We demonstrate the ability of multiple forms of optical coherence tomography (OCT) in the frequency domain to quantitatively size scatterers. Combined with a variety of distinct phantoms, we gain insight into the measurement uncertainties associated with using scattering spectra to size scatterers. We size spherical scatterers on a surface using swept source OCT with an analysis based on a simple slab-mode resonance model. Automating this technique, a two-dimensional (2-D) image is created by raster scanning across a surface phantom designed to have a distinct size transition to demonstrate accuracy and repeatability. We also investigate the potential of a novel sphere-nanotube structure as a quantitative calibration artifact for use in comparing measured intensity and phase scattering spectra directly to Mie theory predictions. In another experiment, we demonstrate tissue-relevant sizing of scatterers as small as 5 υ on a surface by use of a Fourier domain OCT system with 280 nm of bandwidth from a super-continuum source. We perform an uncertainty analysis for our high resolution sizing system, estimating a sizing error of 9% for measurements of spheres with a diameter of 15 υ. With appropriate modifications, our uncertainty analysis has general applicability to other sizing techniques utilizing scattering spectra.
Citation: Journal of Biomedical Optics
Pub Type: Journals
dispersion, group delay, Mie, nanotube, optical coherence tomography, phantom, phase, spectral domain