title: Optimized high-resolution contrast-enhanced hepatobiliary imaging at 3 tesla: a cross-over comparison of gadobenate dimeglumine and gadoxetic acid.
abstract: OBJECTIVE
  To evaluate the signal to noise ratio (SNR) and contrast to noise ratio (CNR) performance of 0.05 mmol/kg gadoxetic acid and 0.1 mmol/kg gadobenate dimeglumine for dynamic and hepatobiliary phase imaging. In addition, flip angles (FA) that maximize relative contrast-to-noise performance for hepatobiliary phase imaging were determined.
  
  
  METHODS
  A cross-over study in 10 volunteers was performed using each agent. Imaging was performed at 3 Tesla (T) with a 32-channel phased-array coil using breathheld 3D spoiled gradient echo sequences for SNR and CNR analysis, and for FA optimization of hepatobiliary phase imaging.
  
  
  RESULTS
  Gadobenate dimeglumine (0.1 mmol/kg) had superior SNR performance during the dynamic phase, statistically significant for portal vein and hepatic vein in the portal venous and venous phase (for all, P < 0.05) despite twice the approved dose of gadoxetic acid (0.05 mmol/kg), while gadoxetic acid had superior SNR performance during the hepatobiliary phase. Optimal FAs for hepatobiliary phase imaging using gadoxetic acid and gadobenate dimeglumine were 25-30° and 20-30° for relative contrast liver versus muscle (surrogate for nonhepatocellular tissues), and 45° and 20° (relative contrast liver versus biliary structures), respectively.
  
  
  CONCLUSIONS
  Gadobenate dimeglumine may be preferable for applications that require dynamic phase imaging only, while gadoxetic acid may be preferable when the hepatobiliary phase is clinically important. Hepatobiliary phase imaging with both agents benefits from flip angle optimization.
authors.affiliation: Department of Radiology, University of Wisconsin-Madison, Wisconsin 73727, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Frydrychowicz
authors.forename: Scott K
authors.initials: SK
authors.lastname: Nagle
authors.forename: Sharon L
authors.initials: SL
authors.lastname: D'Souza
authors.forename: Karl K
authors.initials: KK
authors.lastname: Vigen
authors.forename: Scott B
authors.initials: SB
authors.lastname: Reeder
mesh_terms: D000328:Adult; D001659:Biliary Tract / Q000033:anatomy & histology*; D003287:Contrast Media; D018592:Cross-Over Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C073590:gadolinium ethoxybenzyl DTPA; C064572:gadobenic acid; D008536:Meglumine; D019786:Gadolinium DTPA