:Injections; D007479:Iopamidol / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol