Motivation: Motion is among the most common sources of artifacts in MRI. RF navigators address this challenge by providing a powerful and sensitive method for contact-free motion sensing. Goal(s): This work seeks to evaluate the motion sensitivity of RF navigators towards optimizing their use for head motion sensing. Approach: In this work we characterize a multi-input multi-output system for head motion sensing using pilot tone and beat pilot tone. Results: The frequency-sensitivity of beat pilot tone was evaluated and an optimal transmission frequency was identified for head motion sensing. The impact of artifacts due to vibration is investigate Impact: We present and characterize the first system for multiple-input multiple-output (MIMO) RF motion sensing with BPT and PT, aimed toward head motion sensing and correction at arbitrary frequencies, and simultaneous to the MRI exam.
Krahn et al. (Tue,) studied this question.