Breast Cancer Diagnosis: Ultrasound Quantitative Backscatter & Inverse Scattering

描述（由申请人提供）：本SBIR（第1次重新提交/修订）项目的第1阶段目标是：实施并测试一种成像方法，该方法结合了改进的定量超声背向散射（QUBS）方法，该方法使用散射体尺寸成像（SSI）和声学散射体浓度（ASC）检测乳腺癌。过去的SSI和ASC图像在许多情况下已知即使没有这些改进也可以将癌性肿瘤与良性肿瘤分开。研究设计将联合收割机QUBS与逆散射层析成像（IST）和反射层析成像（RT）结合成一种混合方法。IST将校正RT图像的折射和衰减。校正的RT数据将用于制作校正和复合的QUBS图像，其准确度、精密度和空间分辨率比以前可能的更高。IST和RT是TechniScan，Inc.开发的超声成像方法的两个组成部分。(TSI)，其被称为UltraSound-CTTM（即，USCT）。USCT使用来自研究对象周围360度空间的视图的分散数据重建图像。IST基于使用精确波动方程模型（EWEM）而不是基于射线的方法（这是常见超声成像的基础）对通过组织的超声传播进行建模。只有EWEM可以产生高分辨率（3/4 mm），声速，吸收和密度梯度的定量图像，并可以解释多次散射，折射，衍射，衰减和反射损失的影响。RT成像使用IST来校正折射和吸收（但不校正多重散射或衍射）。RT是部分定量的，并提供高空间分辨率（1/4 mm）。研究方法：通过以下步骤将联合收割机QUBS与IST和RT组合：（1）产生乳房的IST图像;（2）收集数据以产生乳房的RT图像;（3）然后制作折射衰减校正的RT图像;（4）使用这些相同的校正来制作乳房的空间复合、折射校正、衰减校正的QUBS图像。QUBS图像将通过用产生改进的散射体尺寸图像（SSI）的特定算法处理该校正的数据来导出。实现研究设计和方法的具体目的是：（目的1）模拟QUBS算法的性能（目标2）创建待扫描的琼脂体模;使用来自模拟和来自体模和组织的数据分析IST/RT增强的SSI/ACS的性能;（目标3）准备提交具有改进硬件的第2阶段SBIR，该SBIR将测试结合QUBS和USCT的混合方法的协同作用，以创建5个图像（3 + 2 = 5），并且由此5维特征空间用于改进的组织表征（灵敏度和特异性）。每7名女性中就有1人会在一生中患上乳腺癌。然而，目前癌症检测的诊断特异性（使用乳房X线摄影）很差，4次活检中有3次产生良性组织，约10%的癌症被遗漏。该提案结合了两种用于乳腺癌检测的新技术，即定量超声背向散射（QUBS）和超声逆散射断层扫描（IST），具有改善乳腺癌检测的巨大潜力。

DESCRIPTION (provided by applicant): Objective of this Phase-1 SBIR (1st resubmission/amended) project is: to implement and test an imaging method incorporating an improved quantitative ultrasound backscatter (QUBS) method, which uses scatterer size imaging (SSI) and acoustic scatterer concentration (ASC) for detection of breast cancer. Past SSI and ASC images were known in many cases to separate cancerous from benign tumors even without these improvements. The Research Design to combine QUBS with inverse scattering tomography (IST) and reflection tomography (RT) into a hybrid method. IST will correct RT images for refraction and attenuation. The corrected RT data will be used to make corrected and compounded QUBS images of greater accuracy, precision, and spatial resolution than possible previously. IST and RT are the two components of the ultrasound imaging method developed by TechniScan, Inc. (TSI), which is known as UltraSound-CTTM (i.e., USCT). USCT reconstructs an image using scattered data from views spaced a full 360¿around the object under study. IST is based on modeling ultrasound propagation through tissue using an exact wave equation model (EWEM) rather than a ray-based approach, which is the basis of common ultrasound imaging. Only EWEMs can produce high resolution (to 3/4 mm), quantitative images of sound speed, absorption and density gradient and can account for the effects of multiple scattering, refraction, diffraction, attenuation and reflection losses. RT imaging uses IST to correct for refraction and absorption (but not for multiple scattering or diffraction). RT is partially quantitative and provides high spatial resolution (to 1/4 mm). The Research methods: to combine QUBS with IST and RT by the following steps: (1) produce an IST image of the breast; (2) collect data to produce a RT image of the breast; (3) then make a refraction attenuation corrected RT image; (4) use these same corrections to make a spatially compounded, refraction corrected, attenuation corrected QUBS image of the breast. The QUBS image will be derived by processing this corrected data with particular algorithms that yield the improved scatterer size image (SSI). The Specific Aims to implement the Research Design and Methods are: (Aim 1) simulate QUBS algorithm performance (SSI and ACS) performance under the Born approximation using simulated data; (Aim 2) create agar phantoms to be scanned; analyze the performance of IST/RT enhanced SSI/ACS using data from simulations and from phantoms and tissue; (Aim 3) prepare to submit a Phase-2 SBIR with improved hardware that will test the synergy of a hybrid method combining QUBS with USCT to create 5 images (3 + 2 = 5), and thereby a 5-dimensional feature space for improved tissue characterization (sensitivity and specificity). One in every 7 women will develop breast cancer in her lifetime. However, present diagnostic specificity for cancer detection (using mammography) is poor, with 3 in 4 biopsies yielding benign tissue and missing about 10% of cancers. This proposal, which combines two novel techniques for breast cancer detection-namely Quantitative Ultrasound Backscatter (QUBS) and Ultrasound Inverse Scattering Tomography (IST)-has a tremendous potential for improving breast cancer detection.