PROJECT 4 - DTI AND MTI STUDIES IN SCHIZOPHRENIA

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。在过去的十年中，大量的磁共振成像（MRI）研究已经推进了对精神分裂症神经病理学的理解，证实了精神分裂症中存在结构性脑异常，包括脑室、额叶、内侧颞叶、颞上回、下顶叶和皮层下脑区域的体积改变。在精神分裂症中观察到的异常分布模式和数量与大脑区域内部和区域之间的连通性紊乱以及这种神经连通性紊乱背后的白质异常一致。事实上，在精神分裂症患者的大脑中，前额叶灰质体积与杏仁核-海马体复合体和颞上回的体积减少高度相关。虽然许多传统的MRI研究报告了精神分裂症患者的灰质异常，但相对较少的研究专门评估并报告了精神分裂症患者大脑中适度但显著的白质体积减少。较新的技术，如扩散张量成像（DTI），它可以推断白质束的相干性（各向异性），以及磁化转移成像（MTI），它提供了大脑中髓磷脂的假设测量(磁化转移比；MTR)，将我们对白质缺陷的理解从仅仅评估体积损失扩展到为精神分裂症大脑白质束组织减少和髓磷脂含量的细微减少提供初步的影像学证据。这些发现也与揭示精神分裂症患者前额叶皮层髓鞘纤维超微结构改变的显微研究相一致。此外，脱髓鞘疾病，如青少年发病的异色性脑白质营养不良和多发性硬化症，与精神分裂症中观察到的行为和认知障碍相似。这项研究的目的是更多地了解被诊断为精神分裂症的人的不同大脑区域。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Understanding of the neuropathology of schizophrenia has been advanced by numerous magnetic resonance imaging (MRI) studies over the past decade, which confirms the presence of structural brain abnormalities in schizophrenia, including volume alterations of the ventricles, frontal lobe, medial temporal lobe, superior temporal gyrus, inferior parietal lobe and subcortical brain regions. The distributed pattern and number of abnormalities observed in schizophrenia are consistent with a disturbance of connectivity within and between brain regions and a white matter abnormality underlying this disturbed neural connectivity. Indeed, prefrontal grey matter volume has been highly correlated with volume reductions in the amygdala-hippocampus complex and superior temporal gyrus in the brains of schizophrenic patients. While numerous conventional MRI studies have reported grey matter abnormalities in schizophrenia, relatively few in comparison have specifically assessed and reported modest but significant white matter volume decreases in schizophrenic brains. Newer techniques such as diffusion tensor imaging (DTI), which allows inferences of the coherence of white matter tracts (anisotropy), and magnetization transfer imaging (MTI), which provides a putative measure of myelin in the brain (magnetization transfer ratio; MTR), extend our understanding of white matter deficits from merely assessing volumetric loss to providing preliminary imaging evidence for decreased organization in white matter tracts and subtle reductions in the myelin content of schizophrenic brains. These findings are also consistent with microscopic studies revealing ultrastructural alterations of myelinated fibers from the prefrontal cortex of schizophrenic patients. In addition, demyelinating diseases such as adolescent onset metachromatic leukodystrophy and multiple sclerosis are associated with behavioral and cognitive disturbances similar to that observed in schizophrenia. The purpose of this study is to learn more about different brain areas in people who have been diagnosed with schizophrenia.