Acute ex vivo changes in brain white matter diffusion tensor metrics

Autoři: Matthew R. Walker aff001;  Jidan Zhong aff002;  Adam C. Waspe aff003;  Thomas Looi aff003;  Karolina Piorkowska aff003;  James M. Drake aff001;  Mojgan Hodaie aff001
Působiště autorů: Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada aff001;  Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada aff002;  Centre for Image Guided Innovation and Therapeutic Intervention, Hospital for Sick Children, Toronto, Ontario, Canada aff003;  Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada aff004;  Division of Neurosurgery, Hospital for Sick Children, Toronto, Ontario, Canada aff005;  Division of Neurosurgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada aff006
Vyšlo v časopise: PLoS ONE 14(9)
Kategorie: Research Article
doi: 10.1371/journal.pone.0223211



Diffusion magnetic resonance imaging and tractography has an important role in the visualization of brain white matter and assessment of tissue microstructure. There is a lack of correspondence between diffusion metrics of live tissue, ex vivo tissue, and histological findings. The objective of this study is to elucidate this connection by determining the specific diffusion alterations between live and ex vivo brain tissue. This may have an important role in the incorporation of diffusion imaging in ex vivo studies as a complement to histological sectioning as well as investigations of novel neurosurgical techniques.


This study presents a method of high angular resolution diffusion imaging and tractography of intact and non-fixed ex vivo piglet brains. Most studies involving ex vivo brain specimens have been formalin-fixed or excised from their original biological environment, processes both of which are known to affect diffusion parameters. Thus, non-fixed ex vivo tissue is used. A region-of-interest based analysis of diffusion tensor metrics are compared to in vivo subjects in a selection of major white matter bundles in order to assess the translatability of ex vivo diffusion measurements.


Tractography was successfully achieved in both in vivo and ex vivo groups. No significant differences were found in tract connectivity, average streamline length, or apparent fiber density. Significantly decreased diffusivity (mean, axial, and radial; p<0.0005) in the non-fixed ex vivo group and unaltered fractional anisotropy (p>0.059) between groups were observed.


This study validates the extrapolation of non-fixed fractional anisotropy measurements to live tissue and the potential use of ex vivo tissue for methodological development.

Klíčová slova:

Central nervous system – Diffusion magnetic resonance imaging – Diffusion tensor imaging – Nerve fibers – Swine – Tractography – Anisotropy – corpus callosum


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