Birefringent tissue-mimicking phantom for polarization-sensitive optical coherence tomography imaging

Abstract

Significance: Tissue birefringence is an important parameter to consider when designing realistic, tissue-mimicking phantoms. Options for suitable birefringent materials that can be used to accurately represent tissue scattering are limited. Aim: To introduce a method of fabricating birefringent tissue phantoms with a commonly used material—polydimethylsiloxane (PDMS)—for imaging with polarization-sensitive optical coherence tomography (PS-OCT). Approach: Stretch-induced birefringence was characterized in PDMS phantoms made with varying curing ratios, and the resulting phantom birefringence values were compared with those of biological tissues. Results: We showed that, with induced birefringence levels up to 2.1  ×  10  −  4, PDMS can be used to resemble the birefringence levels in weakly birefringent tissues. We demonstrated the use of PDMS in the development of phantoms to mimic the normal and diseased bladder wall layers, which can be differentiated by their birefringence levels. Conclusions: PDMS allows accurate control of tissue scattering and thickness, and it exhibits controllable birefringent properties. The use of PDMS as a birefringent phantom material can be extended to other birefringence imaging systems beyond PS-OCT and to mimic other organs.