Respiratory Triggered MRI using an NMR-on-a-chip Sensor

Motivation: We propose an NMR-on-a-chip sensor as contactless und hysteresis-free alternative for conventional respiratory belts in respiratory-triggered MRI. Goal(s): The objective of this work was to demonstrate the feasibility of a local field probe for monitoring respiratory motion induced magnetic field changes as respiratory motion surrogate. Approach: Respiratory belt and field probe signal were recorded simultaneously clearly showing the accurate identification of the respiratory stage by the field probe. Results: The field probe signal was analysed and fed back to the MR scanner in real-time for proofing its applicability for triggered lung MRI, yielding a sharp lung-liver interface compared with the non-triggered version. Impact: The feasibility of NMR-on-a-chip sensors for monitoring physiologically-induced magnetic field variations is shown. They enable contactless, hysteresis-free and easy-to-use monitoring of physiologically-induced field variations, which can be fed back to the scanner for real-time respiratory motion monitoring and triggering.