糖尿病相关脑连接和脑网络改变与 认知关系研究进展

脑连接和网络的神经影像学研究表明糖尿病病人存在脑结构连接、功能连接和脑网络的异常，且糖尿病病人脑连接及网络属性的改变与认知功能表现间存在相关性，脑连接和网络属性异常可能成为糖尿病的一个重要的病理生理特征。综述糖尿病相关认知功能损害、糖尿病病人基于MRI的脑连接及网络改变、脑连接及网络改变与认知功能状态间的相关性。     

阻塞性睡眠呼吸暂停低通气综合征的神经影像学研究进展

阻塞性睡眠呼吸暂停低通气综合征(OSAHS)以夜间间歇性缺氧和睡眠片断化为特征,常伴有不同程度的神经认知功能损伤,是一种发病率高、严重影响生活并危及生命的睡眠疾病.近年来,随着神经影像学成像方法和图像处理技术的进步,越来越多的研究发现OSAHS病人存在显著的脑结构、代谢和功能异常,从而为深入了解OSAHS神经认知功能改变的病理生理学机制提供了重要信息.综述了神经影像学技术在揭示OSAHS相关脑改变方面的研究进展.     

多模态功能MRI对血管性认知障碍的研究进展

血管性认知障碍(VCI)目前已成为继阿尔茨海默病之后的全球第二大认知障碍类型。利用功能MRI对VCI病人的脑形态和功能进行评价,有利于VCI的早期诊断、治疗和预后评估,同时也对揭示VCI病程演变中病理特征的改变、神经功能预测、行为改变等具有重要意义。综述多模态功能MRI对VCI的研究现状,阐明该技术对探究脑形态、功能与血管性认知改变间关系的作用,为寻求VCI早期诊断的影像诊断标准提供思路。     

孤独症谱系障碍的MRI研究进展

孤独症谱系障碍（ASD）是一组神经发育性障碍,主要症状包括社会交往障碍和重复刻板行为。MRI检查在ASD研究中应用广泛,能够通过无创性评估脑结构形态、物质代谢和功能状态等方面来显示ASD病人神经病理学改变,有助于疾病早期诊断、早期干预。就结构MRI、扩散成像、磁共振波谱（MRS）及功能MRI技术在ASD中的应用进行综述。     

多模态MRI对乳腺癌化疗相关认知功能障碍的研究进展

乳腺癌病人化疗相关认知功能障碍（CRCI）发生的重要神经基础是化疗引起的脑结构、代谢、灌注和功能的改变。多模态MRI可以通过基于体素的形态学测量、扩散张量成像、磁共振波谱、磁敏感加权成像、动脉自旋标记灌注成像和基于血氧水平依赖的功能MRI等技术从局部或全局显示脑灰质体积和密度改变、脑白质纤维损伤、脑代谢改变、脑血流灌注以及脑区激活和功能连接变化等,从而为进一步探索乳腺癌CRCI的发病机制、早期诊断和症状研究提供依据。就多模态MRI在乳腺癌CRCI中的研究进展予以综述。     

功能性MRI对额叶在工作记忆中作用的研究进展

近年来认知神经心理学的发展在研究方法上，越来越受益于研究脑功能活动的新方法。脑功能MRI成像技术的最大优越点是无创性，适用于揭示正常人脑功能的活动规律．弥补了过去研究手段的不足，揭示了一些新的现象和规律。本文即从功能性磁共振成像角度，结合认知心理学的研究方法，对额叶在记忆过程中的作用作一综述。     

地中海贫血的影像学研究进展

地中海贫血（TM）是一种常见的珠蛋白基因缺失或突变引起的遗传性溶血性贫血。X线、CT与常规MRI有助于诊断及评估TM骨骼病变及髓外造血。基于MRI的T₂*定量分析技术、扩散加权成像及磁敏感加权成像可对比分析TM多脏器铁沉积水平。磁共振波谱成像及功能MRI可进一步研究TM神经认知方面的代谢改变及脑区功能连接。就上述各种影像方法在TM骨骼病变、髓外造血、铁沉积及继发脑认知功能改变中的研究进展予以综述。     

MRI在肝移植中的应用

目的评价MRI检查在肝移植术前术后的应用价值。方法将我院2004-01—2005-03收治的22例肝移植患者术前MRI检查结果与手术、病理检查相比较,术后MRI检查与其它影像学检查相比较。结果22例肝移植患者中,肝硬化并门脉高压15例,肝硬化、肝癌6例,严重肝损伤1例;门静脉栓子5例,其中4例为癌栓,1例是管壁样组织,肝右静脉及下腔静脉瘤栓1例;副肝动脉2例,分别发自腹腔干及肠系膜上动脉;胆管吻合口狭窄或胆漏3例;肝动脉可显示2~3级分支,门静脉可显示2~4级分支,肝静脉可显示1~2级分支,胆管显示2~3级分支。结论MRI对肝移植术前和术后的评估具有很大的价值。     

神经影像技术用于创伤后应激障碍的研究进展

创伤后应激障碍(PTSD)是个体暴露于创伤相关应激因素引起一系列严重反应的精神障碍性疾病。近年来,神经影像技术的发展使研究人员发现更多的PTSD相关大脑结构和功能的特征性改变,MRI用于PTSD的研究对观察PTSD病人的脑形态及功能尤其重要。总结神经影像技术在PTSD中的应用现状及主要发现,及其在PTSD发病机制及诊疗研究中的潜力。     

MRI在脊髓型颈椎病中的研究进展

在脊髓型颈椎病(CSM) 的诊断中,常规MRI上脊髓的信号改变与神经功能障碍密切相关,扩散张量成像（DTI）和磁共振波谱（MRS）可以作为寻找神经功能损伤放射学标志物和了解脊髓生理学的工具,而功能MRI（fMRI）有助于评估CSM减压术后神经功能恢复情况。综述常见MRI技术在CSM病人诊断与治疗中的研究进展。     

Renormalization of Thalamic Sub-Regional Functional Connectivity Contributes to Improvement of Cognitive Function after Liver Transplantation in Cirrhotic Patients with Overt Hepatic Encephalopathy

ObjectiveThe role of preoperative overt hepatic encephalopathy (OHE) in the neurophysiological mechanism of cognitive improvement after liver transplantation (LT) remains elusive. This study aimed to explore changes in sub-regional thalamic functional connectivity (FC) after LT and their relationship with neuropsychological improvement using resting-state functional MRI (rs-fMRI) data in cirrhotic patients with and without a history of OHE.Materials and MethodsA total of 51 cirrhotic patients, divided into the OHE group (n = 21) and no-OHE group (n = 30), and 30 healthy controls were enrolled in this prospective study. Each patient underwent rs-fMRI before and 1 month after LT. Using 16 bilateral thalamic subregions as seeds, we conducted a seed-to-voxel FC analysis to compare the thalamic FC alterations before and after LT between the OHE and no-OHE groups, as well as differences in FC between the two groups of cirrhotic patients and the control group. Correction for multiple comparisons was conducted using the false discovery rate (p < 0.05).ResultsWe found abnormally increased FC between the thalamic sub-region and prefrontal cortex, as well as an abnormally decreased FC between the bilateral thalamus in both OHE and no-OHE cirrhotic patients before LT, which returned to normal levels after LT. Compared with the no-OHE group, the OHE group exhibited more extensive abnormalities prior to LT, and the increased FC between the right thalamic subregions and right inferior parietal lobe was markedly reduced to normal levels after LT.ConclusionThe renormalization of FC in the cortico-thalamic loop might be a neuro-substrate for the recovery of cognitive function after LT in cirrhotic patients. In addition, hyperconnectivity between thalamic subregions and the inferior parietal lobe might be an important feature of OHE. Changes in FC in the thalamus might be used as potential biomarkers for recovery of cognitive function after LT in cirrhotic patients.     

基于体素的形态学分析在缺血性脑卒中的研究进展

缺血性脑卒中（IS）是一种严重的脑组织缺血坏死性疾病,其不同病程阶段的脑结构损伤、重塑与病人后期脑神经功能障碍的恢复及生活质量密切相关。基于体素的形态学分析(VBM)能定量分析全脑灰、白质间体积和密度的差异,在IS的病情评估、病程监测、治疗及康复方案选择等方面表现出独特优势。对VBM技术及其在IS运动功能、认知功能及卒中后抑郁研究等方面的进展进行综述。     

脑小血管病患者认知功能障碍的静息态功能磁共振成像研究

目的探讨脑血管病(CSVD)患者认知功能障碍与脑功能活动改变之间的关系,进一步了解CSVD患者认知功能障碍可能的损害机制。方法选取CSVD患者29例,以及性别、年龄、教育年限相匹配的正常对照者(NC)25例,评估受试者神经功能及认知功能。比较两组受试者灰质体积的差异;以灰质体积为协变量,计算并分析两组差异脑区ALFF值及其与认知功能障碍损害评分的相关性。结果与NC组相比,CSVD组患者神经功能及总体认知水平均有所下降,认知障碍主要表现在执行能力、注意力、空间构象等方面(P<0.05);CSVD组右侧基底节的灰质体积减低(AlphaSim校正,P<0.01,体素>71);CSVD组眶部额中回、右侧额上回、左眶部额上回、补充运动区的ALFF值明显减低(AlphaSim校正,P<0.01,体素>71)。结论CSVD患者认知功能障碍主要表现在执行能力、注意力、空间构象等方面,而记忆损害相对较轻;脑自发活动水平减低及灰质萎缩是CSVD的内在表现,为临床治疗提供依据。     

多发性硬化患者弥散张量成像及其与认知功能的关系

目的: 探讨多发性硬化(MS)患者脑内病灶及脑组织的MR弥散张量成像(DTI)特点及其与认知功能的关系.材料和方法:对7例MS患者进行韦氏智力量表测查及头颅DTI检查.结果:病灶、病灶周围看似正常的组织(PWM)、看似正常的白质(NAWM)及看似正常的灰质(NAGM)较对照组相应部位脑组织的表观扩散系数(ADC)值增高,各向异性(FA)值减低.有智能损害的MS患者的NAWM、NAGM的ADC值高于智能正常的患者;而其NAGM的FA值低于智能正常的患者.结论:PWM、NAWM及NAGM组织内存在结构与功能改变,并影响认知功能.DTI有助于发现认知改变的微小结构和功能的异常.     

Magnetic resonance imaging of neuronal and glial swelling as an indicator of function in cerebral tissue slices.

Here we demonstrate a new basis of signal change in magnetic resonance imaging (MRI) related to neuronal function, independent of blood oxygenation or flow. Time series MRI data acquired from living, superfused brain slices of adult rats revealed that the signal intensity reversibly increased with depolarization evoked by briefly elevating extracellular K(+). This was presumably a consequence of increased tissue water in the intracellular compartment. Reversible increases in light transmittance (LT) demonstrating a similar time course in response to K(+) elevation supported cellular swelling as generating the MRI signal intensity changes. This was confirmed by reversibly swelling cells in the slice under hypoosmotic challenge, which increased both MRI and LT signals with an identical time course. Conversely, shrinking cells under hyperosmotic challenge reversibly decreased the MRI and LT signals. We propose that specific MRI of neuronal function (fMRI) signals detected under identical parameters during predominantly proton-density-weighted fMRI of the spinal cord can now be explained by neuronal and glial swelling in activated central nervous system (CNS) regions. These observations demonstrate the biophysical basis of the fMRI contrast mechanism that has been termed "signal enhancement by extravascular water protons," or SEEP.     

不同运动亚型帕金森病轻度认知功能障碍患者fMRI百分比振幅改变

目的 应用静息态fMRI百分比振幅的方法考察不同运动亚型帕金森病合并轻度认知功能障碍(Parkinson's disease with mild cognitive impairment,PD-MCI)的脑功能改变.方法 选取31例PD-MCI患者(13例僵直为主型PD-MCI组,18例震颤为主型PD-MCI组)及17...     

扩散加权成像与短暂性脑缺血发作后认知功能损害的相关性研究

目的初步探讨短暂性脑缺血发作(transient ischemic attacks,TIA)患者认知功能损伤与扩散加权成像(DWI)异常改变之间的关系。资料与方法 49例TIA患者在发病3天内行DWI检查,发病7天内采用中文版蒙特利尔认知评估量表(MoCA)进行认知功能测试。根据是否存在DWI异常,将49例TIA患者分为DWI异常组和DWI正常组,同时选取25名正常健康志愿者作为对照组,比较两组患者神经认知功能评分的差异性。结果 TIA患者的视空间与执行功能、注意、延迟记忆评分及MoCA总分显著低于对照组(P<0.001),且DWI阳性的TIA患者的各项评分均显著低于DWI阴性患者;DWI阳性及DWI阴性组的命名、语言、抽象思维及定向力评分无显著差异,与对照组间差异无统计学意义(P>0.05)。结论 TIA患者存在认知功能损害,DWI阳性认知功能损害的程度较DWI阴性者更显著。     

MRI techniques and cognitive impairment in the early phase of relapsing-remitting multiple sclerosis

Correlation studies between various conventional and non-conventional MRI parameters and cognitive impairment in the early stages of multiple sclerosis (MS) are lacking, although it is known that a number of patients with early MS have mild cognitive impairment. Our aim was to explore whether this cognitive impairment is dependent on the extent and severity of the burden of disease, diffuse microscopic brain damage or both. We studied 63 patients with clinically definite relapsing-remitting (RR) MS, duration of disease 1–10 years and Expanded disability status scale scores ≤ 5.0. Mean age was 35.4 years, mean duration of disease 5.8 years and median EDSS score 1.5. Neuropsychological performance, psychological function, neurological impairment and disability were assessed. The patients also underwent MRI, including magnetisation-transfer (MT) studies. We quantified the lesion load on T2- and T1-weighted images, the magnetisation transfer ratio (MTR) of normal-appearing brain tissue (NABT) and the brain parenchymal fraction (BPF). No significant difference was found between lesion loads in patients with and without cognitive impairment. In 15 patients (23.8 %) with overall cognitive impairment, median BPF and average NABT MTR were significantly lower than those in patients without cognitive impairment (0.868 vs 0.892, P = 0.02 and 28.3 vs 29.7 P = 0.046, respectively). Multiple regression analysis models demonstrated that the only variables independently correlated with cognitive impairment were: BPF (R = 0.89, P = 0.001) and average NABT MTR (R = 0.76, P = 0.012). Our findings support the hypothesis that, cognitive decline in patients with MS, a low disability score and short duration of disease is directly associated with the extent and severity of diffuse brain damage. The loss of brain parenchyma did not correlate with the severity of microscopic damage in the NABT, indicating that the two processes could be distinct in the early stages of the disease. Received: 7 August 2000 Accepted: 18 October 2000     

脑外伤自体神经干细胞移植后的功能影像学研究

目的 探讨脑外伤自体神经干细胞移植后的脑功能变化。资料与方法 对2例脑外伤患者行自体神经干细胞移植，移植前及移植后1个月、3个月，分别行去氧葡萄糖正电子断层扫描（FDG-PET）及磁共振功能成像（fMRI）检查。结果 移植后3个月，患者神经功能明显改善，FDG-PET、fMRI均提示原受损功能区的功能得到恢复。结论自体神经干细胞移植可以改善神经功能，FDG-PET及fMRI是分析神经功能改善的重要手段。