ABSTRACT
Objective To detect the changes of the brain white matter microstructure at the acute stage of posttraumatic stress disorder(PTSD)resulting from a single,extreme and long-lasting trauma.Methods DTI scans were performed on 1 7 survivors of coal mine disaster(PTSD group)and 1 7 cases of normal control(control group).The differences of the mean diffusivity(MD)values measured from the whole brain DTI between the two groups were analyzed based on tract based spatial statistics (TBSS).MD data were statistically compared between the two groups based on nonparametric random permutation test(RPT),and the brain areas of significant differences between the two groups were obtained.Results Compared with the control group,MD values were increased in the bilateral rostral corpus callosum body and left precorona radiata,and decreased in the bilateral superior and posterior corona ra-diate,posterior limb of the left internal capsule,left cerebral peduncle and left thalamic.The differences were statistically significant (P <0.01 TFCE-corrected).Conclusion TBSS is a comprehensive and accurate method for evaluate the changes of brain white mat-ter in PTSD cases.TBSS can provide an objective basis of the pathological brain neural structures imaging for early diagnosis and in-tervention of PTSD.
ABSTRACT
Objective To investigate the relationship between cerebral white matter fractional anisotropy(FA)and metabolite con-centrations measured by 1 H magnetic resonance spectroscopy(1 H-MRS)in healthy adults.Methods Diffusion tensor imaging(DTI) and 1 H-MRS were acquired from thirty-one healthy adults at 3.0 T MR system.The concentrations of N-acetylaspartate(NAA), choline(Cho),creatine(Cr),the ratios of NAA/Cr and FA values of DTI were measured in 353 voxels,covering the bilateral medium corona radiata.According to the age,all voxels were divided into two groups:the senior group (mean age=29 years),and the senior group(mean age=5 6 years).The correlations between FA values and age were analyzed using Pearson’s correlation coefficients.The correlations between FA values and metabolite concentrations were estimated using partial correlations test controlling for the age re-lated bias.Results Pearson’s correlation analysis revealed a negative correlation between FA values and age in 353 voxels(r=-0.146,P<0.05),senior group(r=-0.204,P<0.05)and senior group(r=-0.162,P<0.05).Only the correlation between NAA and FA values were significant(r=0.339,P<0.05;r=0.213,P<0.05;r=0.430,P<0.05).There were positive relation-ships between FA values and NAA/Cr among 353 voxels (r=0.166,P<0.05)and senior group(r=0.305,P<0.05).Conclusion There are correlations between cerebral white matter FA values and metabolite concentrations measured by 1 H-MRS .Combining 1 H-MRS with DTI can reveal the relationship between microscopic white matter integrity and metabolic characteristics of the white matter.