Direct optical measurement of the RF electrical field for MRI

Isabelle Saniour (1) , Anne-Laure Perrier (2) , Gwenaël Gaborit (2, 3) , Jean Dahdah (3) , Lionel Duvillaret (3) , Olivier Beuf (1)

1 RMN et optique : De la mesure au biomarqueur
2 IMEP-LAHC - Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation
3 Kapteos SAS

In magnetic resonance imaging (MRI), the real time measurement of electrical field E associated with the radiofrequency (RF) magnetic field B1 is important to quantify the energy absorbed by the tissues and to assess possible safety hazards due to local heating phenomenon. E-field could effectively increase the temperature in the tissues nearby by inducing RF currentsin any implant or metallic cables used for signal transmission and placed inside the transmit body-coil1, 2. For the measurement of the intensities and the distribution of E-field, the adequate probe should be non-magnetic and non-perturbative regarding the E-field and must have a large working frequency range depending on B0. The commonly used probes have either a metallic structure or a large dimension which limits their bandwidth3, 4 and may disturb the electromagnetic field with bias measurements. Others optical probes do not measure directly the Efield 5. In the following, the E-field measurement experiment using a sub-cm electro-optical (EO) probe in a preclinical 4.7-T MR system is presented.

Domaines: Imagerie

Isabelle Saniour, Anne-Laure Perrier, Gwenaël Gaborit, Jean Dahdah, Lionel Duvillaret, et al.. Direct optical measurement of the RF electrical field for MRI. ISMRM 2016, May 2016, Singapour, Singapore. ⟨hal-01433300⟩