Quantitative Study of MRI and~1H MRS in Normal Adult Brain / 实用放射学杂志

ABSTRACT

Objective:To evaluate magnetic resonance imaging(MRI) and 1 H magnetic resonance spectroscopy( 1HMRS)in the study of normal biochemical process of the brain as well as differentiation of normal senile brain from cerebral diseases related to senility.Methods:180 cases of healthy adults were selected to perform MR examination,in which,none of the subjects had the history of neurological and psychotic diseases according to MRI and clinical results.Meanwhile,60 healthy subjects were selected to perform 1 HMRS examination.The ages ranged from 18 to 80 years.They were divided into six age groups purposely.Point resolved spectroscopy sequence was required for 1 HMRS.The metabolites in the spectra includedN-acetylaspartate(NAA),choline compounds(CHO),creatine compounds(CR),myo-inosito(MI),glutamate and glutamine(Glu-n).Results:(1)In 180 cases of MRI,T 2 relation time was lowest in the deep gray matter in the same age group;T 1relation time was in low-high order,while T 2 relation time was decreased with the increase of age in the different age group.(2)The amplitudes in high-to-low order were as follows in 60 cases of 1 HMRSNAA、CR、CHO、MI、Glu-n.No prominent difference of shape and peak arrangement was seen at the different ipsilateral site in the same age groups;while slight difference at the same site in the different age groups was present.The ratio of NAA/Cr and Glu-n CR was higher in senile age group;while that of MI/Cr was lower.The ratio of CHO/CR was in low-to high order with the difference of age.The ratio of NAA/CR and MI/CR was gradually lower from anterior to posterior part of the brain;the ratio of CHO/CR was highest in occipital cortex however,no definite changing rule was observed in the ration of Glu-n/CR.Correlation of T 1 relation time and partial metabolite ratio with age was present in gray matter.Conclusion:Quantitative study of MRI and 1 HMRS is essential for determination of normal myelinization and neuronal integrity and age-related biochemical changes in the brain.