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="http://jove.unicartagenaproxy.elogim.com/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="http://jove.unicartagenaproxy.elogim.com/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="http://jove.unicartagenaproxy.elogim.com/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="http://jove.unicartagenaproxy.elogim.com/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="http://jove.unicartagenaproxy.elogim.com/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="http://jove.unicartagenaproxy.elogim.com/files/ftp_upload/3236/3236movie6.wmv">点击这里查看电影。</a>

<ol>
	<li>Martinez, L. C., Vano, E., Gutierrez, F., Rodriguez, C., Gilarranz, R., Manzanas, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patient+doses+from+fluoroscopically+guided+cardiac+procedures+in+pediatrics.">Patient doses from fluoroscopically guided cardiac procedures in pediatrics.</a> Phys Med Biol. 52, 4749-4759 (2007).</li><li>Strauss, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pediatric+interventional+radiography+equipment:+safety+considerations.">Pediatric interventional radiography equipment: safety considerations.</a> Pediatr Radiol. 36, 126-135 (2006).</li><li>Preston, D. L., Cullings, H., Suyama, A., Funamoto, S., Nishi, N., Soda, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solid+cancer+incidence+in+atomic+bomb+survivors+exposed+in+utero+or+as+young+children.">Solid cancer incidence in atomic bomb survivors exposed in utero or as young children.</a> J Natl Cancer Inst. 100, 428-436 (2008).</li><li>Wolff, M., Keevil, J., Speidel, M., Wilfey, M., Wilfley, B., Star-Lack, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pilot+study+with+a+scanning-beam+digital+x-ray+system.">Pilot study with a scanning-beam digital x-ray system.</a> Am J Cardiol. 94, (2004).</li><li>Speidel, M. A., Wilfley, B. P., Star-Lack, J. M., Heanue, J. A., Betts, T. D., VanLysel, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+entrance+exposure+and+signal-to-noise+ratio+between+an+SBDX+prototype+and+a+wide-beam+cardiac+angiographic+system.">Comparison of entrance exposure and signal-to-noise ratio between an SBDX prototype and a wide-beam cardiac angiographic system.</a> Med Phys. 33, 2728-2743 (2006).</li><li>Speidel, M. A., Wilfley, B. P., Star-Lack, J. M., Heanue, J. A., VanLysel, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scanning-beam+digital+x-ray+(SBDX)+technology+for+interventional+and+diagnostic+cardiac+angiography.">Scanning-beam digital x-ray (SBDX) technology for interventional and diagnostic cardiac angiography.</a> Med Phys. 33, 2714-2727 (2006).</li><li>Funk, T., Burion, S., Bechtel, K. L., Solomon, E. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> X-ray dose reduction by adaptive source equalization and electronic region-of-interest control. , (2011).</li><li>Burion, S., Bechtel, K. L., Lowell, A. P., Heanue, J. A., Solomon, E. G., Funk, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+equalization+filtration:+dose+savings+with+region-based+exposure+control+using+a+scanning-beam+X-ray+source.">Real-time equalization filtration: dose savings with region-based exposure control using a scanning-beam X-ray source.</a> , (2010).</li><li>Boone, J. M., Duryea, J., Moore, E. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Filter+wheel+equalization+in+chest+radiography:+demonstration+with+a+prototype+system.">Filter wheel equalization in chest radiography: demonstration with a prototype system.</a> Radiology. 196, 845-850 (1995).</li><li>Vlasbloem, H., Kool, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AMBER:+a+scanning+multiple-beam+equalization+system+for+chest+radiography.">AMBER: a scanning multiple-beam equalization system for chest radiography.</a> Radiology. 169, 29-34 (1988).</li></ol>

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

Universidad de Cartagena UDEC

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

Management of Respiratory Motion Artefacts in 18F-fluorodeoxyglucose Positron Emission Tomography using an Amplitude-Based Optimal Respiratory Gating Algorithm

Positron emission tomography (PET) combined with X-ray computed tomography (CT) is an important molecular imaging platform that is required for accurate diagnosis and clinical staging of a variety of diseases. The advantage of PET imaging is the ability to visualize and quantify a myriad of biological processes in vivo with high sensitivity and accuracy. However, there are multiple factors that determine image quality and quantitative accuracy of PET images. One of the foremost factors influencing image quality in PET imaging of the thorax and upper abdomen is respiratory motion, resulting in respiration-induced motion blurring of anatomical structures. Correction of these artefacts is required for providing optimal image quality and quantitative accuracy of PET images.
Several respiratory gating techniques have been developed, typically relying on acquisition of a respiratory signal simultaneously with PET data. Based on the respiratory signal acquired, PET data is selected for reconstruction of a motion-free image. Although these methods have been shown to effectively remove respiratory motion artefacts from PET images, the performance is dependent on the quality of the respiratory signal being acquired. In this study, the use of an amplitude-based optimal respiratory gating (ORG) algorithm is discussed. In contrast to many other respiratory gating algorithms, ORG permits the user to have control over image quality versus the amount of rejected motion in the reconstructed PET images. This is achieved by calculating an optimal amplitude range based on the acquired surrogate signal and a user-specified duty cycle (the percentage of PET data used for image reconstruction). The optimal amplitude range is defined as the smallest amplitude range still containing the amount of PET data required for image reconstruction. It was shown that ORG results in effective removal of respiration-induced image blurring in PET imaging of the thorax and upper abdomen, resulting in improved image quality and quantitative accuracy.

Management of Respiratory Motion Artefacts in 18F-fluorodeoxyglucose Positron Emission Tomography using an Amplitude-Based Optimal Respiratory Gating Algorithm

Amplitude-based optimal respiratory gating (ORG) effectively removes respiratory-induced motion blurring from clinical 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) images. Correction of FDG-PET images for these respiratory motion artefacts improves image quality, diagnostic and quantitative accuracy. Removal of respiratory motion artefacts is important for adequate clinical management of patients using PET.

使用基于振幅的最佳呼吸门控算法对 18个F-氟二氧氧葡萄糖正电子发射断层扫描中的呼吸运动人工制品进行管理

Positron emission tomography (PET) combined with X-ray computed tomography (CT) is an important molecular imaging platform that is required for accurate ...

科研

癌症研究

Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform

A rat glioblastoma model to mimic chemo-radiation treatment of human glioblastoma in the clinic was previously established. Similar to the clinical treatment, computed tomography (CT) and magnetic resonance imaging (MRI) were combined during the treatment-planning process. Positron emission tomography (PET) imaging was subsequently added to implement sub-volume boosting using a micro-irradiation system. However, combining three imaging modalities (CT, MRI, and PET) using a micro-irradiation system proved to be labor-intensive because multimodal imaging, treatment planning, and dose delivery have to be completed sequentially in the preclinical setting. This also results in a workflow that is more prone to human error. Therefore, a user-friendly algorithm to further optimize preclinical multimodal imaging-based radiation treatment planning was implemented. This software tool was used to evaluate the accuracy and efficiency of dose painting radiation therapy with micro-irradiation by using an in silico study design. The new methodology for dose painting radiation therapy is superior to the previously described method in terms of accuracy, time efficiency, and intra- and inter-user variability. It is also an important step towards the implementation of inverse treatment planning on micro-irradiators, where forward planning is still commonly used, in contrast to clinical systems.

Here we present a protocol to perform preclinical positron emission tomography-based radiotherapy in a rat glioblastoma model using algorithms developed in-house to optimize the accuracy and efficiency.

使用小动物辐射研究平台在胶质母细胞瘤大鼠模型中基于正电子发射断层扫描的剂量绘画放射治疗

A rat glioblastoma model to mimic chemo-radiation treatment of human glioblastoma in the clinic was previously established. Similar to the clinical ...

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 ...

医学

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 ...

Cone Beam Intraoperative Computed Tomography-based Image Guidance for Minimally Invasive Transforaminal Interbody Fusion

Transforaminal lumbar interbody fusion (TLIF) is commonly used for the treatment of spinal stenosis, degenerative disc disease, and spondylolisthesis. Minimally invasive surgery (MIS) approaches have been applied to this technique with an associated decrease in estimated blood loss (EBL), length of hospital stay, and infection rates, while preserving outcomes with traditional open surgery. Previous MIS TLIF techniques involve significant fluoroscopy that subjects the patient, surgeon, and operating room staff to non-trivial levels of radiation exposure, particularly for complex multi-level procedures. We present a technique that utilizes an intraoperative computed tomography (CT) scan to aid in placement of pedicle screws, followed by traditional fluoroscopy for confirmation of cage placement. Patients are positioned in the standard fashion and a reference arc is placed in the posterior superior iliac spine (PSIS) followed by intraoperative CT scan. This allows for image-guidance-based placement of pedicle screws through a one-inch skin incision on each side. Unlike traditional MIS-TLIF that requires significant fluoroscopic imaging during this stage, the operation can now be performed without any additional radiation exposure to the patient or operating room staff. After completion of the facetectomy and discectomy, final TLIF cage placement is confirmed with fluoroscopy. This technique has the potential to decrease operative time and minimize total radiation exposure.

The purpose of this article is to provide image-guidance for minimally invasive transforaminal interbody fusion.

锥形束术中计算机断层扫描图像指南,用于微创跨体间融合

Transforaminal lumbar interbody fusion (TLIF) is commonly used for the treatment of spinal stenosis, degenerative disc disease, and spondylolisthesis. ...

Improved Registration of 3D CT Angiography with X-ray Fluoroscopy for Image Fusion During Transcatheter Aortic Valve Implantation

The fusion of 3D anatomical models derived from high-fidelity pre-interventional computed tomography angiography (CTA), and x-ray (XR) fluoroscopy to facilitate anatomical guidance is of huge interest for complex cardiac interventions like TAVI procedures with cerebral protection. Co-registration of CTA and XR has been introduced either based on additional intraoperative non-/contrast-enhanced cone-beam computed tomography (CBCT) or two separate aortograms. With the related increase of radiation exposure and/or contrast agent (CA) dose, a potential additional risk for the patient is introduced. Here, we propose a modified co-registration approach making use of arteriograms of the iliofemoral arteries, routinely performed during the femoral puncture and sheath introduction. On-the-fly refinement of the co-registration during the on-going procedure enables accurate co-registration without any additional angiograms, thus reducing CA, XR dose and procedure time, while simultaneously improving operator confidence and procedure safety.

The aim of this study was to improve the co-registration for image fusion (IF) of pre-interventional CT data with real-time x-ray (XR) fluoroscopy during transfemoral transcatheter aortic valve implantation (TAVI).

经导管主动脉瓣植入术中 X 线透视 3D CT 血管造影的改进与影像融合

The fusion of 3D anatomical models derived from high-fidelity pre-interventional computed tomography angiography (CTA), and x-ray (XR) fluoroscopy to ...

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies

Radiation therapy is a frequently used modality for the treatment of solid cancers. Although the mechanisms of cell kill are similar for all forms of radiation, the in vivo properties of photon and proton beams differ greatly and maybe exploited to optimize clinical outcomes. In particular, proton particles lose energy in a predictable manner as they pass through the body. This property is used clinically to control the depth at which the proton beam is terminated, and to limit radiation dose beyond the target region. This strategy can allow for substantial reductions in radiation dose to normal tissues located just beyond a tumor target. However, the degradation of proton energy in the body remains highly sensitive to tissue density. As a consequence, any changes in tissue density during the course of treatment may significantly alter proton dosimetry. Such changes may occur through alterations in body weight, respiration, or bowel filling/gas, and may result in unfavorable dose deposition. In this manuscript, we provide a detailed method for the delivery of proton therapy using both passive scatter and pencil beam scanning techniques for prostate cancer. Although the described procedure directly pertains to prostate cancer patients, the method may be adapted and applied for the treatment of virtually all solid tumors. Our aim is to equip readers with a better understanding of proton therapy delivery and outcomes in order to facilitate the appropriate integration of this modality during cancer therapy.

The fundamentals of radiation planning and delivery for proton therapy using prostate cancer as a model are presented. The application of these principles to other selected disease sites highlights how proton radiotherapy may enhance clinical outcomes for cancer patients.

质子治疗在实体肿瘤恶性肿瘤选择中的临床应用

Radiation therapy is a frequently used modality for the treatment of solid cancers. Although the mechanisms of cell kill are similar for all forms of ...

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function relationships at the joint level remain challenging to quantify due to difficulties in accurately measuring dynamic joint motion. The soft tissue artifact errors inherent in optical skin marker motion capture are exacerbated by the depth of the hip joint within the body and the large mass of soft tissue surrounding the joint. Thus, the complex relationship between bone shape and hip joint kinematics is more difficult to study accurately than in other joints. Herein, a protocol incorporating computed tomography (CT) arthrography, three-dimensional (3D) reconstruction of volumetric images, dual fluoroscopy, and optical motion capture to accurately measure the dynamic motion of the hip joint is presented. The technical and clinical studies that have applied dual fluoroscopy to study form-function relationships of the hip using this protocol are summarized, and the specific steps and future considerations for data acquisition, processing, and analysis are described.

In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture.

在维沃 使用双氟镜检查进行动态负重活动时臀部关节肌学的量化

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function ...

Reduction of Radiation Exposure during Endovascular Treatment of Peripheral Arterial Disease Combining Fiber Optic RealShape Technology and Intravascular Ultrasound

Vascular surgeons and interventional radiologists face chronic exposure to low-dose radiation during endovascular procedures, which may impact their health in the long term due to their stochastic effects. The presented case shows the feasibility and efficacy of combining Fiber Optic RealShape (FORS) technology and intravascular ultrasound (IVUS) to reduce operator exposure during the endovascular treatment of obstructive peripheral arterial disease (PAD). 
FORS technology enables real-time, three-dimensional visualization of the full shape of guidewires and catheters, embedded with optical fibers that use laser light instead of fluoroscopy. Hereby, radiation exposure is reduced, and spatial perception is improved while navigating during endovascular procedures. IVUS has the capacity to optimally define vessel dimensions. Combining FORS and IVUS in a patient with iliac in-stent restenosis, as shown in this case report, enables passage of the stenosis and pre- and post-percutaneous transluminal angioplasty (PTA) plaque assessment (diameter improvement and morphology), with a minimum dose of radiation and zero contrast agent. The aim of this article is to describe the method of combining FORS and IVUS stepwise, to show the potential of merging both techniques in view of reducing radiation exposure and improving navigation tasks and treatment success during the endovascular procedure for the treatment of PAD.

Described here is a stepwise method of combining Fiber Optic RealShape technology and intravascular ultrasound to show the potential of merging both techniques, in view of the reduction of radiation exposure and improvement of navigation tasks and treatment success during an endovascular procedure for the treatment of peripheral arterial disease.

结合光纤RealShape技术和血管内超声，减少外周动脉疾病血管内治疗期间的辐射暴露

Vascular surgeons and interventional radiologists face chronic exposure to low-dose radiation during endovascular procedures, which may impact their ...

Irradiator Commissioning and Dosimetry for Assessment of LQ &alpha; and &beta; Parameters, Radiation Dosing Schema, and in vivo Dose Deposition

Radiation dosimetry is critical in the accurate delivery and reproducibility of radiation schemes in preclinical models for high translational relevance. Prior to performing any in vitro or in vivo experiments, the specific dose output for the irradiator and individual experimental designs must be assessed. Using an ionization chamber, electrometer, and solid water setup, the dose output of wide fields at isocenter can be determined. Using a similar setup with radiochromic films in the place of the ionization chamber, dose rates for smaller fields at different depths can also be determined. In vitro clonogenic survival assays of cancer cells in response to radiation treatment are inexpensive experiments that provide a measure of inherent radio-sensitivity of cell lines by fitting these data with the traditional linear-quadratic model. Model parameters estimated from these assays, combined with the principles of biologic effective doses, allows one to develop varying fractionation schedules for radiation treatment that provide equivalent effective doses in tumor-bearing animal experiments. This is an important factor to consider and correct for in comparing in vivo radiation therapy schedules to eliminate potential confounding of results due to variance in the delivered effective doses. Taken together, this article provides a general method for dose output verification preclinical animal and cabinet irradiators, in vitro assessment of radio-sensitivity, and verification of radiation delivery in small living organisms.

Irradiator Commissioning and Dosimetry for Assessment of LQ &#945; and &#946; Parameters, Radiation Dosing Schema, and in vivo Dose Deposition

Radiation dosimetry provides a technique for enhancing the accuracy of preclinical experiments and ensuring that the radiation doses delivered are closely related to clinical parameters. This protocol describes steps to be taken at each phase during preclinical radiation experiments to ensure proper experimental design.

LQ α和β参数、辐射剂量模式和体内剂量沉积评估的辐照器调试和剂量测量

Radiation dosimetry is critical in the accurate delivery and reproducibility of radiation schemes in preclinical models for high translational relevance. ...

通过自适应曝光的减少剂量X射线透视影像

摘要

探索更多视频

此视频中的章节

使用基于振幅的最佳呼吸门控算法对 ¹⁸个F-氟二氧氧葡萄糖正电子发射断层扫描中的呼吸运动人工制品进行管理

使用小动物辐射研究平台在胶质母细胞瘤大鼠模型中基于正电子发射断层扫描的剂量绘画放射治疗

自愿屏气技术减少心脏剂量的左乳房放射治疗

非透视导管跟踪透视减少介入电

锥形束术中计算机断层扫描图像指南,用于微创跨体间融合

经导管主动脉瓣植入术中 X 线透视 3D CT 血管造影的改进与影像融合

质子治疗在实体肿瘤恶性肿瘤选择中的临床应用

在维沃使用双氟镜检查进行动态负重活动时臀部关节肌学的量化

结合光纤RealShape技术和血管内超声，减少外周动脉疾病血管内治疗期间的辐射暴露

LQ α和β参数、辐射剂量模式和体内剂量沉积评估的辐照器调试和剂量测量

通过自适应曝光的减少剂量X射线透视影像

摘要

探索更多视频

此视频中的章节

使用基于振幅的最佳呼吸门控算法对 18个F-氟二氧氧葡萄糖正电子发射断层扫描中的呼吸运动人工制品进行管理

使用小动物辐射研究平台在胶质母细胞瘤大鼠模型中基于正电子发射断层扫描的剂量绘画放射治疗

自愿屏气技术减少心脏剂量的左乳房放射治疗

非透视导管跟踪透视减少介入电

锥形束术中计算机断层扫描图像指南,用于微创跨体间融合

经导管主动脉瓣植入术中 X 线透视 3D CT 血管造影的改进与影像融合

质子治疗在实体肿瘤恶性肿瘤选择中的临床应用

在维沃 使用双氟镜检查进行动态负重活动时臀部关节肌学的量化

结合光纤RealShape技术和血管内超声，减少外周动脉疾病血管内治疗期间的辐射暴露

LQ α和β参数、辐射剂量模式和体内剂量沉积评估的辐照器调试和剂量测量

使用基于振幅的最佳呼吸门控算法对 ¹⁸个F-氟二氧氧葡萄糖正电子发射断层扫描中的呼吸运动人工制品进行管理

在维沃使用双氟镜检查进行动态负重活动时臀部关节肌学的量化