Brain structure and cognitive function change in the temporal lobe, hippocampus, and prefrontal cortex of patients with mild cognitive impairment and Alzheimer’s disease, and brain network-connection strength, network efficiency, and nodal attributes are abnormal. However, existing research has only analyzed the differences between these patients and normal controls. In this study, we constructed brain networks using resting-state functional MRI data that was extracted from four populations mal controls, patients with early mild cognitive impairment, patients with late mild cognitive impairment, and patients with Alzheimer’s disease) using the Alzheimer’s Disease Neuroimaging Initiative data set. The aim was to analyze the characteristics of resting-state functional neural networks, and to observe mild cognitive impairment at different stages before the transformation to Alzheimer’s disease. Results showed that as cognitive deficits increased across the four groups, the shortest path in the rest-ing-state functional network gradual y increased, while clustering coefficients gradual y decreased. This evidence indicates that dementia is associated with a decline of brain network efficiency. In tion, the changes in functional networks revealed the progressive deterioration of network function across brain regions from healthy elderly adults to those with mild cognitive impairment and Alzhei-mer’s disease. The alterations of node attributes in brain regions may reflect the cognitive functions in brain regions, and we speculate that early impairments in memory, hearing, and language function can eventual y lead to diffuse brain injury and other cognitive impairments.

人工神经网络技术在疾病诊断中的应用进展

人工神经网络(Artificial Neural Networks , ANN)是在对人脑组织结构和运动机制的认识理解基础上模拟其结构和智能功能而构成的一种信息处理系统[1].具有自学习、联想记忆、高度并行、容错等功能及强大的非线性处理能力[2,3] ,其理论的应用已渗透到各个领域并取得非常令人瞩目的进展,近年来在医学领域的应用也越来越广泛,现将ANN在疾病诊断方面的应用综述如下.

人工神经网络在胃癌中的应用

人工神经网络(Artificial Neural Networks,ANNs)是一种模拟生物神经网络结构和功能进行信息处理的方法,通过调整内部大量节点之间相互连接的关系,达到处理信息的目的.人工神经网络已在包括医学在内的多个领域中得到了广泛应用,在疾病诊断及预后判断中的作用也逐渐引起了临床医生的关注.在肿瘤领域,人工神经网络在胃癌中的应用与其在前列腺癌、肠癌、乳腺癌等肿瘤中的应用一样,不断得到了相关专业医疗人员的认可.本文综述了人工神经网络在胃癌诊断、分期及预后等方面的应用研究进展.

人工神经网络及其在卫生检验中的应用

1引言人工神经网络(Artificial Neural Networks,ANN)是模拟人脑神经系统基本特征,由大量神经元相互联接而成的自适应非线性动态网络系统[1].