由于滤波反投影重建算法要求对成像区域进行全方位扫描以获取完全投影数据,它需要较长时间采集大量数据,使其在医学上的应用受到限制。研究了在有限角度下采用代数重建算法进行光声成像的方法,实验用的光源为YAG激光器,波长为1064 nm,重复频率20 Hz,脉宽为6 ns,探测器为针状的磺化聚二氟乙烯(PVDF)膜水听器,接收面积的直径为1 mm,从仿真和实验结果表明该方法适用于“非完备投影数据”的光声层析成像。从图像重建效果上与滤波反投影算法相比较,该成像算法提高了重建图像的分辨率和对比度。采用代数重建算法的有限角度的光声成像方法,对临床医学的无损伤检测,具有重要的意义。

Since the reconstruction with the filtered backprojection (FBP) algorithm needs sufficient views to all points in the “detection region”, it requires a quite long time to get enough data, which restricts the application in the medical field. The limited-view photoacoustic imaging based on algebraic reconstruction techniques (ART) was studied. A Q-switched Nd∶YAG laser operating at 1064 nm was used as light source. The laser had a pulse width of 6 ns and a repetition frequency of 20 Hz. A needle polyning lidene difluoride (PVDF) hydrophone with diameter of 1 mm was used to detect photoacoustic signals. The simulations and experiments demonstrated that ART works well for limited-view data in photoacoustic imaging, and ART can improve the resolution and contrast of reconstruction images compared with the FBP. Limited-view photoacoustic imaging based on ART has far-reaching significance to noninvasive medical inspectable technology.