多模态MRI在帕金森病的研究进展

帕金森病(PD)是一种常见的神经系统退行性疾病,其病理学改变主要包括黑质-纹状体通路多巴胺能神经元变性坏死及路易氏小体形成,从而引起一系列运动性及非运动性症状。近年随着多模态MRI技术和多模态脑网络分析方法的发展,通过基于结构MRI、扩散张量成像的结构性脑网络以及基于功能MRI的功能性脑网络可以从不同角度研究PD各亚型脑结构及功能改变。就多模态MRI及脑网络分析技术在不同PD亚型中的研究进展予以综述。     

阿尔茨海默病多模态MRI形态和功能研究进展

【摘要】阿尔茨海默病是一种持续发展但尚无有效治疗方法的慢性神经系统退行性疾病，因此早期诊断进而对其进行早期干预治疗具有重要意义。多模态MRI能够反映脑内形态学及功能学改变情况，是诊断和监测干预效果的重要手段。本文对阿尔茨海默病患者的脑结构、血流灌注、代谢以及功能等MRI改变进行综述，旨在提高对此疾病的早期诊断水平，指导临床实现对疾病的早期干预，进而改善患者的预后。     

一体化PET/MR在脑功能方面的研究进展

影像学是无创研究脑功能的重要途径。随着影像学技术的快速发展,从单模态磁共振成像、正电子发射断层成像,到多模态成像PET/CT、PET/MR,多模态已经成为影像学发展的里程碑。目前最先进的多模态成像设备一体化PET/MR可以同时得到PET成像和MRI多序列成像,将两种成像技术结合,为进一步深入研究脑功能提供了可能。本文对目前脑功能方面的研究做一综述。     

MRI在三阴性乳腺癌中的应用进展

三阴性乳腺癌(TNBC)具有特殊的生物学行为及临床病理学特征,侵袭性强,恶性程度高,临床缺乏有效的治疗方法,预后较差。TNBC较非TNBC型乳腺癌在MRI上具有一定的特征表现。灌注加权成像、扩散加权成像及磁共振波谱成像等功能MRI技术运用多定量参数指标可以定量评估TNBC血流灌注情况及细胞代谢状态,并对TNBC术前新辅助化疗效果具有监测作用。就MRI对TNBC与非TNBC的鉴别诊断及TNBC新辅助化疗评估及预后检测予以综述。     

多模态磁共振成像对儿童线粒体脑肌病综合征的鉴别诊断价值

目的 分析儿童线粒体脑肌病(MELAS)综合征的多模态影像学特点,探讨功能成像技术的鉴别诊断价值.方法 回顾性分析8例经过临床、基因检测证实的MELAS患儿的完整磁共振成像(MRI)资料,包括脑MRI平扫、增强、磁共振血管成像(MRA)、扩散加权成像(DWI)、波谱成像(MRS)、动脉自旋标记灌注成像(ASL).结果 ...     

阿尔茨海默病多模态MRI研究进展

阿尔茨海默病(AD)是一种以进行性认知障碍和行为异常为主要表现的神经退行性疾病。早期神经放射学多采用结构MRI研究AD局部脑区的改变,随着多模态MRI的发展,研究者们从功能连接、代谢水平、白质纤维成像、血流动力学等方面对AD进一步评价,从而为AD的临床诊断、分期、治疗和预后提供了放射学依据。就多模态MRI技术在AD中的研究进展予以综述。     

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。     

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。     

帕金森病多模态MRI研究进展

帕金森病(PD)是一种发生率仅次于阿尔茨海默病的神经退行性疾病,其病理改变为黑质内多巴胺能神经元的缺失,引起纹状体内多巴胺含量的减少,进而引起一系列临床症状。早期神经影像检查多采用结构MRI研究局部脑区的改变,随着多模态MRI的发展,从血流动力学、脑白质纤维束成像、代谢水平以及功能连接等不同角度可以对PD行进一步研究及评价,从而为PD的临床诊断、治疗及预后提供更多的影像依据。就多模态MRI技术在PD中的研究进展予以综述。     

MRI在帕金森叠加综合征与帕金森病的鉴别诊断及疾病进展预测中的应用

帕金森叠加综合征（PPS）是一组部分临床症状与帕金森病（PD）相重叠的慢性进行性神经退行性疾病,两者症状的相似性导致了临床鉴别困难。随着神经影像技术的发展,MRI凭借其对结构、扩散、灌注及功能等多模态成像的优势在揭示PPS和PD的脑区灰质体积改变、白质纤维束完整性改变,局部脑区的铁沉积、血流灌注及功能连接等的异常改变方面提供了诸多信息。就MRI在PPS及PD鉴别诊断及疾病进展预测中的应用进展予以综述。     

Regional cerebral blood flow and blood volume in patients with subcortical arteriosclerotic encephalopathy (SAE)

The aim of the present study was a detailed analysis of the regional cerebral blood flow and blood volume in patients with subcortical arteriosclerotic encephalopathy (SAE) by means of functional magnetic resonance imaging (MRI). A group of 26 patients with SAE and a group of 16 age-matched healthy volunteers were examined. Using a well-established dynamic susceptibility contrast-enhanced MRI method, the regional cerebral blood flow (rCBF) and blood volume (rCBV) were quantified for each subject in 12 different regions in the brain parenchyma. As compared to healthy volunteers, patients with SAE showed significantly reduced rCBF and rCBV values in white matter regions and in the occipital cortex. Regions containing predominantly grey matter show almost normal rCBF and rCBV values. In conclusion, quantitative analysis of rCBF and rCBV values demonstrates clearly that SAE is a disease that is associated with a reduced microcirculation predominantly in white matter.     

动脉自旋标记灌注成像在癫痫的研究进展

癫痫是脑神经元异常放电引起反复痫性发作的脑功能失调综合征。对癫痫病人脑功能的研究成为近年来的研究热点。其中动脉自旋标记(ASL)灌注成像是一种无创定量测量脑血流灌注量的MR功能成像新技术,可以反映癫痫病人脑血流动力学的相关情况,能为更好地揭示癫痫的病理生理机制提供新的理论依据。就ASL新技术在癫痫的研究进展及临床应用进行综述。     

Turbo STIR magnetic resonance imaging as a whole-body screening tool for metastases in patients with breast carcinoma: preliminary clinical experience

This study was undertaken to assess the utility of whole-body turbo short tau inversion recovery (STIR) magnetic resonance imaging (MRI) to detect metastases to liver, brain, and bone as a single examination in women with breast cancer. Seventeen patients with biopsy-proven breast cancer and suspected metastatic disease attending over a 12-month period referred for both conventional imaging and whole-body MRI were included in the study. Three patients were found to be free of metastases at both conventional and MR imaging. Appendicular or axial skeletal metastases were identified in 11 of 17 patients, with correlation between findings at whole-body MRI and scintigraphy in 15 of the 17 patients. Five patients had evidence of hepatic metastases on whole-body MRI, of which metastases were identified in only three patients at CT despite contrast enhancement. Four patients had brain abnormalities (metastases in three patients, meningioma in one patient) detected on both whole-body and dedicated brain MRI. Preliminary clinical experience suggests that turbo STIR whole-body MRI may represent a convenient and cost-effective method of total body screening for metastases in patients with breast carcinoma.     

Quantitative cerebral blood flow in dynamic susceptibility contrast MRI using total cerebral flow from phase contrast magnetic resonance angiography

Dynamic susceptibility contrast magnetic resonance imaging during bolus injection of gadolinium contrast agent is commonly used to investigate cerebral hemodynamics. The large majority of clinical applications of dynamic susceptibility contrast magnetic resonance imaging to date have reported relative cerebral blood flow values because of dependence of the result on the accuracy of determining the arterial input function, the robustness of the singular value decomposition algorithm, and others. We propose a calibration approach that directly measures the total (i.e., whole brain) cerebral blood flow in individual subjects using phase contrast magnetic resonance angiography. The method was applied to data from 11 patients with intracranial pathology. The sum of squares variance about the mean (uncorrected: white matter = 105.6, gray matter = 472.2; corrected: white matter = 34.1, gray matter = 99.8) after correction was significantly lower for white matter (P = 0.045) and for gray matter (P = 0.011). However, the mean gray and white matter cerebral blood flow in the contralateral hemisphere were not significantly altered by the correction. The proposed phase contrast magnetic resonance angiography calibration technique appears to be one of the most direct correction schemes available for dynamic susceptibility contrast magnetic resonance imaging cerebral blood flow values and can be performed rapidly, requiring only a few minutes of additional scan time. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.     

乳腺癌MR弥散加权成像研究进展

MR在乳腺癌诊断方面的应用价值已经得到广泛认同,为增加检出乳腺癌的敏感性,需应用多种MR扫描技术。然而,常规MR在检测及描述乳腺病变特征时具有一定的局限性,弥散加权成像作为一种重要的功能成像技术,能够反映组织的生物物理学特征,有较大的发展前景。弥散加权成像是唯一能够检测活体组织内水分子弥散运动的非侵入性方法,可以检测出组织结构在分子水平上的改变。其成像时间短,敏感性高,无需使用对比剂,并且能比常规MR检查更早的发现病变,因此,它已经广泛应用于脑部疾病中,也越来越多地应用于乳腺疾病方面。本文就弥散加权成像在乳腺癌的应用方面予以综述。     

Neuroimaging of autism

Neuroimaging studies done by means of magnetic resonance imaging (MRI) have provided important insights into the neurobiological basis for autism. The aim of this article is to review the current state of knowledge regarding brain abnormalities in autism. Results of structural MRI studies dealing with total brain volume, the volume of the cerebellum, caudate nucleus, thalamus, amygdala and the area of the corpus callosum are summarised. In the past 5 years also new MRI applications as functional MRI and diffusion tensor imaging brought considerable new insights in the pathophysiological mechanisms of autism. Dysfunctional activation in key areas of verbal and non-verbal communication, social interaction, and executive functions are revised. Finally, we also discuss white matter alterations in important communication pathways in the brain of autistic patients.     

Comparison of arterial spin-labeling techniques and dynamic susceptibility-weighted contrast-enhanced MRI in perfusion imaging of normal brain tissue

OBJECTIVES: To evaluate relative cerebral blood flow (rCBF) in normal brain tissue using arterial spin-labeling (ASL) methods and first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) magnetic resonance imaging (MRI). METHODS: Sixty-two patients with brain metastases were examined on a 1.5 T-system up to 6 times during routine follow-up after stereotactic radiosurgery. Perfusion values in normal gray and white matter were measured using the ASL techniques ITS-FAIR in 38 patients, Q2TIPS in 62 patients, and the first-pass DSC echo-planar (EPI) MRI after bolus administration of gadopentetate dimeglumine in 42 patients. Precision of the ASL sequences was tested in follow-up examinations in 10 healthy volunteers. RESULTS: Perfusion values in normal brain tissue obtained by all sequences correlated well by calculating Pearson's correlation coefficients (P < 0.0001) and remained unchanged after stereotactic radiosurgery as shown by analysis of variance (P > 0.05). CONCLUSION: Both ASL and DSC EPI MRI yield highly comparable perfusion values in normal brain tissue.     

Neuroimaging in cerebrovascular disorders: measurement of cerebral physiology after stroke and assessment of stroke recovery

Nuclear medicine imaging can play an important role in the diagnosis of stroke risk, the differential diagnosis of vascular and parenchymal cerebral abnormalities, and the understanding and management of poststroke recovery. Radionuclide brain-imaging methods can assess hemodynamic, vascular, and metabolic status before and after stroke. Several techniques, including vasodilatory stress imaging with regional cerebral blood flow (rCBF) single-photon emission computed tomography (SPECT), oxygen extraction methods with positron emission tomography (PET), and spectroscopic imaging with magnetic resonance spectroscopic imaging, offer ways to distinguish vascular from parenchymal dysfunction and to determine whether any observed abnormalities in cerebral blood flow are primary or secondary disease manifestations. The value of radionuclide imaging in assessing the efficacy of several interventional surgical procedures is presented. Data from several imaging modalities bearing on the controversial issue of luxury perfusion and reperfusion injury are analyzed, including some of the discrepancies between animal and human clinical data. Imaging evidence for white matter disease and microangiopathy is analyzed, including a quantitative rCBF pattern analysis that distinguishes between typical Alzheimer's disease and microangiopathy by using multivariate analysis of variance curve profile analysis, which shows results of significant differences in the circumferential cortical blood flow profiles at P =.01. Microangiopathy showed rCBF reduction in the frontal and frontotemporal regions as compared with the more typical reduction in posterior temporal-parietal rCBF diminution characteristic of Alzheimer's disease. Several functional neuroimaging approaches to the study of cerebral poststroke reorganization are analyzed in the context of 2 major models of recovery: the resolution of diaschisis and reorganization in spared brain. Research on these issues is presented with SPECT, PET, magnetic resonance imaging, and magnetic resonance spectroscopy. Data show how standard structural magnetic resonance imaging, (99m)Tc hexamethylpropylene amine oxime SPECT, PET imaging, and magnetic resonance spectroscopy can be used to identify the extent of permanent damage versus penumbral and remote effects of a stroke. The results of the analysis of the pure-diaschisis model show a high correlation between the rCBF brain SPECT defect volume in the cortex and the magnetic resonance spectroscopic imaging (MRSI) change in the white matter. There is a statistically significant positive correlation between the 2 (P <.01; r(2) = 0.94). The increased creatine/N-acetyl aspartate and reduced rCBF are proposed to be due to an increase in the white matter creatine component due to diaschisis and the repair mechanisms associated with increased astrocytosis, in addition to a reduction of N-acetyl aspartate in diaschitic white matter. Xenon-133 dynamic SPECT is shown to be a quantitative and sensitive measure of cerebrovascular status and hemodynamic constraints in both spared and affected brain, providing evidence for reorganization and cerebral plasticity. Fluorine-18 PET and (31)P spectroscopic imaging data show reorganizational changes in the contralesional hemisphere after stroke. The phosphocreatine-adenosine triphosphate ratio in the contralesional hemisphere was 38% +/- 17% higher than in the ipsilateral hemisphere. The phosphocreatine-adenosine triphosphate ratio was highly correlated (r = 0.88, P <.05) with increasing (18)F-fluorodeoxyglucose uptake. These results showed that there is a parallel change in glucose metabolism and high-energy phosphate metabolism associated with poststroke recovery that is proposed to be due to cerebral reorganization in the contralateral premotor cortex. The value of these results on rehabilitation strategy, including possible criteria for the use of facilitatory versus compensatory approaches, is analyzed.     

老年多发性脑梗死诊断中MRI与CT影像检查的应用研究

目的分析在多发性的脑梗死老年患者中行核磁共振(MRI)和CT诊断的价值。方法纳入2018年1-12月多发性脑梗死老年患者50例,全部患者都分别实施核磁共振(MRI)和CT,比较两种方式诊断情况。结果 MRI组阳性检出率为96.00%显著高于CT组检出率78.00%,差异有显著性意义(P<0.05);在50例多发性脑梗死患者中,经病理诊断证实有150个病灶,其中脑室旁有20个、顶叶15个、脑干10个、额叶20个、颞叶10个、基底结节40个、丘脑30个、小脑5个;CT诊断与核磁共振诊断的颞叶、脑室旁对于差异不显著(P>0.05);MRI诊断的顶叶、脑干、额叶、基底结节、丘脑、小脑准确率明显要比CT诊断的高,对比差异有显著性意义(P<0.05)。结论在多发性的脑梗死老年患者中行核磁共振(MRI)效果显著。     

放射性脑损伤的MRI分析

目的：分析放射性脑损伤的MRI表现及MRI诊断的意义。方法：回顾性分析25例放射性脑损伤患者的MRI资料,观察并比较病变的部位、范围及增强表现。结果：急性放射性脑损伤1例,深部脑白质及胼胝体压部对称性长T2信号,脑白质和胼胝体压部肿胀,增强扫描无强化;早期迟发性放射性脑损伤18例,深部脑白质对称性长T2信号,增强扫描无强化;晚期迟发性放射性脑损伤6例,双侧颞叶不均匀长T1长T2信号,增强扫描呈明显花环样强化。结论：放射性脑损伤具有特征性MRI表现,MRI对诊断放射性脑损伤具有重要价值。