Localized Shims Enable Low-Field Simultaneous Multinuclear NMR Spectroscopy

This Article introduces a smart localized shimset, integrated with a radiofrequency (RF) microsolenoid and optimized as a single unit to locally achieve high-resolution NMR spectroscopy, as a significant advancement toward achieving parallel NMR spectroscopy. The shimset, consisting exclusively of linear shims, demonstrates the capability to improve NMR line width from 84 to 4 Hz in a 1.05 T preclinical MRI scanner. This enhancement enables the resolution of j-couplings in the sample while requiring a total power of 545 mW. Furthermore, a novel method is presented for concurrently obtaining multinuclear NMR spectra using a single RF channel. This approach allows for the utilization of high-sensitivity NMR signals as a reference to correct field drift, facilitating signal averaging in a permanent magnet NMR scanner that is prone to significant temperature-dependent drift.