Next-Generation Tomosynthesis Pilot Study

项目总结 即使有了最新的数字乳房断层合成(DBT)系统，乳腺癌筛查仍然受到影响 由于缺乏特异性。只有大约5%的筛查后被召回的女性最终被发现进行了活组织检查- 已证实是癌症。临床DBT系统存在图像质量各向异性，因为扫描运动 被限制在一个方向(从左到右)。我们建立了下一代断层合成(NGT)系统，能够 以“T”字形扫描。通过幻影和乳房切除标本，我们已经证明了这种设计 减少超分辨率下的锥束伪影、组织叠加效应和各向异性。作为下一步 在我们的研究中，我们将与志愿者一起进行一项试点研究，招募被推荐进行诊断成像的女性 或活组织检查以及接受简化磁共振成像(MRI)的女性。投影图像将被 以这样的方式获得，我们可以从两种扫描方法(常规和T)生成重建。 每种扫描方法都将由放射科医生在不同的阅读环节中分别进行分析。我们将减轻 将研究限制在一个切面(头尾切面)而不是两个切面，对辐射暴露的潜在担忧 视图。我们组建了一支拥有独特优势的团队，包括NGT系统的开发人员， 三名放射科医生，两名统计学家，以及密度和纹理分析专家。这份提案分为两部分 明确的目标。(目标1)：与志愿者一起评估放射科医生在NGT系统试点研究中的表现。我们 将调查T扫描是否在不降低灵敏度的情况下降低了筛查的回调率。 放射科医生还将对恶性肿瘤的总体概率进行评级，并对这些得分进行组合分析 临床随访数据表明，随着T扫描的进行，放射科医生表征结果的能力得到了改善， 具体地说，通过使用刀切替代自由响应接收器工作特性(JAFROC)方法。 (目标2)：对三维乳房轮廓分割、纹理和密度进行定量分析。有乳房 体模，我们以前已经证明，乳房体积在常规扫描中被高估，并且是 在T扫描中计算得更准确。我们的目标是通过以下方式证明同样的结果在人类受试者中也适用 计算两种扫描方法之间的体积差。此外，我们还将分析幂函数噪声。 高阶非高斯纹理度量作为可探测性和组织叠加的替代度量 效果，我们预计这将通过T扫描得到改善。最后，我们将分析百分比密度是否 两种扫描方法的计算结果不同，因为我们预计T扫描中的平面外伪影较少。 尽管新的扫描方法没有被用作志愿者医疗保健的一部分，但总体影响 这项研究的目的是证明在特异性方面的改进，从而有可能将 诊断性成像检查和活检，降低医疗成本，并将总辐射剂量降至最低 筛查和诊断成像。乳房丰满的女性将特别受益于这种新设计，因为 致密的组织可能会掩盖常规DBT扫描中的发现，使其更难定性。

PROJECT SUMMARY Even with the latest digital breast tomosynthesis (DBT) systems, breast cancer screening continues to suffer from poor specificity. Only about 5% of women called-back from screening are ultimately found to have a biopsy- proven cancer. Clinical DBT systems suffer from anisotropies in image quality since the scanning motion is restricted to one direction (left-to-right). We built a next-generation tomosynthesis (NGT) system that is capable of scanning in the shape of a “T”. With phantoms and mastectomy specimens, we have shown that this design mitigates cone-beam artifacts, tissue superposition effects, and anisotropies in super-resolution. As the next step in our research, we will perform a pilot study with volunteers, recruiting women referred for diagnostic imaging or biopsy as well as women having abbreviated magnetic resonance imaging (MRI). Projection images will be acquired in such a way that we can generate reconstructions from two scanning methods (conventional and T). Each scanning method will be analyzed separately by radiologists in different reading sessions. We will mitigate potential concerns about radiation exposure by restricting the study to one view (cranial-caudal) instead of two views. We have put together a team with a unique set of strengths, including the developers of the NGT system, three radiologists, two statisticians, and experts in density and texture analysis. This proposal is divided into two specific aims. (Aim 1): Assess radiologists' performance in a pilot study of the NGT system with volunteers. We will investigate whether the T scan brings down the call-back rate of screening without reducing sensitivity. Radiologists will also rate the overall probability of malignancy, and these scores will be analyzed in combination with clinical follow-up data to show that radiologists' ability to characterize findings is improved with the T scan, specifically by using jackknife alternative free-response receiver operating characteristic (JAFROC) methods. (Aim 2): Perform quantitative analysis of the 3D breast outline segmentation, texture, and density. With breast phantoms, we have previously shown that the breast volume is overestimated in the conventional scan and is calculated more accurately in the T scan. We aim to show that the same result holds in human subjects by calculating volume differences between the two scanning methods. Additionally, we will analyze power-law noise and higher-order non-Gaussian texture measures as surrogate metrics of detectability and tissue superposition effects, which we expect to be improved by the T scan. Finally, we will analyze whether percent density calculations differ between the two scanning methods since we expect fewer out-of-plane artifacts in the T scan. Although the new method of scanning is not being used as part of the volunteers' medical care, the overall impact of this study is to demonstrate improvements in specificity and thus the potential to minimize the number of diagnostic imaging exams and biopsies, lower healthcare costs, and minimize the total radiation dose combining screening and diagnostic imaging. Women with dense breasts will especially benefit from this new design since dense tissue can obscure findings in a conventional DBT scan, making them harder to characterize.