Imaging the Mechanical Properties of Soft Tissue/L'imagerie des caractéristiques mécaniques des tissus mous.

弹性成像是一种较新的软组织弹性分布成像技术。弹性成像提供了可视化弹性对比的能力，在乳腺癌中比x线对比高10-100倍，以及复杂的特性，如组织衰减，能够独特地诊断肝纤维化。由于没有直接成像内部弹性值的方法，弹性成像依赖于三步方法：首先，对组织施加机械驱动（例如振动），产生依赖于内部弹性结构的应变场；其次，采用数字、超声或磁共振成像等方法来捕获这种应变模式；最后，利用数学反问题从实测应变场重构出弹性特性图像。

Elastography is a relatively new technology for imaging the elastic property distribution within soft tissues. Elastography offers the ability to visualize elastic contrast, 10-100X greater than x-ray contrast for breast cancer, as well complex properties such as tissue attenuation, uniquely able to diagnose liver fibrosis. As no direct method for imaging internal elasticity values exists, elastography relies on a three step approach: first, mechanical actuation (e.g. vibration) is applied to the tissue, generating a strain field that is dependent upon the internal elastic structure; second, methods such as digital, ultrasound or magnetic resonance imaging are used to capture this strain pattern; finally, the elastic property image is reconstructed from the measured strain field by means of a mathematical inverse problem. This research program focuses on the engineering systems that underlie this complex imaging process. The goal is to develop practical tools and resources for the application of advanced elastographic imaging methods in-vivo. Key projects to be supported by this research program include: development of methods for imaging anisotropic material properties; improved image reconstruction capability for digital image based elastography; an on-line service available to external research groups for elastographic image reconstruction from 3D Magnetic Resonance displacement data; improved mathematical and statistical methods for elastographic image calculation; and Graphics Processor Unit computing for fast image processing. In each case, the scientific approach consists of identifying the key constraints and objectives of each target application, e.g issues such as cost, processing time, boundary conditions, and complex mechanical behavior. These constraints and conditions are then used to drive the design and implementation of a functioning prototype system. In this way, this program looks to establish a pipeline for generating novel elastography applications, which in turn may be further developed through appropriate outside funding mechanisms.