Sharper MRI scans may be on horizon thanks to new physics-based model

Summary

Walter Chapman and Thiago Pinheiro discuss a molecular model of their research. Researchers at Rice University and Oak Ridge National Laboratory have unveiled a physics-based model of magnetic resonance relaxation that bridges molecular-scale dynamics with macroscopic magnetic resonance imaging (MRI) signals, promising new insight into how contrast agents interact with water molecules. This advancement paves the way for sharper medical imaging and safer diagnostics using MRI. The study was published in The Journal of Chemical Physics Nov. 12. This new approach, known as the NMR eigenmodes framework, solves the full physical equations that can be used to interpret how water molecules relax around metal-based imaging agents, a task that previous models approximated. These findings could alter the development and application of new contrast agents in both medicine and materials science. “By better modeling the physics of nuclear magnetic resonance relaxation in liquids, we gain a tool that doesn’t just predict but also explains the phenomenon,” said Walter Chapman, the William W. Akers Professor of Chemical and Biomolecular Engineering. “That is crucial when lives and technologies depend on accurate scientific understanding.” Modeling a molecular process During an MRI scan, contrast agents are often used to enhance image clarity. These agents, typically based on a gadolinium ion encased in an organic shell, alter the way nearby water molecules respond to magnetic fields. This alteration, known as relaxation, enhances the contrast in tissue images. Until now, most scientific models describing this process have relied on significant simplifications, treating complex molecular motions with limited fidelity to the real system’s behavior, which limited their predictive accuracy. The researchers sought to improve upon this. “Our previous work used detailed simulations to study how water molecules interact with these contrast agents,” said Dilipkumar Asthagiri, a senior compu...