VELOCITY-ESTIMATION ACCURACY AND FRAME-RATE LIMITATIONS IN COLOR DOPPLER OPTICAL COHERENCE TOMOGRAPHY

Color Doppler optical coherence tomography (CDOCT) is a recent innovat ion that allows spatially localized flow-velocity mapping simultaneous ly with microstructural imaging. We present a theoretical model for ve locity-image formation in CDOCT. The proportionality between the heter odyne detector current Doppler power spectrum in CDOCT and the optical source power spectrum is established. We show that stochastic modific ations of the Doppler spectrum by fluctuating scatterer distributions in the flow field give rise to unavoidable velocity-estimation inaccur acies as well as to a fundamental trade-off between image-acquisition rate and velocity precision. Novel algorithms that permit high-fidelit y depth-resolved measurements of velocities in turbid media are also r eported. (C) 1998 Optical Society of America OCIS codes: 170.3340, 170 .4500, 030.6140, 030.6600.