MRI-Based Elasticity Imaging

组织弹性被广泛认为与疾病密切相关，尤其是给定的乳腺癌 体检在乳腺癌筛查中的突出地位。因此，相当大的一部分 已经出现了开发和评估测量和成像的新概念的技术努力 与乳房组织的力学特性有关的参数。项目I，磁共振 弹性成像(MRE)，利用相位对比技术对诱发的简谐机械波进行编码 自定义渐变期间的运动到相位累积，以将全位移场映射为三个 在MR采集分辨率下或接近MR采集分辨率时，根据其得出机械性能估计的尺寸。 在本供资期间，项目I成功地实现了强大的地雷风险评估技术，该技术具有 在临床乳房检查期间进行了有限的部署，以证明可行性，提供初步 估计正常乳房的机械性能，并强调提取更多的机会 复杂的力学行为。现有的MRE方法已准备好用于系统的临床部署和 将用于一项研究计划，该计划包括(A)临床评估、(B)持续技术进步和 (C)组织病理学对照，开始鉴定生物标志的力学性能对比。 继续执行项目I的具体目标包括：(1)发展地雷危险教育驱动和重建 估计乳腺组织粘弹性力学行为的技术，(2)图像的优化 缩短检测时间的采集顺序和方法(3)剪切模量法和粘弹性法 组织充足的乳房切除标本的特性与组织病理学分析的相关性 可用于对成像体积进行空间采样和定向，以及(4)参与临床研究设计 由临床核心执行，针对活检、可触及肿块推荐的异常筛查 关于接受新辅助治疗的局部晚期疾病的临床乳房检查和试点检查。如果 如果成功，这些目标有望产生足够的证据来令人信服地估计 MRE有助于鉴别诊断，试点数据支持在治疗预后和 治疗监测，这将为未来启动更大规模的MRE临床试验提供决策依据。

Tissue elasticity is widely held as being strongly associated with disease, especially breast malignancy given the prominent place that physical examination holds in breast cancer screening. As a result, a sizeable technology effort has emerged to develop and evaluate new concepts for measuring and imaging parameters related to the mechanical characteristics of breast tissue. Project I, Magnetic Resonance Elastography (MRE), exploits phase contrast techniques to encode induced harmonic mechanical wave motion into phase accumulations during customized gradients to map the full displacement field in three dimensions from which mechanical property estimates are derived at or near the MR acquisition resolution. During the current funding period, Project I has successfully realized a robust MRE technique which has been deployed on a limited basis during clinical breast exams to demonstrate feasibility, provide preliminary estimates of the mechanical properties of normal breast, and highlight opportunities for extracting more complex mechanical behaviors. The existing MRE method is ready for systematic clinical deployment and will be used in a research plan consisting of (a) clinical evaluation, (b) continued technical advancement and (c) histopathological correlation to begin to identify the biological signatures of mechanical property contrast. The specific aims for continuation of Project I include (1) development of MRE driving and reconstruction techniques to estimate viscoelastic mechanical behavior in breast tissue, (2) Optimization of image acquisition sequences and methods to reduce exam time (3) exploration of shear modulus and viscoelastic property correlations with histopathological analyses in mastectomy specimens where adequate tissue is available to spatially sample and orient the imaged volume, and (4) participation in the clinical study designs executed by the Clinical Core targeting screening abnormalities recommended for biopsy, palpable masses on clinical breast exams and pilot exams of locally-advanced disease receiving neoadjuvant therapy. If successful, these aims are expected to generate evidence sufficient to estimate convincingly the potential of MRE to contribute to differential diagnosis, and pilot data in support of a role in treatment prognosis and therapy monitoring which will inform decisions on the initiation of larger clinical trials with MRE in the future.