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Development of the next generation MR Elastography actuator

开发下一代 MR 弹性成像执行器

基本信息

批准号：
22791211
负责人：
NUMANO Tomokazu
金额：
$ 1.75万
依托单位：
Tokyo Metropolitan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (B)
财政年份：
2010
资助国家：
日本
起止时间：
2010 至 2012
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22791211/
关键词：
核磁気共鳴画像(MRI)MR Elastography MRI Actuator shear wave Magnetic Resonance Imaging : MRI Ball-vibrator Motion Sensitizing Gradient : MSG MR Phase image Elastogram Synchronization Wave image Magnetic Resonance Imagin : MRI

项目摘要

The purpose of this study was to develop a new technique for a powerful compact MR elastography (MRE)actuator based on a pneumatic ball-vibrator. This is a compact actuator that generates powerful centrifugal force vibrations via high speed revolutions of an internal ball using compressed air. This equipment is easy to handle due to its simple principles and structure. Vibration frequency and centrifugal force are freely adjustable via air pressure changes (air flow volume), and replacement of the internal ball. In order to achieve MRI compatibility, all parts were constructed from non-ferromagnetic materials. Vibration amplitudes (displacements) were measured optically by a laser displacement sensor. From a bench test of displacement, even though the vibration frequency increased, the amount of displacement did not decrease. An essential step in MRE is the generation of mechanical waves within tissue via an actuator, and MRE sequences are synchronized to several phase offsets of vibration. In this system, the phase offset was detected by a four-channel optical-fiber sensor, and it was used as an MRI trigger signal. In an agarose gel phantom experiment, this actuator was used to make an MR elastogram. This study shows that the use of a ball actuator for MRE is feasible.

本研究的目的是开发一种新的技术，强大的紧凑型MR弹性成像（MRE）致动器的基础上，气动球振动器。这是一个紧凑的致动器，通过使用压缩空气的内部球的高速旋转产生强大的离心力振动。该设备由于其简单的原理和结构而易于操作。振动频率和离心力可通过气压变化（空气流量）和更换内部球来自由调节。为了实现MRI兼容性，所有部件均由非铁磁材料制成。通过激光位移传感器光学测量振动幅度（位移）。从位移的台架试验来看，即使振动频率增加，位移量也没有减少。MRE中的一个重要步骤是通过致动器在组织内产生机械波，并且MRE序列与振动的几个相位偏移同步。在该系统中，相位偏移检测由一个四通道光纤传感器，它被用来作为MRI触发信号。在琼脂糖凝胶体模实验中，该致动器用于制作MR弹性图。这项研究表明，使用球致动器的MRE是可行的。