Frontiers in Neurology (Jan 2015)

lop-DWI: A Novel Scheme for Pre-Processing of Diffusion Weighted Images in the Gradient Direction Domain

  • Farshid eSepehrband,
  • Farshid eSepehrband,
  • Jeiran eChoupan,
  • Jeiran eChoupan,
  • Emmanuel eCaruyer,
  • Nyoman Dana Kurniawan,
  • Yaniv eGal,
  • Quang M Tieng,
  • Katie eMcMahon,
  • Viktor eVegh,
  • David C Reutens,
  • Zhengyi eYang,
  • Zhengyi eYang

DOI
https://doi.org/10.3389/fneur.2014.00290
Journal volume & issue
Vol. 5

Abstract

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We describe and evaluate a pre-processing method based on a periodic spiral sampling of diffusion gradient directions for high angular resolution diffusion magnetic resonance imaging. Our pre-processing method incorporates prior knowledge about the acquired diffusion-weighted signal, facilitating noise reduction. Periodic spiral sampling of gradient direction encodings results in an acquired signal in each voxel that is pseudo periodic with characteristics that allow separation of low-frequency signal from high frequency noise. Consequently, it enhances local reconstruction of the orientation distribution function used to define fibre tracks in the brain. Denoising with periodic spiral sampling was tested using synthetic data and in vivo human brain images. The level of improvement in signal-to-noise ratio and in the accuracy of local reconstruction of fibre tracks was significantly improved using our method.

Keywords