Development of super resolution ultrasound for detecting microcalcifications

项目摘要 大量研究表明，癌症的早期发现可以改善患者的预后。通过 及早发现癌症，当肿瘤处于初发期时，可以在转移之前进行治疗 已经发生了。微钙化(MC)的存在表明乳房和 用现代成像技术提高检测MC的能力仍然是一个悬而未决的问题。他的存在 乳腺癌的发生与乳腺癌的存在有关，即所有未触及的乳腺癌的30%-50% 使用乳房X光检查的检测是基于识别MC的存在。因此，改善 影像技术检测乳腺MC的敏感性将为早期诊断乳腺癌提供重要作用 乳腺癌的检测和诊断。 最近，我们开发了一种用于超声阵列的新型非线性波束形成技术，该技术提供了 超高分辨率的超声图像(分辨率提高高达25倍)。波束形成技术， 所谓的零点减影成像(NSI)，利用波束模式中的零点来使用超声波创建图像。 NSI提供的横向分辨率提高伴随着所有束流中存在的旁瓣的减少 信噪比(SNR)的模式和增加。使用NSI构建的超声图像导致 斑点伪影的抑制和奇异目标的增强。因此，我们假设NSI 成像将很好地执行特定的成像任务，即检测组织中的MC。我们将发展和 通过两个目标验证NSI对乳腺癌动物模型中MC的成像和检测。 在第一个目标中，我们将量化NSI在动物模型中检测MC的能力，并与 常规的超声波和X射线成像技术。我们假设NSI的使用将导致 与传统的超声方法相比，在动物模型中定量地改进了对MC的检测 和X射线成像。传统的超声方法使用延迟和求和来进行波束形成，并且可以使用 使用不同的信号处理工具来改进MC检测。常规超声B型成像 成像和X射线CT将用于检测乳腺癌大鼠模型中的MC及其检测 将对性能(敏感性和特异性)进行比较。 在第二个目标中，我们将开发和验证在接收上增加扫描线密度的方法 使用NSI时。我们假设在不使用NSI的情况下可以充分地增加扫描线密度 物理平移换能器。因为与NSI相关的成像波束非常窄， 每一步以一个节距平移波束的传统线性顺序扫描技术导致 未询问的梁之间的空间。以确保在此过程中不会遗漏任何组织区域 扫描时，要增加询问组织的光束密度。这可以通过以下方式完成 通过使用常规方法来增加扫描线密度，即，内插或栅格聚焦。

Project Summary Abundant research demonstrates that early detection of cancer leads to improved patient prognosis. By detecting cancer earlier, when tumors are in their primary stages, treatment can be applied before metastases have occurred. The presence of microcalcifications (MCs) is indicative of malignancy in the breast and improving the ability to detect MCs with modern imaging technology remains an open question. The presence of MCs is associated with presence of cancer in the breast, i.e., 30-50% of all nonpalpable breast cancers detected using mammograms are based on identifying the presence of MCs. Therefore, improving the sensitivity of imaging techniques to detect MCs in the breast will provide an important role for the early detection and diagnosis of breast cancer. Recently, we developed a novel nonlinear beamforming technology for ultrasonic arrays that provides super resolution of ultrasonic images (up to 25 times improvements in resolution). The beamforming technique, called null subtraction imaging (NSI), utilizes nulls in the beam pattern to create images using ultrasound. Lateral resolution gains provided by NSI are accompanied by a reduction in side lobes present in all beam patterns and increases in the signal-to-noise ratio (SNR). Ultrasonic images constructed with NSI result in suppression of speckle artifacts and an intensification of singular targets. Therefore, we hypothesize that NSI imaging will perform well for the specific imaging task of detection of MCs in tissues. We will develop and validate NSI for imaging and detecting MCs in an animal model of breast cancer through two aims. In the first aim we will quantify the ability of NSI to detect MCs in an animal model compared to conventional ultrasonic and X-ray imaging techniques. We hypothesize that the use of NSI will result in a quantifiably improved detection of MCs in animal models compared to conventional ultrasound approaches and X-ray imaging. Conventional ultrasound approaches use delay and sum to do beam formation and can use different signal processing tools to improve MC detection. Conventional ultrasound B-mode imaging, NSI imaging and X-ray CT will be used to detect MCs in a rat model of breast cancer and their detection performance (sensitivity and specificity) will be compared. In the second aim we will develop and validate approaches on receive to increase the density of scan lines when using NSI. We hypothesize that the scan line density can be sufficiently increased using NSI without physically translating the transducer. Because the imaging beam associated with NSI is so narrow, conventional linear sequential scanning techniques that translate a beam at each step by one pitch cause spaces between the beams that are not interrogated. To ensure that no tissue region is missed during scanning, it is necessary to increase the density of beams interrogating tissue. This can be accomplished on receive by using conventional methods to increase scan line density, i.e., interpolation or gird focusing.