DTI Study Of Periventricular Fibre Bundles In Infants With Obstructive Hydrocephalus

Objective : To research the variety of diffusion tensor imaging in periventricular fibre bundles of the infants with obstructive hydrocephalus.Materials and methods:32 children with obstructive hydrocephalus(OSHP)within 1 years of age(12 cases of aqueduct obstruction,20 cases of ventricle or cerebral pool system tumor)and 32 cases of normal infants(CP1)was selected.They all divided into three groups based on age(1-3M as group one,4-6M group two,7-12 M as three).10 cases of ventriculoperitoneal shunt were performed in the midbrain aqueduct.The postoperative follow-up time was 3.58 0.53 M,with an average age of 8.24 2.5M.The compared group 2(CP2),10 normal infants matched by sex and age,with an average age of 8.33 2.39 M.All the subjects used 3.0T SIEMENS Skyra scanner to collect data.In the post processing station,DTI was used to observe the fibers bundles in the posterior limb of the inner capsule(PLIC),the Genu of corpus callosum(g CC),the Splenium of corpus callosum(s CC)region of interest(ROI),and to calculate the ROIs to Fractional anisotropy(FA),the average diffusivity(MD),axial Axial diffusivity(AD)and Radial diffusivity(RD).T The values of FA in different age groups were analyzed by single factor variance and the difference between the statistics was compared with the LSD group.The DTI index parameters of each group were analyzed by the Wilcoxon test of two independent samples,and the comparison group perioperatively matched the Wilcoxon rank and test of the paired samples.Results:The FA values of PLIC,g CC and s CC in three age groups of CP1 group and OSHP group were not homogeneous(P <0.05).The FA value and AD value of PLIC in group OSHP were higher than those in CP1 group(P <0.05),while the RD value in group three decreased(P <0.05),the rest had no difference.The projective fibers in the ROI of the PLIC were significantly compressed.The FA values of g CC and s CC in group OSHP were lower than those in group CP1(P <0.001),MD value,AD value and RD value were higher than those in normal group(P <0.05).The joint fibers in the ROI of g CC and s CC were destroyed and the number was reduced.The values of MD,RD and AD of PLIC,g CC and s CC decreased after operation(P <0.05),while the FA values of g CC and s CC increased(P <0.05).Compared with CP2,the FA and RD values of PLIC increased(P <0.05),while FA value of g CC and s CC decreased(P <0.05),MR value,AD value and RD value increased(P <0.05).After operation,the fiber bundles in the ROI of PLIC,s CC and g CC were different degrees of improvement.Conclusion:The microstructures of PLIC,g CC and s CC in infants with obstructive hydrocephalus are abnormal.Their fiber bundles are involved in different degrees.DTI showed that postoperative index parameters and fiber bundles improved and tended to be normal,which could provide certain value for clinical evaluation of postoperative efficacy.