采用一种基于光学相干层析成像(OCT)技术的深度分辨散射系数计算方法来量化表征细胞分布特性。该方法基于单散射模型获取深度分辨散射系数分布图,并通过散射系数直方图统计发现细胞分布规律。通过多层散射介质模型验证了该方法的有效性。实验结果表明:根据散射系数分布图可以深度分辨细胞分布特性,相比OCT强度图像,细胞和背景的对比更明显;不同浓度细胞悬浮液的OCT强度信号直方图无明显区别,散射系数直方图则出现了表征细胞浓度的特征峰,且该特征峰与背景散射特征峰的偏离程度与细胞浓度呈线性关系。利用OCT散射系数分布图检测到生物三维打印水凝胶支架内细胞分布与H&E染色结果有较好的对应关系,且相应的散射系数直方图分布中出现了表征细胞浓度的特征峰。

Cell distribution can be characterized quantitatively using a depth-resolved scattering coefficient calculation method based on optical coherence tomography (OCT). This method uses a single scattering model to obtain a depth-resolved scattering coefficient distribution map, and the law of cell distribution is verified using the histogram statistics of the scattering coefficient. A multilayer scattering medium model is used to verify the effectiveness of the proposed method. The experiments reveal that the scattering coefficient distribution maps can resolve the cell distribution depth and provide a more obvious contrast between the cell and background compared with an intensity map. There are no significant differences in the distributions of the OCT intensity signal histograms of various cell suspensions. The histogram of the scattering coefficient contains the characteristic cell concentration peak, and the degree of deviation between the characteristic peak and background scattering characteristic peak is linear with the cell concentration. The cell distribution in the bio-3D printed hydrogel scaffold detected by the OCT scattering coefficient distribution map corresponds well with the H&E staining results, and the corresponding scattering coefficient histogram distribution exhibits peaks characteristic of the cell concentration.