New Design of a Photon Counting Detector for Breast CT

描述（由申请人提供）：乳腺癌是一种严重的疾病，仅在美国每年就有大约40,000人死亡。不幸的是，没有一种简单、容易解决的乳腺癌病因，在能够确定和消除根本原因之前，预防死亡的最佳方法是及早发现。在过去的15年里，乳腺癌的死亡率显著降低，部分原因是由于乳房x光片筛查。然而，传统的乳腺膜筛检缺乏敏感性，特别是对于某些亚群的妇女，如乳腺组织致密的妇女。数字乳房x线照相术在致密乳腺组织成像方面显示出了希望，但在其他方面，与胶片x线照相术相比，仅显示出适度的临床效果。通过改善乳房组织的可视化，乳房的x射线计算机断层扫描（CT）可能比传统的乳房x光检查更能提高诊断的准确性。然而，不幸的是，目前的乳腺CT原型系统使用“集成”检测器，这导致次优的空间分辨率和降低病变对比度。由于这种检测器无法区分直接辐射和散射辐射，因此图像中的总体信噪比（SNR）也会降低，这进一步降低了对组织密度和微钙化存在的细微变化的可探测性。为了解决这些问题，我们建议开发一种具有成本效益的高分辨率探测器元件，用于光子计数数字x射线成像系统。该模块将包括一个适当厚度的单片传感器，以高效率吸收x射线，再加上我们特别设计的数字像素传感器（DPS）读出器。这些像素中的每一个都将支持足够高的数据速率，以有效地测量单个x射线源。实际的考虑，如设计模块化将被强调。除了传感器头外，探测器模块还包括读出电子设备、必要的数据采集硬件和软件。对于乳房x线照相术和数字x线照相术中通常使用的x射线能量，该探测器将提供高效率、高分辨率和光子计数能力，并具有适当的能量鉴别水平。因此，模块化检测器有望成为具有临床意义的乳房CT仪器，以及其他医疗和非医疗CT系统和放射照相扫描仪的重要基本构建块。公共卫生相关性：拟议研究的目标是开发一种性能非常高、成本效益高的单个光子计数检测器，用于乳腺CT以及其他医学CT和数字放射摄影。这种探测器的发展将大大提高测量的分辨率和灵敏度。反过来，这将使精确的筛选、诊断和分期以及治疗成为可能，从而遏制甚至治愈某些癌症、心脏疾病和循环系统紊乱。在医疗用途之外，这种探测器对于机场和边境的x射线检查等应用将非常重要。

DESCRIPTION (provided by applicant): Breast cancer is a serious disease that accounts for approximately 40,000 deaths per year in the United States alone. Unfortunately, there is no simple, easily addressed cause of breast cancer, and until the root causes can be identified and eliminated, the best way to prevent mortality is early detection. In the past 15 years, breast cancer mortality has been reduced significantly, which is in part due to screening with film-screen mammography. Nonetheless, conventional film-screen mammography lacks sensitivity, especially for certain subgroups of women such as those with dense breast tissue. Digital mammography has shown promise in imaging dense breast tissue, but has otherwise shown only modest clinical effectiveness over film screen mammography. By improving visualization of breast tissue, X-ray computed tomography (CT) of the breast could potentially provide improvements in diagnostic accuracy over conventional mammography. Unfortunately, however, current breast CT prototype systems use "integrating" detectors, which result in sub- optimal spatial resolution and reduced lesion contrast. Since such detectors have no means to distinguish between direct and scattered radiation, overall signal-to-noise ratio (SNR) in the image is also degraded, which further reduces detectability of subtle changes in the tissue density and presence of microcalcifications. To address these issues we propose to develop a cost-effective high-resolution detector element for use in photon-counting digital X-ray imaging systems. The module will consist of a monolithic sensor of appropriate thickness to absorb X-rays with high efficiency, coupled to our specially designed Digital Pixel Sensor (DPS) readout. Each of these pixels will support a high enough data rate to effectively measure individual source X-rays. Practical considerations such as design modularity will be emphasized. In addition to the sensor head, the detector module will include readout electronics, the necessary data acquisition hardware, and software. For the X-ray energies typically used in mammography and digital radiography, this detector would provide high efficiency, high resolution, and photon counting capability with appropriate levels of energy discrimination. Thus, the modular detector is expected to form an important basic building block for clinically meaningful breast CT instruments in particular and for other medical and non-medical CT systems and radiography scanners in general. PUBLIC HEALTH RELEVANCE: The goal of the proposed research is to develop a very high performance, cost effective, individual photon counting detector for breast CT as well as for other medical CT and digital radiography use. The development of such a detector will significantly improve the resolution and sensitivity with which measurements can be made. In turn, this will allow precise screening, diagnosis and staging, and treatments to curtail the progression of and even cure certain cancers, diseases of the heart and disorders of the circulatory system. Outside medical use, this detector will be extremely important for such applications as X-ray inspections at airports and borders.