Effect of gradient pulse duration on MRI estimation of the diffusional kurtosis for a two-compartment exchange model

J Magn Reson. 2011 Jun;210(2):233-7. doi: 10.1016/j.jmr.2011.03.012. Epub 2011 Mar 17.

Abstract

Hardware constraints typically require the use of extended gradient pulse durations for clinical applications of diffusion-weighted magnetic resonance imaging (DW-MRI), which can potentially influence the estimation of diffusion metrics. Prior studies have examined this effect for the apparent diffusion coefficient. This study employs a two-compartment exchange model in order to assess the gradient pulse duration sensitivity of the apparent diffusional kurtosis (ADK), a quantitative index of diffusional non-Gaussianity. An analytic expression is derived and numerically evaluated for parameter ranges relevant to DW-MRI of brain. It is found that the ADK differs from the true diffusional kurtosis by at most a few percent. This suggests that ADK estimates for brain may be robust with respect to changes in pulse gradient duration.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain Mapping / methods*
  • Diffusion Magnetic Resonance Imaging / methods*
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Models, Theoretical