Doppler standard deviation imaging for clinical monitoring of in vivo human skin blood flow

Abstract

We used a novel phase-resolved optical Doppler tomographic (ODT) technique with very high flow-velocity sensitivity (10microm/s) and high spatial resolution (10microm) to image blood flow in port-wine stain (PWS) birthmarks in human skin. In addition to the regular ODT velocity and structural images, we use the variance of blood flow velocity to map the PWS vessels. Our device combines ODT and therapeutic systems such that PWS blood flow can be monitored in situ before and after laser treatment. To the authors' knowledge this is the first clinical application of ODT to provide a fast semiquantitative evaluation of the efficacy of PWS laser therapy in situ and in real time.

Differential standard deviation of log‐scale intensity based optical coherence tomography angiography

“…Various OCT angiography (OCTA) techniques have been presented [13,14], such as phase resolved Doppler OCT (PRDOCT) [15][16][17][18][19][20], phase-variance OCT (PVOCT) [21][22][23], optical microangiography (OMAG) [24,25], correlation mapping OCT (cmOCT) [26], speckle variance OCT (svOCT) [27,28], absolute intensity difference(AID) [29] and power intensity differential method (PID) [30]. PRDOCT and PVOCT detect the blood flow by comparing the phase information of OCT signals acquired at different time (between A-scans or between B-scans).…”

Volumetric Doppler angle correction for ultrahigh-resolution optical coherence Doppler tomography

“…1 Owing to its intrinsic Doppler effect induced by the red blood cell velocity (v RBC ), lODT detects the apparent v RBC , i.e., the averaged axial component v z of v RBC by calculating the accumulative phase shift between two successive A-scans. 2 In other words, the Doppler angle h z , the angle between v RBC and the beam incidence, ought to be decoupled to retrieve the absolute flow velocity v RBC (i.e., v RBC ¼ v z / cosh z ). 2 As h z (x, y, z) is a 3D matrix and varies dramatically with flow locations, this remains a challenge for lODT to accurately image absolute flow velocities.…”

“…2 In other words, the Doppler angle h z , the angle between v RBC and the beam incidence, ought to be decoupled to retrieve the absolute flow velocity v RBC (i.e., v RBC ¼ v z / cosh z ). 2 As h z (x, y, z) is a 3D matrix and varies dramatically with flow locations, this remains a challenge for lODT to accurately image absolute flow velocities.…”

Phase-Resolved Doppler Optical Coherence Tomography

“…Phase-resolved ODT (PRODT) was developed to overcome these limitations. This method uses the phase change between sequential A-line scans for velocity image reconstruction [7][8][9]. PRODT decouples spatial resolution and velocity sensitivity in flow images and increases imaging speed by more than two orders of magnitude without compromising spatial resolution and velocity sensitivity [7].…”

“…PRODT decouples spatial resolution and velocity sensitivity in flow images and increases imaging speed by more than two orders of magnitude without compromising spatial resolution and velocity sensitivity [7]. The first demonstration of PRODT was based on time domain OCT systems [7][8]. Recently, the development of Fourier domain OCT systems have greatly improved the imaging speed and sensitivity [10][11][12].…”