Flexible and Efficient Crossed-Grid System for General Radiography

描述(由申请人提供)：众所周知，传统的防散射栅格在控制普通射线照相中的散射的能力方面是有限的。近年来，由于使用效率较低的栅格(薄、高线密度、低铅含量)以及患者规模的增加，这一问题变得更加严重。因此，放射图像质量通常不足以回答有关创伤和其他临床领域的问题，患者需要接受额外的更高剂量、更昂贵的成像检查。在许多情况下，如果有更好的放射成像系统，这些额外的检查可以被取消，医疗保健成本也可以降低。我们提出了一种粗的、高比的空间网格耦合到一个垂直排列的低比常规网格上。综合起来，它们将有效地消除散射，并具有可与常用栅格相媲美的初级传输。低比例网格与一定范围的源到图像距离(SID)兼容。粗略的网格将有铰接式网格板，允许可变的SID和角度视图。为了建立一个紧凑和临床可接受的系统，粗略的网格只能移动一小段距离来模糊网格线。已经证明，这可以通过采用准梯形X射线管电流波形来实现。 在第一阶段中，我们建议证明在普通射线照相中可以获得合适的准梯形X射线管电流波形。在第二阶段，我们建议设计和构建一个紧凑和高效的交叉网格系统，将其连接到X射线发生器，并证明它可以比传统网格更有效地控制散射。该系统将能够适应普通X光照相、胸部X光照相、角度投影、断层照相和一系列小岛屿发展中国家。它可以与屏幕-胶片或数字图像接收器一起使用，并将改进断层合成和双重能量应用。 与公共卫生的相关性：普通射线照相(x射线图像)在卫生保健提供中发挥着重要作用。散射辐射会降低图像质量；近年来，社会和技术趋势加剧了这一问题。我们提出了一种散射控制系统，它在不增加患者剂量的情况下极大地提高了X射线图像的图像质量。

DESCRIPTION (provided by applicant): It is known that conventional anti-scatter grids are limited in their ability to control scatter in general radiography. In recent years this problem has been aggravated by the use of less efficient (thin, high line density, low lead content) grids, and the increasing size of patients. As a result, radiographic image quality is often insufficient to answer questions concerning trauma and other clinical areas, and patients undergo additional higher dose, more expensive imaging exams. In many instances these additional exams could be eliminated and health care costs reduced if a better radiographic imaging system were available. We propose a coarse, high-ratio air interspace grid coupled to an orthogonally aligned low-ratio conventional grid. Together, these will effectively eliminate scatter and will have a primary transmission comparable to commonly used grids. A low-ratio grid is compatible with a range of source-to-image distances (SIDs). The coarse grid will have articulating grid slats, permitting variable SIDs and angled views. In order to build a compact and clinically acceptable system, the coarse grid can only move a short distance to blur out grid lines. It has been demonstrated that this can be accomplished by employing a quasi-trapezoidal x-ray tube current waveform. In Phase I we propose to demonstrate that an appropriate quasi-trapezoidal x-ray tube current waveform can be obtained in general radiography. In Phase II we propose to design and construct a compact and high efficiency crossed-grid system, interface it to an x-ray generator, and demonstrate that it can control scatter much more effectively than a conventional grid. The system will be able to accommodate general radiography, chest radiography, angled projections, tomography, and a range of SIDs. It can be used with either screen-film or digital image receptors, and will improve tomosynthesis and dual energy applications. RELEVANCE TO PUBLIC HEALTH: General radiography (x-ray images) plays an important role in health care delivery. Scattered radiation degrades image quality; social and technical trends have aggravated this problem in recent years. We propose a scatter control system that greatly increases the image quality of x- ray images without increasing patient dose.