title: Combined gadoxetic acid and gadofosveset enhanced liver MRI: A feasibility and parameter optimization study.
abstract: OBJECTIVE
  Demonstration of feasibility and protocol optimization for the combined use of gadofosveset trisodium with gadoxetic acid for delayed T1-weighted liver MRI.
  
  
  METHODS
  Eleven healthy volunteers underwent hepatobiliary phase imaging at 3 Tesla (T) using gadoxetic acid. Multiple breathheld T1-weighted three-dimensional spoiled gradient echo sequences were performed at varying flip angles before and after injection of gadofosveset. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured to determine optimal T1-weighting. Examples of three patients with focal liver lesions were acquired.
  
  
  RESULTS
  The addition of gadofosveset to the hepatobiliary phase of gadoxetic acid renders vessels isointense to liver tissue at low flip angles due to increased vessel SNR (P < 0.001). The lowest CNR of liver relative to portal vein (CNR = 15; 95% confidence interval [CI]: -14-44) was observed at a 10º flip angle. The highest CNR of liver relative to muscle (CNR = 214; 95% CI: 191-237) was observed at a 20º flip angle. The combined enhancement leads to homogenously enhanced liver tissue and liver vasculature. Cysts were detected in three volunteers and metastases were detected in two patients. In these anecdotal cases the cysts and metastases stood out as conspicuous focal hypointensities on combined gadoxetic acid and gadofosveset enhanced images.
  
  
  CONCLUSIONS
  Combined gadoxetic acid and gadofosveset enhanced liver MRI is feasible, with low flip angles minimizing contrast between vessels and liver. Further clinical studies are needed to confirm that low flip angles provide an optimal combination of sensitivity and specificity for lesion detection in patients.
authors: Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
authors: Peter
authors: P
authors: Bannas
authors: Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Radiology, University of Yamanashi, Yamanashi, Japan.
authors: Utaroh
authors: U
authors: Motosugi
authors: Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Diego
authors: D
authors: Hernando
authors: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Mahdi Salmani
authors: MS
authors: Rahimi
authors: Global MR Applications and Workflow, GE Healthcare, Madison, Wisconsin, USA.
authors: James H
authors: JH
authors: Holmes
authors: Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.|Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors: Scott B
authors: SB
authors: Reeder
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage; D004338:Drug Combinations; D004357:Drug Synergism; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium / Q000008:administration & dosage*; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; C073590:gadolinium ethoxybenzyl DTPA; D005682:Gadolinium; D019786:Gadolinium DTPA; C109932:gadofosveset trisodium
keywords: MRI; gadofosveset trisodium; gadoxetic acid; hepatobiliary imaging; liver