滑动焦点光声显微成像方法

在高分辨光声显微成像系统中,只有在有限焦深范围内的吸收体可以获得高分辨率高信噪比的成像,而实际的生物组织往往具有不规则的轮廓,导致成像结果分辨率和信噪比不均匀。提出了一种基于稀疏扫描轮廓的滑动焦点光声显微成像方法,首先在固定的焦点上稀疏扫描轮廓,人工选择轮廓点获取轮廓的稀疏矩阵,然后通过双调和(Biharmonic)插值获取完整的轮廓矩阵,并将轮廓矩阵转化为焦点位置移动矩阵,最后进行二次扫描,根据焦点位置移动矩阵在每次扫描之前调整焦点位置,使得在整个扫描过程中,样品始终处于焦深的范围,从而获得分辨率和信噪比均匀的光声显微图像。通过模型实验和在体皮下血管成像、颅下血管成像,证明了该方法可以有效地提高光声成像的质量。

Method of Sliding Focus Photoacoustic Microscopic

Absorbers locating in the area of finite focal depth can be imaged with high resolution and signal-to-noise-ratio (SNR) using high resolution photoacoustic microscopy, whereas contours of actual biological tissues turn out to be irregular, causing non-uniform resolution and SNR in photoacoustic images. Sliding focus method based on sparse contour scanning is introduced, first scan contour sparsely based on fixed focus, manually choose contour locations, then obtain the full contour matrix using biharmonic interpolation, which is then transformed to sliding focus matrix, second scanning is done in the last, during which the focus location is adjusted before each scanning step to make sure the absorbers locate in the area of focal depth, thereby images with uniform resolution and SNR can be obtained. Phantom experiment and in vivo blood vessels imaging are conducted to prove the validity of the method.