瞬态磁共振弹性成像的仿真与算法研究

磁共振弹性成像技术可以量化人体组织弹性属性。磁共振弹性成像的弹性波激励方式有稳态和瞬态两种。由于人体组织的特殊性，弹性波在组织中传播情况复杂。文章通过建立一个磁共振弹性成像的有限元仿真平台，对瞬态磁共振弹性成像技术进行数值建模，并针对瞬态磁共振弹性成像设计了基于到达时间的弹性重构算法。通过 MATLAB编程处理仿真得到的瞬态磁共振弹性成像数据，最终导出瞬态磁共振弹性成像的结果。数值平台仿真的稳态和瞬态磁共振弹性成像对比实验表明，瞬态磁共振弹性成像对于反射和衍射具有较好的抗干扰能力，对于深处的小尺寸组织，具有较高的灵敏度和较好的精准度，而基于到达时间的算法能够实现瞬态磁共振弹性成像的弹性重构。

Numerical Modeling of Transient Magnetic Resonance Elastography

Magnetic resonance elastography (MRE) can noninvasively quantify tissue elastic properties. There are two kinds of dynamic actuation in MRE, namely harmonic excitation and transient excitation. Due to the complexity of human organs and tissues, the propagation of elastic waves suffers from relfection, diffraction and other interfering effects. In this study, a numerical platform was established to simulate transient MRE. Furthermore, an algorithm of elasticity reconstruction was developed in accordance with time of arrival. A series of numerical experiments were carried out for harmonic and transient MREs. The results show that transient MRE has good anti-interference ability on relfection and diffraction, and the developed algorithm can perform elasticity reconstruction for transient MRE successfully.