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New Acquisition and Reconstruction Techniques for Interventional Flat Detector-Based C-Arm CT

基于介入性平面探测器的 C 形臂 CT 的新采集和重建技术

基本信息

批准号：
233427018
负责人：
Professor Dr. Marc Kachelrieß
金额：
--
依托单位：
Ziehm Imaging GmbH
依托单位国家：
德国
项目类别：
Research Grants (Transfer Project)
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/233427018?language=en
关键词：
New Acquisition Reconstruction Techniques Interventional

项目摘要

Interventional imaging using C-arm systems is a widely available and well-accepted tool to guide interventional procedures. Besides projective imaging more and more systems are capable of acquiring tomographic data. However, tomographic image quality suffers from many limitations and, compared to diagnostic CT, is rather low. On the one hand this is due to the flat detector technology used in C-arm systems. On the other hand there are a number of methods known and used in diagnostic CT that are not adapted and utilized yet for interventional imaging.This project aims at improving image quality in C-arm-based flat detector CT. To do so, scan trajectories other than the circle scan shall be introduced. Of course the well-known and highly successful spiral trajectory of diagnostic CT cannot be used in C-arm systems. As an alternative, however, the use of two circle scans acquired at different tilt angles, or the combination of a circle trajectory with a line or arc trajectory may be highly promising. The arising redundancies have the potential to allow ignoring rays running through the long axis of metal implants, i.e. those that are responsible for metal artifacts, during image reconstruction. Thus a dedicated scan protocol that avoids metal artifacts can be designed. In a similar manner, cone-beam artifacts can be reduced or avoided. In addition new trajectories will help to increase the size of the field of measurement.We are also planning to improve image quality and to reduce patient dose by introducing dual energy CT methods into interventional imaging. This also requires modifications of the x-ray generator and x-ray tube control. Besides the improvement of the contrast-to-noise ratio in tomographic images this will also allow to apply projective imaging methods such as virtual digital subtraction angiography where the background is automatically removed from the vessel of interest.The project shall be conducted in collaboration with the company Ziehm Imaging Gmbh, Nürnberg, Germany, the leading manufacturer of mobile C-arm systems. An existing functional model of a C-arm system, that differs from the Ziehm products in allowing for a full angular range of 180° plus fan angle and therefore does not suffer from limited angle artifacts, will be dedicated to the project. This functional model will be modified according to the project's needs, e.g. to allow to move along the new trajectories or to be able to acquire dual energy data with fast tube voltage switching. The control interface to the functional model shall be generalized and made available to the research unit to allow an easy implementation and realization of the new ideas.

使用C型臂系统的介入成像是一种广泛可用和被广泛接受的指导介入操作的工具。除了投影成像，越来越多的系统能够获取层析数据。然而，断层图像质量受到许多限制，与诊断性CT相比，相当低。一方面，这是由于C形臂系统中使用的平板探测器技术。另一方面，已知并用于诊断CT的许多方法还没有适应和用于介入成像。本项目旨在提高基于C臂的平板探测器CT的图像质量。为此，应引入圆扫描以外的扫描轨迹。当然，众所周知和非常成功的螺旋轨迹诊断性CT不能用于C形臂系统。然而，作为另一种选择，使用在不同倾角获得的两次圆形扫描，或者将圆形轨迹与直线或弧形轨迹相结合，可能是非常有希望的。在图像重建期间，产生的冗余可能允许忽略穿过金属植入物的长轴的射线，即那些负责金属伪影的射线。因此，可以设计一种避免金属伪影的专用扫描方案。以类似的方式，可以减少或避免锥束伪影。此外，新的轨迹将有助于增加测量范围。我们还计划通过将双能量CT方法引入介入成像来提高图像质量和减少患者剂量。这也需要对X射线发生器和X射线管控制进行改进。除了提高断层图像的对比度噪声比外，这还将允许应用虚拟数字减影血管成像等投影成像方法，其中背景会自动从感兴趣的血管中移除。该项目将与移动C形臂系统的领先制造商德国纽伦堡Ziehm成像有限公司合作进行。C形臂系统的现有功能模型将专门用于该项目，该模型与Ziehm产品的不同之处在于允许180°加扇角的全角度范围，因此不会受到有限角度伪影的影响。这个功能模型将根据项目的需要进行修改，例如，允许沿着新的轨迹移动，或者能够通过快速的管电压切换来获取双能源数据。应推广功能模型的控制接口，并提供给研究单位，以便于新想法的实施和实现。