作者想感谢安妮SANDMAN，基思西原和布赖恩Wilfley三重环网技术，他们在这个项目中的贡献。这项工作是由美国国立卫生研究院的挑战格兰特5RC1HL100436 - 0。

1。系统设置<ol><li>成立魅影图像等中心（即从准直仪40厘米）。 </li><li>成立磷酸二铵仪，X射线剂量测量前的准直器（图4）。 </li><li>对SBDX系统的电源。 </li><li>选择系统的运行模式。目前，我们正在使用的15fps的帧速率的视角（FOV）7"领域的X射线源的峰值电压设置在9KW X射线源动力80kVp。 </li></ol> 2。数据采集<ol><li>从控制计算机启动数据采集。在数据采集过程中，探测器的图像被保存到系统内存。在SBDX系统下面的步骤: <ol><li>电子束扫描每个焦斑位置，顺序栅格时尚（图5）。 </li><li>电子束击中传输的目标，并产生X -射线（电影2）。 </li><li>在每个焦斑位置，X射线光子照亮使用聚焦准直器的探测器，从而投射到探测器的成像量的一小部分。 </li><li>对于每个焦斑位置，探测器将创建一个探测器的形象，这是直接存储在系统内存中。 </li><li> 7选定的操作模式"15fps的协调中心提供71x71点。每个焦斑位置是照亮共8微秒。曝光时间必须被打破，因为X射线目标的热限制为1微秒增量。因此，光束照亮每1微秒，并移动到下一个聚焦点位置的焦斑位置的目标。在稍后的时间，每个焦斑重新讨论，以完成8微秒曝光。作为一个探测器图像创建为每个焦斑照明，有共有40328探测器，在大约60ms的采集和存储到内存中的图像。 </li></ol></li></ol> 3。图像重建<ol><li>该SBDX本质上是一个断层合成系统，对象是根据不同的角度，从源头照明。位于准直器和检测器之间的成像体积内的任何飞机可以被重建。下列步骤说明如何重建个人飞机的部分图像，或将一个复合或平面选定的图像。在临床SBDX系统的步骤3.2至3.4将实时执行。 </li><li>重建模拟器上选择图像重建参数。 </li><li>运行图像重建算​​法。在图像重建算​​法执行以下步骤: <ol><li>阅读每一个人的探测器形象。 </li><li>规模探测器图像平面重建的规模相匹配。 </li><li>转移的图像，根据他们的焦斑源位置，并把它们添加到重建的平面（电影3）。 </li><li>为每个焦斑位置重复最后两个步骤。 </li><li>执行后处理过滤，除去移位操作所造成的模式。 </li><li>此时，一个平面重建（图6），解剖我们的对象是可见的。 </li></ol></li><li>如果要求，运行算法来创建一个平面上选定的图像。该算法执行下列步骤: <ol><li>重复点3.2.1至3.2.6创建平面选定的图像所需的32架飞机。飞机通常有一个0.5毫米（图7和电影5 4，电影）的间距。 </li><li>对于每一个图像的一部分，包含在重点对象的飞机被选定为最终选定的平面图像（图8和电影6）的一部分。 </li></ol></li><li>如果有必要，重新放置在视野的中心心脏的幻象。 </li><li>执行步骤2.1至3.3幻象是正确的，直到视野内。 </li><li>记录从这种非均衡的形象DAP米的剂量面积乘积。 </li></ol> 4。自适应曝光的文件生成新的运作模式<ol><li>装入以前获得的探测器图像自适应曝光模拟器。 </li><li>选择算法参数自适应曝光。 </li><li>运行自适应曝光模拟器。模拟器执行下列步骤: <ol><li>每个探测器形象的光子的目标是确定基于用户选择的门槛。 </li><li>对于每个焦斑位置，在光子探测器的图像数目是确定的。从该焦斑位置探测器的图像积累，直到达到的光子的目标号码或最多8个重新扫描（图9）。 </li><li>因此，我们得到了一个重新扫描地图，详细介绍每个焦斑位置是多少次亮起（图10）。 </li><li>重新扫描地图是合并文件是用来运行的SBDX系统操作模式。 </li></ol></li></ol> 5。均衡的图像采集<ol><li>装入更新的运作模式文件SBDX系统。 </li><li>从控制计算机启动数据采集。数据采集​​是进行详细的2.1.1至2.1.5。在对比以前的收购，X射线束焦斑位置打开或关闭，根据我们的重新扫描地图。由于对照明的总人数小于标准收购，X射线剂量减少。 </li><li>记录磷酸二铵计测量剂量面积乘积。 </li><li>新收购扳平的详细在3.2至3.4的数据运行的图像重建算​​法。 </li><li>显示扳平重建的图像（图11）。 </li></ol> 6。数据分析<ol><li>比较的非均衡的图像和均衡的图像测量的剂量。 </li><li>观察重建图像之间的均衡和非均衡的差异。 </li></ol> 7。代表性的成果: 图8和图11显示了一个标准的形象和一个均衡的图像之间的比较。与DAP米的剂量测量证明节省30％的剂量，在均衡使用重新扫描遮罩，如图10所示的图像。 此外，均衡是一种非常有效的方式，压缩动态范围，使的图像更美观，无需后处理的需要。 如图所示，均衡过滤可用于保存剂量。然而，均衡还可以用来增加的源动力相匹配的非均衡形象的辐射剂量，提高图像质量。这样，图像的黑暗区域获得更多的光子，导致降低图像的噪点。 <img src="/files/ftp_upload/3236/3236fig1.jpg" alt="图1" /> 图1。常规的X线透视系统 。常规系统有一个单一的焦斑X射线源和大面积探测器。病人是定位接近探测器。 <img src="/files/ftp_upload/3236/3236fig2.jpg" alt="图2" /> 图2。 SBDX系统。SBDX系统在逆几何。一个大扫描束X射线源，照亮了小面积的探测器。病人是远从探测器定位。 <img src="/files/ftp_upload/3236/3236fig3.jpg" alt="图3" /> 图3。 1） 数据采集流程图。一个非均衡形象的幻影收购。 2）提取数据从磁盘阵列。 3）自适应曝光算法作为输入数据，创建一个曝光或重新扫描面具。 4）重新扫描面膜结合源控制计算机的原始操作模式。 5）一个相同的幻像扳平图像获取，存储到磁盘阵列中。 6）非均衡和均衡的数据集是从磁盘阵列中提取，图像重建软件重建每个数据集在不同的平面。 7）两个图像重建软件的输出。 8）这两种图像显示。 <img src="/files/ftp_upload/3236/3236fig4.jpg" alt="图4" /> 图4。系统设置。幻像是摆在等中心的X射线源和探测器之间的病人表。 X射线源和幻象之间放置一个剂量面积乘积米。 <img src="/files/ftp_upload/3236/3236fig5.jpg" alt="图5" /> 图5。 X射线源产生的电子束是由电子枪，扫描每个准直孔栅格方式。从准直仪的一侧开始，束扫描每一洞的顺序。在该行的结束，梁被关闭，并在下一行的开始位置，并扫描该行开始。通过这种方式，电子束扫描整个准直仪，由71孔71扫描约60ms的八倍。 <img src="/files/ftp_upload/3236/3236fig6.jpg" alt="图6" /> 图6。标准的重建图像 。我们的拟人化的显示与碘化冠状动脉心脏幻象的重建图像。 7"视野和15fps的图像，并在45厘米从单一平面的X射线的目标是重建。 <img src="/files/ftp_upload/3236/3236fig7.jpg" alt="图7" /> 图7。多平面重建表示准直器和检测器之间的不同重建飞机。蓝色锥体说明如何探测器图像重建飞机backprojected。 <img src="/files/ftp_upload/3236/3236fig8.jpg" alt="图8" /> 图8。选定的平面图像 ，这张图片是32架飞机组成。只有船只的selecte对比图6二维平面中的重点，每艘船是关注的焦点。 <img src="/files/ftp_upload/3236/3236fig9.jpg" alt="图8" /> 图9。均等过滤步骤。准直仪扫描（顶部），探测器接收到一个不同的计数率，根据对象的不透明度（底部）。每个准直孔是八倍（八重新扫描）扫描。在第一次重新扫描，联络点被点亮顺序沿行，从左边开始，和通量测量每孔。在未来重新扫描，照明是重复的行开始。对于每个焦斑，计数添加到以前的值。如果计数的总数超过了原先设定的阈值，这个洞不会被照亮在下面的重新扫描。在当前的实现，这个过程是离线执行，导致创造的面具，随后将被用于获取一个均衡的图像重新扫描。 <img src="/files/ftp_upload/3236/3236fig10.jpg" alt="图10" /> 图10。重新扫描地图生成均衡过滤算法 ，这个图片的每个像素代表的准直器的焦斑。因此，该图像是71x71像素。每个像素点​​的灰度级的重新扫描，焦斑，从0（黑）8个（白色）。我们观察到的图像的右侧部分，重新​​扫描数是非常低的。因此，这些联络点，每年只有一次或两次将亮起。这个区域对应的重建图像肺场区（图6），其中的图像几乎是因为这方面的低X射线吸收饱和的。 <img src="/files/ftp_upload/3236/3236fig11.jpg" alt="图11" /> 图11。飞机选择了扳平的形象 ，这个形象是自适应曝光后的重建算法的输出。此图片已获得相同的操作模式7"为标准的图像（图8）15fps的，但与自适应曝光，使基于扫描面具图10。图像更均匀强度，并因此船只出现在更高的对比度，尤其是在黑暗的地区，在图像的右侧，有没有在肺野不再饱和。 电影1。逆几何动画的SBDX系统。SBDX系统的运作。一个大扫描束X射线源，照亮了小面积的探测器。病人是从探测器定位为止。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/3236/3236movie1.swf">点击这里查看电影。</a> 电影2。产生X射线 ，在每个焦斑，电子束撞击钨靶产生X射线。重点朝着探测器的X射线束的准直器， <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/3236/3236movie2.swf">点击这里查看影片。</a> 电影3。图像重建的动画，这个动画使用探测器图像重建的最终图像的过程。对于每个准直仪（左下）焦斑，相应的探测器（左上）被投影到平面重建（右）。在这个动画中，我们代表了三个在不同的X射线源的距离<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/3236/3236movie3.avi">正在重建的飞机。</a>点击这里查看电影。 电影4。平面选择。SBDX系统是一个断层合成成像系统。平面重建和可视化，可以由<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/3236/3236movie4.swf">用户选择，点击这里</a>查看电影。 电影5。多平面动画视频显示不同平面重建增加准直器的距离。值得注意的是，碘的冠状动脉和重点取决于它们的物理位置<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/3236/3236movie5.avi">。点击这里查看影片</a> 。 电影6。选择3D平面动画 ，三维可视化重建焦平面。焦平面随着深度的增加转向更多。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/3236/3236movie6.wmv">点击这里查看电影。</a>

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作者是三重环网技术的员工产生在这篇文章中使用的仪器。

我们表明，剂量节省可以使用均衡技术。在本文中，我们只能说明我们的技术是如何应用，不讨论图像质量的影响。但是，重要的是要注意，我们的目标是，保持均衡的图像目标信噪比。基本假设是，在非均衡的图像，信噪比是高度非均匀。特别是，像肺野的明亮区域表现出更高的信号噪音比率比要执行的诊断任务。均衡让我们降低了信号的信噪比，在这些领域，以保持信号在图像较暗区域的噪声比。目前，我们正在执行噪声测量的研究，以验证我们的做法。初步结果显示，节省30％的剂量是可以实现的，相当于信号暗区的图像7，8信噪比。 在多年的科学文献，均衡过滤的潜力已被确认。但是，到目前为止，所有公布的实现涉及机械快门或过滤器，极大地阻碍了这种方法9,10的实用工具。在这里，我们表明，均衡的基础上全面电子化的方式，克服机械实现的问题。 在临床SBDX系统，这里介绍的步骤大部分将在硬件中实现，并会在实时数据采集过程中进行。均衡算法实时运行，所显示的图像会被默认扳平。该算法将动态调整其参数，根据成像的主体，主体的议案，并改变龙门位置。我们将继续改善我们的算法，并进一步发展我们的方法将是必要的的，以便实时实现。

x-ray dose reduction through adaptive exposure in fluoroscopic imaging

广泛用于X射线透视图像引导，在心脏介入。然而，在这些程序中的辐射剂量可以高，这是一个重大关切，特别是在儿科的应用，。儿科程序一般比对成年人进行的复杂得多，因此长四到八倍，平均1。此外，儿童可以接受由10岁至10透视程序，并已被证明有三倍其整个2,3比一般人群的生活发展的致命癌症的风险较高。 我们已经表明，辐射剂量可显著减少成人心脏手术，通过使用我们的扫描光束数字化X射线系统（SBDX）4 -透视成像系统，采用逆成像几何5,6（图1，电影1和图2）。而不是一个单一的焦斑和扩展的探测器，在传统的系统中使用的，我们的方法利用扩展的X射线源与多个焦点集中于一个小型探测器点。我们的X射线源，由电子束扫描顺序照明可达9000焦斑位置。每个焦斑项目到探测器上的成像量的一小部分。在最终图像直接到探测器预计于传统的系统相比，SBDX使用一个专门的算法，从9000探测器图像重建的最终图像。 儿科的应用，预计将节约与SBDX系统的剂量小于成人程序。然而，SBDX系统允许通过实施电子自适应曝光技术，节省额外的剂量。这种方法的关键是多束扫描的SBDX系统技术，而不是具有相同的辐射剂量暴露的图像的每一个部分，我们可以动态地改变曝光取决于暴露了该地区的不透明度。因此，我们可以显着降低暴露在放射线地区和保持更多的不透明区域的曝光。在我国目前实施的自适应曝光需要用户交互（图3）。然而，在未来，自适应曝光将实时和全自动。 我们已经完成了拟人化的幻像的实验和比较测量辐射剂量与不使用剂量面积乘积（DAP）米的自适应曝光。这里介绍在实验中，我们发现30％的剂量减少。

Watch this Scientific Journal Video about X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging at JoVE.com

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

我们正在开发一个动态自适应曝光技术，使用我们的扫描光束数字X射线系统。 ，而不是均匀暴露的对象，曝光调整，根据对象的不透明度。在这里，我们显示一个拟人化的幽灵，在节约30％的剂量的实验。

通过自适应曝光的减少剂量X射线透视影像

X-ray fluoroscopy is widely used for image guidance during cardiac intervention. However, radiation dose in these procedures can be high, and this is a ...

x-ray-dose-reduction-through-adaptive-exposure-in-fluoroscopic-imaging

Nanyang Technological University

Research

JoVE Journal

Medicine

14.3K 次观看.  Triple Ring Technologies. 我们正在开发一个动态自适应曝光技术，使用我们的扫描光束数字X射线系统。 ，而不是均匀暴露的对象，曝光调整，根据对象的不透明度。在这里，我们显示一个拟人化的幽灵，在节约30％的剂量的实验。

视频: X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

Segmentation and Measurement of Fat Volumes in Murine Obesity Models Using X-ray Computed Tomography

Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are associated with obesity, though the precise underlying mechanisms that contribute to the disease are currently being delineated.2,3 Several small animal models of obesity have been developed and are employed in a variety of studies.4 A critical component to these experiments involves the collection of regional and/or total animal fat content data under varied conditions.
Traditional experimental methods available for measuring fat content in small animal models of obesity include invasive (e.g. ex vivo measurement of fat deposits) and non-invasive (e.g. Dual Energy X-ray Absorptiometry (DEXA), or Magnetic Resonance (MR)) protocols, each of which presents relative trade-offs. Current invasive methods for measuring fat content may provide details for organ and region specific fat distribution, but sacrificing the subjects will preclude longitudinal assessments. Conversely, current non-invasive strategies provide limited details for organ and region specific fat distribution, but enable valuable longitudinal assessment. With the advent of dedicated small animal X-ray computed tomography (CT) systems and customized analytical procedures, both organ and region specific analysis of fat distribution and longitudinal profiling may be possible. Recent reports have validated the use of CT for in vivo longitudinal imaging of adiposity in living mice.5,6 Here we provide a modified method that allows for fat/total volume measurement, analysis and visualization utilizing the Carestream Molecular Imaging Albira CT system in conjunction with PMOD and Volview software packages.

Fat content analysis is routinely conducted in studies utilizing murine obesity models. Emerging methods in small animal CT imaging and analysis are providing for longitudinal detail rich fat content analysis. Here we detail step by step procedures for performing small animal CT imaging, analysis, and visualization.

利用X射线计算机断层扫描在小鼠肥胖模型的FAT卷的分割和测量

Obesity is associated with increased morbidity and mortality as well as reduced metrics in quality of life.1 Both environmental and genetic factors are ...

科研

医学

Assessing Teratogenic Changes in a Zebrafish Model of Fetal Alcohol Exposure

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, including mental retardation due to disordered and damaged brain development. Fetal alcohol spectrum disorder (FASD) is a term used to cover a continuum of birth defects that occur due to maternal alcohol consumption, and occurs in approximately 4% of children born in the United States. With 50% of child-bearing age women reporting consumption of alcohol, and half of all pregnancies being unplanned, unintentional exposure is a continuing issue2. In order to best understand the damage produced by ethanol, plus produce a model with which to test potential interventions, we developed a model of developmental ethanol exposure using the zebrafish embryo. Zebrafish are ideal for this kind of teratogen study3-8. Each pair lays hundreds of eggs, which can then be collected without harming the adult fish. The zebrafish embryo is transparent and can be readily imaged with any number of stains. Analysis of these embryos after exposure to ethanol at different doses and times of duration and application shows that the gross developmental defects produced by ethanol are consistent with the human birth defect. Described here are the basic techniques used to study and manipulate the zebrafish FAS model.

In order to understand the molecular mechanisms of the ethanol-induced developmental damage, we have developed a zebrafish model of ethanol exposure and are exploring the physical, cellular, and genetic alterations that occur after ethanol exposure1. We then seek to find potential interventions and rapidly test them in this animal model.

在斑马鱼模型的胎儿酒精暴露评估致畸的变化

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, ...

Imaging Glioma Initiation In Vivo Through a Polished and Reinforced Thin-skull Cranial Window

Glioma is the one of the most lethal forms of human cancer. The most effective glioma therapy to date-surgery followed by radiation treatment-offers patients only modest benefits, as most patients do not survive more than five years following diagnosis due to glioma relapse 1,2. The discovery of cancer stem cells in human brain tumors holds promise for having an enormous impact on the development of novel therapeutic strategies for glioma 3. Cancer stem cells are defined by their ability both to self-renew and to differentiate, and are thought to be the only cells in a tumor that have the capacity to initiate new tumors 4. Glioma relapse following radiation therapy is thought to arise from resistance of glioma stem cells (GSCs) to therapy 5-10. In vivo, GSCs are shown to reside in a perivascular niche that is important for maintaining their stem cell-like characteristics 11-14. Central to the organization of the GSC niche are vascular endothelial cells 12. Existing evidence suggests that GSCs and their interaction with the vascular endothelial cells are important for tumor development, and identify GSCs and their interaction with endothelial cells as important therapeutic targets for glioma. The presence of GSCs is determined experimentally by their capability to initiate new tumors upon orthotopic transplantation 15. This is typically achieved by injecting a specific number of GBM cells isolated from human tumors into the brains of severely immuno-deficient mice, or of mouse GBM cells into the brains of congenic host mice. Assays for tumor growth are then performed following sufficient time to allow GSCs among the injected GBM cells to give rise to new tumors-typically several weeks or months. Hence, existing assays do not allow examination of the important pathological process of tumor initiation from single GSCs in vivo. Consequently, essential insights into the specific roles of GSCs and their interaction with the vascular endothelial cells in the early stages of tumor initiation are lacking. Such insights are critical for developing novel therapeutic strategies for glioma, and will have great implications for preventing glioma relapse in patients. Here we have adapted the PoRTS cranial window procedure 16and in vivo two-photon microscopy to allow visualization of tumor initiation from injected GBM cells in the brain of a live mouse. Our technique will pave the way for future efforts to elucidate the key signaling mechanisms between GSCs and vascular endothelial cells during glioma initiation.

Imaging Glioma Initiation In Vivo Through a Polished and Reinforced Thin-skull Cranial Window

By combining a polished and reinforced thin-skull (PoRTS) cranial window and glioblastoma (GBM) cell injection, we can observe glioma initiation and growth from injected GBM cells in the brain of a live mouse longitudinally.

成像神经胶质瘤启动<em在体内</em&gt;通过抛光和增强的薄膜头骨的颅窗

Glioma is the one of the most lethal forms of human cancer. The most effective glioma therapy to date-surgery followed by radiation treatment-offers ...

Minimal Erythema Dose (MED) Testing

Ultraviolet radiation (UV) therapy is sometimes used as a treatment for various common skin conditions, including psoriasis, acne, and eczema. The dosage of UV light is prescribed according to an individual's skin sensitivity. Thus, to establish the proper dosage of UV light to administer to a patient, the patient is sometimes screened to determine a minimal erythema dose (MED), which is the amount of UV radiation that will produce minimal erythema (sunburn or redness caused by engorgement of capillaries) of an individual's skin within a few hours following exposure. This article describes how to conduct minimal erythema dose (MED) testing. There is currently no easy way to determine an appropriate UV dose for clinical or research purposes without conducting formal MED testing, requiring observation hours after testing, or informal trial and error testing with the risks of under- or over-dosing. However, some alternative methods are discussed.

Minimal Erythema Dose MED Testing

This article describes how to conduct minimal erythema dose (MED) testing in order to determine the lowest dose of ultraviolet radiation that will cause erythema (burning) when administered to an individual.

最小红斑剂量（MED）测试

Ultraviolet radiation (UV) therapy is  sometimes used as a treatment for various common skin conditions, including  psoriasis, acne, and eczema. The ...

Dual-phase Cone-beam Computed Tomography to See, Reach, and Treat Hepatocellular Carcinoma during Drug-eluting Beads Transarterial Chemo-embolization

The advent of cone-beam computed tomography (CBCT) in the angiography suite has been revolutionary in interventional radiology. CBCT offers 3 dimensional&#160;(3D) diagnostic imaging in the interventional suite and can enhance minimally-invasive therapy beyond the limitations of 2D angiography alone. The role of CBCT has been recognized in transarterial chemo-embolization (TACE) treatment of hepatocellular carcinoma (HCC). The recent introduction of a CBCT technique: dual-phase CBCT (DP-CBCT) improves intra-arterial HCC treatment with drug-eluting beads (DEB-TACE). DP-CBCT can be used to localize liver tumors with the diagnostic accuracy of multi-phasic multidetector computed tomography (M-MDCT) and contrast enhanced magnetic resonance imaging (CE-MRI) (See the tumor), to guide intra-arterially guidewire and microcatheter to the desired location for selective therapy (Reach the tumor), and to evaluate treatment success during the procedure (Treat the tumor). The purpose of this manuscript is to illustrate how DP-CBCT is used in DEB-TACE to see, reach, and treat HCC.

Dual-phase cone-beam computed tomography (DP-CBCT) is a useful intraprocedural imaging technique for transarterial chemo-embolization treatment with drug-eluting beads of hepatocellular carcinoma. DP-CBCT has been used to perform three major steps in oncologic interventional radiology: tumor localization (see), navigation and intraprocedural catheter guidance (reach), and intraprocedural evaluation of treatment success (treat).

双相位锥束CT看看，到达，并在药物洗脱珠Transarterial化疗栓塞治疗原发性肝癌

The advent of cone-beam computed tomography (CBCT) in the angiography suite has been revolutionary in interventional radiology. CBCT offers 3 ...

Controlling Parkinson's Disease With Adaptive Deep Brain Stimulation

Adaptive deep brain stimulation (aDBS) has the potential to improve the treatment of Parkinson&#39;s disease by optimizing stimulation in real time according to fluctuating disease and medication state. In the present realization of adaptive DBS we record and stimulate from the DBS electrodes implanted in the subthalamic nucleus of patients with Parkinson&#39;s disease in the early post-operative period. Local field potentials are analogue filtered between 3 and 47 Hz before being passed to a data acquisition unit where they are digitally filtered again around the patient specific beta peak, rectified and smoothed to give an online reading of the beta amplitude. A threshold for beta amplitude is set heuristically, which, if crossed, passes a trigger signal to the stimulator. The stimulator then ramps up stimulation to a pre-determined clinically effective voltage over 250 msec and continues to stimulate until the beta amplitude again falls down below threshold. Stimulation continues in this manner with brief episodes of ramped DBS during periods of heightened beta power.
Clinical efficacy is assessed after a minimum period of stabilization (5 min) through the unblinded and blinded video assessment of motor function using a selection of scores from the Unified Parkinson&#39;s Rating Scale (UPDRS). Recent work has demonstrated a reduction in power consumption with aDBS as well as an improvement in clinical scores compared to conventional DBS. Chronic aDBS could now be trialed in Parkinsonism.

Adaptive deep brain stimulation (aDBS) is effective for Parkinson&#8217;s disease, improving symptoms and reducing power consumption compared to conventional deep brain stimulation (cDBS). In aDBS we track a local field potential biomarker (beta oscillatory amplitude) in real time and use this to control the timing of stimulation.

控制帕金森氏症与自适应深部脑刺激

Adaptive deep brain stimulation (aDBS) has the potential to improve the treatment of Parkinson&#39;s disease by optimizing stimulation in real time ...

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these techniques, patients hold their breath while radiotherapy is delivered, pushing the heart down and away from the radiotherapy field. Despite clear dosimetric benefits, these techniques are not yet in widespread use. One reason for this is that commercially available solutions require specialist equipment, necessitating not only significant capital investment, but often also incurring ongoing costs such as a need for daily disposable mouthpieces. The voluntary breath-hold technique described here does not require any additional specialist equipment. All breath-holding techniques require a surrogate to monitor breath-hold consistency and whether breath-hold is maintained. Voluntary breath-hold uses the distance moved by the anterior and lateral reference marks (tattoos) away from the treatment room lasers in breath-hold to monitor consistency at CT-planning and treatment setup. Light fields are then used to monitor breath-hold consistency prior to and during radiotherapy delivery.

The current priority in breast cancer radiotherapy is to reduce cardiac doses without compromising target tissue coverage. The voluntary breath-hold technique described here is a simple, inexpensive solution to this problem and capable of being instituted widely without the need for specialized equipment.

自愿屏气技术减少心脏剂量的左乳房放射治疗

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these ...

Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab. Furthermore, in a subset of indications such as supraventricular tachycardias, NFCV enables a fully non-fluoroscopic procedure and allows the lab staff to work without wearing lead aprons. With this protocol, we demonstrate that even complex procedures such as ablations of atrial fibrillation, that are typically associated with fluoroscopy times of &#62;30 min in conventional settings, can safely be performed with a reduction of &#62;90% in fluoroscopy exposure by the additional use of NFCV.

Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system.

非透视导管跟踪透视减少介入电

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that ...

Real-time X-ray Imaging of Lung Fluid Volumes in Neonatal Mouse Lung

At birth, the lung undergoes a profound phenotypic switch from secretion to absorption, which allows for adaptation to breathing independently. Promoting and sustaining this phenotype is critically important in normal alveolar growth and gas exchange throughout life. Several in vitro studies have characterized the role of key regulatory proteins, signaling molecules, and steroid hormones that can influence the rate of lung fluid clearance. However, in vivo examinations must be performed to evaluate whether these regulatory factors play important physiological roles in regulating perinatal lung liquid absorption. As such, the utilization of real time X-ray imaging to determine perinatal lung fluid clearance, or pulmonary edema, represents a technological advancement in the field. Herein, we explain and illustrate an approach to assess the rate of alveolar lung fluid clearance and alveolar flooding in C57BL/6 mice at post natal day 10 using X-ray imaging and analysis. Successful implementation of this protocol requires prior approval from institutional animal care and use committees (IACUC), an in vivo small animal X-ray imaging system, and compatible molecular imaging software.

We present a protocol to assess the rate of alveolar fluid clearance or pulmonary edema in neonatal mouse lung using X-ray imaging technology.

在新生小鼠肺肺流体体积的实时X射线成像

At birth, the lung undergoes a profound phenotypic switch from secretion to absorption, which allows for adaptation to breathing independently. Promoting ...

Two-Dimensional X-Ray Angiography to Examine Fine Vascular Structure Using a Silicone Rubber Injection Compound

Angiography is an essential tool for the study of vascular structures in various research fields. The aim of this study is to introduce a simple angiographic method for examining the fine vascular structure of unfixed, fresh tissue using a silicone rubber injection compound and soft tissue X-ray system. This study is especially focused on flap territories used in reconstructive surgery. This study employs angiography with a silicone rubber injection compound in various experimental conditions using Sprague-Dawley rats. First, 15 mL of MV compound and 15 mL of diluent is mixed. Then, 1.5 mL of the curing agent is prepared, and a 24G catheter is cannulated in the common carotid artery of the rat. A three-way stopcock is then connected to a catheter, and the radiopaque agent, after being mixed with the prepared curing agent, is injected immediately without spillage. Finally, as the agent solidifies, the specimen is harvested, and an angiographic image is obtained using a soft tissue X-ray system. This method indicates that high-quality angiography showing fine vascular structures can be easily and simply obtained within in a short period of time.

This study presents a simple two-dimensional angiographic method to examine fine vascular structures using a silicone rubber injection compound and soft tissue X-ray system.

通过自适应曝光的减少剂量X射线透视影像

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