Dynamics of magnetization in hyperpolarized gas MRI of the lung.

Journal Article (Journal Article)

The magnetization in hyperpolarized gas (HP) MRI is generated by laser polarization that is independent of the magnet and imaging process. As a consequence, there is no equilibrium magnetization during the image acquisition. The competing processes of gas inflow and depolarization of the spins lead to large changes in signal as one samples k-space. A model is developed of dynamic changes in polarization of hyperpolarized 3He during infusion and in vivo imaging of the lung and verified experimentally in a live guinea pig. Projection encoding is used to measure the view-to-view variation with temporal resolution < 4 ms. Large excitation angles effectively sample the magnetization in the early stages of inflow, highlighting larger airways, while smaller excitation angles produce images of the more distal spaces. The work provides a basis for pulse sequences designed to effectively exploit HP MRI in the lung.

Full Text

Duke Authors

Cited Authors

  • Johnson, GA; Cates, G; Chen, XJ; Cofer, GP; Driehuys, B; Happer, W; Hedlund, LW; Saam, B; Shattuck, MD; Swartz, J

Published Date

  • July 1997

Published In

Volume / Issue

  • 38 / 1

Start / End Page

  • 66 - 71

PubMed ID

  • 9211381

International Standard Serial Number (ISSN)

  • 0740-3194

Digital Object Identifier (DOI)

  • 10.1002/mrm.1910380111


  • eng

Conference Location

  • United States