Anatomical MRI templates of tree shrew brain for volumetric analysis and voxel-based morphometry

J Neurosci Methods. 2013 Oct 30;220(1):9-17. doi: 10.1016/j.jneumeth.2013.08.023. Epub 2013 Sep 4.

Abstract

Background: Tree shrews are close relatives of primates, and are increasingly used as models in the research of vision, social stress and neurological/psychiatric diseases. However, neuroimaging techniques, for example magnetic resonance (MR) imaging, are only rarely applied to this species to study the structure and function of the brain. A template MR image set, which is essential for morphometry/volumetric analysis, of tree shrew brain has been lacking in the literature.

New method: High-resolution anatomical MR images and diffusion tensor images of the brain were acquired from male Chinese tree shrews (Tupaia belangeri chinensis), and resampled to an isotropic resolution of 200 μm × 200 μm × 200 μm. Population-based image templates of tree shrew brain, including gray matter/white matter/cerebrospinal fluid probability maps and a fractional anisotropy template, were constructed at this spatial resolution, all in a reference space. Digital masks of representative anatomical structures, including hippocampus, amygdala and cingulum bundle, were created.

Result: With the templates constructed, the volumes of bilateral hippocampus and amygdala were measured using a template-facilitated semi-automated approach to be 59.8 ± 8.3 and 64.3 ± 3.4 mm(3), respectively.

Comparison with existing method(s): For the first time, high-resolution MR image templates of tree shrew brain were reported. The average volume of bilateral hippocampus measured with the template-facilitated semi-automated approach was found to be similar to the result obtained by the much more labor-intensive manual approach.

Conclusions: The MR image templates obtained in this study are useful for analyzing neuroimage data of tree shrew brain. The templates are freely available to the scientific community upon request.

Keywords: Brain; Magnetic resonance imaging; Template; Tree shrew; Volumetric measurement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anatomy, Artistic*
  • Animals
  • Atlases as Topic*
  • Brain / anatomy & histology*
  • Diffusion Tensor Imaging
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging*
  • Male
  • Tupaiidae / anatomy & histology*