Conceptual design of a cryogen-free μMRI device

[摘要] To perform Micro Magnetic Resonance Imaging (mMRI) analysis on small regions such as skins, articulations or small animals, the required spatial resolution implies to dramatically improve the sensitivity of the detection. One way to go is to use small radio-frequency superconducting coil that allow, among others, increasing significantly the signal-to-noise ratio. The RF probe, constituted of an optimized YBaCuO film coil cooled below nitrogen temperature, must be located no further than few millimeters from the biological region to be imaged in a clinical MRI magnet. To fulfill the medical environment and constraints, a cryogen-free cooling scheme has been developed to maintain the superconducting coil at the working temperature. The cryogenic design is based on a pulse tube cryocooler and solid thermal links inserted in a non-magnetic cryostat to avoid creating any electromagnetic perturbations to the MRI magnet and the measurements. We report here the conceptual design of the cryogenic system with the required thermal performances, the corresponding layout and architecture of the system as well as the main technical challenges met for the construction.

[发布机构] Irfu, CEA, Unversité Paris-Saclay, Gif-sur-Yvette; F-91191, France^1;IR4M, UMR8081, Université Paris-Sud, CNRS, Université Paris-Saclay, Orsay, France^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Electromagnetic perturbations;Nitrogen temperatures;Pulse tube cryocoolers;Radio frequencies;Spatial resolution;Technical challenges;Thermal Performance;Working temperatures