title: Influence of osmolarity of contrast medium and saline flush on computed tomography angiography: comparison of monomeric and dimeric iodinated contrast media with different iodine concentrations at an identical iodine delivery rate.
abstract: OBJECTIVE
  To evaluate the influence of osmolarity of iodinated contrast media and saline flush on the contrast effect in thoracic computed tomography angiography (CTA) at an identical iodine delivery rate (IDR).
  
  
  METHODS
  Seven beagles were used in a cross-over experiment. The contrast media used were iohexol 350 mgI/ml (IOH350; osmolarity 844 mmol/kg) and iodixanol 320 mgI/ml (IDX320; osmolarity 290 mmol/kg). Each contrast medium was administered to groups with and without saline flush at 40.0 mgI/kg/s for all experiments. Dynamic CT scanning was performed at the ninth thoracic vertebra level. The peak value, area under the curve (AUC), and time to peak (TTP) were calculated from the time attenuation curves of the pulmonary artery and aorta.
  
  
  RESULTS
  There was no significant difference between IOH350 and IDX320 with or without saline flush in the peak values for the pulmonary artery and aorta. AUC was significantly higher in groups with saline flush for both contrast media and arteries (p<0.05) with no significant difference between contrast media. TTP was significantly longer in groups with saline flush than without saline flush for both contrast media and arteries (p<0.05), with no significant difference between contrast media.
  
  
  CONCLUSIONS
  There were no significant differences in the contrast effects of monomeric IOH350 and dimeric IDX320 in thoracic CTA when used at an identical IDR. Moreover, saline flush prolonged the peak duration at 600 mgI/kg.
authors.affiliation: Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan. miori@mx6.et.tiki.ne.jp
authors.forename: Miori
authors.initials: M
authors.lastname: Kishimoto
authors.forename: Shoko
authors.initials: S
authors.lastname: Doi
authors.forename: Junichiro
authors.initials: J
authors.lastname: Shimizu
authors.forename: Ki-Ja
authors.initials: KJ
authors.lastname: Lee
authors.forename: Toshiroh
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Yoh-Ichi
authors.initials: Y
authors.lastname: Miyake
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Yamada
mesh_terms: D000792:Angiography; D000818:Animals; D001011:Aorta; D019540:Area Under Curve; D003287:Contrast Media / Q000737:chemistry*; D018592:Cross-Over Studies; D004285:Dogs; D007472:Iohexol / Q000737:chemistry*; D009994:Osmolar Concentration; D011651:Pulmonary Artery; D013902:Radiography, Thoracic; D012965:Sodium Chloride / Q000008:administration & dosage; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; D012965:Sodium Chloride; C044834:iodixanol