Department of Mechanical Engineering, University of Washington, Seattle, Washington.
Icahn School of Medicine at Mount Sinai, Biomedical Engineering and Imaging Institute, New York, New York.
Curr Protoc. 2022 Mar;2(3):e379. doi: 10.1002/cpz1.379.
Magnetic resonance elastography (MRE) is a technique for determining the mechanical response of soft materials using applied harmonic deformation of the material and a motion-sensitive magnetic resonance imaging sequence. This technique can elucidate significant information about the health and development of human tissue such as liver and brain, and has been used on phantom models (e.g., agar, silicone) to determine their suitability for use as a mechanical surrogate for human tissues in experimental models. The applied harmonic deformation used in MRE is generated by an actuator, transmitted in bursts of a specified duration, and synchronized with the magnetic resonance signal excitation. These actuators are most often a pneumatic design (common for human tissues or phantoms) or a piezoelectric design (common for small animal tissues or phantoms). Here, we describe how to design and assemble both a pneumatic and a piezoelectric MRE actuator for research purposes. For each of these actuator types, we discuss displacement requirements, end-effector options and challenges, electronics and electronic-driving requirements and considerations, and full MRE implementation. We also discuss how to choose the actuator type, size, and power based on the intended material and use. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Design, construction, and implementation of a convertible pneumatic MRE actuator for use with tissues and phantom models Basic Protocol 2: Design, construction, and implementation of a piezoelectric MRE actuator for localized excitation in phantom models.
磁共振弹性成像（MRE）是一种通过对材料施加谐波变形并利用运动敏感的磁共振成像序列来测定软物质力学响应的技术。该技术可以阐明有关人类组织（如肝脏和大脑）健康和发育的重要信息，并已在模型（例如琼脂、硅树脂）上进行了使用，以确定其是否适合作为实验模型中人类组织的力学替代物。MRE 中应用的谐波变形是由致动器产生的，以特定持续时间的脉冲形式传输，并与磁共振信号激励同步。这些致动器最常用于气动设计（常用于人体组织或模型）或压电设计（常用于小动物组织或模型）。在这里，我们描述了如何设计和组装用于研究目的的气动和压电 MRE 致动器。对于这两种致动器类型，我们都讨论了位移要求、末端执行器选项和挑战、电子和电子驱动要求和考虑因素以及完整的 MRE 实现。我们还讨论了如何根据预期的材料和用途选择致动器类型、尺寸和功率。 © 2022 威利父子公司。基础方案 1：用于组织和模型的可转换气动 MRE 致动器的设计、构建和实施基础方案 2：用于模型局部激励的压电 MRE 致动器的设计、构建和实施
