Study In Youth With Major Depression Using Three-dimension Hydrogen Proton Magnetic Resonance Spectroscopy And Diffusion Tensor Imaging

Objective1.To determine the normal distribution pattern of metabolites in the youth normal helthy adults using three-dimension proton magnetic resonance spectroscopy(3D ~1H-MRS) and DTI parameters at 1.5 Tesla.2.To find the characterisitics of metabolic changes in patients with youth major depression(MD)(in the ROIs of bilateral dorsolateral frontal white matter,cingulate gyrus gray matter,caput nuclei caudati,lentiform nucleus and thalamic) through comparing 3D ~1H-MRS diferences in youth MD patients with age- and sex-matched controls.To investigate the neurobiology mechanism of youth MD.3.To determine the DTI parameters of bilateral dorsolateral frontal white matter,the genu,body and splenium of corpus callosum.To investigate the histological structure changes(limbic-cortical-striatal-pallidal-thalamic tract) in youth MD.MethodsFifty-four patients with youth MD[male:female,36:18;mean age,(22±7) years]and fifty normal age marched controls[male:female,33:17;mean age, (20±6) years]were involved.MRI,3D ~1H-MRS and DTI brain scans were obtained on all participants.In the bilaterally dorsolateral white matter and cingulate gray matter of the frontal lobe,lentiform nucleus,the head of caudate nucleus and thalamus,the ratios of N-acetylaspartate(NAA), choline(Cho),myo-inositol(mI) to creatine(Cr) levels were computed.The apparent diffusion coefficients(ADC) and fractional antisotropys(FA) were measured in the bilaterally white matter of frontal lobe,the genu(anterior), body and splenium(posterior) of corpus callosum.ResultsThe Cho/Cr and mI/Cr ratios in cingulate gyrus gray,lentiform nucleus and the head of caudate nucleus were significant higher in youth MD patients than those in normal control patients(P＜0.05),but no significant difference was detected in the NAA/Cr ratio in cingulate,lentiform nucleus and the head of caudate nucleus between two groups(P＞0.05).There were no significant differences in the levels of NAA/Cr,Cho/Cr,mI/Cr ratios in dorsolateral white matter of the frontal lobe and thalamus between both groups(P＞0.05).The values of ADC were significantly increased and FA significantly reduced in white matter of frontal lobe,the genu and body but not the splenium of the corpus callosum in the youth MD group compared with the comparison group(P＜0.01).ConclusionThere are some neurochemical and histological structure changes in youth MD patients.3D ~1H-MRS and DTI can find these changes through assessing the metabolic abnormailites and diffusion changes;it presents a new valuable method in the studies of MD.