Birefringence phantoms for polarization sensitive optical coherence tomography (Conference Presentation)

Polarization sensitive optical coherence tomography (PS-OCT) is increasingly used in a range of applications, both in bench-top and catheter-based imaging configurations. Reconstruction of tissue birefringence is subject to many system and processing-dependent artifacts. However, methods for the calibration and validation of PS-OCT are missing. Here, we report on a method to fabricate tissue-like imaging phantoms exhibiting clearly defined regions with controllable amounts of birefringence. We employed the photoelastic effect to enable the generation of controllable amounts of stress-induced birefringence in rubber samples, verified with polarized light microscopy. Pigmented ink was added to liquid latex solution to mold and cure rubber bands with controlled backscattering and transparency. Differently stretched segments were embedded in a stress-free background matrix to generate clearly defined areas with high birefringence contrast in an area of homogenous backscatter intensity. Arranged in planar geometry or on the outside of a glass capillary, the stretched rubber bands defined phantoms for bench-top and catheter-based imaging, respectively. Segmentation of the defined regions of interest in the reconstructed volumetric birefringence tomograms enabled assessing measurement consistency, between repeated imaging with a single system, or between independent imaging systems. Consistent and durable imaging phantoms are crucial for advancing PS-OCT imaging technology. Our tissue-like imaging phantoms exhibit clearly defined regions with controlled amounts of birefringence and facilitate testing, calibration, and validation of imaging systems and reconstruction strategies.