title: Identification of the iodine concentration that yields the highest intravascular enhancement in MDCT angiography.
abstract: OBJECTIVE
  The objective of our study was to identify the iodine concentration that yields the highest intravascular contrast enhancement in MDCT angiography by intraindividual comparison in an animal model.
  
  
  METHODS
  Six pigs underwent repeated chest MDCT examinations under standardized conditions using the same contrast medium (iopromide) with different iodine concentrations (150, 240, 300, and 370 mg I/mL). The contrast injection protocol was adapted to ensure an identical iodine delivery rate of 1.5 g I/s and the same total iodine dose of 300 mg/kg of body weight for all studies. Dynamic CT scans were acquired at the levels of the pulmonary artery and the ascending and descending aorta. Pulmonary and aortic peak enhancement values as well as time to peak (TTP) were calculated from time-enhancement curves.
  
  
  RESULTS
  Pulmonary and aortic peak contrast enhancement values were significantly higher with the 240 and 300 mg I/mL contrast media than the 150 and 370 mg I/mL contrast media (e.g., ascending aorta: 240 vs 150, p = 0.0070; 300 vs 150, p = 0.0096; 240 vs 370, p = 0.0262; 300 vs 370, p = 0.0079). TTP values tended to be lower for the 150 mg I/mL contrast medium than for the contrast media with higher iodine concentrations.
  
  
  CONCLUSIONS
  Comparison of contrast media with iodine concentrations ranging from 150 to 370 mg I/mL showed that contrast enhancement was significantly improved with the use of 240 and 300 mg I/mL contrast media given a fixed identical iodine delivery and normalized total iodine load in a porcine model. Contrast media with a moderate iodine concentration are most suitable for obtaining the highest intravascular contrast enhancement in CT angiography.
authors.affiliation: Department of Radiology, RWTH Aachen University, North Rhine-Westphalia, Germany. fbehrendt@ukaachen.de
authors.forename: Florian F
authors.initials: FF
authors.lastname: Behrendt
authors.forename: Hubertus
authors.initials: H
authors.lastname: Pietsch
authors.forename: Gregor
authors.initials: G
authors.lastname: Jost
authors.forename: Moritz
authors.initials: M
authors.lastname: Palmowski
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
mesh_terms: D000792:Angiography / Q000379:methods*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide