Numerical Optimization of Multichannel Rx-only RF Coil for Parallel Imaging at 0.07T

The concept of portable ultra-low-field MRI has been actively studied in the past few years. Many approaches focused on using of different software methods for image reconstruction, post-processing and noise reduction. Signal-to-noise ration (SNR) of images could be also enhanced by improving hardware of low-field MRI system. In this work, we propose a method to improve the performance of ultralow-field head MRI by using multichannel Rx arrays combined with parallel imaging techniques. We designed three different Rx-only four-channel array configurations aiming to minimize g-factor and maximize SNR compared to single-channel Tx/Rx solenoid coil. Using the results of numerical electromagnetic simulations, individual sensitivity profiles of array elements were obtained in order to calculate SNR and g-factor of simulated arrays. As a result, a four-channel Rx-array coil with a low g-factor for ultra-low field head MRI has been designed. Using a four-channel Rx-only array with proposed geometry will allow to reduce image acquisition time by using parallel imaging in ultra-low field MRI.