low-dose and high-resolution tomosynthesis for lung cancer screening

描述(申请人提供)：肺癌仍然是世界上癌症死亡的首要原因。尽管对诊断和治疗进行了数十年的研究，但存活率仍然很低。计算机断层扫描(CT)可以很容易地发现微小的肺结节，但需要显著更高的辐射剂量。数字胸部断层合成(DCT)通过在患者面前扫描X射线管来创建类似CT的3D图像，以在有限的角度范围内获得多个视图。与CT相比，它使用的成像剂量和成本都要低得多。临床研究表明，与常规CT相比，当呼吸运动最小时，DCT可以达到90%以上的敏感性。目前的DCT系统的扫描时间比呼吸周期要长得多。即使在患者屏住呼吸的情况下，患者和信号源的运动模糊也会降低图像质量。当存在运动伪影时，检测灵敏度降低到常规2D胸部摄影(CR)的水平。本研究的目的是提高DCT的层析合成图像质量。利用空间分布碳纳米管X射线源阵列技术，我们提出了一种固定式离散余弦变换(S-离散余弦变换)系统。该系统通过在没有任何机械运动的情况下电子激活源阵列中的各个X射线源来生成多个投影图像。我们的目标是在2s或更短的时间内实现完整的胸部CT扫描，即目前商用DCT扫描仪的1/3-1/5，这有望减少患者呼吸运动造成的图像模糊。碳纳米管X射线源阵列技术进一步实现了更宽的角度覆盖范围，以减少面外伪影和可提供更各向同性的面内分辨率的新颖成像几何结构。这一假说得到了先前临床研究的支持，即图像质量的改善将导致 肺癌的敏感性和特异性提高到接近CT的水平。除了肺癌筛查，低剂量和高灵敏度的3D DCT肺部成像方式可能会在监测儿科囊性纤维化患者等领域找到应用，在这些领域，减少成像剂量是至关重要的。这项拟议的研究是两位物理学家(周博士和卢博士)和北卡罗来纳大学的一位翻译放射学家(李博士/博士)之间的密切合作。北卡罗来纳大学心胸外科模拟实验室将用于生理模型研究。我们合作了十多年，卓有成效地合作了十多年，并在将从基础研究到临床试验和商业产品的新技术应用方面取得了良好的记录。成功的例子包括CNT X射线源阵列技术的开发；现在UNC作为用户设施安装在小动物核心的动态微型计算机断层扫描仪；以及目前正在进行试点临床试验的固定式数字乳房断层扫描。

DESCRIPTION (provided by applicant): Lung cancer continues to be the leading cause of cancer deaths in the world. In spite of decades of research on diagnosis and therapy, survival rates remain poor. Computed tomography (CT) scans can readily detect small lung nodules, but requires significantly higher radiation dose. Digital chest tomosynthesis (DCT) creates CT-like 3D images by scanning an x-ray tube in front of the patient to obtain multiple views over a limited angular range. It uses significantly lower imaging dose and costs less compared to CT. Clinical studies have shown that DCT can achieve sensitivities of over 90% as compared to conventional CT in detecting small lung nodules when respiratory motion is at a minimum. The scanning time of the current DCT systems is considerably longer than a respiratory cycle. The motion blurring of the patient and the source degrade image quality even with the patient holding their breath. When motion artifacts are present, the detection sensitivity is reduced to the level of conventional 2D chest radiography (CR). The goal of this study is to increase tomosynthesis image quality of DCT. Utilizing the spatially distributed carbon nanotube (CNT) x-ray source array technology we propose to develop a stationary DCT (s- DCT) system. The system generates the multiple projection images by electronically activating the individual x- ray sources in the source array without any mechanical motion. Our goal is to achieve a full chest tomosynthesis scan in 2s or less, 1/3 - 1/5 of the current commercial DCT scanners, which is expected to reduce image blurring due to patient respiratory motion. The CNT x-ray source array technology further enables a wider angular coverage that reduces the out-of-plane artifact and novel imaging geometries that may provide a more isotropic in-plane resolution. The hypothesis, supported by prior clinical studies, is that the improved image quality will lead to an improved sensitivity and specificity for lung cancer to the level approaching that of CT. Beyond lung cancer screening, the low-dose and highly sensitive 3D DCT lung imaging modality will likely to find applications in areas such as monitoring pediatric cystic fibrosis patients where reduction of imaging dose is critical. The proposed study is a close collaboration between two physical scientists (Zhou, PhD, and Lu, PhD) and a translational radiologist (Lee, MD/PhD) at UNC. The UNC cardiothoracic surgery simulation lab will be utilized for the physiological phantom studies. We have worked together productively for over a decade and have a demonstrated record of taking new technologies from basic research to clinical trials and commercial products. Successful examples include the development of the CNT x-ray source array technology; the dynamic micro-computed tomography scanner now installed at UNC in the small animal core as a user facility; and stationary digital breast tomosynthesis currently undergoing a pilot clinical trial.