<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_raon-2016-0018_s_001_w2aab3b8c57b1b7b1aab1c15b1Aa"><h3>Background</h3><p>Diffusion tensor imaging exploits preferential diffusional motion of water molecules residing within tissue compartments for assessment of tissue structural anisotropy. However, instrumentation and post-processing errors play an important role in determination of diffusion tensor elements. In the study, several experimental factors affecting accuracy of diffusion tensor determination were analyzed.</p></sec><sec id="j_raon-2016-0018_s_002_w2aab3b8c57b1b7b1aab1c15b2Aa"><h3>Materials and methods</h3><p>Effects of signal-to-noise ratio and configuration of the applied diffusion-sensitizing gradients on fractional anisotropy bias were analyzed by means of numerical simulations. In addition, diffusion tensor magnetic resonance microscopy experiments were performed on a tap water phantom and bovine articular cartilage-on-bone samples to verify the simulation results.</p></sec><sec id="j_raon-2016-0018_s_003_w2aab3b8c57b1b7b1aab1c15b3Aa"><h3>Results</h3><p>In both, the simulations and the experiments, the multivariate linear regression of the diffusion-tensor analysis yielded overestimated fractional anisotropy with low SNRs and with low numbers of applied diffusion-sensitizing gradients.</p></sec><sec id="j_raon-2016-0018_s_004_w2aab3b8c57b1b7b1aab1c15b4Aa"><h3>Conclusions</h3><p>An increase of the apparent fractional anisotropy due to unfavorable experimental conditions can be overcome by applying a larger number of diffusion sensitizing gradients with small values of the condition number of the transformation matrix. This is in particular relevant in magnetic resonance microscopy, where imaging gradients are high and the signal-to-noise ratio is low.</p></sec></abstract>

BackgroundDiffusion tensor imaging exploits preferential diffusional motion of water molecules residing within tissue compartments for assessment of tissue structural anisotropy. However, instrumentation and post-processing errors play an important role in determination of diffusion tensor elements. In the study, several experimental factors affecting accuracy of diffusion tensor determination were analyzed.Materials and methodsEffects of signal-to-noise ratio and configuration of the applied diffusion-sensitizing gradients on fractional anisotropy bias were analyzed by means of numerical simulations. In addition, diffusion tensor magnetic resonance microscopy experiments were performed on a tap water phantom and bovine articular cartilage-on-bone samples to verify the simulation results.ResultsIn both, the simulations and the experiments, the multivariate linear regression of the diffusion-tensor analysis yielded overestimated fractional anisotropy with low SNRs and with low numbers of applied diffusion-sensitizing gradients.ConclusionsAn increase of the apparent fractional anisotropy due to unfavorable experimental conditions can be overcome by applying a larger number of diffusion sensitizing gradients with small values of the condition number of the transformation matrix. This is in particular relevant in magnetic resonance microscopy, where imaging gradients are high and the signal-to-noise ratio is low.

Diffusion tensor MR microscopy of tissues with low diffusional anisotropy

TU Ilmenau, Institute of Physics, Fachgebiet Technische Physik II, Ilmenau, Germany

Jožef Stefan Institute, Ljubljana, Slovenia

Radiology and Oncology

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

{"article-title":"Diffusion tensor MR microscopy of tissues with low diffusional anisotropy"}

BackgroundDiffusion tensor imaging exploits preferential diffusional motion of water molecules residing within tissue compartments for assessment of tissue...

Diffusion tensor MR microscopy of tissues with low diffusional anisotropy

Article Category: Research Article

Published Online: Apr 03, 2016

Page range: 175 - 187

Received: Aug 27, 2015

Accepted: Feb 08, 2016

DOI: https://doi.org/10.1515/raon-2016-0018

Keywords
microscopy, diffusion tensor imaging, anisotropy, signal-to-noise ratio, cartilage

© 2016 Radiol Oncol

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Diffusion tensor MR microscopy of tissues with low diffusional anisotropy

Article Category: Research Article

Published Online: Apr 03, 2016

Page range: 175 - 187

Received: Aug 27, 2015

Accepted: Feb 08, 2016

DOI: https://doi.org/10.1515/raon-2016-0018

Keywordsmicroscopy, diffusion tensor imaging, anisotropy, signal-to-noise ratio, cartilage

© 2016 Radiol Oncol

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Keywords
microscopy, diffusion tensor imaging, anisotropy, signal-to-noise ratio, cartilage