A Novel Radiolucent Phased Array Design Suitable for MR Guided Radiation Therapy

Introduction: MR guided Radiation Therapy (MRgRT) is a new hybrid technique that combines MR’s soft tissue contrast for better accuracy in tumor delineation during the planning stage and reduction of healthy tissue damage during the treatment stage with Radiation therapy equipment such as LINACs. One more important aspect of such a hybrid system is the real time monitoring of the motion for the radiating tissue using MR. In such an occasion RF coils that are both radiolucent and MR compatible are placed as close as possible to the anatomy in the region of interest in order to achieve high signal-to-noise ratio (SNR). As a workflow benefit it is ideal to leave the coils in place during radiation therapy treatment. Recent attempts to design radiolucent coils have used aluminum as the conductor and have been successful [1]; however, aluminum coils have higher resistivity than copper which reflects in lower Q and subsequently lower SNR values for these coils. In addition aluminum is not an easy material to work with for RF coil fabrication.