Profound sensorineural hearing loss (SNHL) can affect subjects in the development of their language, social skill, and psychology, which reduces the quality of their life. At present, the most effective treatment for SNHL is Cochlear Implantation (CI), but it costs so much and exists risk during the surgery. Therefore, it is crucial to evaluate the effect of postoperative rehabilitation before the surgery of CI, and investigation to the brain plasticity in subjects with SNHL is an effective way. In this paper, we used multi-modal magnetic resonance imaging (MRI) to investigate both the structural and functional brain plasticity in adolescents with SNHL. The contributions the this dissertation are presented as follows: (1) We proposed a research scheme to quantativelyevalute the effectiveness of voxel-based morphometry (VBM), including the standard VBM, optimized VBM and VBM-DARTEL (Diffeomorphic Anatomical Registration ThroughExponentiated Lie algebra). We first constructed simulated model to simulate brain atrophies. The results show that VBM-DARTEL is the most robust and effective VBM method to detect structural brain abnormalites when compared with the other two VBM methods. Optimized VBM can provide a more accurate result than standard VBM. Additionally, we used clinical data to investigate structural brain changes, and the results indicate VBM-DARTEL can detect accurate brain changes as well. The results from both the simulated and clinical experiments indicate the robustness of VBM-DARTEL in detecting brain structral changes, which provides valuable methodological instructions when investigating brain structural abnormalities on a voxel level. (2) We proposed an analytical framework which combined VBM-DARTEL and cortical thickness analyses to simutanousely study changes of brain and its asymmetry in adolescents with SNHL using structural MRI. VBM revealed grey matter volume did not change in deaf subjects, but white matter volume decreased significantly in the left middle frontal gyrus and the right inferior occipital gyrus. Furthermore, we found cortical thickness was significantly thinner in the left precentralgyrus, right postcentralgyrus, left superior occipital gyrus and left fusiform gyrus of the deaf adolescents relative to the normal controls. For the analysis of brain asymmetry, VBM revealed significant asymmetry changes in grey matter volume of the cerebellum and white matter volume of the inferior frontal gyrus in deaf subje...
修改评论