Feasibility of In-vivo Determination of Absolute Elastic Tissue

描述（由申请人提供）：拟议的研究将调查将力传感器集成到二维（2D）超声换能器阵列中的可行性，以测量超声弹性成像过程中的接触力。接触力信息将提供与皮肤表面接触时间的绝对度量，以及在扫描过程中任何一点施加的总力。该信息将用于校准（相对）机械应变图像，以比较应变图像对比度随变形增加的变化，并可用于绝对弹性模量重建。初步数据证明了这种装置的潜在收益。首先，当采用二维阵列实现三维跟踪时，应变图像质量得到显著改善。其次，各种组织类型的弹性非线性似乎是独特的，并且具有潜在的意义，但需要对接触力进行定量测量，以便对数据进行无偏比较。第三，最近的研究结果表明，乳房组织的弹性非线性参数可以成像，乳房组织样本的体外测量发现，导管原位癌（DCIS）具有最高的弹性非线性。因此，直接成像DCIS在乳腺内的三维分布是可能的。这可能对乳腺癌筛查、早期发现和治疗预后产生深远影响。该研究包括一项有限的I期临床试验，以测试联合成像/力传感器设备在临床环境中的性能。测试该技术的受试者池将集中于恶性肿瘤概率最高的患者（即BIRADS 4b或4c），这些患者计划进行超声引导活检。如果2-D b模式图像适合指导临床乳房弹性成像，如果体积数据采集速度足够快，可以徒手进行弹性成像，如果获得可靠、稳定的力传感器测量，如果力传感器鲁棒、敏感，并且具有足够的动态范围来确定临床乳房成像过程中与皮肤表面的初始接触和总接触力，则该设备的可行性将得到证明。如果可行性被证明，未来将要求资金来优化组合换能器，以进行更全面的非线性乳房弹性成像临床试验，可能针对DCIS检测。公共卫生相关性：这是一项研究创建二维超声阵列换能器的可行性的建议，该换能器具有集成的力传感器，用于在弹性成像实验中检测接触力。该传感器将能够在临床上估计软组织的非线性力学特性，并可能最终实现导管原位癌的直接成像，从而提高乳腺癌的早期检测。

DESCRIPTION (provided by applicant): The proposed research will investigate the feasibility of integrating a force sensor into a two-dimensional (2D) ultrasound transducer array for measuring the contact force during ultrasound elasticity imaging procedures. The contact force information will provide an absolute measure of the time at which contact is made with the skin surface and the total force applied at any point during scanning. That information will be used to calibrate (relative) mechanical strain images for comparing strain image contrast changes with increasing deformation and can be used for absolute elastic modulus reconstruction. Preliminary data demonstrate the potential gain from such a device. First, significant improvement in strain image quality is available when 3D tracking, enabled by a 2D array, is employed. Second, the elastic nonlinearity of various tissue types appears to be unique, and of potential significance, but a quantitative measure of the contact force is needed for an unbiased comparison of data. Third, recent results suggest it is possible to image the elastic nonlinearity parameter of breast tissues, and in vitro measurements of breast tissue samples found that ductal carcinoma in situ (DCIS) has the highest elastic nonlinearity. So, it might be possible to directly image the 3D distribution of DCIS in the breast. This could have a profound impact on breast cancer screening, early detection and treatment prognosis. The study involves a limited Phase I clinical trial to test performance of the combined imaging/force sensor device in a clinical environment. The subject pool for testing this technology will focus on patients with the highest probability of malignancy (i.e., BIRADS 4b or 4c) who are scheduled for ultrasound-guided biopsy. Feasibility of the device will be demonstrated if 2-D B-mode images are suitable for guiding clinical breast elastography, if the volume data acquisition rate is sufficiently fast to allow freehand elasticity imaging, if reliable, stable, force sensor measurements are obtained, and if the force sensor is robust, sensitive and has sufficient dynamic range to determine the initial contact with the skin surface and the total contact force during clinical breast imaging. If feasibility is demonstrated, future funding will be requested to optimize the combined transducer for a more comprehensive clinical trial of nonlinear breast elasticity imaging potentially targeting DCIS detection. PUBLIC HEALTH RELEVANCE: This is a proposal to study the feasibility of creating a two-dimensional ultrasound array transducer that has an integrated force sensor for detecting the contact force during elasticity imaging experiments. This transducer will enable clinically estimating the nonlinear mechanical properties of soft tissues and might eventually enable directly imaging ductal carcinoma in situ and thereby improve early detection of breast cancer.