Kübler Johannes, Zoutenbier Vincent S, Amelink Arjen, Fischer Jörg, de Boer Johannes F
LaserLaB, Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, The Netherlands.
Heidelberg Engineering GmbH, Heidelberg, Germany.
Biomed Opt Express. 2021 Oct 7;12(11):6814-6830. doi: 10.1364/BOE.440574. eCollection 2021 Nov 1.
The attenuation coefficient provides a quantitative parameter for tissue characterization and can be calculated from optical coherence tomography (OCT) data, but accurate determination requires compensation for the confocal function. We present extensive measurement series for extraction of the focal plane and the apparent Rayleigh length from the ratios of OCT images acquired with different focus depths and compare these results with two alternative approaches. By acquiring OCT images for a range of different focus depths the optimal focus plane difference is determined for intralipid and titanium oxide (TiO) phantoms with different scatterer concentrations, which allows for calculation of the attenuation coefficient corrected for the confocal function. The attenuation coefficient is determined for homogeneous intralipid and TiO samples over a wide range of concentrations. We further demonstrate very good reproducibility of the determined attenuation coefficient of layers with identical scatter concentrations in a multi-layered phantom. Finally, this method is applied to in vivo retinal data.
衰减系数为组织特征描述提供了一个定量参数，并且可以从光学相干断层扫描（OCT）数据中计算得出，但准确测定需要对共焦函数进行补偿。我们展示了大量测量系列，用于从不同焦深获取的OCT图像比率中提取焦平面和表观瑞利长度，并将这些结果与两种替代方法进行比较。通过获取一系列不同焦深的OCT图像，针对具有不同散射体浓度的脂质体和二氧化钛（TiO）模型确定了最佳焦平面差异，这使得能够计算出针对共焦函数校正后的衰减系数。在很宽的浓度范围内测定了均匀脂质体和TiO样品的衰减系数。我们还进一步证明了在多层模型中具有相同散射浓度的层所测定的衰减系数具有非常好的重现性。最后，该方法被应用于体内视网膜数据。
