Magnetic Resonance Elastography

描述(申请人提供)：许多疾病过程的特征是与周围正常组织的机械性能有很大的不同。这解释了触诊作为一种检测癌症和其他异常情况的临床技术的有效性。事实上，许多甲状腺、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，触诊是一种主观技术，微小的或无法接触到的异常无法通过触摸检测到。诸如超声波、计算机断层扫描(CT)和磁共振成像(MRI)等常规成像方法不提供以任何方式类似的信息。这项研究的目标是开发、验证、探索和识别一种新的诊断成像技术的高影响力应用，以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，一种非常敏感的相衬磁共振技术，使用同步运动敏感梯度，直接成像波的传播模式。专门开发的数学算法被用来分析波图像，并生成描述组织的僵硬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，它将有助于检测和表征可能难以用其他方法研究的局灶性和弥漫性疾病过程。在这笔赠款的最后一个周期中的研究通过开发、验证并将基于MRE的诊断慢性肝病的技术引入临床研究，证实了这一假设。研究表明，在这一角色中，MRE是一种比活组织检查更舒适、更安全、更便宜的选择。下一个赠款周期的研究计划包括调查，以进一步了解和开发MRE的基本技术，开发应用其他应用的实用方法，并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、基本的MRI脉冲序列开发、设备工程、动物和人体组织样本的研究，以及对正常和患者志愿者的方案测试研究。预计进一步的进展将提供一种越来越有用的成像工具，具有以下能力：(1)通过成像以非侵入性的方式触及医生手无法触及的身体区域，(2)在严重到可以通过触摸检测到之前勾勒出肿瘤和其他异常，(3)为评估组织机械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的定量成像生物标记物。 与公共卫生相关：这项研究将开发和探索一种新的成像技术(磁共振弹性成像)，它提供使用传统成像技术无法获得的独特诊断信息。研究已经表明，作为侵入性活检的替代方法，磁共振弹性成像在检测慢性肝病的重要并发症方面具有很好的作用。慢性肝病是美国和世界范围内的一个重要健康问题。磁共振弹性成像还有许多其他潜在的应用，例如癌症检测。

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.