频域OCT的背向散射率补偿

Compensation of Backscattering Coefficient in Fourier-Domain Optical Coherence Tomography

针对频域OCT中背向散射光的强度随探测深度加深而急剧减弱,从而导致最后的组织成像模糊不清的现象,提出了一种对不同探测深度图像灰度补偿的方法。该方法通过补偿样品每层析面的入射光功率与背向功率散射率,来得到样品每层析面图像的真实灰度,提高了OCT图像质量。以理想的、由多层均匀介质组成的组织模型为基础,深入剖析了影响深度图像灰度的主要因素。通过建立以多层盖玻片为被测物体的频域OCT系统,得到多层盖玻片的深度图像。在对以盖玻片为被测物体的前提下,得出逐层深度图像灰度补偿的公式。并将理论补偿和实验系统的复杂情况相结合,对深度灰度图像进行入射和出射光强的补偿。实验结果证明这种补偿法是一种有效可行的补偿方法。

According to the phenomenon that the intensity of backscattering light decreases dramatically as the detecting depth increases, causing blurred imaging in Fourier-domain optical coherence tomography （FDOCT）, a compensation method used for different detecting depth was advanced in the present paper. Through compensating the incident power and scattering coefficient of back-scattered light in each layer of the sample, the real gray level of the image was obtained. With the model of multi-layered homogeneous tissue, the main factors influencing image gray were analyzed. Establishing the FDOCT system with multi-layer cover-glass to be the sample, the structure image was obtained. On the basis of cover-glass as the sample, the general formulas for multi-layer compensation were derived. Combining the theoretical compensation and experimental situation, the obtained data were compensated from incident and emergent intensity. The results show that this compensation method is an effective and feasible way to make the deep layer more visible.