Normal diffusivity of the domestic feline brain

• Published in: Journal of comparative neurology (1911) Vol. 527; no. 5; pp. 1012 - 1023
• Main Authors: Barry, Erica F., Cerda‐Gonzalez, Sofia, Luh, Wen‐Ming, Daws, Richard E., Raj, Ashish, Johnson, Philippa J.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.04.2019; Wiley Subscription Services, Inc
• Subjects: Anatomy; Anisotropy; automated parcellation; Brain architecture; CATLAS; Cerebellum; Data processing; diffusion tensor imaging; DTI; Felis catus; Magnetic resonance imaging; Mesencephalon; Neuroimaging; NMR; Nuclear magnetic resonance; Substantia alba; Thalamus; DTI; diffusion tensor imaging; Felis catus; automated parcellation; CATLAS
• ISSN: 0021-9967; 1096-9861
• DOI: 10.1002/cne.24553

Diffusion magnetic resonance imaging (MRI) provides useful information about neuroanatomy and improves detection of neuropathology. As yet, a comprehensive evaluation of the diffusivity parameters within the feline brain has not been documented. In this study, we anesthetized and performed in vivo MRI on the brain of eight neurologically normal felines. A T1‐weighted structural sequence with a resolution of 0.5 mm3 and a parallel diffusion weighted sequence with 61 directions and a resolution of 1.5 mm3 was obtained. After correction and processing the diffusion brain data were parcellated into 151 regions of interest using previously published priors. These regions were grouped according to their lobar location within the brain (frontal, occipital, temporal, parietal, thalamus, midbrain, cerebellum, and white matter). The mean and standard deviation of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for these 151 individual regions and lobar groups were calculated and averaged across participants, creating a comprehensive distribution range of diffusion tensor values. When regions were statistically evaluated, white matter had significantly higher FA and RD and lower AD and MD diffusivity parameters when compared to other regions. Additionally, thalamic regions had significantly higher FA values than parietal and occipital regions. This information will not only help inform feline neuroanatomy but also will serve as a reference standard for future feline neuroimaging studies. The novel advanced neuroimaging technique of diffusion tractography is used to characterize the morphology of a corpus callosum malformation and compared with the white matter anatomy of a normal control brain. This technique characterized the malformation in high anatomical detail and identified a lack of interhemispheric crossing fibers through the rostral corpus callosum and formation of longitudinal callosal fasciculi (Probst bundles).