title: Intraindividual Crossover Comparison of Gadoxetic Acid Dose for Liver MRI in Normal Volunteers.
abstract: OBJECTIVE
  We performed a quantitative intraindividual comparison of the performance of 0.025- and 0.05-mmol/kg doses for gadoxetic acid-enhanced liver magnetic resonance (MR) imaging.
  
  
  METHODS
  Eleven healthy volunteers underwent liver MR imaging twice, once with a 0.025- and once with a 0.05-mmol/kg dose of gadoxetic acid. MR spectroscopy and 3-dimensional gradient-echo T1-weighted images (3D-GRE) were obtained before and 3, 10, and 20 min after injection of the contrast medium to measure T1 and T2 values and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) performance. During the dynamic phase, highly time-resolved 3D-GRE was used to estimate the relative CNR (CNRrel) of the hepatic artery and portal vein (PV) to the liver. We used paired t-tests to compare the results of different doses.
  
  
  RESULTS
  During the hepatobiliary phase, we observed shorter T1 values and higher SNRs of the liver (P < 0.001) and higher liver-to-PV and liver-to-muscle CNRs (P < 0.002) using 0.05 mmol/kg compared to 0.025 mmol/kg. Increasing the dose to 0.05 mmol/kg yielded a greater T1-shortening effect at 10 min delay even compared with 0.025 mmol/kg at 20 min (P < 0.001). During the dynamic phase, the peak CNRrel for the hepatic artery and portal vein were higher using 0.05 mmol/kg (P = 0.007 to 0.035).
  
  
  CONCLUSIONS
  Use of gadoxetic acid at a dose of 0.05 mmol/kg leads to significantly higher SNR and CNR performance than with 0.025 mmol/kg. Quantitatively, a 10-min delay may be feasible for hepatobiliary-phase imaging when using 0.05 mmol/kg of gadoxetic acid.
authors.affiliation: Department of Radiology, University of Wisconsin.
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Peter
authors.initials: P
authors.lastname: Bannas
authors.forename: Diego
authors.initials: D
authors.lastname: Hernando
authors.forename: Mahdi
authors.initials: M
authors.lastname: Salmani Rahimi
authors.forename: James H
authors.initials: JH
authors.lastname: Holmes
authors.forename: Scott B
authors.initials: SB
authors.lastname: Reeder
mesh_terms: D000328:Adult; D001659:Biliary Tract / Q000033:anatomy & histology; D003287:Contrast Media / Q000008:administration & dosage*; D018592:Cross-Over Studies; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006499:Hepatic Artery / Q000033:anatomy & histology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008099:Liver / Q000033:anatomy & histology* / Q000098:blood supply; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D011169:Portal Vein / Q000033:anatomy & histology; D011446:Prospective Studies; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D055815:Young Adult
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA