Magnetic Resonance Elastography

描述(由申请人提供)： 人们早就知道，恶性肿瘤的特征通常是与周围正常组织的机械性能有本质上的不同。这就解释了触诊作为一种临床技术在身体可触及的区域检测癌症的有效性。事实上，大多数甲状腺、乳腺和前列腺的肿瘤仍然是通过这种有数百年历史的诊断技术首次发现的。不幸的是，小的或无法接触到的病变不能通过触摸来检测，传统的诊断成像方法，如超声波、计算机断层扫描(CT)和磁共振成像(MRI)不能提供以任何方式类似的信息。这项提议的目标是继续开发和验证用于定量描绘组织机械特性的诊断成像技术。这项技术将机械波应用于组织，并通过分析波的传播模式来测量区域弹性。这一方法的一个关键组成部分是灵敏的MRI方法，该方法使用具有同步运动敏感梯度的MRI序列直接观察组织中传播的声波。这项工作的中心假设是，所提出的技术可以作为一种实用的科学和临床工具成功实施，并将有助于检测和表征局灶性和弥漫性疾病过程，这可能是其他方法难以研究的。研究计划包括以下几个方面的研究：(1)改进磁共振声波成像技术，(2)开发将声波应用于组织的有效方法，(3)设计处理波数据的数学算法，以及(4)对新技术的选定应用进行初步研究。此次延续的研究计划将再次包括理论工作、基本核磁共振脉冲序列开发、设备工程、动物和人体组织样本研究，以及正常志愿者和患者志愿者的试验。进一步的进展有望提供一种越来越有用的成像工具，具有以下能力：(1)通过成像非侵入性地“触诊”医生手无法触及的身体区域，(2)在肿瘤大到可以通过触摸发现之前勾勒出它们，(3)为评估组织弹性的变化提供更高的灵敏度，以及(4)为描述组织的特征提供有用的新的量化科学工具。

DESCRIPTION (provided by applicant): It has long been known that malignant tumors are often characterized by substantially different mechanical properties than surrounding normal tissue. This accounts for the efficacy of palpation as a clinical technique to detect cancer in accessible regions of the body. Indeed, most tumors of the thyroid, breast, and prostate are still first detected by this centuries-old diagnostic technique. Unfortunately, small or inaccessible lesions cannot be detected by touch, and conventional diagnostic imaging methods such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) do not provide information that is in any way analogous. The goal of this proposal is to continue to develop and validate a diagnostic imaging technique for quantitatively delineating mechanical properties of tissues. The technique applies mechanical waves to tissue and measures regional elasticity by analyzing the pattern of wave propagation. A critical component of this approach is sensitive MRI method for directly observing propagating acoustic waves in tissue, using an MRI sequence with synchronous motion-sensitizing gradients. The central hypothesis of this work is that the proposed technique can be successfully implemented as a practical scientific and clinical tool and that it will be useful for detecting and characterizing focal and diffuse disea.se processes that may be difficult to investigate by other methods. The research plan includes investigations in the following areas (1) improving the MR acoustic wave imaging technique, (2) developing effective methods for applying acoustic waves to tissue, (3) devising mathematical algorithms for processing the wave data, and (4) conducting pilot studies of selected applications of the new technology. The research plan in this continuation will again encompass theoretical work, basic MRI pulse sequence development, device engineering, studies of animal and human tissue specimens, and trials with normal and patient volunteers. Further progress is expected to provide an increasingly useful imaging tool with capabilities to: (1) noninvasively "palpate by imaging" regions of the body that are beyond the reach of the physician's hand, (2) delineate tumors before they are large enough to detect by touch, (3) provide greater sensitivity for assessing changes in tissue elasticity, and (4) provide a useful new quantitative scientific tool for characterizing tissue.