基于柱弥散光源体内辐照的前列腺扫描光声成像仿体实验

光声成像技术是一种非常有前景的前列腺早期检测与成像的新技术. 在现有前列腺光声成像技术中, 通常采用的腺体外光源辐照方式由于受外围组织的影响, 容易减弱深部前列腺组织的光能量吸收, 导致辐照范围减小, 引起光声成像深度不足, 难以实现无损前列腺癌的检测. 本文基于前列腺组织的结构特征, 依据一种以柱状弥散光纤在尿道对前列腺实施光辐照、并利用外置于直肠内的长焦区聚焦式超声换能器检测光声信号的前列腺光声扫描成像技术, 构建了光声成像实验系统, 开展了仿体实验. 测试结果表明, 系统能够实现样品中吸收体的定位和成像, 结合柱弥散光源体内辐照可使成像深度提高, 同时侧向成像范围也较大. 初步结果表明, 借助柱弥散光源进行体内光辐照的光声信号新激发方式结合长焦区超声探头在前列腺癌早期无创诊断上具有潜在的应用前景.     

Monitoring photo-thermal response and collagen remodeling of mouse skin with multiphoton microscopy

Two-photon excitation fluorescence （TPEF） and second-harmonic generation （SHG） are detected through multiphoton microscopy （MPM）. The major signals have the potential to monitor the process of tissue changes. TPEF and SHG are used to monitor the skin photo-thermal response to irradiation with intense pulsed light sources （A is in the range of 560-1200 nm） and trace the process of skin remodeling in vivo at different time intervals. TPEF intensity is nearly unchanged at different time intervals after irradiation, whereas SHG intensity changes considerably. The results reveal the photo-thermal effect of nonablative light sources and the process of collagen remodeling at the sub-micron level.