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Development of practical system for high-speed magnetic resonance elastography

高速磁共振弹性成像实用系统开发

基本信息

批准号：
14570854
负责人：
MATSUDA Tetsuya
金额：
$ 2.24万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

Magnetic resonance elastography (MRE) can provide quantitative measurements of tissue elasticity by visualizing the strain waves applied from the body surface. Though MRE is expected to be a powerful diagnostic tool for tissue characterization, its long acquisition time limits the practical application to the area such as brain, extremities, and breast, where respiratory motion was not necessarily considered. To realize in vivo measurement of tissue elasticity in human abdomen, we aimed to develop a high speed MRE acquisition method by introducing our original technique of phase velocity encoding that could be combined with various high speed MR imaging methods as preparation pulses. The technique translated the velocity encoded phase shift into the longitudinal magnetization and the velocity information was retrieved from the signal intensity after the image acquisition. In this research project, we also designed an oscillation system that generates strain waves appropriate to calculate the elasticity from the acquired images.Introduction of our original technique of phase velocity encoding to a high speed MR imaging method successfully acquired MRE images during a single breath-hold period. The oscillation system we proposed in this research project was a bed-type oscillator on which patients rested. We constructed a prototype of table oscillator and MRE images obtained from an elastic phantom on the table oscillator demonstrated that flat strain waves were generated. Since pure transverse waves were generated independently from longitudinal wave components, shear modulus of the phantom could be calculated from the obtained MRE images without contamination of Young' s modulus. While tissue elasticity of abdominal organ has not been obtained yet, essential methodology for abdominal MRE was established in this research project.

磁共振弹性成像(MRE)可以通过可视化从身体表面施加的应变波来提供组织弹性的定量测量。虽然MRE有望成为一种强大的组织定征诊断工具，但其较长的获取时间限制了其在脑、肢体和乳房等不一定考虑呼吸运动的区域的实际应用。为了实现人体腹部组织弹性的活体测量，我们的目标是通过引入我们独创的相速度编码技术来开发一种高速MRE采集方法，该技术可以与各种高速MR成像方法相结合作为准备脉冲。该技术将速度编码的相移转化为纵向磁化强度，从图像采集后的信号强度中提取速度信息。在这个研究项目中，我们还设计了一种振荡系统，可以从采集的图像中产生合适的应变波来计算弹性。将我们独创的相速度编码技术引入到高速磁共振成像方法中，成功地在单个屏气期内获得了MRE图像。我们在本研究项目中提出的振动系统是一种床式振荡器，患者可以在其上休息。我们构建了一个台式振荡器的原型，通过弹性体模在台式振荡器上获得的磁流变成像表明，产生了平坦的应变波。由于纯横波是从纵波分量独立产生的，因此可以从获得的磁共振成像图像中计算出体模的剪切模数，而不会受到杨氏S模数的影响。虽然腹部器官的组织弹性还没有得到，但本研究项目建立了腹部磁共振成像的基本方法学。