MAGNETIC RESONANCE ELASTOGRAPHY

人们早就知道恶性肿瘤的特征往往是 与周围环境相比， 正常组织这就解释了触诊作为一种 临床技术，以检测癌症在可访问的区域， 身体事实上，大多数甲状腺、乳腺和前列腺肿瘤都是 仍然是由这种有着几百年历史的诊断技术首次发现的。 不幸的是，小的或难以接近的病变不能被检测到， 触摸和传统的诊断成像方法， 超声、计算机断层扫描（CT）和磁共振成像 (MRI)不要提供任何类似的信息。 本提案的目标是开发和验证一个诊断 用于定量描绘机械的成像技术 组织的特性。所提出的技术适用于机械 波组织和测量区域弹性通过分析 波传播的模式。这一新技术的关键组成部分 技术是一种最近发展起来的直接观测方法 在组织中传播声波，使用MRI序列， 同步运动敏感梯度。的中心假设 这项工作是，所提出的技术可以成功地 作为一种临床工具，它将是有用的 检测和表征局灶性和弥漫性疾病过程 这可能很难通过其他方法进行调查。 研究计划包括以下几个方面的调查（一） 改进磁共振声波成像序列，（2）发展 将声波应用于组织的有效方法，（3） 细化所需的图像处理方法，（4）研究 组织表征技术的潜力，以及（5） 在人类研究中应用这项技术。述方法将 包括理论工作，基本的MRI脉冲序列开发， 设备工程，动物和人体组织标本的研究， 以及正常和患者志愿者的试验，特别强调 优化乳腺癌检测技术。 如果这项研究成功，它将产生一种新的诊断方法， 成像工具，其可以：（I）提供非侵入性“触诊”的手段 通过成像”身体的区域， （2）在肿瘤足够大之前描绘肿瘤 通过触摸进行检测，（3）提供更高的灵敏度以评估 组织弹性的变化，和（4）提供一个有用的新的 用于表征组织的定量工具。

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 develop and validate a diagnostic imaging technique for quantitatively delineating mechanical properties of tissues. The proposed technique applies mechanical waves to tissue and measures regional elasticity by analyzing the pattern of wave propagation. A critical component of this new technique is a recently-developed 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 clinical tool and that it will be useful for detecting and characterizing focal and diffuse disease processes that may be difficult to investigate by other methods. The research plan includes investigations in the following areas (I) improving the MR acoustic wave imaging sequence, (2) developing effective methods for applying acoustic waves to tissue, (3) refining the required image processing methods, (4) studying the potential of the technique for tissue characterization, and (5) implementing the technique in human studies. The methods will encompass theoretical work, basic MRI pulse sequence development, device engineering, studies of animal and human tissue specimens, and trials with normal and patient volunteer's, special emphasis on optimizing the technique for breast cancer detection. If the research is successful, it will yield a new diagnostic imaging tool that may: (I) provide a means to 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 tool for characterizing tissue.