Spectral Doppler imaging of micro-vasculature response to laser irradiation

Bin Rao,Lingfeng Yu,Wangcun Jia,Ronald M Kurtz,J Stuart Nelson,Bernard Choi,Zhongping Chen

doi:10.1117/12.809692

Abstract

Doppler Optical Coherence Tomography (DOCT) imaging of in-vivo retinal blood flow was widely studied as efforts of research community to push this technology into clinic. Spectral Doppler imaging of DOCT has been demonstrated as a quantification method of in-vivo pulsatile retinal blood flow in human eye. This technology has the all the advantages inherited from OCT comparing to Doppler ultrasound. Comparing to normal spatial-distributed color Doppler imaging of DOCT, spectral Doppler imaging can reveal more haemodynamics details on the time dimension. Although resistance index (RI) of a micro-vascular can be measured in vivo from human retina, the clinical significance of RI measurements still needs to be investigated. In vitro experiment conduced with ultrasound has demonstrated the higher vascular resistance value is associated with the higher RI measured assuming the constant compliance of vascular tube. In this study, the rodent window-chamber model (RWCM) was used as a platform to investigate the RI change as the micro-vasculature response to laser irradiation. The higher RI was measured after the occlusion of two veins (should it be arterials) that was verified with laser speckle imaging in our preliminary experiment results.

Highlights

In-vivo human blood flow imaging with color Doppler optical coherence tomography (OCT) was demonstrated as early as 2000 with a time-domain system [1], there is still no commercial available Doppler OCT instrument for blood flow imaging in eye clinic
Preliminary Results 3.1 Photograph and Laser speckle imaging before and after laser irradiation Figure 2 showed the photography of the rodent dorsal skinfold window chamber and the location of laser irradiation area identified by the circle on the photography
The increased resistance index (RI) is in accordance with the laser speckle imaging results

Summary

Introduction

In-vivo human blood flow imaging with color Doppler OCT was demonstrated as early as 2000 with a time-domain system [1], there is still no commercial available Doppler OCT instrument for blood flow imaging in eye clinic. A few technology obstacles exist in applying the time-domain Doppler OCT into clinic. The first obstacle is eye movement, when there is no tracking device installed. The second obstacle is Doppler angle problem associated with all Doppler devices. The third obstacle is the limited velocity range that can be measured. The fourth obstacle lies in the difficulties of Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XIII, edited by James G.

Methods

Results

Conclusion