Viscoelastic Parameters estimation and imaging for Thyroid Nodule differentiation

描述(申请人提供)：目前，迫切需要对甲状腺结节进行活检前评估。常规超声对甲状腺结节的检出非常敏感，但传统超声的低特异性导致大量不必要的(即良性的)活检，给患者带来了巨大的经济和身体负担。因此，为了克服目前具有挑战性的两难境地，开发新的低成本和非侵入性的技术来评估高敏感性和特异性的甲状腺结节是非常重要的。本研究的目的是推进、优化和评估一种新的非侵入性方法，即多光谱成像和弹性评估(MIEA)，该方法由三种基于超声的技术组成：振动声学(VA)、梳状推进超声横波弹性成像(CUSE)和剪切波色散超声测振术(SDUV)。术语多光谱是指在多个频段评估甲状腺组织以获得最大信息的概念。MIEA方法将提供诊断性超声成像无法提供的额外信息。Va是一种成像方法，它提供关于结节形状和结节中是否存在微钙化的信息，CUSE是一种二维弹性测绘方法，SDUV是一种点测量弹性和粘性的方法。弹性和钙化在恶性结节的诊断中都很重要，并将评估粘度在这种鉴别中的作用。该项目的长期目标是开发一种评估甲状腺结节的新工具。我们的假设是，MIEA方法提高了甲状腺癌检测的敏感性和特异性。因此，通过改进甲状腺结节活检的选择，该方法减少了不必要的FNAB的数量，并减少了患者的相关成本和负担。MIEA可以在传统的超声扫描仪上实施，并且可以在B型超声成像的指导下使用相同的超声探头进行测量。所提出的MIEA方法具有快速、低成本、便携和非侵入性的特点，因此它可以适用于大量的患者。这项提议侧重于两个具体目标。目标1：为患者研究准备系统-改进、优化和自动化用于人类甲状腺研究的MIEA方法；目标2：人类研究-通过将结果与手术病理相关联作为金标准，评估MIEA方法在甲状腺结节鉴别诊断中的价值。方法：Va、SDUV和CUSE将在可编程超声系统上实施，它们的性能将使用模拟甲状腺的体模进行测试和优化。结果将使用独立的测量进行验证。在第二个目标中，我们将对一组患者进行人体研究，这些患者被安排进行临床指征的甲状腺活检，以诊断可疑的甲状腺结节。这些患者将接受血管成像、CUSE的2D弹性图和SDUV的粘弹性测量，结果将与病理学家报告的手术活检结果相关联。结果将会是 评价MIEA对甲状腺结节鉴别诊断的敏感性和特异性。

DESCRIPTION (provided by applicant): Currently, there is an urgent need for pre-biopsy assessment of thyroid nodules. Conventional ultrasound is quite sensitive for detection of thyroid nodules; however, low specificity of traditional ultrasound leads to a great number of unnecessary (i.e. benign) biopsies that causes a significant financial and physical burden to the patients. To overcome the present challenging dilemma, it is thus important to develop new low- cost and noninvasive techniques to evaluate thyroid nodules with high sensitivity and specificity. The purpose of our research is to advance, optimize and evaluate the efficacy of a new noninvasive method called Multispectral Imaging and Elasticity Assessment (MIEA), which is comprised of three ultrasound-based techniques: vibro-acoustography (VA), comb-push ultrasound shear wave elastography (CUSE), and shear wave dispersion ultrasound vibrometry (SDUV) for characterization of thyroid nodules. The term multispectral refers to the concept of evaluating thyroid tissue at multiple frequency bands to obtain maximum information. The MIEA method will provide additional information not available from diagnostic US imaging. VA is an imaging method that provides information about the nodule shape and the presence of microcalcifications in the nodules, CUSE is a method for 2D mapping of elasticity, and SDUV is a method for point measurement of elasticity and viscosity. Both elasticity and calcifications are important in diagnosis of malignant nodules and will evaluate the effects of viscosity in this differentiation. The long-term goal of this project is to develop a new tool for assessment of thyroid nodules. Our hypothesis is that the MIEA method improves the sensitivity and specificity of thyroid cancer detection. Hence by improving the selection of thyroid nodules for biopsy, this method reduces the number of unnecessary FNAB and the associated cost and burden to the patients. MIEA can be implemented on conventional ultrasound scanners, and measurements can be made under the guidance of B-mode ultrasound imaging using the same ultrasonic probe. The proposed MIEA method is fast, low cost, portable, and noninvasive, thus it can be available to a large patient population. This proposal focuses on two specific Aims. Aim # 1: Prepare system for patient studies - Advance, optimize, and automate the MIEA method for human thyroid study; Aim # 2: Human study - Assess diagnostic value of the MIEA method in differentiation of thyroid nodules by correlating the results to surgical pathology as the gold standard. Approach: VA, SDUV, and CUSE will be implemented on a programmable ultrasound system and their performance will be tested and optimized using thyroid-mimicking phantoms. The results will be validated using independent measurements. In the second Aim, we will conduct a human study on a group of patients who are scheduled to have clinically-indicated thyroid biopsy for suspected thyroid nodules. VA imaging, 2D elasticity mapping by CUSE, and viscoelasticity measurement by SDUV will be performed on these patients and the results will be correlated with the findings of surgical biopsy as reported by the pathologist. The results will be used to evaluate the sensitivity and specificity of MIEA for differentiation of thyroid nodules.