MAGnetic Resonance Invisible Coil (MAGIC) using liquid metal for Sequential PET-MRI image acquisition.

Motivation: Existing hardware techniques for reducing PET attenuation cannot eliminate the attenuation due to the MRI coil conductor and tuning capacitors during sequential PET-MRI image acquisition. Goal(s): Is eliminating the PET attenuation due to the MRI coil conductor and tuning capacitors feasible without physically removing the MRI coil from the PET FOV? Approach: Using liquid metal and manual pneumatic pumping method inject the coil conductor and tuning capacitor in the rigid coil substrate during MRI imaging and remove it during PET imaging. Results: We formed the liquid metal MRI coil and matched it to 50 ohm and removed it using manual pneumatic pumping method. Impact: PET-MRI surface array coils contain loops and/or dipoles made of copper, which attenuate the PET radiations significantly. The presented research motivated us to ask how to estimate the gain in PET attenuation reduction for the proposed coil architecture before proceeding.