Deterministic Tractography Analysis of Rat Brain Using SIGMA Atlas in 9.4T MRI

Abstract

Preclinical studies using rodents have been the choice for many neuroscience researchers due totheir close reflection of human biology. In particular, research involving rodents has utilized MRI to accurately identify brain regions and characteristics by acquiring high resolution cavity images with different contrasts non-invasively, and this has resulted in high reproducibility and throughput. In addition, tractographic analysis using diffusion tensor imaging to obtain information on the neural structure of white matter has emerged as a major methodology in the field of neuroscience due to its contribution in discovering significant correlations between altered neural connections and various neurological and psychiatric diseases. However, unlike image analysis studies with human subjects where a myriad of human image analysis programs and procedures have been thoroughly developed and validated, methods for analyzing rat image data using MRI in preclinical research settings have seen significantly less developed. Therefore, in this study, we present a deterministic tractographic analysis pipeline using the SIGMA atlas for a detailed structural segmentation and structural connectivity analysis of the rat brain’s structural connectivity. In addition, the structural connectivity analysis pipeline presented in this study was preliminarily tested on normal and stroke rat models for initial observation.

Diffusion tensor imaging reveals sex differences in pain sensitivity of rats

“…Subsequently, all data were linearly registered and spatially normalized into SIGMA space using FMRIB's Linear Image Registration Tool function (Barrière et al, 2019). DTI data were denoised using MRtrix3 and corrected for distortions and motion artifacts using the eddy-correct tool in FSL (Im et al, 2021).…”