title: Multicenter comparison of high concentration contrast agent iomeprol-400 with iso-osmolar iodixanol-320: contrast enhancement and heart rate variation in coronary dual-source computed tomographic angiography.
abstract: OBJECTIVE
  To compare a contrast agent with high iodine concentration with an iso-osmolar contrast agent for coronary dual-source computed tomography angiography (DS-CTA), and to assess whether the contrast agent characteristics may affect the diagnostic quality of coronary DS-CTA.
  
  
  METHODS
  Patients were randomized to receive either 80 mL of iodixa:nol-320 (Visipaque, GE Healthcare, Chalfont St. Giles, United Kingdom) or iomeprol-400 (Iomeron, Bracco Imaging SpA, Milan, Italy) at 5 mL/s. Mean, minimum, maximum heart rate, and its variation (max-min) were assessed during calcium scoring scan and coronary DS-CTA. Three off-site readers independently evaluated the image sets in terms of technical adequacy, reasons for inadequacy, vessel visualization, diagnostic confidence (based on a 5-point scale), and arterial contrast opacification in Hounsfield units (HUs).
  
  
  RESULTS
  Ninety-six patients were included in the final evaluation. No significant differences were observed for pre- and postdose heart rate values for iomeron-400 compared with iodixanol-320, and changes in heart rate variation were also not significantly different (-2.3 ± 11.7 vs. -2.5 ± 7.3 bpm, P > 0.1). Contrast measurements in all analyzed vessels were significantly higher for iomeprol-400 (mean, 391.5-441.4 HU) compared with iodixanol-320 (mean, 332.3-365.5 HU, all P ≤ 0.0038). There was no significant difference in qualitative visualization of coronary arteries (mean scores, 4.3-4.5 for iomeprol, 4.1-4.3 for iodixanol, P = 0.15-0.28), or in diagnostic confidence scores. HU were inversely correlated with the number of insufficiently opacified segments (all readers P ≤ 0.0006).
  
  
  CONCLUSIONS
  The high-iodine concentration contrast medium iomeprol-400 demonstrated significant benefit for coronary arterial enhancement compared with the iso-osmolar contrast medium iodixanol-320 when administered at identical flow rates and volumes for coronary DS-CTA. In addition, higher enhancement levels were found to be associated with lower numbers of inadequately visualized segments. Finally, observed mean heart rate changes after intravenous contrast injection were generally small during the examination and comparable for both agents.
authors.affiliation: University Hospital of Munich Großhadern, Department of Radiology, Munich, Germany. christoph.becker@med.uni-muenchen.de
authors.forename: Cristoph R
authors.initials: CR
authors.lastname: Becker
authors.forename: Angelo
authors.initials: A
authors.lastname: Vanzulli
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
authors.forename: Daniele
authors.initials: D
authors.lastname: de Faveri
authors.forename: Stefano
authors.initials: S
authors.lastname: Fedeli
authors.forename: Roberto
authors.initials: R
authors.lastname: Dore
authors.forename: Pietro
authors.initials: P
authors.lastname: Biondetti
authors.forename: Alex
authors.initials: A
authors.lastname: Kuettner
authors.forename: Martin
authors.initials: M
authors.lastname: Krix
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ascenti
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D014283:Triiodobenzoic Acids / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C057937:iomeprol; C044834:iodixanol; D007479:Iopamidol