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光声成像是采用“光激发超声波成像”的新型成像技术,它是检测强散射介质内部光吸收分布的一种有效医学影像技术.用短脉冲激光照射强散射介质(如生物组织),强散射介质由于光声效应产生超声信号,使用具有成像能力的声透镜把声压分布成像于像面上,然后利用具有空间分辨能力的阵列光声传感器,把同一像面上的光声信号强度记录下来,最后根据光声信号强度的空间分布进行图像重组.根据成像系统物像共轭原理,同一物平面的光声信号到达像面的时延相等,而不同物面的光声信号到达同一个探测器平面的时延各不相同,因此,利用BOXCAR的门控积分技术,控制BOXCAR采样门的不同时延就能获得散射介质内不同层面的光声图像.实验成功地获得了强散射介质内不同层面的光声层析图像,图像清晰,对比度高.这种层析成像方法不需要复杂的重建算法,可以实现快速层析成像.
Photoacoustic imaging is a new imaging technique based on “photoexcited ultrasound imaging”, which is an effective medical imaging technique for detecting the light absorption distribution inside a strong scattering medium. Strong scattering medium (such as biological tissue) is irradiated by short pulse laser, The medium generates ultrasonic signals due to the photoacoustic effect. The sound pressure distribution is imaged on the image plane by using an imaging lens. Then, the photoacoustic signal intensity on the same image plane is recorded by using an array photoacoustic sensor with spatial resolution , And finally the image is reconstructed according to the spatial distribution of the photoacoustic signal intensity.According to the principle of object-image conjugation of the imaging system, the photoacoustic signals reaching the image plane in the same object plane have the same delay and the photoacoustic signals of different object surfaces reach the same detection Therefore, using the gated integral technique of BOXCAR to control the different time delay of BOXCAR sampling gate, the photoacoustic images of different layers in the scattering medium can be obtained.The experiments have successfully obtained the results of different scattering media Level photoacoustic tomography images, clear images, high contrast.This tomography method does not require complex reconstruction algorithm, you can achieve a fast layer Imaging.