Two‐step anomalous diffusion tensor imaging
- 3 August 2011
- journal article
- research article
- Published by Wiley in NMR in Biomedicine
- Vol. 25 (2) , 286-294
Abstract
We extend the formalism of anomalous diffusion imaging to include directional anisotropy of fitted parameters. The resulting technique is termed anomalous diffusion tensor imaging (aDTI), and allows the directional properties of the distributed diffusion coefficient (α) and the anomalous diffusion exponent, (γ) to be analysed using the same analytical techniques as regular diffusion tensor imaging (DTI). Together, these parameters quantify the rate of diffusion (α) and the complexity of the diffusion environment (γ).We generated tensor images for the anomalous exponent tensor (Γ) and distributed diffusivity tensor (A) from in vivo human brain data and present images of eigenvalues, eigenvectors, Trace/3 (Tr), fractional anisotropy (FA) and tensor shape measures. In white matter, A is found to have a median Tr = 0.56 × 10− 3mm2s− 1, FA = 0.58 and Γ Tr = 0.69, FA = 0.13.We observed that white matter shows a similar anisotropic geometry for the distributed diffusion tensor as for the regular diffusion tensor, whereas the anomalous exponent tensor exhibits a different shape characteristic which may be informative of tissue microstructure. Copyright © 2011 John Wiley & Sons, Ltd.Keywords
Funding Information
- St. George's Healthcare National Health Service (NHS) Trust (EP/E0596938/1)
- EPSRC
This publication has 21 references indexed in Scilit:
- Studies of anomalous diffusion in the human brain using fractional order calculusMagnetic Resonance in Medicine, 2010
- Biexponential analysis of diffusion-related signal decay in normal human cortical and deep gray matterMagnetic Resonance Imaging, 2008
- From diffusion‐weighted MRI to anomalous diffusion imagingMagnetic Resonance in Medicine, 2008
- Water diffusion heterogeneity index in the human brain is insensitive to the orientation of applied magnetic field gradientsMagnetic Resonance in Medicine, 2006
- Three‐dimensional characterization of non‐gaussian water diffusion in humans using diffusion kurtosis imagingNMR in Biomedicine, 2006
- Diffusional kurtosis imaging: The quantification of non‐gaussian water diffusion by means of magnetic resonance imagingMagnetic Resonance in Medicine, 2005
- Characterization of continuously distributed cortical water diffusion rates with a stretched‐exponential modelMagnetic Resonance in Medicine, 2003
- Statistical model for diffusion attenuated MR signalMagnetic Resonance in Medicine, 2003
- An analytical model of restricted diffusion in bovine optic nerveMagnetic Resonance in Medicine, 1997
- Toward a quantitative assessment of diffusion anisotropyMagnetic Resonance in Medicine, 1996