核磁共振成像在喉部占位的诊断与应用

通过对喉部占位的MRI检查,并与其他影像诊断、动态喉镜像及术中所见,术后病理进行对照分析。认为MRI在显示肿瘤占位、大小、浸润范围等方面,尤其在早期喉癌的诊断上有独特的优点。可为临床选择术式、制定治疗方案等提供可靠的依据。     

97例肝实性占位病变的彩超、MRI诊断与病理分析

为了评估彩超、MRI对肝实性占位病变（删）诊断价值，采用Simens Sonolin Uersa彩超及Synphony1．5T磁共振仪，对HM回声、血供与MRI动态增强扫描（DES）作了比较，并用SPSS10．0软件进行统计分析．结果显示：97例中，血管瘤、转移癌、局灶性结节增生、小肝癌、肝脓肿、肝腺瘤、胆管细胞癌、炎性假瘤分别为29、22、14、12、8、5、4、3例．彩超对其边界、内部回声及血供、血管走行较敏感，MRI对其形态结构及信号能清楚判断；DES能显示其时间一信号曲线特征．彩超、MRI诊断SNL的敏感性、特异性与准确性分别为91％和99％、86％和86％、90％和98％．研究表明：彩超与MRI检查诊断HM均有较高价值，后者对鉴别诊断有重要意义．     

Transputer在核磁共振成像系统中的应用

选择Ｔｒａｎｓｐｕｔｅｒ和ｉＲＭＸ操作系统作为核磁共振成像计算机系统基本的硬件和软件开发环境，使整个系统既有高速的计算能力，又有适应多任务环境的强大的实时控制能力。为了解决缺乏Ｍｕｌｔｉｂｕｓ宿主环境的Ｔｒａｎｓｐｕｔｅｒ开发系统的问题，设计了Ｍｕｌｔｉｂｕｓ总线接口的Ｔｒａｎｓｐｕｔｅｒ母板，并利用ＰＣ机的Ｔｒａｎｓｐｕｔｅｒ开发系统成功地开发了运行在Ｍｕｌｔｉｂｕｓ总线宿主环境中的Ｔｒａｎｓｐ     

磁共振成像技术在颅脑疾病临床中的应用

通过对磁共振成像技术的系统分析，综合介绍了脑功能成像技术在颅脑临床研究中的应用，提出fMRI在临床中的应用目前正在逐步开发。并且对未来提高外科手术质量和病人的生存质量具有巨大的作用。     

核磁共振技术在生物和医学上的应用

本文介绍了在生物和医学领域内应用核磁共振技术的历史，应用的主要方面，以及三种常用的自旋核，并指出了与传统的技术和ＣＴ成像相比，磁共振技术具有更多的优点．     

水灌肠法在大肠癌核磁共振检查中的应用

大肠癌核磁共振成像 (以下简称ＭＲＩ)检查常用的肠道对比剂有气体、水以及含钆的制剂等。本文采用水作为肠道对比剂 ,对 31例大肠癌进行ＭＲＩ检查 ,并对两种水灌肠方法进行比较。1　临床资料(1)一般资料 :本组收集了 2 0 0 1年 3月 - 2 0 0 2年 3月临床诊断为大肠癌而行ＭＲ     

时空编码核磁共振方法及其应用

时空编码(spatiotemporal encoding,SPEN)技术自2002年提出以来以其独特的性质在核磁共振领域引起了广泛的关注.利用SPEN技术可以实现超快速采样,有效降低磁共振波谱和成像的扫描时间;SPEN还具有一定的抗磁场不均匀性影响的能力,可开发应用于磁场条件较差的场合.本文简要介绍了SPEN磁共振波谱...     

磁共振成像诊断听神经瘤的价值

目的：为评价磁共振成像（ＭＲＩ）诊断听神经瘤的价值，本文分析４４例听神经瘤ＭＲＩ表现，探讨该瘤囊性的病理基础及鉴别诊断。方法：采用德国Ｓｉｅｍｅｎｓ１．０Ｔ超导ＭＲ系统，常规ＳＥ序列或快速ＳＥ序列Ｔ１中权，Ｔ２加权成像，层厚３－７ｍｍ，其中３６例静脉内注射Ｇｄ－ＤＴＰＡ增强扫描。结果：本组４６个肿瘤中，有２个（４．３％）地内耳道ＩＡＣ内；６个（１３％）仅限于桥小脑角（ＣＰＡ）；３８个（８２．６％）     

The preparation and application of microbubble contrast agent combining ultrasound imaging and magnetic resonance imaging

Encapsulated gas microbubbles are well known as ultrasound contrast agents （UCAs） for medical ultrasound （US） imaging. With the development of shell materials and preparation technologies, the application of microbubbles has been enormously popular in molecular imaging, drug delivery and targeted therapy, etc. The objective of this study is to develop Fe3O4 nanoparticle-inclusion microbubble construct. The in vitro US imaging experiment indicates that the Fe3O4 nanoparticle-inclusion microbubbles have higher US enhancement than those without Fe3O4 nanoparticle-inclusion. According to the microbubble dynamic theory, the acoustic scattering properties can be quantified by scattering cross-section of the shell. The scattering study on Fe3O4 nanoparticle-inclusion microbubbles of different concentration shows that within a certain range of concentration, the scattering cross-section of microbubble increases with the addition of Fe3O4 nanoparticles. When exceeding the concentration range, the ultrasonic characteristic of microbubbles is damped. On the other hand, since Fe3O4 nanoparticles can also serve as the Magnetic Resonance Imaging （MRI） contrast agent, they can be potentially used as contrast agents for the double-modality （MRI and US） clinical studies. However, it is important to control the concentration of Fe3O4 nanoparticles in the shell in order to realize the combined functions of US and MRI.     

On-demand degradable magnetic resonance imaging nanoprobes

Theranostic nanoprobes can potentially integrate imaging and therapeutic capabilities into a single platform,offering a new personalized cancer diagnostic tool....     

Functional magnetic resonance imaging of amphetamine craving

The aim of this study is to identify the brain activity associated with amphetamine craving for understanding the neurobiology of addiction by watching pictures of happy, sad or amphetamine. Brain activity was measured in 12 amphetamine addicts and 12 healthy subjects by fMRI while the subjects watched pictures designed to elicit happy feelings, sad feelings, or the desire to use amphetamine. The result demonstrated that amphetamine cues led to abnormally high cingulate and low frontal lobe activation in amphetamine addicts, who showed abnormalities in affect-related brain activation.     

Functional magnetic resonance imaging of amphetamine craving

The aim of this study is to identify the brain activity associated with amphetamine craving for understanding the neurobiology of addiction by watching pictures of happy, sad or amphetamine. Brain activity was measured in 12 amphetamine addicts and 12 healthy subjects by fMRI while the subjects watched pictures designed to elicit happy feelings, sad feelings, or the desire to use amphetamine. The result demonstrated that amphetamine cues led to abnormally high cingulate and low frontal lobe activation in amphetamine addicts, who showed abnormalities in affect-related brain activation.     

关于磁共振图像质量评价方法的探讨

磁共振信号得到的人体断层图像,不仅可以反映形态学的信息,还可以从图像中得到与病理有关的信息,其图像质量的好坏将直接影响着医护人员对病人的诊断结果.目前对磁共振图像质量评价的重要指标是信号强度均匀度.但在信号强度几乎相同的条件下,这一评价指标的有效性较低.为了对磁共振图像质量作更加有效的评判,可采用比较信噪比的最大与最小区域的信号强度标准差的方法,其评价的有效性较高.     

磁纳米分子影像探针研究热点与挑战

 近年来,磁纳米材料在分子影像领域的应用得到科研人员的广泛关注。常用的磁性纳米探针是超顺磁性氧化铁颗粒（SPION）,它具有较好的水质子横向弛豫时间（T₂）弥散加权核磁共振成像造影剂的性能。通过对SPION制备及表面修饰进行改进,使纳米颗粒具有磁共振造影功能和干细胞标记、药物/基因递送的功能。综述了SPION兼具影像探针和磁共振成像可视化治疗方面的功能。虽然已有多种磁纳米材料进入临床研究,但结合当前研究瓶颈以及纳米药物制备方法的发展,制备造影效果较好、药物生物相容性较高、具有靶向性及临床转换潜力较强的SPION是新一代磁纳米探针研究亟需解决的问题。     

Research progress of magnetic resonance imaging contrast agents

Magnetic resonance imaging (MRI) is a clinical diagnostic modality, which has become popular in hospitals around the world. Approximately 30% of MRI exams include the use of contrast agents. The research progress of the paramagnetic resonance imaging contrast agents was described briefly. Three important approaches in the soluble paramagnetic resonance imaging contrast agents design including nonionic, tissue-specific and macromolecular contrast agents were investigated. In addition, the problems in the research and development in future were discussed.     

Nuclear magnetic resonance imaging of a single cell

Nuclear magnetic resonance (NMR) imaging is now an established tool in clinical imaging and competes favourably with conventional X-ray computerized tomography (CT) scanning. The drive behind NMR imaging has primarily been in the area of whole-body imaging, which has been limited clinically to fields of up to 1.5 T (60 MHz). It is recognized that there may be substantial advantages in obtaining images with sub-millimetre spatial resolution. Also, there may be benefits to imaging at higher fields, since the signal increases as the square of the magnetic field. Using a modified 9.5 T 89-mm-bore high-resolution NMR spectrometer, we have now obtained the first NMR images of a single cell, demonstrating the advent of the NMR imaging microscope. The NMR microscope is expected to have considerable impact in the areas of biology, medicine and materials science, and may serve as a precursor to obtaining such resolutions on human subjects.     

基于正则化的SPACE-RIP并行磁共振成像重建算法

采用并行磁共振成像可以提高成像速度和图像分辨率,但这是以牺牲重建图像的信噪比为代价的。为此,该文提出了一种基于正则化的并行磁共振成像重建算法,降低由于阵列线圈的几何相关而造成的信噪比损失。以预扫描图像作为最后重建图像的先验信息,用L曲线方法求解最佳正则化参数。实验表明,该方法能较大限度地减弱噪声对重建结果的影响,当SPACE-RIP并行成像技术的加速因子达到4时,仍可得到高质量的高分辨率重建影像。重建后的图像质量良好,对临床诊断具有较高实用价值。