Expandable Transmission Line Resonators for Intraventricular 19F MRI

Motivation: 19F-MRI can be used to monitor immune cell response to myocardial infarction, yet the low signal-to-noise ratio in the myocardium must be compensated by long measurement times and low spatial resolution. Goal(s): To enable high spatial and temporal resolution 19F-MRI using an intraventricular expanding RF coil that can be introduced via a catheter. Approach: A superelastic, self-resonant shielded-loop-resonator was developed to fit into a guiding catheter and the SNR was measured for different coil shapes. Results: The expandable coil does not require re-tuning even at extreme shape deformations, and it can even be used as an active marker for real time 1H guidance. Impact: Intraventricular MRI of 19F-labeled immune cells will enable effective monitoring at myocardial infarction after fluorine labeling. The expandable SLR coil can be inserted via guiding catheters and used as 1H tracking coil without tuning or additional adjustments.