Magnetic Resonance Elastography

描述（由申请人提供）：许多疾病过程的特点是与周围正常组织的机械特性有本质上的不同。这说明了触诊作为一种检测癌症和其他异常的临床技术的有效性。事实上，甲状腺、乳腺和前列腺的许多肿瘤仍然是由这种已有几百年历史的诊断技术首先检测出来的。不幸的是，触诊是一种主观技术，小的或难以接近的异常不能通过触摸检测。传统的成像方法，如超声、计算机断层扫描（CT）和磁共振成像（MRI）不能提供任何类似的信息。本研究的目标是开发、验证、探索和确定一种新的诊断成像技术的高影响力应用，用于定量评估组织的机械性能。我们称这项技术为磁共振弹性成像（MRE）。机械波是在组织中产生的，一种非常灵敏的相位对比MRI技术，使用同步运动敏化梯度，用于直接成像波的传播模式。专门开发的数学算法用于分析波动图像，并生成描述组织刚度和其他机械特性的定量图像。在这项研究开始时，中心假设是MRE可以作为一种实用的科学和临床工具成功实施，并且它将有助于检测和表征其他方法可能难以调查的局灶性和弥漫性疾病过程。该资助的最后一个周期的研究通过开发、验证并将基于MRE的慢性肝病诊断技术引入临床研究，证实了这一假设。研究表明，在这种情况下，MRE是一种比活检更舒适、更安全、更便宜的替代方法。下一个资助周期的研究计划包括进一步了解和开发MRE的基础技术，开发应用于其他应用的实用方法，以及探索在诊断疾病方面有前景的新应用。该研究计划包括理论工作、基础MRI脉冲序列开发、设备工程、动物和人体组织标本研究以及正常和患者志愿者的方案测试研究。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)非侵入性“通过成像触诊”医生无法触摸到的身体区域，(2)在肿瘤和其他异常严重到可以通过触摸检测到之前描绘出来，(3)为评估组织力学特性的变化提供更高的灵敏度，以及(4)为表征组织特性提供有用的新定量成像生物标志物。

DESCRIPTION (provided by applicant): Many disease processes are characterized by substantially different mechanical properties than surrounding normal tissue. This accounts for the efficacy of palpation as a clinical technique to detect cancer and other abnormalities. Indeed, many tumors of the thyroid, breast, and prostate are still first detected by this centuries- old diagnostic technique. Unfortunately, palpation is a subjective technique and small or inaccessible abnormalities cannot be detected by touch. Conventional 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 research is to develop, validate, explore and identify high-impact applications of a new diagnostic imaging technology for quantitatively assessing the mechanical properties of tissues. We call this technique Magnetic Resonance Elastography (MRE). Mechanical waves are generated in tissue and a remarkably sensitive phase-contrast MRI technique, using synchronous motion-sensitizing gradients, is used to directly image the pattern of wave propagation. Specially-developed mathematical algorithms are used to analyze the wave images and to generate quantitative images depicting the stiffness and other mechanical properties of tissue. At the onset of this research, the central hypothesis was that MRE can be successfully implemented as a practical scientific and clinical tool and that it would be useful for detecting and characterizing focal and diffuse disease processes that may be difficult to investigate by other methods. The research in the last cycle of this grant has confirmed this hypothesis by developing, validating, and introducing into clinical research an MRE- based technique for diagnosing chronic liver disease. The research has indicated that in this role, MRE is a more-comfortable, safer, less-expensive alternative to biopsy. The research plan for the next grant cycle includes investigations to further understand and develop the underlying technology of MRE, to develop practical methods for applying other applications, and to explore promising new applications in diagnosing disease. The research plan involves theoretical work, basic MRI pulse sequence development, device engineering, studies of animal and human tissue specimens, and protocol testing studies 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 and other abnormalities before they are severe enough to detect by touch, (3) provide greater sensitivity for assessing changes in tissue mechanical properties, and (4) provide useful new quantitative imaging biomarkers for characterizing tissue properties. PUBLIC HEALTH RELEVANCE: This research will develop and explore a new imaging technology (MR Elastography) that provides unique diagnostic information that cannot be obtained using conventional imaging techniques. The research has already shown that MR Elastography has a promising role in detection of important complications of chronic liver disease, an important health problem in the US and worldwide, as an alternative to invasive biopsy. MR Elastography has many other potential applications, such as cancer detection.