title: In Vitro Longitudinal Relaxivity Profile of Gd(ABE-DTTA), an Investigational Magnetic Resonance Imaging Contrast Agent.
abstract: OBJECTIVE
  MRI contrast agents (CA) whose contrast enhancement remains relatively high even at the higher end of the magnetic field strength range would be desirable. The purpose of this work was to demonstrate such a desired magnetic field dependency of the longitudinal relaxivity for an experimental MRI CA, Gd(ABE-DTTA).
  
  
  METHODS
  The relaxivity of 0.5mM and 1mM Gd(ABE-DTTA) was measured by Nuclear Magnetic Relaxation Dispersion (NMRD) in the range of 0.0002 to 1T. Two MRI and five NMR instruments were used to cover the range between 1.5 to 20T. Parallel measurement of a Gd-DTPA sample was performed throughout as reference. All measurements were carried out at 37°C and pH 7.4.
  
  
  RESULTS
  The relaxivity values of 0.5mM and 1mM Gd(ABE-DTTA) measured at 1.5, 3, and 7T, within the presently clinically relevant magnetic field range, were 15.3, 11.8, 12.4 s-1mM-1 and 18.1, 16.7, and 13.5 s-1mM-1, respectively. The control 4 mM Gd-DTPA relaxivities at the same magnetic fields were 3.6, 3.3, and 3.0 s-1mM-1, respectively.
  
  
  CONCLUSIONS
  The longitudinal relaxivity of Gd(ABE-DTTA) measured within the presently clinically relevant field range is three to five times higher than that of most commercially available agents. Thus, Gd(ABE-DTTA) could be a practical choice at any field strength currently used in clinical imaging including those at the higher end.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.
authors.forename: Akos
authors.initials: A
authors.lastname: Varga-Szemes
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.
authors.forename: Pal
authors.initials: P
authors.lastname: Kiss
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.
authors.forename: Andras
authors.initials: A
authors.lastname: Rab
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.
authors.forename: Pal
authors.initials: P
authors.lastname: Suranyi
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.|Heart Institute, Medical School, University of Pecs, Pecs, Hungary.
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Lenkey
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.|Heart Institute, Medical School, University of Pecs, Pecs, Hungary.
authors.forename: Tamas
authors.initials: T
authors.lastname: Simor
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA, United States of America.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bryant
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States of America.|Elgavish Paramagnetics Inc., Birmingham, AL, United States of America.
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Elgavish
mesh_terms: D003287:Contrast Media / Q000737:chemistry*; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D009942:Organometallic Compounds / Q000737:chemistry*; D004369:Pentetic Acid / Q000737:chemistry
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C120791:gadolinium N-(2-butyryloxyethyl)-N'-(2-ethyloxyethyl)-N,N'-bis(N'',N''-bis(carboxymethyl)acetamido)-1,2-ethanediamine; D004369:Pentetic Acid