目的: 利用光声层析成像技术(photoacoustic tomography, PAT)监测针灸小鼠阳陵泉穴位(GB34)、静脉注射造影剂金纳米颗粒溶液这两种方法分别施加, 以及共同施加对小鼠大脑皮层脉管系统成像的影响。方法: PAT技术能够对生物组织进行高分辨率无损成像, 反映生物组织的光吸收特性等功能信息。本项研究工作, 利用PAT技术实验获取了正常小鼠活体脑皮层随时间变化的图像, 探讨了针灸及造影剂分别作用以及共同作用下皮层脉管系统的光吸收特性的变化。结果: 三组活体实验发现在针灸及造影剂各自作用下, 皮层脉管系统的光吸收峰值增强比率分别为23.87%以及38.56%; 而在两者共同作用情况下, 其皮层脉管系统的光吸收比外源刺激前进一步增加66.75%。结论: 实验结果显示, PAT技术不但能够全程监测小鼠大脑皮层脉管系统随时间变化的光吸收信息, 而且能够诠释金纳米颗粒结合针灸两者共同作用产生的皮层光吸收增强的复合效应远大于任何一种单独作用产生的效应, 这揭示了针灸辅助造影剂方法有助于大大提高光声脑成像对比度。

Objective: To visualize the vasculature of mouse cerebral cortex separately and together in response to acupuncture at Yanglingquan acupoint (GB34) and intravenous administration of Au nanoparticles using photoacoustic tomography (PAT). Methods: PAT provides an emerging noninvasive tool to extract functional information such as hemoglobin of biological tissue with high-resolution. In this work, PAT was utilized to obtain images of in vivo mouse cerebral cortex over time, and to monitor the changes of optical absorption of living mouse brain vasculature separately and together in response to Au nanoparticles injection and acupuncture. Results: Photoacoustic data from three groups of mice showed that with contrast agents injection or acupuncture, the absorption enhancement ratios of the cortical vasculature were 23.87% and 38.56%, respectively. With both contrast agent injection and acupuncture, the light absorption of the cortical vasculature was increased by 66.75%. Conclusion: The achieved results exhibit that the optical absorption of in vivo mouse cerebral cortex over time can be clearly monitored by PAT. The optical absorption enhancement induced by combined method of acupuncture and Au nanoparticles injection was much greater than that by any one method alone. The results also indicate that the integration of acupuncture and contrast agents would greatly enhance the photoacoustic imaging contrast.