Comments about the above article [1] were proposed. We thank and reply to the authors of the comments about our model of high-permittivity dielectric ring resonators used as microscopy magnetic... Show moreComments about the above article [1] were proposed. We thank and reply to the authors of the comments about our model of high-permittivity dielectric ring resonators used as microscopy magnetic resonance probes. In this prospect, we reply part by part to the comments. Show less
In this paper we address the possibility to perform imaging of two samples within the same acquisition time using coupled ceramic resonators and one transmit/receive channel. We theoretically and... Show moreIn this paper we address the possibility to perform imaging of two samples within the same acquisition time using coupled ceramic resonators and one transmit/receive channel. We theoretically and experimentally compare the operation of our ceramic dual-resonator probe with a wire-wound solenoid probe, which is the standard probe used in ultrahigh-field magnetic resonance microscopy. We show that due to the low-loss ceramics used to fabricate the resonators, and a favorable distribution of the electric field within the conducting sample, a dual probe, which contains two samples, achieves an SNR enhancement by a factor close to the square root of 2 compared with a solenoid optimized for one sample. Show less
Moussu, M.A.C.; Abdeddaim, R.; Dubois, M.; Georget, E.; Webb, A.G.; Nenasheva, E.; ... ; Enoch, S. 2020
Magnetic resonance imaging (MRI) is an imaging technique exploiting the magnetic resonance (MR) of specific nuclear spins, like protons. In this article, MR probes based on dielectric ring... Show moreMagnetic resonance imaging (MRI) is an imaging technique exploiting the magnetic resonance (MR) of specific nuclear spins, like protons. In this article, MR probes based on dielectric ring resonators are investigated from a theoretical approach. We take advantage of the high-permittivity and low-loss properties of the ceramic material used for manufacturing these probes for microscopy applications. Magnetic resonance microscopy (MRM) aims at imaging tiny samples with a sufficient resolution to distinguish small details. In this framework, compact resonators, called volume probes, contain the investigated sample and are used for both signal transmission and reception. The newly developed semi-analytical model enables the estimation of the frequency of the first transverse electric mode of a cylindrical resonator. It also provides a method to compute the corresponding magnetic field distribution, the dielectric losses contributions from the probe and the sample, and the signal-to-noise ratio (SNR). The proposed approach aims at providing design guidelines for dielectric probes. Show less
The spatial resolution and signal-to-noise ratio (SNR) attainable in magnetic resonance microscopy (MRM) are limited by intrinsic probe losses and probe-sample interactions. In this work, the... Show moreThe spatial resolution and signal-to-noise ratio (SNR) attainable in magnetic resonance microscopy (MRM) are limited by intrinsic probe losses and probe-sample interactions. In this work, the possibility to exceed the SNR of a standard solenoid coil by more than a factor-of-two is demonstrated theoretically and experimentally. This improvement is achieved by exciting the first transverse electric mode of a low-loss ceramic resonator instead of using the quasi-static field of the metal-wire solenoid coil. Based on theoretical considerations, a new probe for microscopy at 17 T is developed as a dielectric ring resonator made of ferroelectric/dielectric low-loss composite ceramics precisely tunable via temperature control. Besides the twofold increase in SNR, compared with the solenoid probe, the proposed ceramic probe does not cause static-field inhomogeneity and related image distortion. Show less
