Tomosynthesis for improved pulmonary nodule detection

描述（由申请方提供）：这些研究的目的是评价数字断层合成摄影是否可以作为传统胸部X线摄影的辅助手段，以改善肺结节的临床检测。数字断层合成通过一系列纵向切片图像提供三维信息，增强了传统胸部检查。这些切片图像重建从一组离散的投影图像采集在不同的角度，使用传统的X射线管和一个新的数字平板X射线探测器。断层合成的图像可以在“虚拟荧光透视”观察环境中逐层观察或作为3-D体积绘制投影来观察。断层合成的诊断益处是使用3-D信息通过消除重叠结构的混淆来改善肺结节的检测和区分。一旦检测到结节，CT将仍然是临床检查的金标准，断层合成提供了一种低剂量/低成本的方法来提高初始检测的准确性。在临床上，每当进行数字PN侧胸部检查时都会采集断层合成图像，但是侧部图像的曝光减少，使得来自PA/侧部/断层合成检查的总患者剂量将与来自常规PN侧胸部检查的总剂量大致相当。预期断层合成将实现比单独的常规胸部X射线照相术更高的肺结节检测的灵敏度和特异性。因此将潜在地导致肺癌的早期检测，其成本显著低于低剂量CT。 该提案是先前研究的竞争性延续，该研究开发并优化了断层合成技术。本研究将在CT证实结节的人类受试者队列中对断层合成用于肺结节检测进行临床评价。本研究将包括三个部分：（1）使用放射科医师作为观察者评价断层合成，（2）使用三维断层合成数据开发和评价计算机辅助诊断（CAD）方法用于肺结节检测，以及（3）测量放射科医师使用断层合成定位结节深度和直径的准确性。该项目的具体目标还包括在大规模收集人类受试者数据之前进行试点研究，以优化断层合成方法。这些试点研究将表征患者运动的影响并将其最小化，优化重建平面和患者入口曝光的数量，并评价切片查看与容积渲染。

DESCRIPTION (provided by applicant):The purpose of these studies is to evaluate whether digital tomosynthesis can serve as an adjunct to conventional chest radiography for improving clinical detection of pulmonary nodules. Digital tomosynthesis augments a conventional chest exam by providing three-dimensional information through a series of longitudinal slice images. These slice images are reconstructed from a set of discrete projection images acquired at different angles, using a conventional x-ray tube and a new digital flat-panel x-ray detector. The tomosynthesized images may be viewed slice-by-slice or as a 3-D volume-rendered projection in a "virtual fluoroscopy'' viewing environment. The diagnostic benefit of tomosynthesis is the use of 3-D information to improve detection and discrimination of pulmonary nodules by eliminating the confusion of overlying structures. CT would remain the gold standard for clinical workup once nodules are detected, with tomosynthesis providing a low-dose/low-cost method for improving initial detection accuracy. Clinically the tomosynthesis images would be acquired whenever a digital PNlateral chest exam is taken, but with reduced exposure for the lateral image such that the total patient dose from the PA/lateral/tomosynthesis exam would be about comparable to the overall dose from a conventional PNlateral chest exam. It is anticipated that tomosynthesis will enable higher sensitivity and specificity for pulmonary nodule detection than conventional chest radiography alone, and hence will potentially lead to earlier detection of lung cancer, at a cost significantly less than low-dose CT. This proposal is a competing continuation of a previous study that developed and optimized the tomosynthesis technique. The present study will conduct a clinical evaluation of tomosynthesis for pulmonary nodule detection in a cohort of human subjects with CT-proven nodules. This study will have three parts: (1) an evaluation of tomosynthesis using radiologists as observers, (2) development and evaluation of a computer-aided diagnosis (CAD) method using three-dimensional tomosynthesis data for pulmonary nodule detection, and (3) a measurement of the accuracy with which radiologists can use tomosynthesis to localize the depth and diameter of nodules. The specific aims of the project also include pilot studies to optimize the tomosynthesis method before the large-scale collection of human subject data. These pilot studies will characterize and minimize effects of patient motion, optimize the number of reconstructed planes and patient entrance exposure, and evaluate slice viewing vs volume rendering.