Assessment of collagen changes in ovarian tissue by extracting optical scattering coefficient from OCT images

Optical scattering coefficient from ex-vivo unfixed normal and malignant ovarian tissue was quantitatively extracted by fitting optical coherence tomography (OCT) A-line signals to a single scattering model. 1097 average A-line measurements at a wavelength of 1310nm were performed at 108 sites obtained from 18 ovaries. The average scattering coefficient obtained from normal group consisted of 833 measurements from 88 sites was 2.41 mm -1 (±0.59), while the average coefficient obtained from malignant group consisted of 264 measurements from 20 sites was 1.55 mm -1 (±0.46). Using a threshold of 2 mm -1 for each ovary, a sensitivity of 100% and a specificity of 100% were achieved. The amount of collagen within OCT imaging depth was analyzed from the tissue histological section stained with Sirius Red. The average collagen area fraction (CAF) obtained from normal group was 48.4% (±12.3%), while the average CAF obtained from malignant group was 11.4% (±4.7%). Statistical significance of the collagen content was found between the two groups (p < 0.001). The preliminary data demonstrated that quantitative extraction of optical scattering coefficient from OCT images could be a potential powerful method for ovarian cancer detection and diagnosis.