Crossing fibers, diffractions and nonhomogeneous magnetic field

correction of artifacts by bipolar gradient pulses

Amnon Bar-Shir, Yoram Cohen

Research output: Contribution to journalArticle

Abstract

In recent years, diffusion tensor imaging (DTI) and its variants have been used to describe fiber orientations and q-space diffusion MR was proposed as a means to obtain structural information on a micron scale. Therefore, there is an increasing need for complex phantoms with predictable microcharacteristics to challenge different indices extracted from the different diffusion MR techniques used. The present study examines the effect of diffusion pulse sequence on the signal decay and diffraction patterns observed in q-space diffusion MR performed on micron-scale phantoms of different geometries and homogeneities. We evaluated the effect of the pulse gradient stimulated-echo, the longitudinal eddy current delay (LED) and the bipolar LED (BPLED) pulse sequences. Interestingly, in the less homogeneous samples, the expected diffraction patterns were observed only when diffusion was measured with the BPLED sequence. We demonstrated the correction ability of bipolar diffusion gradients and showed that more accurate physical parameters are obtained when such a diffusion gradient scheme is used. These results suggest that bipolar gradient pulses may result in more accurate data if incorporated into conventional diffusion-weighted imaging and DTI.

Original languageEnglish (US)
Pages (from-to)801-808
Number of pages8
JournalMagnetic Resonance Imaging
Volume26
Issue number6
DOIs
StatePublished - Jul 2008
Externally publishedYes

Fingerprint

Magnetic Fields
Artifacts
artifacts
Diffraction
Magnetic fields
gradients
fibers
Fibers
pulses
diffraction
magnetic fields
Diffusion tensor imaging
Diffusion Tensor Imaging
Eddy currents
Diffraction patterns
eddy currents
diffraction patterns
tensors
Fiber reinforced materials
fiber orientation

Keywords

  • Bipolar diffusion gradients
  • Crossing fibers
  • Diffraction patterns
  • Diffusion MRS
  • Fiber direction
  • q-Space diffusion

ASJC Scopus subject areas

  • Biophysics
  • Clinical Biochemistry
  • Structural Biology
  • Radiology Nuclear Medicine and imaging
  • Condensed Matter Physics

Cite this

Crossing fibers, diffractions and nonhomogeneous magnetic field : correction of artifacts by bipolar gradient pulses. / Bar-Shir, Amnon; Cohen, Yoram.

In: Magnetic Resonance Imaging, Vol. 26, No. 6, 07.2008, p. 801-808.

Research output: Contribution to journalArticle

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