Effect of tissue frozen on quantitative optical properties using optical coherence tomography.

The purpose is to demonstrate the optical charactering concerning nasopharyngeal tissue of pig by fresh sections and frozen correlating sections with optical coherence tomography (OCT). After being imaged on a fresh specimen, samples are then stored in low temperature refrigerators (-80°C) for one year for the second OCT measurement. The OCT structure of the epithelium, lamina propria, and the basement membrane are still resolvable; the median scattering coefficients and anisotropy factors fitting from OCT images based on the multiple scattering effects for epithelium are 27.6  mm-1 [interquartile range (IQR) 23.6 to 29.3  mm-1] versus 22.5  mm-1 (IQR 20.5 to 24.4  mm-1), 0.86 (IQR 0.81 to 0.9) versus 0.88 (IQR 0.87 to 0.9) for fresh and frozen tissue, respectively; and 10.2  mm-1 (IQR 8.1 to 13.6  mm-1) versus 9.6  mm-1 (IQR 8.1 to 13.8  mm-1), 0.96 (IQR 0.93 to 0.98) versus 0.92 (IQR 0.9 to 0.98) for lamina propria, respectively. The results show that the frozen storage method can be used for OCT research.