基于激光多普勒测振技术的磁声耦合成像方法

Magneto-acoustic tomography (MAT) is an emerging noninvasive functional imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. MAT takes advantage of the high contrast of electrical impedance tomography (EIT) and the high spatial resolution of ultrasound imaging (US), therefore, it has attracted lots of attention. Currently, ultrasound detector is widely applied to acquire acoustic signal for reconstruction, however, because of the electromagnetic radiation during measurement, MAT images suffer from a low signal-to-noise ratio (SNR). Furthermore, MAT imaging spatial resolution is also affected by the low central frequency and narrow bandwidth of ultrasound detector. In this study, we, for the first time, propose a laser doppler vibrometry (LDV) technique based MAT. Take advantage of optical measurement method, LDV technique based MAT gets rid of the limitation of acoustic signal detection method, that it could have a higher SNR and better spatial resolution. The LDV technique based MAT forward model has been built, in addition, numerical simulations and phantom experiments have been performed to demonstrate the feasibility of the proposed method.

磁声耦合成像是一种新型无损功能成像技术，能够实现毫米量级的生物组织电导率分布重建。磁声耦合成像融合了电阻抗成像方法的高对比度和超声成像的高分辨率优点，引起了国内外研究人员的关注。当前，采用超声探头接收声场信号用于磁声耦合图像重建，这种测量方式易受电磁辐射干扰，导致信噪比较低。此外，超声探头较低的中心探测频率和较窄的测量频带也影响了MAT成像空间分辨率。在本研究中，作者首次提出了一种基于激光多普勒测振技术的磁声耦合成像方法。凭借光学精密测量优势，可以克服声场信号探测的局限性，使基于激光多普勒测振技术的磁声耦合成像方法具有更高的信噪比和更好的空间分辨率。我们建立了基于激光多普勒测振技术的磁声耦合成像方法的正向模型，并通过数值模拟和仿体实验论证了新方法的可行性。

磁声耦合成像是一种无损功能成像技术，能够实现毫米量级的生物组织电导率分布重建。磁声耦合成像融合了电阻抗成像方法的高对比度和超声成像的高分辨率优点，引起了国内外研究人员的关注。当前，采用超声探头接收声场信号用于磁声耦合图像重建，这种测量方式易受电磁辐射干扰，导致信噪比较低。此外，超声探头较低的中心探测频率和较窄的测量频带也影响了磁声耦合成像空间分辨率。在本研究中，作者提出一种基于激光多普勒测振技术的磁声耦合成像方法。凭借光学精密测量优势，可以克服声场信号探测的局限性，使基于激光多普勒测振技术的磁声耦合成像方法具有更高的信噪比和更好的空间分辨率。我们建立了基于激光多普勒测振技术的磁声耦合成像方法的正向模型，并通过数值模拟和仿体实验论证了新方法的可行性。