title: Enhancement effects and relaxivities of gadolinium-DTPA at 1.5 versus 3 Tesla: a phantom study.
abstract: OBJECTIVE
  To investigate the difference in enhancement effects and relaxivities of the gadolinium chelate at 1.5 and 3 Tesla (T) and to elucidate the contribution of the high magnetic field to contrast enhancement in spin-echo (SE) and gradient-echo (GRE) images.
  
  
  METHODS
  Phantoms containing water with or without gadopentetate dimeglumine (Gd-DTPA) at different concentrations were scanned using 1.5T and 3T MRI scanners of the same manufacturer and under the same temperature conditions and scanning parameters. Relaxivities of gadolinium, R1 and R2, were estimated from serial T1 and T2 values of the phantoms using linear regression. Contrast enhancement ratios in SE and GRE T1-weighted images were compared at 1.5 and 3T.
  
  
  RESULTS
  The R1 and R2 of Gd-DTPA at 1.5 and 3T were 4.79 and 5.14, and 4.50 and 5.09, respectively. Although the relaxivities at 3T were slightly lower than those at 1.5T, the contrast enhancement ratio improved in both SE and GRE images as a result of T1 prolongation of the water at 3T.
  
  
  CONCLUSIONS
  The decrease in relaxivities of the Gd-DTPA at 3T appears to be so small that T1 prolongation of the water improves contrast enhancement, suggesting a potential clinical advantage in administration of Gd-DTPA at high field strength.
authors.affiliation: Department of Radiology, Iwate Medical University, School of Medicine, Morioka, Japan. masasaki@iwate-med.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Eri
authors.initials: E
authors.lastname: Shibata
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kanbara
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ehara
mesh_terms: D003287:Contrast Media / Q000493:pharmacokinetics*; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA