Tomosynthesis for improved pulmonary nodule detection

描述(由申请人提供)：这些研究的目的是评估数字断层合成技术是否可以作为传统胸部摄影的辅助手段，以改善肺部结节的临床检测。数字断层合成通过一系列纵向切片图像提供三维信息，从而增强了传统的胸部检查。这些切片图像是使用传统的X射线管和新的数字平板X射线探测器，从一组在不同角度获得的离散投影图像重建的。层析合成的图像可以逐个切片地查看，或者作为一个3-D体积再现的投影在“虚拟透视”查看环境中查看。断层合成的诊断益处是利用3-D信息通过消除覆盖结构的混乱来提高对肺结节的检测和辨别。一旦发现结节，CT仍将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步检测的准确性。临床上，无论何时进行数字化PN侧位胸部检查，都会获得断层合成图像，但减少了侧位图像的曝光，使得PA/侧位/断层合成检查的患者总剂量与传统PN侧位胸部检查的总剂量大致相当。可以预期的是，与传统的胸部摄影相比，断层合成将使肺结节的检测具有更高的敏感性和特异性，因此有可能导致肺癌的更早发现，而成本明显低于低剂量CT。 这项提议是对先前开发和优化断层合成技术的研究的竞争性延续。本研究将对CT证实的肺结节的受试者进行CT扫描检测肺结节的临床评价。这项研究将包括三个部分：(1)使用放射科医生作为观察者的断层合成的评估；(2)利用三维断层合成数据检测肺结节的计算机辅助诊断(CAD)方法的开发和评估；以及(3)放射科医生使用断层合成定位结节深度和直径的准确性的测量。该项目的具体目标还包括在大规模收集人体受试者数据之前进行优化断层合成方法的试点研究。这些先导性研究将确定患者运动的特征并将其影响降至最低，优化重建平面的数量和患者入口处的暴露，并评估切片查看与体积渲染的效果。

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.