Article in La Lettre d’AMU n°83 – October 2020
Marine Moussu is a 3rd year PhD student at Institut Fresnel, Aix-Marseille University, and cofinanced by Multiwave Imaging, a start-up established in Marseille. Her doctorate project focuses on modelling magnetic resonance imaging (MRI) coils. The later are used to induce the excitation magnetic field in the sample. Conventional coils are metallic and generate such a magnetic field due to the electric current circulation (Ampere’s law). The electromagnetic field frequency and distribution is related to the coil geometry. The coil efficiency is defined as the ratio of the magnetic field induced in the sample, over the measurement noise, that mainly depends on two contributions: the intrinsic losses of the coil itself, and dielectric losses due to the electric field interaction with the sample. The later is significant when using metallic coils. An alternative design of MRI coils is now under study, that exploit the eigenmodes of non-metallic resonators, that is built with dielectric materials like water or ceramics. In that case, it is possible to contain the electric field within the resonator only. The project of Marine Moussu is to propose modelling tools that enable to maximise the efficiency of dielectric coils, and then to improve the image quality. So far she has been working on microscopy applications, and her next goal is to develop a dielectric coil for clinical wrist imaging, in collaboration with the CRMBM, a laboratory of Aix-Marseille University dedicated to preclinical and clinical MRI.