Next generation micro CT

描述(由申请人提供)：商业上可用的Micro-CT(计算机断层扫描)系统已经不能满足对小动物成像的挑战性要求，而不仅仅是对良好空间分辨率的单一要求。具体地说，他们没有考虑到，与人类相比，老鼠的体积小了1000倍，同时心率也快了10倍，呼吸频率和循环时间也增加了。因此，目前可用的系统仅限于：(1)活体体积CT，主要用于解剖图像与正电子发射断层扫描(PET)或单光子发射计算机断层扫描(SPECT)提供的功能图像的联合配准，但速度非常慢(几分钟)；或(2)体外高空间分辨率CT，对于标本成像具有良好的对比度分辨率，但对于活体受试者来说剂量太高。因此，这些商业系统都不能满足微CT的重要应用，如肿瘤灌注和心脏射血分数研究。该项目的目标是开发下一代微型CT，用于药物开发和医学研究的临床前成像。该系统将在小鼠和大鼠体内提供临床质量的CT图像，性能规格经过优化，以适应目前医学研究中最关键领域的苛刻要求。具体地说，该仪器将提供非常高的空间分辨率(&lt；100 mm)，超快的帧速度(&lt；1秒)，以及对对象的低辐射剂量。这将利用用于X射线采集的光子计数模式而不是标准电流积分模式来实现。该系统将能够提供总能量信息和能量储存，因此将提供“彩色CT(Tm)”能力，从而实现组织成分分析。为了实现这些进步，该系统将配备先进的CdZnTe固态探测器，并与用于信号处理的高速集成电路相结合，以实现主要CT制造商目前使用的传统技术无法实现的性能特征。 在第一阶段项目中，我们将开发一个X射线探测器模块，其中包括一个4 x像素的镉锌Te探测器，以及高速定制集成电路读出电子设备。将在现有CT机架上对高强度X射线流量下的探测器性能进行评估，包括光谱质量、能量分辨率和计数率性能。探测器的能力将通过与商用集成模式体积CT探测器进行并列比较来评估，这些探测器涉及所需的系统规格，如对比度、剂量和采集速度。在第二阶段，将开发一种快速动态多层彩色CT(Tm)扫描仪原型，在一种结合了非常快的X射线源的新型系统设计中采用多个探测器模块。

DESCRIPTION (provided by applicant): Commercially available micro-CT (computer tomography) systems have failed to meet the challenging demands for small animal imaging, beyond the single requirement for good spatial resolution. Specifically, they have failed to take into account that the thousand times smaller volume in mice, compared to humans, is also coupled with 10 times faster heart rates, and increased respiratory rates and circulation times. Thus, the currently available systems have been limited to either: (1) in-vivo volume CT, which is primarily useful for co-registration of anatomical with functional images provided by positron emission tomography (PET) or single photon emission computer tomography (SPECT), but is very slow (several minutes); or (2) ex-vivo high spatial resolution CT, with good contrast resolution for specimen imaging but at too high dose for live subjects. Thus, these commercial systems all fail to address significant applications for micro-CT, such as tumor perfusion and cardiac ejection fraction studies. The goal of this project is to develop a next generation micro-CT for pre-clinical imaging for drug development and medical research. The system will be designed to provide clinical quality CT images in vivo in mice and rats, with performance specifications optimized to accommodate the demanding requirements of the most critical areas currently in medical research. Specifically, the instrument will provide very high spatial resolution (< 100 mm), ultra fast frame speeds (< 1 second), and low radiation dose to the subject. This will be achieved utilizing a photon counting mode for x-ray acquisition, instead of the standard current integration mode. The system will be capable of gross energy information and energy binning, and thus will provide "Color-CT(tm)" capability, allowing tissue compositional analysis. To accomplish these advances, the system will feature advanced CdZnTe solid state detectors, coupled to high speed integrated circuits for signal processing, to achieve performance characteristics not currently possible from conventional technologies used by the major CT manufacturers. During the Phase I project, we will develop an x-ray detector module incorporating a 4 x 64 pixel CdZnTe detector, coupled to high speed custom integrated circuit readout electronics. The detector performance will be evaluated in response to a high intensity x-ray flux, on an existing CT gantry, with regard to spectral quality, energy resolution and count rate performance. The detector capabilities will be evaluated in a side-by-side comparison with a commercial integrating mode volume-CT detector, with regard to required system specifications such as contrast, dose, and acquisition speed. In Phase II, a fast dynamic multi-slice Color-CT(tm) scanner prototype will be developed, employing multiple detector modules in a novel system design incorporating a very fast x-ray source.