Multiple-quantum vector field imaging by magnetic resonance.

Published

Journal Article

We introduce a method for non-invasively mapping fiber orientation in materials and biological tissues using intermolecular multiple-quantum coherences. The nuclear magnetic dipole field of water molecules is configured by a CRAZED sequence to encode spatial distributions of material heterogeneities. At any given point r in space, we obtain the spherical coordinates of fiber orientation (theta,phi) with respect to the external field by comparing three signals ||G(X)||, ||(Y)||, and ||G(Z)|| (modulus), acquired with linear gradients applied along the X, Y, and Z axes, respectively. For homogeneous isotropic materials, a subtraction ||G(Z)|| - ||G(X)|| - ||G(Y)|| gives zero. With anisotropic materials, we find an empirical relationship relating ||G(Z)|| - ||G(X)|| - ||G(Y)||/(||G(X)|| + ||G(Y)|| + ||G(Z)||) to the polar angle theta, while ||G(X|| - ||G(Y)||/(||G(X)|| + ||G(Y)|| + ||G(Z)||) is related to the azimuthal angle phi. Experiments in structured media confirm the structural sensitivity. This technique can probe length scales not accessible by conventional MRI and diffusion tensor imaging.

Full Text

Duke Authors

Cited Authors

  • Bouchard, L-S; Warren, WS

Published Date

  • November 2005

Published In

Volume / Issue

  • 177 / 1

Start / End Page

  • 9 - 21

PubMed ID

  • 16087374

Pubmed Central ID

  • 16087374

Electronic International Standard Serial Number (EISSN)

  • 1096-0856

International Standard Serial Number (ISSN)

  • 1090-7807

Digital Object Identifier (DOI)

  • 10.1016/j.jmr.2005.06.019

Language

  • eng