Work

Metabolite Relaxation Times at 3T From Birth to 7 Years

Year: 2026

Type: preprint

Abstract: Purpose With growing interest in pediatric MRS to understand the neurochemistry of brain development, it is essential to establish pediatric-specific metabolite T 1 and T 2 relaxation times for reliable quantification of metabolites. Furthermore, characterization of age-related changes in relaxation times may provide insight into developmental differences in tissue microstructure and cellular composition. Therefore, the goals of this study were two-fold: (1) to estimate metabolite T 1 and T 2 relaxation times in a pediatric cohort; and (2) to assess linear relationships between age and relaxation times. Methods TI- and TE-series data were acquired from the bilateral thalamus in 20 and 25 participants aged between 0 and 7 years, respectively. Data were processed and modelled in Osprey 2.5.0. Metabolite T 1 and T 2 relaxation times of total N-acetylaspartate at 2.0 ppm (tNAA 2.0 ), total creatine at 3.0 ppm (tCr 3.0 ), total creatine at 3.9 ppm (tCr 3.9 ), total choline (tCho), myo-inositol (mI) and the combined glutamate and glutamine (Glx) were estimated by fitting the modelled signal amplitudes to TI-series inversion recovery signal and TE-series exponential decay equations, respectively. Linear relationships with age were tested for metabolite T 1 and T 2 relaxation times using Spearman correlations. Results tNAA 2.0 and Glx showed significant changes in T 1 with age. tNAA 2.0 , tCr 3.0 , tCho and mI showed significant decrease in T 2 with age. Conclusion Several metabolites showed significant changes in relaxation times with age in the thalamus region. Therefore, use of age-specific relaxation correction for pediatric studies using the linear equations provided is encouraged for reliable quantification of metabolites.

Source: bioRxiv (Cold Spring Harbor Laboratory)

DOI: 10.64898/2026.10.02.754450