1. Improving the characterization of ex vivo human brain optical properties using high numerical aperture optical coherence tomography by spatially constraining the confocal parameters
- Author
-
Bruce Fischl, Hui Wang, David A. Boas, Francesco S. Pavone, Jianbo Tang, Kıvılcım Kılıç, Irene Costantini, Smrithi Sunil, Divya Varadarajan, Caroline Magnain, Blaire Lee, Jiarui Yang, Ichun Anderson Chen, Shuaibin Chang, and Shih-Chi Chen
- Subjects
Paper ,Point spread function ,Materials science ,genetic structures ,Confocal ,Physics::Medical Physics ,Neuroscience (miscellaneous) ,01 natural sciences ,law.invention ,010309 optics ,03 medical and health sciences ,0302 clinical medicine ,Optics ,Optical coherence tomography ,Confocal microscopy ,law ,0103 physical sciences ,medicine ,Radiology, Nuclear Medicine and imaging ,optical coherence tomography ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,Estimation theory ,business.industry ,Research Papers ,eye diseases ,human brain tissue ,Numerical aperture ,Rayleigh length ,index matching ,sense organs ,Focus (optics) ,business ,030217 neurology & neurosurgery - Abstract
Significance: The optical properties of biological samples provide information about the structural characteristics of the tissue and any changes arising from pathological conditions. Optical coherence tomography (OCT) has proven to be capable of extracting tissue’s optical properties using a model that combines the exponential decay due to tissue scattering and the axial point spread function that arises from the confocal nature of the detection system, particularly for higher numerical aperture (NA) measurements. A weakness in estimating the optical properties is the inter-parameter cross-talk between tissue scattering and the confocal parameters defined by the Rayleigh range and the focus depth. Aim: In this study, we develop a systematic method to improve the characterization of optical properties with high-NA OCT. Approach: We developed a method that spatially parameterizes the confocal parameters in a previously established model for estimating the optical properties from the depth profiles of high-NA OCT. Results: The proposed parametrization model was first evaluated on a set of intralipid phantoms and then validated using a low-NA objective in which cross-talk from the confocal parameters is negligible. We then utilize our spatially parameterized model to characterize optical property changes introduced by a tissue index matching process using a simple immersion agent, 2,2’-thiodiethonal. Conclusions: Our approach improves the confidence of parameter estimation by reducing the degrees of freedom in the non-linear fitting model.
- Published
- 2020
- Full Text
- View/download PDF