CCD MOSAIC DIGITAL MAMMOGRAPHY

具体目标和假设：本项目的目标是开发 用于全尺寸数字X射线乳房摄影的成像模块。 我们建议 探索一种CCD成像技术，使用一种新的区域扫描，辐射， 屏蔽机制 这个概念使用了一个6x 8的CCD图像拼接。 这些 CCD安装在载体平台上，其有源 15毫米宽的区域。 该平台位于一个 标准乳房X线摄影单位。 一个铅过滤器被插入到X射线 来源和患者。 铅过滤器有一个镶嵌的CCD和移动 与CCD同步 以提供完整且连续的映像 马赛克实际上会被重新定位三次，总共四次， 进行X射线曝光。 所提出的技术的独特之处在于 大视场（18 cm x 24 cm）、高空间分辨率（16 lp/mm至18 lp/mm），散射抑制和出色的对比度 临床条件下的特征和病变可检测性。 方法和实验：所提出的成像概念是独特的，因为 其新颖的光学配置和扫描采样方法不同， 从现有技术来看， 为了验证我们的假设， 我们建议建立一个实验室系统来测量调制传递 功能、信噪比、检测量子效率和病变 可探测性 我们还建议进行体模研究。 基于我们 初步实验，剂量有效，x射线量子噪声有限 系统将实现使用建议的CCD成像模块。 病变 这种数字乳腺摄影技术的可检测性与 在相同条件下的屏-膜技术的金标准。

Specific Aims and Hypotheses: The objective of this project is to develop an imaging module for full size digital x-ray mammography. We propose to explore a CCD imaging technique using a novel area-scanning, radiation- shielding mechanism. The concept uses a 6x8 mosaic of CCD imagers. These CCDs are mounted on a carrier platform with gaps between their active areas that are exactly 15 mm in width. The platform is placed under a standard mammographic unit. A lead filter is interposed between the x-ray source and the patient. The lead filter has a mosaic of CCDs and is moved in synchronism with the CCDs. To provide a complete and contiguous image the mosaic will actually be repositioned three times, and a total of four x-ray exposures is made. The unique features of the proposed technique are: large field coverage (18 cm x 24 cm), high spatial resolution (16 lp/mm to 18 lp/mm), scatter rejection and excellent contrast characteristics and lesion detectability under clinical conditions. Methods and Experiments: The proposed imaging concept is unique because its novel optical configuration and scanning-sampling method differs significantly from existing techniques. In order to test our hypotheses, we propose to build a laboratory system to measure modulation transfer function, signal-to-noise ratio, detective quantum efficiency, and lesion detectability. We also propose to conduct phantom studies. Based on our preliminary experiments, a dose efficient, x-ray quantum noise limited system will be achieved using the proposed CCD imaging module. The lesion detectability of this digital mammographic technique is comparable to the gold standard of screen-film technique under the same conditions.