Abstract
Purpose: :
To demonstrate the quantification of retinal vessel geometry and blood flow with ultrahigh-resolution Doppler optical coherence angiography (D-OCA)
Methods: :
Three-dimensional high-speed, ultrahigh-resolution spectral domain OCT imaging is applied for the in vivo human eye. This system operates at 27,000 A-scan/s and has ~3 µm axial resolution. Three-dimensional blood vessel imaging is achieved with Doppler analysis. For vessel quantification, semi-automatic vessel quantification algorithm is applied. First the target vessel is pointed out by operator on an en-face retinal vessel image. Then, this vessel image is processed to determine the orientation and diameter. And two representative vessel cross sections are made from the 3D vessel image to evaluate the depth of the vessel and Doppler angle. Retinal blood flow velocity and volume rate are measured in a healthy normal volunteer.
Results: :
From the determined retinal vessel parameters, absolute blood flow speed and instantaneous blood flow volume rate are obtained. At a bifurcation of a retinal artery, the blood conservation is verified. Incoming and outgoing blood volume rate are in good agreement. The intraclass correlation coefficient was 0.74 (p = 0.000124). The absolute blood flow velocity distribution in the retinal vessels can be observed.
Conclusions: :
Doppler OCA enables the quantitative measurements of retinal blood flow properties. The blood flow velocity distribution measurement in the retinal vessel will leads to non-invasive blood property measurement.
Keywords: blood supply • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina