仿体表面磁共振声辐射力成像位移精度检测研究
Displacement Accuracy of Magnetic Resonance Acoustic Radiation Force Imaging on Phantom Surface
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摘要: 磁共振声辐射力成像(Magnetic Resonance Acoustic Radiation Force Imaging, MR-ARFI)是一种超声焦点定位技术, 可通过检测声辐射力作用到生物体内时在局部组织区域产生的微米级位移, 实现对超声焦点的定位。基于 MR-ARFI 位移检测结果, 可实现经颅超声焦点定位及相位矫正。但目前仍较少研究对 MR-ARFI 定量技术的位移检测精度进行标定。该文在超声作用参数(输入功率、时长、脉冲重复频率)完全一致的条件下, 以激光多普勒技术测得的位移作为金标准, 与 MR-ARFI 测得的位移值进行比对, 探究 MR-ARFI 的位移检测精度。研究结果显示, 激光多普勒测量的最大位移值和位移分布图与 MR-ARFI 测量结果具有良好的一致性。这表明 MR-ARFI 定位技术具有较高的位移检测精度, 可反映检测对象的真实运动情况, 有望在脑科学领域发挥重要作用。Abstract: Magnetic resonance acoustic radiation force imaging (MR-ARFI) is a developing ultrasound focalization technology. It can localize the focus of ultrasound by detecting the local micron-scale displacement in the tissue induced by acoustic radiation force. Based on the displacement map, transcranial focus localization and phase aberration correction can be conducted. However, only few studies focused on the accuracy of displacement detection using MR-ARFI. In this paper, the displacement detection accuracy of MR-ARFI was investigated. Under completely consistent experiment conditions (input power, ultrasonic duration and pulse repetition frequency), the displacement measured by laser Doppler technique was used as the gold standard and compared with the displacement measured by MR-ARFI. The results demonstrate that the maximum displacement and the displacement map measured by laser Doppler and MR-ARFI show high consistency. The research proves that MR-ARFI technology has high displacement accuracy, can reflect the real displacement in the object, and has great potentials in brain science.