RF mode switching based Tx coil system for B1+ homogeneity mitigation at 7T: basic concept and preliminary study

To mitigate B1 inhomogeneity problems in ultra-high-field MRI, we proposed RF-mode switching technique which doesn’t need an expensive parallel transmit (pTx) system. As a preliminary study, we developed an RF-switching circuit (one of the main parts of the system) and validated its function through phantom experiments. The results showed that the switching function works well, although a certain degree of power-loss was observed both at bench (< -1dB) and on the images. We have re-designed a new switching circuit and will continue to the development to demonstrate this technique at a fraction of the cost of a pTx system.