Saliency enhancement method for photoacoustic molecular imaging based on Grüneisen relaxation nonlinear effect

• Published in: Journal of biophotonics 2024-06, Vol.17 (6), p.e202400004-n/a
• Main Authors: Wang, Xiatian, Xie, Zhihua, Lin, Riqiang, Shu, Chengyou, Lv, Shengmiao, Guo, Pengkun, Xu, Haoxing, Zhang, Jinke, Dong, Liquan, Gong, Xiaojing
• Format: Article
• Language: English
• Subjects: Blood; Grüneisen relaxation; Imaging; Medical research; molecular imaging; photoacoustic effect; Probes; Salience; saliency enhancement
• ISSN: 1864-063X; 1864-0648
• DOI: 10.1002/jbio.202400004

Photoacoustic molecular imaging technology has a wide range of applications in biomedical research. In practical scenarios, both the probes and blood generate signals, resulting in the saliency of the probes in the blood environment being diminished, impacting imaging quality. Although several methods have been proposed for saliency enhancement, they inevitably suffer from moderate generality and detection speed. The Grüneisen relaxation (GR) nonlinear effect offers an alternative for enhancing saliency and can improve generality and speed. In this article, the excitation and detection efficiencies are optimized to enhance the GR signal amplitude. Experimental studies show that the saliency of the probe is enhanced. Moreover, the issue of signal aliasing is studied to ensure the accuracy of enhancement results in the tissues. In a word, the feasibility of the GR‐based imaging method in saliency enhancement is successfully demonstrated in the study, showing the superiorities of good generality and detection speed. Molecular probes are usually surrounded by blood vessels. For photoacoustic imaging, hemoglobin also generates strong signals, making it difficult to distinguish between probe and vessels at a single wavelength and reducing the saliency of the probe. To address this issue, this article presents a saliency enhancement method based on the Grüneisen relaxation nonlinear effect and validates its feasibility through phantom and in‐vivo experiments. This method offers a novel idea for expanding the applications of probes operating in visible wavelengths.