Novel tileable scintillator-based photon counting detector for clinical X-ray CT

用于临床 X 射线 CT 的新型可平铺闪烁体光子计数探测器

• 批准号: 8952025
• 负责人: Hamid Sabet
• 金额: $ 8.7万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8952025
• 关键词: Affect; Algorithms; Amplifiers; Applications Grants; Area; Attention; Behavior; CdZnTe; Cerium; Charge; Clinical; Consumption; Coupled; Data; Development; Diagnostic; Diagnostic Imaging; Diagnostic radiologic examination; Dose; Electric Capacitance; Electronics; Feasibility Studies; Future; Goals; Image; Individual; Lasers; Light; Lutetium; Mammography; Measures; Medical Imaging; Noise; Nuclear; Optics; Output; Patients; Performance; Photons; Physiologic pulse; Process; Property; Radiation; Research; Research Proposals; Resolution; Roentgen Rays; Semiconductors; Shapes; Side; Signal Transduction; System; Technology; Thick; Time; X-Ray Computed Tomography; base; clinical application; contrast imaging; cost; cost effective; density; design; detector; imaging system; improved; indexing; meetings; millimeter; novel; photon-counting detector; public health relevance; reconstruction; technology development

 DESCRIPTION (provided by applicant): Delivering high contrast diagnostic CT images while minimizing patient radiation dose has been the center of majority of all CT-related research. In this regard, improvement in the detector technology (alongside with automatic exposure control and improved reconstruction algorithms) may have the greatest impact. Current X- ray CT detectors operating in integration mode are not able to provide spectral information and also introduce large electronic noise in the acquired images. Current photon counting detectors (as alternative for integrating CT detectors) are based on direct conversion of the x-rays to electrica signal which relies on utilizing semiconductor materials (mainly Si, CdTe, CZT). For X-ray energies in medical imaging applications, Si becomes almost transparent resulting in a very low sensitivity and high patient dose. CdTe and CZT have been used for these energy ranges, however imposing technical challenges and performance issues such as charge sharing, pulse pileup and count rate capability, relatively low effective Z and low density compared with the current CT detector materials. Furthermore, limited availability of high purity materials (e.g. CZT can make a large area detector for clinical applications prohibitively expensive. While scintillation-based detectors are used in clinical nuclear imaging systems they cannot satisfy all the stringent requirements for clinical CT system at high flux mainly due to the lack of high light output scintillators with fast decay time as well as lack of reliable scintillator pixelation technologies to fabricate pixels smaller than 0.5x0.5 mm2. Our goal is to study the feasibility of a scintillator-based photon counting detector using pixelated high Z scintillator coupled with a dedicated ASIC where each ASIC pixel has a built-in photodiode, a charge sensitive preamplifier, a shaping amplifier with programmable peaking time, 3-4 energy windows and their associated counters. The significance of this research is that by using our scintillator pixelation technology, development of high-resolution photon counting CT detectors is achievable in a cost effective manner. The proposed detector will categorize the incident X-rays based on their energy and will handle the incident X-ray flux up to 108 photon/mm2/second as needed in clinical CT imaging.

 描述（由申请人提供）：提供高对比度诊断 CT 图像，同时最大限度地减少患者辐射剂量一直是大多数 CT 相关研究的中心。在这方面，探测器技术的改进（以及自动曝光控制和改进的重建算法）。 ）可能会产生最大的影响，当前以集成模式运行的 X 射线 CT 探测器无法提供光谱信息，并且还会在采集的图像中引入大量电子噪声。直接的X 射线到电信号的转换依赖于利用半导体材料（主要是 Si、CdTe、CZT）。对于医学成像应用中的 X 射线能量，Si 几乎是透明的，导致灵敏度非常低且患者剂量很高。和 CZT 已用于这些能量范围，但是带来了技术挑战和性能问题，例如电荷共享、脉冲堆积和计数率能力、与当前 CT 探测器材料相比相对较低的有效 Z 和低密度，此外，高可用性有限。纯度材料（例如，CZT 可以使用于临床应用的大面积探测器过于昂贵。虽然基于闪烁的探测器用于临床核成像系统，但它们无法满足高通量临床 CT 系统的所有严格要求，主要是由于缺乏高光 我们的目标是研究使用像素化高 Z 闪烁体输出和专用闪烁体的闪烁体光子计数探测器的可行性。 ASIC，其中每个 ASIC 像素都有一个内置光电二极管、一个电荷敏感前置放大器、一个具有可编程峰值时间的整形放大器、3-4 个能量这项研究的意义在于通过使用我们的闪烁体像素化。 技术，可以以经济有效的方式开发高分辨率光子计数 CT 探测器。所提出的探测器将根据入射 X 射线的能量对其进行分类，并将处理高达 108 光子/平方毫米/秒的入射 X 射线通量。根据临床 CT 成像的需要。