Motion detection using Doppler radar: Towards subject- and organ-specific motion correction

Motivation: Limitations of existing motion-mitigation strategies continue to pose a barrier for clinical adoption of MRI in some patient groups and body regions. Goal(s): To develop an RF-based sensor that utilizes the Doppler effect to detect various types of bulk and internal body motion, operating independently from the MRI scanner. Approach: Implemented a continuous-wave Doppler radar with software-defined radio. Results: In this pilot study focusing on respiration, the developed radar sensor generated motion curves comparable to reference techniques and reduced motion blurring in abdominal MRI. Impact: Radar is a powerful tool for sensing motion. The independence from the MRI receive chain and frequency range offers advantages for detecting diverse types of motion across MR applications, body regions, and possibly even outside the scanner during interventional procedures.