Transient MR elastography (t-MRE) using ultrasound radiation force: theory, safety, and initial experiments in vitro.
The purpose of our study was to assess the feasibility of using ultrasound radiation force as a safe vibration source for transient MR elastography (t-MRE). We present a theoretical framework to predict the phase shift of the complex MRE signal, the temperature elevation due to ultrasound, and safety indicators (I(SPPA), I(SPTA), MI). Next, we report wave images acquired in porcine liver samples in vitro. MR thermometry was used to estimate the temperature elevation induced by ultrasound. Finally, we discuss the implications of our results with regard to the feasibility of using radiation force for t-MRE in a clinical setting, and a specific echo-planar imaging (EPI) MRE sequence is proposed.
Souchon
Rémi
R
Inserm, U556, Lyon, France. Remi.Souchon@inserm.fr
Salomir
Rares
R
Beuf
Olivier
O
Milot
Laurent
L
Grenier
Denis
D
Lyonnet
Denis
D
Chapelon
Jean-Yves
JY
Rouvière
Olivier
O
D000818:Animals; D003198:Computer Simulation; D054459:Elasticity Imaging Techniques / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D008099:Liver / Q000033:anatomy & histology* / Q000502:physiology* / Q000528:radiation effects; D008954:Models, Biological; D010865:Pilot Projects; D013010:Sonication; D013552:Swine