Abstract
Objective:
To study the effects of aging and gender on the cortical thickness on a large diverse data.
Background:
Cortical thickness (CTH) has been intricately linked to the pathogenesis of various neurodegenerative diseases. The assessment of CTH via Magnetic Resonance Imaging indicates that reductions in CTH exhibit a robust correlation with the severity of clinical impairment making it a promising avenue for further exploration. This study investigates inter and intra-group variations in CTH, seeking to understand the consistency of gender differences in different ethnicities.
Design/Methods:
The study included 8,624 participants (53% male, 47% female) aged 18–97, with uniform data collection across two sites using Siemens scanners to reduce scanner-related biases. Our cohort comprised 57.48% Caucasian, 15.11% Mixed, 8.62% Asian, 6.54% South Asian and 12.25% other ethnic categories.
CTH measurements utilized a deep learning method, fastCSR, trained on T1-mprage acquired at 1.5T with FreeSurfer-v6.0 serving as the ground truth. Our approach reduced processing time to 35-mins from 8-hours making it suitable for large-scale analysis. Linear regression was employed to analyze the trends in the dataset.
Results:
CTH in the human-brain varies systematically, showing gender-related differences, with females generally having thicker cortices than males. These differences may stem from inherent sex-linked genetic-traits and the influence of gender-related cultural/environmental factors during development. When ethnicity-related factors were considered, this CTH pattern held true across most ethnic groups, except for South-Asians, where no gender-related CTH difference was found. Analyzing CTH variations within brain substructures revealed that the entorhinal, insula, and inferior temporal-cortex had thicker cortices, while the pericalcarine, cuneous, and postcentral-cortex had thinner cortices for all groups. Additionally, a linear-regression analysis demonstrated an annual CTH decrease of 0.36%, with females experiencing a slightly higher rate of CTH thinning (0.4%) compared to males (0.32%).
Conclusions:
Study finds systematic CTH variations by gender, with females experiencing a slightly faster decline in thickness.
