Internal gradient distributions: A susceptibility-derived tensor delivering morphologies by magnetic resonance.
Gonzalo A ÁlvarezNoam ShemeshLucio FrydmanPublished in: Scientific reports (2017)
Nuclear magnetic resonance is a powerful tool for probing the structures of chemical and biological systems. Combined with field gradients it leads to NMR imaging (MRI), a widespread tool in non-invasive examinations. Sensitivity usually limits MRI's spatial resolution to tens of micrometers, but other sources of information like those delivered by constrained diffusion processes, enable one extract morphological information down to micron and sub-micron scales. We report here on a new method that also exploits diffusion - isotropic or anisotropic- to sense morphological parameters in the nm-mm range, based on distributions of susceptibility-induced magnetic field gradients. A theoretical framework is developed to define this source of information, leading to the proposition of internal gradient-distribution tensors. Gradient-based spin-echo sequences are designed to measure these new observables. These methods can be used to map orientations even when dealing with unconstrained diffusion, as is here demonstrated with studies of structured systems, including tissues.
Keyphrases
- magnetic resonance
- contrast enhanced
- diffusion weighted
- high resolution
- magnetic resonance imaging
- single molecule
- diffusion weighted imaging
- health information
- gene expression
- high glucose
- computed tomography
- oxidative stress
- diabetic rats
- healthcare
- molecular dynamics simulations
- room temperature
- anti inflammatory
- high density
- case control
- transition metal
- solid state
- light emitting