Influence of Age on Global and Regional Brain Stiffness in Young and Middle-Aged Adults

Abstract

Background: An understanding of potential age-related changes in brain stiffness and its regional variation is important for further clinical application of MR elastography.

Purpose: To investigate the effect of age on global and regional brain stiffness in young and middle-aged adults.

Study type: Prospective.

Subjects: Fifty subjects with normal brains and aged in their 20s, 30s, 40s, 50s, or 60s (five men, five women per decade).

Field strength/sequence: 3.0T MRI and elastography with a vibration frequency of 60 Hz.

Assessment: Stiffness was measured in nine brain regions (cerebrum, temporal lobes, sensorimotor areas, frontotemporal composite region, deep gray matter and white matter (deep GM/WM), parietal lobes, occipital lobes, frontal lobes, and cerebellum) using an atlas-based region-of-interest approach. The influence of age on regional brain stiffness was evaluated.

Statistical tests: Multiple linear regression analysis, followed by Dunnett's multiple comparisons test, using subjects in their 20s as controls.

Results: Following adjustment for sex, multiple linear regression revealed a significant negative correlation between age and stiffness of the cerebrum (P < 0.0001), temporal lobes (P < 0.0001), sensorimotor areas (P < 0.0001), frontotemporal composite region (P < 0.0001), deep GM/WM (P = 0.0028), parietal lobes (P < 0.0001), occipital lobes (P = 0.0055), and frontal lobes (P < 0.0001). Dunnett's multiple comparison test showed that the stiffness of the sensorimotor areas, frontotemporal composite region, and frontal lobes was significantly decreased in subjects in their 40s (P < 0.0367), 50s (P < 0.0001), and 60s (P < 0.0001), while that of the cerebrum, temporal lobes, and parietal lobes was significantly decreased only in subjects in their 50s (P < 0.0012) and 60s (P < 0.0031) when compared with the controls.

Data conclusion: There is an age-related decrease in brain stiffness that varies across the different regions.

Level of evidence: 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:727-733.

Keywords: age-related; brain stiffness; global; magnetic resonance elastography; magnetic resonance imaging; regional.