Wang Yiyun, Zhong Hongtao, Jiang Daohuai, Lan Hengrong, Zhang Juze, Yaxin Ma, Gao Feng, Gao Fei
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:1911-1914. doi: 10.1109/EMBC44109.2020.9175740.
Photoacoustic imaging has shown its great potential in biomedical imaging. A variety of imaging applications, like blood oxygenation for functional imaging, have been widely studied during the past few decades. Most of the previous works are based on the tissue's endogenous or nanoprobe's extraneous optical absorbance. In this paper, we proposed frequency-domain dual-contrast photoacoustic imaging aiming at exploring both optical absorption and mechanical property (e.g., viscoelasticity) of tissue. Instead of conventionally used pulsed excitation, a chirp-modulated laser signal is used to excite the sample to induce photoacoustic signals. On one hand, the optical absorption contrast is obtained by cross-correlating the PA signals with the chirp pattern. On the other hand, mechanical property is obtained by performing the Fourier transform to analyze the frequency spectrum. Experimental results revealed that samples with higher density-to-viscoelasticity ratio show larger quality factor in the received PA signals' spectrum. Both theoretical analysis and experimental demonstrations are performed to prove the feasibility of the proposed method.
光声成像在生物医学成像中已展现出巨大潜力。在过去几十年里，诸如用于功能成像的血氧定量等各种成像应用得到了广泛研究。先前的大多数工作基于组织的内源性或纳米探针的外源性光吸收。在本文中，我们提出了频域双对比度光声成像，旨在探索组织的光吸收和力学性质（如粘弹性）。与传统使用的脉冲激发不同，采用啁啾调制激光信号来激发样品以诱导光声信号。一方面，通过将光声信号与啁啾模式进行互相关来获得光吸收对比度。另一方面，通过执行傅里叶变换来分析频谱以获得力学性质。实验结果表明，具有较高密度与粘弹性比的样品在接收到的光声信号频谱中显示出更大的品质因数。进行了理论分析和实验演示以证明所提方法的可行性。
