Bi-phase age-related brain gray matter magnetic resonance T1rho relaxation time change

TL;DR

This study characterizes how brain gray matter T1rho relaxation times change with age, revealing a bi-phase pattern with significant differences before and after age 40.

Contribution

It provides the first detailed analysis of age-related T1rho changes in gray matter, highlighting a bi-phase pattern in adults aged 22-68 years.

Findings

T1rho values decrease with age in individuals under 40.

No significant correlation between T1rho and age after 40.

Regional differences in T1rho among gray matter areas.

Abstract

Objectives: To investigate normative value and age-related change of brain magnetic resonance T1rho relaxation at 1.5 T. Methods: 20 males (age: 40.7+/-15.5 years, range: 22-68 years) and 22 females (age: 38.5 +/-14.8 years, range: 21-62 years), were scanned at 1.5 Tesla using 3D fluid suppressed turbo spin echo sequence. Regions-of-interests (ROIs) were obtained by atlas-based tissue segmentation and T1rho was calculated by fitting the mean value to monoexponential model. Correlation between T1rho relaxation of brain gray matter regions and age was investigated. Results: A regional difference among individual gray matter areas was noted; with hippocampus (98.37+/-5.37 msec) and amygdala (94.95+/-4.34 msec) have the highest measurement, while pallidum (83.81+/-5.49) and putamen (83.93+4.76) the lowest measurement. T1rho values decreased slowly (mean slope: -0.256) and significantly (p<0.05) with age in gray matter for subjects younger than 40 years old, while for subjects older than 40 years old there was no significant correlation between T1rho relaxation and age. Conclusion: T1rho relaxation demonstrates a bi-phase change with age in adults of 22-68 years.