Compressed perovskite aqueous mixtures near their phase transitions show very high permittivities: New prospects for high-field MRI dielectric shimming - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Magnetic Resonance in Medicine Année : 2017

Compressed perovskite aqueous mixtures near their phase transitions show very high permittivities: New prospects for high-field MRI dielectric shimming

Lisa Leroi
  • Fonction : Auteur
Zo Raolison
  • Fonction : Auteur
Thibaut Letertre
  • Fonction : Auteur
Redha Abdeddaim
  • Fonction : Auteur
Stefan Enoch
Jérôme Wenger
Johann Berthelot
  • Fonction : Auteur
Nicolas Mallejac
  • Fonction : Auteur
Franck Mauconduit
Alexandre Vignaud
Pierre Sabouroux
  • Fonction : Auteur

Résumé

Purpose: Perovskites are greatly used nowadays in many technological applications because of their high permittivity, more specifically in the form of aqueous solutions, for MRI dielectric shimming. In this study, full dielectric characterizations of highly concentrated CaTiO 3 /BaTiO 3 water mixtures were carried out and new permittivity maxima was reached. Methods: Permittivity measurements were done on aqueous solutions from 0%v/v to dry powder. The permittivity dependence with pressure was investigated. Scanning electron micros-copy images were performed on a few representative solutions. BaTiO 3 pressed pads of different thicknesses, permittivities, and distances to the head were compared in a 7T MRI scanner. Results: Perovskite aqueous mixtures undergo a pressure-dependent phase transition in terms of permittivity, with increasing water content. A new relative permittivity maximum of 475 was achieved. Microscopic images revealed structural differences between phases. A B þ 1 improvement in the temporal lobe was obtained with thin, high permittivity BaTiO 3 head. Conclusions: This new preparation method allows improved pad geometry and placement, as a result of the high relative permittivity values achieved. This method has great significance for medical applications of MRI dielectric shimming, being easy to replicate and implement on a large scale.
Fichier principal
Vignette du fichier
Neves_et_al-2017-Magnetic_Resonance_in_Medicine.pdf (1.33 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01540002 , version 1 (15-06-2017)

Identifiants

Citer

Ana L. Neves, Lisa Leroi, Zo Raolison, Nicolas Cochinaire, Thibaut Letertre, et al.. Compressed perovskite aqueous mixtures near their phase transitions show very high permittivities: New prospects for high-field MRI dielectric shimming. Magnetic Resonance in Medicine, 2017, 76, pp.1951 - 0. ⟨10.1002/mrm.26771⟩. ⟨hal-01540002⟩
457 Consultations
229 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More