Development of the human brain: <i>In vivo</i> quantification of metabolite and water content with proton magnetic resonance spectroscopy

TLDR

Quantitative proton MRS is valuable for diagnosing and monitoring infant pathology because metabolite ratios can be misleading. This study aims to characterize absolute cerebral metabolite concentrations and relaxation times across age in children. Absolute metabolite concentrations and water content were measured with localized proton MRS in 50 children, and metabolite peak ratios were evaluated in 173 short‑echo spectra. Normative curves were established, revealing that myo‑inositol dominates at birth, choline peaks in older infants, and creatine and N‑acetyl concentrations increase with age, with myo‑inositol correlating best with postnatal age.

Abstract

Abstract Cerebral metabolite concentrations and water content were measured by means of localized proton magnetic resonance spectroscopy in 50 children, while metabolite peak ratios in short echo time spectra were evaluated in 173 examinations. Normative curves for normal development were established for two cerebral locations. The current report presents the first study of absolute metabolite concentrations and T 1 ‐and T 2 ‐relaxation as a function of age. Myo ‐inositol was found dominating the spectra at birth (12 mmoles/kg), while choline is responsible for the strongest peak in older infants (2.5 mmoles/kg). Creatine and N ‐acetyl groups are at significantly lower concentrations in the neonate than in the adult (Cr: 6, NA: 5 mmoles/kg). NA and Cr are determined by gestational age, whereas the concentration of ml correlates best with postnatal age. Quantitative l H MRS is expected to be of particular value in diagnosis and monitoring of pathology in infants, since metabolite ratios are often misleading.