Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria.
J Biophotonics. 2021 Apr;14(4):e202000323. doi: 10.1002/jbio.202000323. Epub 2021 Jan 11.
Polarization-sensitive optical coherence tomography (PS-OCT) enables three-dimensional imaging of biological tissues based on the inherent contrast provided by scattering and polarization properties. In fibrous tissue such as the white matter of the brain, PS-OCT allows quantitative mapping of tissue birefringence. For the popular PS-OCT layout using a single circular input state, birefringence measurements are based on a straight-forward evaluation of phase retardation data. However, the accuracy of these measurements strongly depends on the signal-to-noise ratio (SNR) and is prone to mapping artifacts when the SNR is low. Here we present a simple yet effective approach for improving the accuracy of PS-OCT phase retardation and birefringence measurements. By performing a noise bias correction of the detected OCT signal amplitudes, the impact of the noise floor on retardation measurements can be markedly reduced. We present simulation data to illustrate the influence of the noise bias correction on phase retardation measurements and support our analysis with real-world PS-OCT image data.
偏振敏感光学相干断层扫描（PS-OCT）利用散射和偏振特性提供的固有对比度实现生物组织的三维成像。在纤维组织（如大脑的白质）中，PS-OCT 允许对组织双折射进行定量映射。对于使用单个圆形输入状态的流行 PS-OCT 布局，双折射测量基于对相位延迟数据的直接评估。然而，这些测量的准确性强烈依赖于信噪比（SNR），并且当 SNR 较低时容易出现映射伪影。在这里，我们提出了一种简单而有效的方法来提高 PS-OCT 相位延迟和双折射测量的准确性。通过对检测到的 OCT 信号幅度进行噪声偏置校正，可以显著降低噪声基底对延迟测量的影响。我们呈现了模拟数据来说明噪声偏置校正对相位延迟测量的影响，并使用真实世界的 PS-OCT 图像数据支持我们的分析。
