多核磁共振19F-MRI在分子影像学中的应用

随着杂核氟、钠、磷等探针和成像技术的发展以及磁共振成像设备和序列的优化,多核磁共振迅速崛起,尤其是其在分子影像方面的研究与应用使包括心血管、肿瘤等众多疾病从传统的形态学影像诊断模式转向早期分子影像精准诊治模式。其中,19F-MRI多核磁共振分子成像近年来备受瞩目。虽然19F-MRI的成像敏感度是1H-MRI的82%,但人体只有牙齿中含有少量的氟,因此无背底噪声的干扰。19F-MRI应用氟类探针,19F自然丰度100%,且无放射性。本文简述了多核磁共振在分子影像学中的应用,并重点介绍19F-MRI分子影像及其应用探针在精准诊治方面的应用。     

乳腺癌功能磁共振成像与生物学预后因子的研究进展

乳腺癌已成为女性最为常见的恶性肿瘤,如何对乳腺癌进行早期诊断、合理化治疗及判断预后意义重大。雌激素受体(ER)、孕激素受体(PR)、Ki-67、人表皮生长因子受体2(HER-2)等免疫组化指标在判断乳腺癌临床类型、转移情况及预后等方面具有重要作用。随着功能磁共振的发展,氢质子磁共振波谱(1H-MRS)、动态增强磁共振成像(DCE-MRI)、扩散加权成像(DWI)等被越来越广泛的用于乳腺组织的检查。研究功能磁共振与乳腺癌预后因子的相关性,对乳腺癌的临床分型、治疗及预后等方面有一定的指导作用。本文就相关进展进行综述。     

早期动态18F-FDG PET/CT成像在实体肿瘤评估中的应用

~(18)F-FDG PET/CT常规代谢成像反应肿瘤的葡萄糖代谢及乏氧情况,而~(18)F-FDG PET/CT早期动态成像能反映PET/CT成像早期肿瘤的灌注情况。由于肿瘤的异质性,在早期动态~(18)F-FDG PET/CT成像,即~(18)F-FDG PET/CT灌注成像中,存在独立于常规60 min~(18)F-FDG PET/CT代谢成像的SUVmax(最大标准摄取值)高摄取区。因此,在临床工作中应用~(18)F-FDG PET/CT早期动态成像,能够进一步对实体肿瘤的活性区域进行评估,能够更好评价患者预后、完善治疗方案。当前~(18)F-FDG早期动态成像已经应用在肝癌、肾癌以及膀胱癌等实体肿瘤诊断中。早期动态~(18)F-FDG PET/CT成像结合常规标准~(18)F-FDG PET/CT代谢成像,对实体肿块进行一站式成像方法,能够更好的对肿瘤进行评估。     

磁共振功能成像在监测乳腺癌新辅助化疗中的应用和进展

近年来,新辅助化疗在原发乳腺癌治疗中运用越来越广泛。影像学手段在评价新辅助化疗疗效、指导临床治疗方案的制定中发挥重要作用。磁共振功能成像的引入,可以加深对恶性乳腺肿瘤的病理生理活动及分子生物学特性的了解,监测化疗疗效,提高早期预测的准确性。本文总结功能学MRI(磁共振成像)探测乳腺癌患者生物标志物的研究现状及发展情况,描述各种生物学标志物特性,评价其潜在的临床应用价值和局限性。以下将对动态增强磁共振成像、弥散加权成像、血氧水平依赖成像以及波谱成像等几种磁共振功能学成像方法的原理进行描述,重点对其在监测乳腺癌新辅助化疗中的应用进行综述。     

观察大脑的秘密

功能磁共振成像(fMRI)是近些年来最受神经科学家宠爱的研究工具。这种技术的历史最早可以追溯到20世纪40年代。当时,科学家首次发现了核磁共振现象(NMRI)——把某些原子的原子核放入磁场     

缺血性心肌病的多模态心血管影像学方法进展

近年来,超声(ultrasound, US)、CT冠状动脉造影(CT coronary angiography, CCTA)、血管内超声(intravenous ultrasound,IVUS)、光学相干断层成像(optical coherence tomography, OCT)、多层螺旋CT成像(multi-slice computed tomography, MSCT)、单光子发射计算机断层成像(single-photon emission computed tomography, SPECT)、正电子发射计算机断层成像(positron emission computed tomography, PET)及心脏磁共振(cardiac magnetic resonance, CMR)等多种心血管成像技术能够提供与冠脉病变及心肌形态和功能相关的解剖学、血流动力学、细胞生物学及病理生理学等方面的重要信息,在缺血性心肌病的临床诊疗及预后评估中发挥着日益重要的作用。然而,如何恰当选择的多模态心血管影像技术是临床医师面临的一大难题。因此,本文在归纳总结主要心血管成像技术临床应用进展的基础上,对多模态心血管影像学在缺血性心肌病相关的冠脉解剖与斑块成像、心肌功能、心肌灌注及心肌活性显像中的临床应用价值进行综述。旨在帮助临床医师客观认识各种成像技术的优势与不足,从而制定最优化的选择方案。     

脊髓磁共振成像技术：方法与应用

脊髓磁共振成像是将磁共振成像应用于脊髓部分(主要是颈髓)的先进研究技术,在人体感觉、运动等基础科学研究,以及脊髓损伤、脊髓炎、慢性疼痛等疾病的临床应用中均已逐渐得到使用。脊髓磁共振成像的发展相比脑成像而言仍处于起步阶段,这主要受限于目前的磁共振成像技术和数据分析方法。本文以认知神经科学和医学领域的基础研究为主,聚焦于脊髓磁共振成像技术的方法与应用。首先介绍了常用多模态脊髓磁共振成像技术的成像原理、成像方法、测量指标及其应用现状,具体包括脊髓定量磁共振成像(结构成像、弥散成像、波谱成像、髓磷脂水分数成像、磁化转移成像和化学交换饱和转移成像等)和脊髓功能磁共振成像等;其次从噪声控制、数据处理流程优化以及可重复性与可信度三个维度介绍了脊髓磁共振成像在数据分析上所面临的技术挑战以及应对策略;最后对脊髓磁共振成像的应用现状和发展前景进行了总结与展望。     

磁共振成像术的基本原理和基本结构

核磁共振(Magnetic Pesonance)作为一种物理现象,用于物理、化学、生物学和医学领域已有20余年的历史。1973年Lauterbur等人首先报导核磁共振成像的技术。近年来作为医学影像的一部门,发展十分迅速,已在世界范围内得到推广。我国也开展了这方面的工作。为避免与核医学中放射成像混淆,现在将此技术称为磁共振成像术(Magnetic Resonance Imaging,简称MRI)。MRI提供的信息量不但大于医学影像学中的其他许多成像术,也不同于已有的X线成像术(CT)。所以用电诊断疾病具有很大的潜在优越性,MRI虽与CT有许多不同之处,但也似都属于计算机成像。且所成图像都是体层图像。因此在图像解释上的许     

弥散加权成像及1H磁共振波谱在新生儿缺氧缺血性脑病中的诊断价值

目的:探讨弥散加权成像、1H磁共振波谱诊断新生儿缺氧缺血性脑病的应用价值。方法:以本院收治的缺氧缺血性脑病新生儿37例为研究组,另选择健康新生儿40例作为对照组,两组新生儿均接受弥散加权成像及1H磁共振波谱检查,观察研究组新生儿普通MRI与弥散加权成像检查结果,对比研究组和对照组新生儿的脑代谢化合物相对浓度。结果:与普通MRI检出率相比,研究组患儿的弥散加权成像信号明显升高,差异存在统计学意义(P0.05)。研究组NAA/Cr比值低于对照组,Cho/Cr、MI/Cr、Glu-Gln/Cr、Lac/Cr比值高于对照组,差异存在统计学意义(P0.05)。结论:临床上诊断新生儿缺氧缺血性脑病时,弥散加权成像与1H磁共振波谱的联合应用可提升诊断准确率,通过对代谢物浓度的分析有利于评价缺氧缺血导致脑组织损害的严重程度。     

乳腺三维超声成像的文献计量和可视化分析*

目的:研究乳腺三维超声成像领域的发展态势并识别研究热点。方法:本研究选取PubMed数据库中乳腺三维超声成像领域的论文为研究对象,采用文献计量学方法,结合可视化分析工具,从论文数量、生命周期、国家/地区分布及合作、机构分布及合作、研究热点等多个角度对乳腺三维超声成像领域进行研究。结果:乳腺三维超声成像领域共发表论文213篇;25个国家/地区在该领域开展研究,其中美国发文量全球排名第一位;全球有100多个机构开展研究,主要以医院和大学为主;识别出研究热点有4个,分别是:乳腺肿瘤的三维弹性成像研究,乳腺X线图像的计算机辅助诊断方法研究,乳腺癌的磁共振成像诊断研究,乳腺肿瘤超声图像特征的算法研究。结论:乳腺三维超声成像领域近几年发展较快,其研究热点主要围绕乳腺癌诊断的相关研究。     

In vivo 19F NMR chemical-shift imaging of Ancistrocladus species

Summary ¹⁹F nuclear magnetic resonance (NMR) imaging and¹⁹F NMR chemical-shift imaging (¹⁹F CSI) have been used to localize fluorinated compounds administered to stems ofAncistrocladus heyneanus andA. abbreviatus for the elucidation of biosynthetic pathways in living plants. This first application of¹⁹F CSI on plants proved CSI to be a valuable technique for mapping fluorinated molecules in plants. Exemplarily using trifluoroacetate as a model compound allowed to select appropriate feeding methods and to optimize both concentration and duration of the application to the plant. The time course of the uptake and distribution of trifluoroacetate was monitored by both¹⁹F imaging and¹⁹F CSI. Fluorinated metabolites formed by uptake of 3-fluoro-3-deoxy-D-glucose were detected with¹⁹F CSI.Abbreviations 3-FDG 3-fluoro-3-deoxy-D-glucose - CSI chemicalshift imaging - NMR nuclear magnetic resonance - SNR signal-to-noise ratio - TFA trifluoroacetate Dedicated to Professor Manfred Christi on the occasion of his 60th birthday     

Determination of the mode of interaction of Mn2+ and Cu2+ with cis-inositol by 13C NMR spectroscopy

Natural abundance ¹³C nuclear magnetic resonance spectroscopy (¹³C NMR) was used to study the mode of binding of Mn²⁺ and Cu²⁺ to the cyclitol, cis-inositol. Resonance linewidths and the electron nuclear relaxation rates [(T₁^e)^?1 values] were used to establish that a unique binding site exists for these metal-ions on this cyclitol involving only the three axial hydroxyl groups. This work may aid in the development of new organometallic complexes used as paramagnetic relaxation agents in magnetic resonance imaging research.     

磁共振弥散加权成像及ADC值对鼻咽癌颅底放疗疗效的评价价值

目的:探讨磁共振弥散加权成像(DWI)及表观扩散系数(ADC)值在鼻咽癌颅底放疗中的临床价值。方法:收集我院于2013年6月~2014年6月复查的40例鼻咽癌患者,分别于放疗前及放疗结束12个月以后对所有患者行常规核磁共振成像(MRI)及DWI检查,测量放疗前、后ADC值,根据影像学检查以及临床诊断结果分为复发组(n=5)及未复发组(n=35)。结果:复发组放疗前ADC值为(0.797±0.031)×10~(-3)mm~2/s,与未复发组放疗前ADC值(0.805±0.028)×10~(-3)mm~2/s比较,差异无统计学意义(P0.05)。复发组放疗结束12个月以后ADC值为(1.097±0.091)×10~(-3)mm~2/s,与未复发组放疗结束12个月以后ADC值(1.705±0.128)×10~(-3)mm~2/s比较,差异有统计学意义(P0.05)。结论:DWI作为一种新兴的磁共振成像技术,对于鼻咽癌颅底放疗疗效的评价具有重要价值,通过DWI对ADC值的测量,可有效的预测患者预后是否良好。     

The efficacy of new colchicine derivatives and viability of the T-Lymphoblastoid cells in three-dimensional culture using F MRI and HPLC-UV ex vivo

The paper describes ex vivo applications of colchicine derivatives for the treatment of human T-Lymphoblastoid (CEM) cells. Moreover, the role of the substitutions of ring A at C-1 and C-7 side chain of colchicine analogues was probed by the synthesis and examination of their effects on the three-dimensional (3-D) CEM cells’ growth. The CEM cells were cultured in the hollow fiber bioreactor (HFB) device. We used ¹H and ¹⁹F magnetic resonance imaging (MRI) to monitor changes in 3-D CEM cell culture. ¹⁹F MRI was used for visualization of the cellular uptake of new fluorine derivatives. Before and after treatment CEM cells profile was investigated with high performance liquid chromatography (HPLC-UV).     

In Vivo Quantification of Inflammation in Experimental Autoimmune Encephalomyelitis Rats Using Fluorine-19 Magnetic Resonance Imaging Reveals Immune Cell Recruitment outside the Nervous System

Progress in identifying new therapies for multiple sclerosis (MS) can be accelerated by using imaging biomarkers of disease progression or abatement in model systems. In this study, we evaluate the ability to noninvasively image and quantitate disease pathology using emerging “hot-spot” ¹⁹F MRI methods in an experimental autoimmune encephalomyelitis (EAE) rat, a model of MS. Rats with clinical symptoms of EAE were compared to control rats without EAE, as well as to EAE rats that received daily prophylactic treatments with cyclophosphamide. Perfluorocarbon (PFC) nanoemulsion was injected intravenously, which labels predominately monocytes and macrophages in situ. Analysis of the spin-density weighted ¹⁹F MRI data enabled quantification of the apparent macrophage burden in the central nervous system and other tissues. The in vivo MRI results were confirmed by extremely high-resolution ¹⁹F/¹H magnetic resonance microscopy in excised tissue samples and histopathologic analyses. Additionally, ¹⁹F nuclear magnetic resonance spectroscopy of intact tissue samples was used to assay the PFC biodistribution in EAE and control rats. In vivo hot-spot ¹⁹F signals were detected predominantly in the EAE spinal cord, consistent with the presence of inflammatory infiltrates. Surprising, prominent ¹⁹F hot-spots were observed in bone-marrow cavities adjacent to spinal cord lesions; these were not observed in control animals. Quantitative evaluation of cohorts receiving cyclophosphamide treatment displayed significant reduction in ¹⁹F signal within the spinal cord and bone marrow of EAE rats. Overall, ¹⁹F MRI can be used to quantitatively monitored EAE disease burden, discover unexpected sites of inflammatory activity, and may serve as a sensitive biomarker for the discovery and preclinical assessment of novel MS therapeutic interventions.     

Development of radioligands with optimized imaging properties for quantification of nicotinic acetylcholine receptors by positron emission tomography

AimsThere is an urgent need for positron emission tomography (PET) imaging of the nicotinic acetylcholine receptors (nAChR) to study the role of the nicotinic system in Alzheimer's and Parkinson's diseases, schizophrenia, drug dependence and many other disorders. Greater understanding of the underlying mechanisms of the nicotinic system could direct the development of medications to treat these disorders. Central nAChRs also contribute to a variety of brain functions, including cognition, behavior and memory.Main methodsCurrently, only two radiotracers, (S)-3-(azetidin-2-ylmethoxy)-2-[¹⁸F]fluoropyridine (2-[¹⁸F]FA) and (S)-5-(azetidin-2-ylmethoxy)-2-[¹⁸F]fluoropyridine (6-[¹⁸F]FA), are available for studying nAChRs in human brain using PET. However, the “slow” brain kinetics of these radiotracers hamper mathematical modeling and reliable measurement of kinetic parameters since it takes 4–7 h of PET scanning for the tracers to reach steady state. The imaging drawbacks of the presently available nAChR radioligands have initiated the development of radioligands with faster brain kinetics by several research groups.Key findingsThis minireview attempts to survey the important achievements of several research groups in the discovery of PET nicotinic radioligands reached recently. Specifically, this article reviews papers published from 2006 through 2008 describing the development of fifteen new nAChR ¹¹C-and ¹⁸F-ligands that show improved imaging properties over 2-[¹⁸F]FA.SignificanceThe continuous efforts of radiomedicinal chemists led to the development of several interesting PET radioligands for imaging of nAChR including [¹⁸F]AZAN, a potentially superior alternative to 2-[¹⁸F]FA.