Frequency Selective Flux Focusing Passive Lenz Resonators for Substantial MRI Signal-to-Noise Ratio Amplification

Motivation: Despite numerous developments since MRI’s invention, low sensitivity remains the main limitation. Goal(s): We aimed to improve upon the Lenz lens design for passive signal amplification in MRI, ultimately improving the signal-to-noise ratio. Approach: We created a first-in-kind Lenz resonator, a passive frequency selective flux-focusing circuit, to isolate and enhance the signal from a desired nucleus. Results: Performing RF testing with a vector network analyzer there was a 60 times signal amplification for the proton resonance frequency. At 3.0T, MRI demonstrated an experimental amplification of the signal-to-noise ratio by 3.9 times using an MRI insert of two coaxial Lenz resonators. Impact: The substantial SNR boost produced by our Lenz resonators has a paramount importance for the field of MRI. The superior increase in SNR allows quicker scans, higher resolution scans, and precise disease detection.