학술지명 : IBRO (International Brain Research Organization)
The pathology of Parkinson’s disease (PD) involves the
death of dopaminergic neurons in the substantia nigra (SN), which slowly
influences downstream basal ganglia pathways as dopamine transport diminishes.
Diffusion magnetic resonance imaging (MRI) has been used to diagnose PD by
assessing white matter connectivity in some brain areas. For this study, we
applied Lead-DBS to human connectome project data to automatically segment 11
subcortical structures of 49 human connectome project subjects, reducing the
reliance on manual segmentation for more consistency. The Lead-connectome
pipeline, which utilizes DSI Studio to generate structural connectomes from
each 3T and 7T diffusion image, was applied to 3T and 7T data to investigate
possible differences in diffusion measures due to different acquisition
protocols. Significantly higher fractional anisotropy (FA) values were found in
the 3T left SN; significantly higher MD values were found in the 3T left SN and
the right amygdala, SN, and subthalamic nucleus (STN); significantly higher AD
values were found in the right RN and STN; and significantly higher RD values
were found in the left RN and right amygdala. Additionally, connectivity
between ROIs showed more significant increases in FA, MD, and QA in 3T diffusion
images when compared with 7T diffusion images. At the time of acquiring 3T and
7T data, 7T scanners were relatively new compared to 3T scanners, meaning that
there was little time for the project to experiment with custom hardware or
protocols to optimize 7T protocols. Maximizing the spatial resolution of
diffusion imagers is crucial to minimize voxels containing multiple fiber
orientations, making acquisitions with higher field strengths to generate the
accurate connectome possible. We illustrate a methodology for obtaining
diffusion measures of basal ganglia and basal ganglia connectivity using
diffusion images, as well as show possible differences in diffusion measures
that can arise due to the differences in MRI acquisitions.