title: T1 efficacy of EVP-ABD: a potential manganese-based MR contrast agent for hepatic vascular and tissue phase imaging.
abstract: OBJECTIVE
  To evaluate the T1 efficacy of EVP-ABD, a new manganese (Mn)-based contrast agent, for vascular and liver tissue enhancement in comparison with currently approved agents.
  
  
  METHODS
  Ten Yorkshire pigs (body weight, 26 -46 kg) were used for the efficacy evaluation, nine for kinetic T1 evaluation (three each agent) and one for post EVP-ABD imaging. With a fast imaging scheme to monitor T1 values of blood and liver, 10 micromol/kg EVP-ABD was injected intravenously and compared with gadopentetate dimeglumine (Magnevist, GdDTPA) and mangafodipir trisodium (Teslascan, mangafodipir trisodium) at routine clinical dosages. All were imaged with 3D T1 Gradient Recalled Echo (GRE) sequence (TR/TE/alpha = 3.8/1.6/25 degrees ) prior to and 10 minutes post injection using a 1.5-T whole-body scanner. Additional high-resolution 2D liver images (TR/TE/alpha = 50/4.6/40 degrees ) and arterial phase images of the upper aorta were acquired from the pig for post EVP-ABD imaging.
  
  
  RESULTS
  At 10 micromol/kg, EVP-ABD provided a dramatic decline in blood T1, comparable to 0.1 mmol/kg GdDTPA, followed by a rapid return to blood baseline T1 values. In addition to the blood enhancement phase, EVP-ABD achieved a 70% reduction in liver T1 within 2 minutes postadministration, with an imaging window of at least 2 hours. A substantially improved signal-to-noise ratio (SNR) was observed in both the 2D and 3D liver images postcontrast.
  
  
  CONCLUSIONS
  EVP-ABD demonstrated peak vascular enhancement similar to GdDTPA and prolonged specific liver enhancement exceeding mangafodipir trisodium. EVP-ABD has favorable T1 enhancing characteristics with the potential to allow for a comprehensive liver evaluation.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA. czuo@caregroup.harvard.edu
authors.forename: C S
authors.initials: CS
authors.lastname: Zuo
authors.forename: P
authors.initials: P
authors.lastname: Seoane
authors.forename: T
authors.initials: T
authors.lastname: Lanigan
authors.forename: P
authors.initials: P
authors.lastname: Harnish
authors.forename: P V
authors.initials: PV
authors.lastname: Prasad
authors.forename: P
authors.initials: P
authors.lastname: Storey
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.forename: N M
authors.initials: NM
authors.lastname: Rofsky
mesh_terms: D000818:Animals; D001011:Aorta; D003287:Contrast Media / Q000493:pharmacokinetics; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D019786:Gadolinium DTPA / Q000493:pharmacokinetics; D008099:Liver / Q000098:blood supply*; D008279:Magnetic Resonance Imaging; D008345:Manganese; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D013552:Swine
chemical_list: D003287:Contrast Media; C472505:EVP-ABD; D008345:Manganese; D011732:Pyridoxal Phosphate; D004492:Edetic Acid; D019786:Gadolinium DTPA; C060076:N,N'-bis(pyridoxal-5-phosphate)ethylenediamine-N,N'-diacetic acid