Comparison ofSeveralWhiteMatterTracts inFeline andCanineBrain byUsingMagneticResonanceDiffusionTensorImaging

Abstract

Recently, we published a first anatomical diffusion tensor imaging (DTI) atlas regarding white matter tracts in the canine brain. The purpose of this study was to show the significance of DTI in the revelation of the white matter fibres in the feline brain (i.e., to obtain an anatomical DTI atlas of images) and to descriptively compare these to previously obtained white matter fibre images of the canine brain. DTI MR Images of four cats euthanized for reasons other than neurological disorders were obtained with a 3 T system. Combined fractional anisotropic (FA) and directional maps were obtained within the hour after death. An experienced anatomist tracked white matter tracts of clinical relevance using the scanner software. After validation of these tracts, we compared relevant neurological connections between the cat and the dog. Comparison of cerebral structures between different species is easier when the three dimensional anatomy is visualized by using DTI. 3D rendered DTI images clearly show major differences in neurological architecture between cats and dogs for example, the more important space occupying role of the limbic system, and the less diffuse, less nodular, less pronounced and thinner fibre bundles in the feline brain compared to the canine brain (except for the cerebellum different parts connecting fibres passing through the brainstem which are pronouncedly developed). Anat Rec, 300:1270-1289, 2017. © 2017 Wiley Periodicals, Inc.

Stereotaxic Diffusion Tensor Imaging White Matter Atlas for the in vivo Domestic Feline Brain

“…dissected pathways (right; mean 49.6 ± 6.2 mm and left; mean 47.7 ± 7.7 mm; Table 1). The structure of the CST is similar to that observed in other tractography descriptions (Dai et al, 2016;Jacqmot et al, 2017).…”

“…The fibers are in close relation to the cerebral ventricles in multiple section planes. The structure of the fornix identified is consistent with that dissected anatomically and described with tractography (Dai et al, 2016;Jacqmot et al, 2017;Pascalau et al, 2018).…”

“…White matter tract reconstructions were performed using the FACT algorithm (Mori et al, 1999) with a step length of 0.5 mm and angle threshold of 35 • in TrackVis (Wang et al, 2007) within a binary brain mask. The ROI seed placement adapted from that described by Catani and Thiebaut de Schotten (2008) and feline tractography descriptions (Dai et al, 2016;Jacqmot et al, 2017). Seed regions were delineated on the FA maps and once tracts were generated obvious spurious tracts were removed.…”

“…Both these forms of tractography have been used to create functional white matter brain maps that are routinely used, in the human, rhesus macaque, rat, mouse, dog and ferret research (Mori et al, 2008;Jiang and Johnson, 2011;Rumple et al, 2013;Zakszewski et al, 2014;Calabrese et al, 2015;Robinson et al, 2016;Hutchinson et al, 2017). Tractography techniques have been used to document the anatomy of feline white matter tracts (Jacqmot et al, 2017) and evaluate the development and regional variation of white matter in the juvenile feline brain (Takahashi et al, 2009;Dai et al, 2016). These articles have provided information on the location and diffusivity characteristics of several pathways; however, these previous articles do not compare in vivo tract reconstructions with ex vivo gross anatomic dissection.…”

The use of diffusion tractography to characterize a corpus callosum malformation in a dog

“…Tractography has been used to document white matter projections in the normal canine brain and specifically to segment and delineate the CC, but this technique has not yet been applied in the evaluation of white matter malformations . To date in the dog, CCM has only been diagnosed using standard structural MRI sequences, limiting our ability to determine the exact malformations present .…”