自身免疫性脑炎的MRI研究进展

自身免疫性脑炎（AE）是一组由抗神经元抗体导致的炎性脑病,炎症进程可以发生在大脑边缘系统等多个脑区。在常规MRI上常表现为T₂WI及T₂-FLAIR高信号,并有扩散受限,但仍有部分AE常规MRI表现为阴性;而高级MRI技术包括结构和功能MRI,可以利用基于体素的形态学分析（VBM）、基于表面的形态学分析（SBM）、扩散张量成像（DTI）及静息态功能连接（FC）、低频振幅（ALFF）、脑网络和任务态功能MRI（fMRI）等方法从多角度研究AE脑结构及功能改变,有助于探索疾病潜在的神经病理机制。就AE的常规MRI表现及高级MRI研究进展予以综述。     

进食障碍脑结构MRI研究进展

进食障碍（ED）谱系疾病是一组严重的精神类疾病,常见类型为神经性厌食症（AN）、神经性贪食症（BN）、暴食障碍（BED）。ED与脑结构重塑有关,结构MRI包括基于体素的形态学分析（VBM）、基于表面的形态学分析（SBM）和扩散张量成像（DTI）,可用于观察脑灰质形态学和白质微观改变。综述多种结构MRI技术在AN、BN、BED中的研究进展,以期揭示ED的神经病理学机制,为治疗提供新思路。     

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。     

产后抑郁症的MRI研究进展

产后抑郁症（PPD）为常见的产后精神障碍,其发病机制尚不清楚。基于体素的形态学分析、基于表面的形态学测量、扩散张量成像、扩散峰度成像、血氧水平依赖功能MRI、MR波谱成像等多种MRI技术已广泛用于探究PPD病人的脑结构、功能和代谢中发生的异常改变,这些技术使得明确PPD的神经生物学机制成为可能,也可为该病的早期诊断和预后判断提供客观的影像依据。就MRI在PPD中的影像学研究进展予以综述。     

空气粉尘污染对大脑影响的MRI研究进展

空气粉尘污染会对大脑结构与功能产生损害。MRI技术可用于观察空气粉尘污染对脑结构与功能的影响,包括基于T1加权的三维磁化强度预备快速梯度回波（T1WI-3D-MPRAGE）、液体衰减反转恢复（FLAIR）、扩散加权成像（DWI）、扩散张量成像（DTI）、血氧水平依赖成像（BOLD）和MR波谱成像（MRS）等序列。MRI不仅能观察到空气粉尘对大脑整体形态、灰白质以及脑深部核团等重要解剖结构的影响,还能反映大脑神经纤维发育、脑网络功能连接和神经元代谢方面的功能改变。就MRI用于空气粉尘污染对大脑影响的研究及进展作一综述。     

定量MRI诊断直肠癌淋巴结转移的研究进展

评估直肠癌淋巴结转移对治疗和预后至关重要。常规MRI诊断直肠癌淋巴结转移主要依据淋巴结的短径和形态学特征,诊断效能较低。定量MRI包括动态增强MRI（DCE-MRI）、动态磁敏感增强MRI（DSC-MRI）、单指数模型扩散加权成像（DWI）、扩散峰度成像（DKI）、体素内不相干运动扩散加权成像（IVIM-DWI）等,可以对直肠癌淋巴结及原发灶进行定量分析,从而有助于诊断淋巴结转移。就常规MRI及定量MRI诊断直肠癌淋巴结转移的研究进展予以综述。     

MRI对上皮性卵巢癌组织学分型的诊断应用

常规MRI可从形态学角度评估上皮性卵巢癌（EOC）组织学分型,扩散加权成像（DWI）、体素内不相干运动成像（IVIM）及动态增强MRI（DCE-MRI）等功能成像技术可进行定量后处理分析。基于MRI的影像组学通过全面分析Ⅰ型和Ⅱ型EOC的影像特征,在术前可以预测EOC分型,有助于制定个体化治疗方案及评估预后。就DWI、IVIM、DCE-MRI及影像组学在鉴别EOC分型中的应用进行综述。     

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。     

常规MRI联合MR脑血管成像在围产期脑后部可逆性脑病综合征中的应用研究

目的：探讨常规磁共振成像（MRI）联合MR脑血管成像在围产期脑后部可逆性脑病综合征（PRES）诊断和鉴别诊断中的应用价值。方法：5例围产期PRES患者,平均年龄为26.5岁,且均于起病后2 d内行常规MRI和MR脑血管成像,MR脑血管成像包括MR脑动脉成像（MRA）和MR脑静脉成像（MRV）。结果：病变均累及双侧顶枕叶,另累及额叶2例,基底节区2例,桥脑1例,病变占位效应不明显。病变主要位于皮层下白质,其中1例累及皮质。病变T1WI呈低、等信号,T2WI及液体衰减反转恢复序列（FLAIR）呈高信号。3例磁共振扩散加权成像（DWI）呈等信号,表观扩散系数（ADC）图为高信号,另2例部分病变DWI为高或稍高信号。增强扫描以上病变未见明确强化,MRA、MRV未见明确异常。结论：围产期RPES的MRI表现较具特征性,常规MRI联合MR脑血管成像有助于本病的早期诊断和鉴别诊断。     

高级别胶质瘤假性进展的功能MRI研究

高级别胶质瘤（HGG）治疗后可发生假性进展,但常规MRI对HGG假性进展的诊断价值有限。目前多种功能MRI技术已用于HGG假性进展与真性进展的鉴别诊断,包括扩散成像、¹H-MR波谱成像（MRS）、灌注加权成像（PWI）、酰胺质子转移成像（APT）等,联合这些功能MRI技术及人工智能可进一步改善诊断效能。就这些功能成像及其参数在假性进展方面的研究进展进行综述。     

平原正常成人脑的高海拔适应性改变：静息态f MR I研究

目的：应用基于体素形态学(VBM)、低频振幅(ALFF)和局部一致性(ReHo)方法探讨平原正常成人脑结构及脑功能对高海拔低氧的适应性变化。方法对19例年龄、受教育程度、原居住地海拔高度相匹配的初入高海拔1周内的平原成人行静息态功能磁共振(fMRI)全脑扫描,移居1年后同批受检者再行此检查,应用 VBM技术、ALFF 和 ReHo 方法对脑功能数据进行分析。结果平原正常成人移居高海拔地区1年前后自身脑结构比较,未发现显著性差异;在静息状态下,脑功能方面存在显著性差异,移居高海拔1年后受检者左侧额中回 ALFF增加,右侧舌回的 ALFF减低(P<0.01);左侧眶内额上回的 ReHo增加,右侧楔叶、右侧顶叶 ReHo减低(P<0.05)。结论正常成人移居高海拔1年后存在脑功能的改变,这可能与长期处于低氧环境有关。     

Brain magnetic resonance imaging (MRI) and neurological changes after a single high altitude climb.

PURPOSE: Neurological impairment, mental dysfunction, and brain imaging changes caused by severe hypoxia have been described by several authors. However, the occurrence of transitory, long lasting, or permanent brain damage has been debated. Although climbing to 8000 m is reserved to a small number of climbers, there are hundreds of lowlanders spending relatively short holidays climbing peaks up to 6000 m in the Andes or in the Himalayas. They are usually not well acclimated and often suffer from acute mountain sickness (AMS). The aim of this study was to examine the effect of a single high altitude exposure on the changes in brain MRI and neuropsychological testing in climbers. METHODS: Brain MRI, medical history, and a battery of neuropsychological tests were obtained in eight male climbers between 31 and 48 yr of age a few days before and between 5 and 10 d after returning to sea level following ascent to altitudes of over 6000 m without oxygen. RESULTS: The mean AMS symptom score recorded at 5500 m was three in all climbers, headache being the predominant symptom. CONCLUSION: We did not observe the changes in brain imaging and in neuropsychological testing observed by other authors. The residual central nervous system impairment following return from high altitude was not observed in our study, and the good results in neuropsychological testing were well correlated with the unchanged brain MRI imaging.     

多模态MRI在颈椎间盘源性疼痛的研究进展

颈椎病是一种多病因、症状复杂的临床综合征,其中颈椎间盘退变是其重要病因之一。多模态MRI技术能够准确评估病人颈椎间盘形态和信号异常以及继发性脊髓和大脑结构与功能的细微改变,为深入理解颈椎间盘源性疼痛的发病机制及疗效评估提供重要影像学依据。就多模态MRI技术(常规MRI、基于体素的形态学分析、功能MRI、扩散张量成像、磁共振波谱等)对颈椎间盘源性疼痛的研究现状和进展予以综述。     

Image evaluation of HIV encephalopathy: a multimodal approach using quantitative MR techniques

Introduction  

A multimodal approach of the human immunodeficiency virus (HIV) encephalopathy using quantitative magnetic resonance (MR) techniques can demonstrate brain changes not detectable only with conventional magnetic resonance imaging (MRI). The aim of this study was to compare conventional MRI and MR quantitative techniques, such as magnetic resonance spectroscopy (MRS) and relaxometry and to determine whether quantitative techniques are more sensitive than conventional imaging for brain changes caused by HIV infection.     

多模态影像技术在僵直少动型帕金森病的脑机制及TMS治疗中的研究进展

僵直少动型帕金森病(AR-PD)病人更易出现运动障碍且预后较差。多模态影像技术为评估PD病人大脑结构及功能改变提供了无创手段。经颅磁刺激(TMS)作为一种无创的治疗方法,可以通过改变刺激脑区的兴奋性达到改善PD运动症状的效果。总结AR-PD的临床特征,并就基于磁敏感加权成像、结构MRI、血氧水平依赖功能MRI和扩散张量成像等多模态MRI以及核医学技术对AR-PD的脑机制及其在AR-PD TMS治疗中的研究进展予以综述。     

Diffusion-weighted imaging: basic concepts and application in cerebral stroke and head trauma

Diffusion-weighted imaging (DWI) of the brain represents a new imaging technique that extends imaging from depiction of neuroanatomy to the level of function and physiology. DWI measures a fundamentally different physiological parameter compared with conventional MRI. Image contrast is related to differences in the diffusion rate of water molecules rather than to changes in total tissue water. DWI can reveal pathology in cases where conventional MRI remains unremarkable. DWI has proven to be highly sensitive in the early detection of acute cerebral ischemia and seems promising in the evaluation of traumatic brain injury. DWI can differentiate between lesions with decreased and increased diffusion. In addition, full-tensor DWI can evaluate the microscopic architecture of the brain, in particular white matter tracts, by measuring the degree and spatial distribution of anisotropic diffusion within the brain. This article reviews the basic concepts of DWI and its application in cerebral ischemia and traumatic brain injury.     

The effect of bulk susceptibility on murine snapshot imaging at 7.0 T: a comparison of snapshot imaging techniques.

The sensitivity of several single-shot imaging techniques to local field gradients (LFGs) generated by discontinuities in bulk magnetic susceptibility (BMS) were compared in mouse brain at 7.0 T. At high field, differences in BMS can cause substantial signal attenuation and image distortion. Because susceptibility effects scale with B(o), mouse brain single-shot imaging at high field is particularly susceptible to the effects of LFGs. The spin-echo techniques GRASE and RARE were found to have a decreased sensitivity to LFGs compared to echo-planar imaging (EPI). Images obtained using EPI and SE-EPI exhibit severe signal attenuation in regions of high LFGs such as near air-tissue interfaces and at the brain edges. In applications such as functional MRI and diffusion MRI, GRASE and RARE are likely to provide more comprehensive whole brain coverage in mouse brain at high field than EPI techniques, which are likely to image regions of the brain with strong LFGs with low signal to noise, reducing the probability of detecting significant physiologically based changes.     

盆腔器官脱垂病变的MRI技术应用进展

盆腔器官脱垂（POP）的准确诊断对制定治疗策略及评估疾病预后至关重要。MRI具有无辐射、软组织分辨力高及可无创性反映组织微观结构及功能变化等优点,在POP的评估中具有重要价值。目前,传统的动态MRI（dMRI）及三维MRI、扩散张量成像（DTI）、T₂ mapping等功能成像在POP术前、术后及康复治疗后的应用逐步发展。就各种MRI技术在POP诊疗中的研究进展予以综述。