Doppler Optical Coherence Tomography

Leitgeb, Rainer A.; Werkmeister, René M.; Blatter, Cédric; Schmetterer, Leopold

doi:10.1016/j.preteyeres.2014.03.004

Cited by 354 publications

(261 citation statements)

References 121 publications

(94 reference statements)

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“…OCT is a noninvasive and rapid method for multi-modal imaging the retina and choroid. In combination with an enhanced depth imaging (EDI) feature, SD-EDI OCT enables the identification of specific layers within the retina in high resolution, as well as deeper structures such as the choroid, in a way only previously possible in histological samples [15]. plaques, decreasing oxidative stress and inflammation, and inhibiting the thrombogenic response [16].…”

Section: Introductionmentioning

confidence: 99%

Relationship Between Angiographic Coronary Slow Flow Phenomenon and Subfoveal Choroidal Thickness: What is The Effect of Atorvastatin Therapy?

Kanar¹,

Kanar²

2018

Eur J Exp Bio

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Objective: Although the pathophysiological mechanisms underlying coronary slow flow (CSF) phenomenon still remains uncertain, the microvascular dysfunction has been first implicated. The CSF phenomenon may not only affect the coronary arteries but it may also be a part of vascular problem that affect other arteries. The aim of the present study is to evaluate the relationship between CSF phenomenon and subfoveal choroidal thickness (SFCT) and to investigate the effect of short-term atorvastatin therapy on SFCT in patients with CSF. Methods:The study population consisted of 48 patients with CSF and 41 healthy control participants. Coronary flow patterns of the patients were determined by thrombolysis in myocardial infarction (TIMI) frame count method. Spectral-domain optical coherence tomography (SD-OCT) measurements of SFCT and lipid parameters were obtained before and after 2 weeks of daily single dose of 80 mg atorvastatin therapy. Results:We found that patients with CSF had thinner SFCT compared with control group. There was a significant negative correlation between mean TIMI frame count and baseline SFCT (r=-0.69, p=0.001). ROC curve analysis revealed that SFCT <259 m predicted CSF with a 85% sensitivity and 88% specificity. The SFCT significantly increased after the short-term atorvastatin therapy. Conclusion:There was a close negative correlation between CSF phenomenon and SFCT. Endothelial dysfunction (ED) and the resultant microvascular dysfunction might be operative on both coronary and ocular choriocapillary arteries in patients with CSF. Increase of SFCT after the short-term atorvastatin therapy might be an indicator of microvascular dysfunction improvement in patients with CSF.

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Section: Introductionmentioning

confidence: 99%

Relationship Between Angiographic Coronary Slow Flow Phenomenon and Subfoveal Choroidal Thickness: What is The Effect of Atorvastatin Therapy?

Kanar¹,

Kanar²

2018

Eur J Exp Bio

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“…This is because the backscattered light not only provides information on the depth-dependent amplitude and phase, but also on physical quantities such as the polarization and the optical frequency shift, which are progressively used for functional tissue imaging. An important enhancement is Doppler OCT (DOCT) for blood flow measurements [10,11]. Most of the proposed Doppler approaches are based on the phase shift between subsequently detected OCT signals, which is widely referred to as phase-resolved Doppler OCT (PR-DOCT) [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Flow Measurement by Lateral Resonant Doppler Optical Coherence Tomography in the Spectral Domain

Walther

Koch

2017

Applied Sciences

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Abstract:In spectral domain optical coherence tomography (SD-OCT), any transverse motion component of a detected obliquely moving sample results in a nonlinear relationship between the Doppler phase shift and the axial sample velocity restricting phase-resolved Doppler OCT (PR-DOCT). The size of the deviation from the linear relation depends on the amount of the transverse velocity component, given by the Doppler angle, and the height of the absolute sample velocity. Especially for very small Doppler angles between the horizontal and flow direction, and high flow velocities, the detected Doppler phase shift approaches a limiting value, making an unambiguous measurement of the axial sample velocity by PR-DOCT impossible. To circumvent this limitation, we propose a new method for resonant Doppler flow quantification in spectral domain OCT, where the scanner movement velocity is matched with the transverse velocity component of the sample motion similar to a tracking shot, where the camera is moved with respect to the sample. Consequently, the influence of the transverse velocity component of the tracked moving particles on the Doppler phase shift is negligible and the linear relation between the phase shift and the axial velocity component can be considered for flow velocity calculations. The proposed method is verified using flow phantoms on the basis of 1% Intralipid solution and diluted human blood.

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“…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).…”

Section: Introductionmentioning

confidence: 99%

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

Shi

Gao

Chen

et al. 2017

Journal of Biophotonics

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In this paper, a differential standard deviation of log‐scale intensity (DSDLI) based optical coherence tomography angiography (OCTA) is presented for calculating microvascular images of human skin. The DSDLI algorithm calculates the variance in difference images of two consecutive log‐scale intensity based structural images from the same position along depth direction to contrast blood flow. The en face microvascular images were then generated by calculating the standard deviation of the differential log‐scale intensities within the specific depth range, resulting in an improvement in spatial resolution and SNR in microvascular images compared to speckle variance OCT and power intensity differential method. The performance of DSDLI was testified by both phantom and in vivo experiments. In in vivo experiments, a self‐adaptive sub‐pixel image registration algorithm was performed to remove the bulk motion noise, where 2D Fourier transform was utilized to generate new images with spatial interval equal to half of the distance between two pixels in both fast‐scanning and depth directions. The SNRs of signals of flowing particles are improved by 7.3 dB and 6.8 dB on average in phantom and in vivo experiments, respectively, while the average spatial resolution of images of in vivo blood vessels is increased by 21%.

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Doppler Optical Coherence Tomography

Cited by 354 publications

References 121 publications

Relationship Between Angiographic Coronary Slow Flow Phenomenon and Subfoveal Choroidal Thickness: What is The Effect of Atorvastatin Therapy?

Relationship Between Angiographic Coronary Slow Flow Phenomenon and Subfoveal Choroidal Thickness: What is The Effect of Atorvastatin Therapy?

Flow Measurement by Lateral Resonant Doppler Optical Coherence Tomography in the Spectral Domain

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

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