Structural anisotropy and internal magnetic fields in trabecular bone: coupling solution and solid dipolar interactions.

Journal Article (Journal Article)

We investigate the use of intermolecular multiple-quantum coherence to probe structural anisotropy in trabecular bone. Despite the low volume fraction of bone, the bone-water interface produces internal magnetic field gradients which modulate the dipolar field, depending on sample orientation, choice of dipolar correlation length, correlation gradient direction, and evolution time. For this system, the probing of internal magnetic field gradients in the liquid phase permits indirect measurements of the solid phase dipolar field. Our results suggest that measurements of volume-averaged signal intensity as a function of gradient strength and three orthogonal directions could be used to non-invasively measure the orientation of structures inside a sample or their degree of anisotropy. The system is modeled as having two phases, solid and liquid (bone and water), which differ in their magnetization density and magnetic susceptibility. A simple calculation using a priori knowledge of the material geometry and distribution of internal magnetic fields verifies the experimental measurements as a function of gradient strength, direction, and sample orientation.

Full Text

Duke Authors

Cited Authors

  • Bouchard, L-S; Wehrli, FW; Chin, C-L; Warren, WS

Published Date

  • September 2005

Published In

Volume / Issue

  • 176 / 1

Start / End Page

  • 27 - 36

PubMed ID

  • 15953742

Electronic International Standard Serial Number (EISSN)

  • 1096-0856

International Standard Serial Number (ISSN)

  • 1090-7807

Digital Object Identifier (DOI)

  • 10.1016/j.jmr.2005.05.012


  • eng