Improving Signal‐to‐Noise Ratio of 1.5T MRI Scans Using High‐Q Resonators Based on Coupled Octa‐Spirals

Abstract

Metamaterials or metamaterial‐inspired structures/resonators have yielded significant advancement in the imaging capabilities of Magnetic Resonance Imaging (MRI) by boosting its performance parameter, i.e., signal‐to‐noise ratio (SNR). Metamaterials have a distinctive ability to boost and redistribute magnetic fields inside the subject undergoing scan when integrated as accessories between receive arrays and the subject. However, the translation of most reported metamaterials into a clinical accessory is still limited and challenging due to their low sensitivity, sub‐optimal performance, and bulky footprints for integration inside MRI scanners. Herein, a metamaterial‐inspired structure is developed using coupled octa‐spiral resonators to boost magnetic field localization inside the scanned region. In addition, the high‐Q resonance of the metamaterial‐inspired structure improves impedance matching and enhances the transmit/receive efficiency of MRI coils. Theoretical analysis of electromagnetic responses and full‐wave simulations show a homogeneous boost in SNR by over times throughout a human‐properties mimicking phantom using the resonator with a maximum SNR enhancement factor (EF) of . The spatial distribution of SNR EF inside the phantom is also validated by preliminary laboratory experiments. Thus, the developed coupled octa‐spirals resonator can pave the way for developing and adopting metamaterial‐inspired devices as clinical accessories for facilitating better, faster, and cost‐effective MRI scans.