Wearable Magnetic Resonance RF Coil Technology And Its Application Exploration

Magnetic resonance RF receive only coil technology has matured in the past 20 years.In order to improve the imaging quality of coils,mainstream researchers rely on phased array coil technology to reduce coil size and increase the number of channels.However,too small a loop size means a decrease in the quality factor of the coil and an increase in the coil noise,thereby affecting the improvement of the image quality;The Lufkin RB study shows that the SNR(Signal to Noise Ratio)is proportional to its fill factor.Therefore,the pursuit of optimal coil fill factor is an important way to improve the imaging quality of the coil.The higher the coil fill factor,the higher the image SNR.Commercial coils used have a large mechanical structure(such as knee joint coils,head coils and wrist joint coils).Different sizes of patients using the same coil will cause different coil filling factors,and the imaging quality will be different.To obtain a high coil filling factor at all times,the coil is required to be deformed according to the measured tissue size of different patients.It is difficult to design a coil for each patient.The introduction of the wearable concept into the coil design has become one of the effective strategies to solve this problem.The application of wearable technology to the development of magnetic resonance RF receiving coil is directly related to maximizing the coil filling factor.Based on the experimental demonstration of the selection of conductor materials and the performance of elastic materials is still good.The knee receiving coil and the head receiving coil developed by the combination of flexible and elastic materials realize the deformation characteristics of the coil according to the corresponding tissue size change of the patient within a certain range,and realize the largest tissue for different sizes of patients.The purpose of the coil fill factor is to obtain good SNR images for different patient scans using the same coil.In this paper,the concept of combining flexible materials and elastic materials is introduced into the coil design.The 1.5T 5-channel knee receiving only coil with geometric structure and the more complex 3T 32-channel head receiving only coil are designed.Through experiment and verification,the electrical characteristics of the coil can be changed within a certain range of deformation to meet the performance requirements.The 1.5T knee coil achieved SNR performance of 2-4 times that of a commercial 8-channel knee coil in the shallow to deep tissue within a 16% deformation range,the 3T head coil scan test image has good symmetry,as the imaging depth increases,the SNR gradually decreases.The shallow SNR is up to 3 times deeper,and in the 12% deformation range,it is 0-2 times the commercial 8 head coil channel in the surface layer to 46 mm tissue depth.