Hyperpolarized 3He microspheres as a novel vascular signal source for MRI.

Journal Article

Hyperpolarized (HP) 3He can be encapsulated within biologically compatible microspheres while retaining sufficient polarization to be used as a signal source for MRI. Two microsphere sizes were used, with mean diameters of 5.3 +/- 1.3 microm and 10.9 +/- 3.0 microm. These suspensions ranged in concentration from 0.9-7.0% gas by volume. Spectroscopic measurements in phantoms at 2 T yielded 3He relaxation times that varied with gas concentration. At the highest 3He concentration, the spinlattice relaxation time, T1, was 63.8 +/- 9.4 sec, while the transverse magnetization decayed with a time constant of T2* = 11.0 +/- 0.4 msec. In vivo MR images of the pelvic veins in a rat were acquired during intravenous injection of 3He microspheres (SNR approximately equal 15). Advantages such as intravascular confinement, lack of background signal, and limited recirculation indicate quantitative perfusion measurements may be improved using this novel signal source.

Full Text

Duke Authors

Cited Authors

  • Chawla, MS; Chen, XJ; Cofer, GP; Hedlund, LW; Kerby, MB; Ottoboni, TB; Johnson, GA

Published Date

  • March 2000

Published In

Volume / Issue

  • 43 / 3

Start / End Page

  • 440 - 445

PubMed ID

  • 10725887

International Standard Serial Number (ISSN)

  • 0740-3194

Language

  • eng

Conference Location

  • United States