Optimized Digital Mammography with an a-Se FP Imager

描述(由申请人提供)： 乳腺癌已被认为是对妇女健康和长寿的主要威胁，特别是在北美。美国9名女性中有1人可能会在有生之年被诊断出患有乳腺癌。尽管超声、磁共振和光学成像技术取得了进步，但X射线乳房X光照相仍然是早期发现乳腺癌和随后的诊断检查的主要工具。因此，改进乳腺X线摄影技术对优化乳腺癌的检测和诊断具有重要意义。随着对改善图像质量和图像管理的渴望，已经有了从传统的屏幕/胶片技术转向数字图像获取技术的强烈动机。几种数字化乳房X光摄影技术已经开发并商业化。这些技术中的每一种在某些方面可能具有优势，而在其他方面可能存在缺陷。本研究的目标是优化和研究一种数字乳房X光检查技术，以提高数字乳房X光检查的质量和利用率。 为了实现这些目标，我们将使用基于非晶硒和非晶硅薄膜晶体管(ASE/ASI TFT)阵列的平板成像器作为X射线探测器来设计、构建和研究扫描均衡数字乳房摄影(SEDM)系统。将使用区域调制波束宽度的缝隙扫描来实现散射抑制和曝光均衡。将实施和研究一种新的图像读出技术，以实现电子后视准直。将实施和测试一种重新缩放技术，以生成外观类似于常规乳房X光检查的数字乳房X光图像，但具有改进的对比度色调比(CNR)、均衡的信噪比(SNR)并能够进行准确的传输测量。我们将通过物理测量和观察者基于模拟临床乳房X光照片的体模图像进行的性能研究来评估和研究建议的SEDM系统。 预计拟议的系统将改进对微钙化和肿块的检测和可视化，并在筛查和诊断性乳房X光检查中更好地利用图像数据。这是通过：(1)利用基于ASE/ASI TFT的FP探测器改进的调制传递函数(MTF)和探测量子效率(DQE)，(2)在与反散射栅格技术相比具有相似甚至更好的散射抑制的情况下，将探测器的曝光增加约两倍，(3)将X射线通量从高透射区重新分配到密集组织区域(曝光均衡)，以实现更均匀的图像SNR，以及(4)提供具有均衡SNR的几乎无散射的图像数据，以便更好地进行图像处理、分析和定量研究。

DESCRIPTION (provided by applicant): Breast cancer has been recognized as a major threat to women's health and longevity particularly in North America. one of 9 women in the United States may be diagnosed to have breast cancer in her lifetime. Despite advances of ultrasound, magnetic resonance and optical imaging techniques, x-ray mammography remains the main tool for early detection of breast cancer and subsequent diagnostic workup. It is therefore of great importance to improve the x-ray mammography techniques to optimize the detection and diagnosis of breast cancer. With a desire to improve image quality and image management, there has been a strong motivation to shift from the conventional screen/film techniques to digital image acquisition techniques. Several digital mamrnography techniques have been developed and commercialized. Each of these techniques may have advantages in some aspects and drawbacks in others. The goals of this research are to optimize and investigate a digital mammography technique to improve the quality and utilization of the resulting digital mammograms. To achieve these goals, we will design, construct and investigate a Scanning Equalization Digital Mammography (SEDM) system using an amorphous selenium and amorphous silicon thin film transistor (aSe/aSi TFT) array based flat-panel imager as the x-ray detector. Slot scanning with regionally modulated beam width will be used to achieve both scatter rejection and exposure equalization. A novel image readout technique will be implemented and investigated to allow for electronic aft-collimation. A re-scaling technique will be implemented and tested to generate digital mammography images with appearance similar to that of a regular mammogram but with improved contrast-tonoise ratios (CNRs), equalized signal-to-noise ratios (SNRs) and enabling accurate transmission measurement. We will evaluate and investigate the proposed SEDM system with physical measurements and observers' performance studies based on phantom images designed to mimic clinical mammograms. The proposed system is expected to result in improved detection and visualization of microcalcifications and masses and better utilization of image data in both screening and diagnostic mammography. This is achieved through: (1) improved modulation transfer function (MTF) and detective quantum efficiency (DQE) with an aSe/aSi TFT based FP detector, (2) an approximately twofold increase of the detector exposure with similar or even better scatter rejection as compared to the anti-scatter grid technique, (3) a redistribution of x-ray fluence from highly transmitted areas to dense tissue regions (exposure equalization) to achieve more uniform image SNRs, and (4) provision of nearly scatterfree image data with equalized SNRs for better image processing, analysis and quantitative studies.