Magnetic Resonance Imaging Study Of Morphological Structure And Microstructure Of Cerebral Cortex In Normal Subjects

Part I:Study of magnetic resonance imaging of the relationship between morphology and microstructure of normal human cortexObjective: Magnetic resonance high-resolution structural imaging and neurite orientation dispersion and density imaging are used to study the relationship of normal cortical structure,including the relationship between cortical morphology and microstructure,the intrinsic relation of morphology structure.Methods: High resolution MRI images and NODDI diffusion images are performed in 55 healthy volunteers aged 22-28,and 34 brain regions marked by desikan-killiany brain template are selected as the regions of interest(ROI).The surface-based morphological parameters of high-resolution structural images are extracted by freesurfer software,and the microstructure parameters of NODDI scanning of cortical brain regions are extracted by extracting the median value of individual level ROI from cortical surface.The correlation between cortical morphological parameters and microstructural parameters are analyzed by partial correlation and bivariate correlation。Results: 1.There is no significant correlation between cortical microstructural parameters(Viso/ Vec/Viso/ODI)and cortical morphological parameters(IC/CC/GI/CT/ CA/CV)in each brain region.2.There is a strong positive correlation between IC and GI /CC/CA/CV in some brain regions.,among which the correlation between IC and GI is strong positive.There is a relatively strong correlation between CV and CA/CT/GI in most brain regions,among which CA and GI/CVare strongly positive correlated in each brain region.There is a strong positive correlation between CC and GI in most brain regions,CT has correlation with CA/CC/GI/IC in a few brain regions,no correlation in most brain regions.Conclusion: At the desikan-killiany 34 cortex areas of hemisphere level:There could be no direct correlation between cortical microstructures(neurite density,neurite orientation dispersion,and extraneuronal space)and cortical morphological structure(CV/CT/ CA/IC/ CC/GI),so microstructural changes cannot be inferred through morphological structure.Tangential expansion of the cortical surface(CA representation)and differential expansion(IC representation)are closely related to cortical folding(GI)(positive correlation).differential expansion(IC)is also an important factor affecting cerebral gyrus morphology(CC).Cortical thickness and surface area are independent of each other,and cortical volume is mainly affected by surface area.Each brain region has unity and difference,which may be related to the spatial arrangement and distribution of neuron clusters or brain regions,or to the different functions performed by different brain regions.Part 11:Study of morphology and microstructure asymmetry in auditory and language-related regions of the normal human brain cortexObjective: Current studies have found that the human hemisphere is functionally and structurally asymmetrical.In this study,high-resolution T1 WI MRI and NODDI are used to study the laterality of cortical structures in the auditory and language-related brain regions of the normal brain at different scales.Methods: High resolution MRI images and NODDI diffusion images are performed in 50 healthy volunteers aged 22-25,nine auditory and language-related brain regions in desikan-killiany brain template are selected as the regions of interest(ROI): Middle frontal gyrus poste,Angular gyrus,Inferior frontal gyrus opercular,Inferior frontal gyrus triangular,Supramarginal gyrus,Insula,Superior temporalgyrus poste,Heschl gyrus,Superior temporal gyrus,Using freesurfer software to extract IC/CC/GI and other indexes after surface reconstruction,using the method of extracting the median value of ROI at individual level based on the cortical surface to extract Vic/Vec/Viso/ODI in NODDI,and compare the indexs of left and right sides of each ROI with the paired t test,and single sample t test is used to analyze laterality index(LI).Results: The difference of microstructural indexes in the Middle frontal gyrus poste is not statistically significant,morphological indexes,IC/ CA/CVand GI left side larger than the right has statistical significance.In the microstructural indexs of the Angular gyrus,only the right side of ODI more than the left side is statistically significant,and the morphological indexes IC/CA/CV/CT/GI that right side larger than the left is statistically significant.The difference of microstructural indexes in the bilateral Inferior frontal gyrus opercular is not statistically significant,and morphological indexs CA/CT/CV left side is bigger than the right which has statistical significance.The difference of microstructural indexes in the bilateral Inferior frontal gyrus triangular is not statistically significant,and the morphological indexes IC/ GI/CA/CV /CC are statistically significant on right side bigger than the left and left CT more than the right.The microstructure of the Supramarginal gyrus is only Vic right side larger than the left that has statistical significance,the morphological indexes IC/CC/CA /CV has statistical significance on right side bigger than that of the right.The microstructural indexs of the insula is statistically significant only on the right side of Viso bigger than that on the left,the right side of IC/CC bigger than the left are statistically significant.There is no significant difference in bilateral superior temporal gyrus posterior microstructural indexs,and morphological indexs CA left side is larger than right side,CT right side is larger than left side,which is statistically significant.The microstructural indexs Vec of bilateral Heschl gyrus is statistically significant on the left bigger than the right,and the morphological index CA/CV are statistically significant on the left bigger than the right.There is no significant difference in bilateral superior temporal gyrus microstructural indexs,and morphological indexs CA/CV left side larger than right side is statistically significant.Conclusion: At the desikan-killiany 34 cortex areas of hemisphere level,the ODI of the Angular gyrus,the Vic of the Supramarginal gyrus and the Viso of the Insular involving the language-related brain region could be rightward asymmetry,the cortical morphological asymmetry of language brain regions are different,Middle frontal gyrus poste,Inferior frontal gyrus opercular,Supramarginal gyrus and Superior temporal gyrus poste are mainly leftward asymmetry,Inferior frontal gyrus triangular,Angular gyrus and Insula are rightward asymmetry.Only Heschl gyrus Vec in auditory brain regions is leftward asymmetry,and morphological structure(CA/CV)Heschl gyrus and Superior temporal gyrus poste are all leftward asymmetry.