Association between cognitive function and relaxation rates of the cerebral cortex

Abstract

Objective: We aimed to elucidate the correlation between cognitive function and relaxation rates of the cerebral cortex in the early stages of cognitive decline.

Methods: Brain MRI was performed on 97 community-dwelling elderly participants aged 65-84 years. R1 (1/T1) and R2 (1/T2) maps were obtained with synthetic MRI (SyMRI). Cognitive function was evaluated using the Japanese version of the Montreal Cognitive Assessment (MoCA). Participants were categorized into mild cognitive impairment (n = 47) and healthy control (n = 50) groups. Voxel-based quantification (VBQ) and voxel-based morphometry (VBM) analyses were conducted using two-sample t-tests and multiple regression models, with age and sex as covariates.

Results: VBQ revealed a significant negative correlation between R1 values and MoCA visuospatial/executive score in the bilateral frontal pole and left superior frontal gyrus (family-wise error-corrected p < 0.05). No significant correlations were found between R2 values and visuospatial/executive score. The multiple regression analysis for VBM showed no significant correlations, and the two-sample t-tests for both VBQ and VBM revealed no significant group differences.

Conclusion: Visuospatial/executive impairment correlated with higher R1 and R2 values in the frontal cortex, suggesting their potential as biomarkers for early cognitive decline.

Keywords: Mild cognitive impairment; Relaxation rates; Synthetic MRI; Visuospatial/executive function; Voxel-based quantification.