scholarly journals Retinal blood flow reversal quantitatively monitored in out-of-plane vessels with laser Doppler holography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Léo Puyo ◽  
Michel Paques ◽  
Michael Atlan
Keyword(s):  
Blood Flow ◽  
Color Doppler ◽  
Laser Doppler ◽  
Retinal Blood Flow ◽  
Doppler Imaging ◽  
Doppler Spectrum ◽  
High Temporal Resolution ◽  
Directional Information ◽  
Out Of Plane ◽  
Flow Reversals

AbstractLaser Doppler holography is a planar blood flow imaging technique recently introduced in ophthalmology to image human retinal and choroidal blood flow non-invasively. Here we present a digital method based on the Doppler spectrum asymmetry that reveals the local direction of blood flow with respect to the optical axis in out-of-plane vessels. This directional information is overlaid on standard grayscale blood flow images to depict flow moving towards the camera in red and flow moving away from the camera in blue, as in ultrasound color Doppler imaging. We show that thanks to the strong contribution of backscattering to the Doppler spectrum in out-of-plane vessels, the local axial direction of blood flow can be revealed with a high temporal resolution, which enables us to evidence pathological blood flow reversals. We also demonstrate the use of optical Doppler spectrograms to quantitatively monitor retinal blood flow reversals.

scholarly journals Сolor Doppler Imaging in Eye Hemodynamics Evaluation in Syndrome of Thrombotic Microangiopathy

2019 ◽  
Vol 15 (4) ◽  
pp. 455-462 ◽  
Author(s):  
T. V. Smirnova ◽  
N. I. Kozlovskaya ◽  
V. M. Sheludchenko ◽  
D. V. Andzhelova ◽  
E. E. Kazaryan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Thrombotic Microangiopathy ◽  
Color Doppler ◽  
Color Doppler Imaging ◽  
The State ◽  
Doppler Imaging ◽  
Doppler Spectrum ◽  
Diastolic Velocity ◽  
Retrobulbar Space ◽  
Retrobulbar Vessels

Purpose.To assess the state of blood flow in retrobulbar vessels using the method of color Doppler imaging in thrombotic microangiopathy (TMA) associated with atypical hemolytic uremic syndrome (aHUS), malignant hypertension (MH) and catastrophic antiphospholipid syndrome (CAPS).Methods. The study involved 16 patients aged from 18 to 43 years with TMA associated with aHUS (13 patients), MH (2 patients) and CAPS (1 patient). All patients underwent a study of the state of blood flow in the vessels of the retrobulbar space by color Doppler imaging using a multifunctional ultrasonic diagnostic device Voluson 730 Pro and Voluson E8. The spectrum of blood flow in the ophthalmic artery (OA), central retinal artery (CRA), central retinal vein (CRV), in the medial and lateral short posterior ciliary arteries (SPCA) was recorded and the following parameters were determined: maximum systolic velocity (Vsyst), final diastolic velocity (Vdiast), peripheral resistance index (RI), pulsation index (PI).Results. The analysis of the Doppler blood flow spectrum in all patients with TMA syndrome revealed a decrease in Vsyst in the vessels of the retrobulbar space, more pronounced in the CRA, with an increase in the venous component of the Doppler spectrum. In patients with TMA associated with aHUS and MH Vdiast in the studied vessels were in normal limits or increased, RI and PI were reduced. In aHUS a statistically significant correlation was found between Vdiast in OA and the level of haptoglobin in blood serum, which is a classic marker of intravascular hemolysis.Conclusion. Color Doppler imaging of retrobulbar vessels is an important method for the diagnosis of ocular hemodynamics disorders in the syndrome of TMA. All patients with TMA syndrome are characterized with a decrease in the systolic component of the Doppler spectrum of blood flow in the vessels of the retrobulbar space, especially in the CRA, with an increase in the venous component. With aHUS and MH diastolic blood flow in the retrobulbar vessels corresponds to the norm or increases, RI and PI decrease. In TMA associated with aHUS, the final diastolic velocity of blood flow in OA depends on the level of microvascular  hemolysis.

scholarly journals ET-1 plasma levels and ocular blood flow in retinitis pigmentosaThis article is one of a selection of papers published in the two-part special issue entitled 20 Years of Endothelin Research.

2010 ◽  
Vol 88 (6) ◽  
pp. 630-635 ◽  
Author(s):  
Mauro Cellini ◽  
Ernesto Strobbe ◽  
Corrado Gizzi ◽  
Emilio C. Campos
Keyword(s):  
Blood Flow ◽  
Plasma Levels ◽  
Color Doppler ◽  
Cold Pressor Test ◽  
Peak Systolic Velocity ◽  
Cold Pressor ◽  
Retinal Blood Flow ◽  
Doppler Imaging ◽  
Choroidal Blood Flow ◽  
Doppler Flowmetry

Retinitis pigmentosa (RP) is an inherited retinal disorder clinically characterized by a pale, waxy optic nerve head, attenuated retinal blood vessels, and bone spicule pigment in the retina. Hemodynamic studies have demonstrated that RP is associated with a reduction in the retinal and choroidal blood flow. Retinal hemodynamic impairment is also present in early stages of RP, and various hypotheses have been advanced as to the cause. The authors studied 20 patients, 12 males and 8 females, aged 26–42 years (mean 35.1 years) and affected by simplex RP. The patients had a visual acuity of 0.9 ± 0.1, visual field mean defect of –6.52 ± 3.58 dB, and b-wave electroretinogram amplitude of 260.08 ± 8.24 µV. An increase in plasma levels of endothelin-1 (ET-1) was found: 1.910 ± 0.317 pg/mL versus 1.180 ± 0.210 pg/mL in non-RP controls (p < 0.02). Moreover both an ocular and systemic vascular impairment was detected by means of color Doppler imaging and laser Doppler flowmetry performed during a cold pressor test. We found a correlation between the increase of ET-1 plasma levels in RP and the decrease of peak systolic velocity in the ophthalmic artery (p < 0.03) and in the posterior ciliary arteries (p < 0.006). It is thought that an increase of ET-1 and retinal oxygen levels in RP could lead to vasoconstriction and a decrease of the retinal blood flow, worsening the abiotrophic process.

Abstract 15137: Vector Flow Mapping is a Novel Useful Technique in Assessing Inertia Force of Late Systolic Aortic Flow and Left Ventricular Early Diastolic Function

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Kazuaki Wakami ◽  
Kenta Hachiya ◽  
Syunsuke Murai ◽  
Tsuyoshi Ito ◽  
Hiroshi Fujita ◽  
...  
Keyword(s):  
Blood Flow ◽  
Time Constant ◽  
Color Doppler ◽  
Left Ventricular ◽  
Doppler Imaging ◽  
Inertia Force ◽  
Lv Function ◽  
Flow Mapping ◽  
Vector Flow Mapping ◽  
Late Systole

Background: We previously reported that the inertia force (IF) of blood flowing out of left ventricle (LV) during late-systole produces greater LV elastic recoil force and brings faster LV relaxation. Vector flow mapping (VFM TM , Hitachi-Aloka) enables us to see blood flow velocity vectors that are generated from conventional color Doppler imaging data at any phase of cardiac cycle without angle dependency. Using VFM, kinetic energy (KE) of ejecting blood flow during systole at the LV outflow tract (LVOT) can be obtained. Thus, we investigated whether the KE obtained at the LVOT during late systole (KE-ls) had any relations with the IF and invasively obtained LV function parameters. Method: Study subjects were 33 patients who underwent diagnostic cardiac catheterization and echocardiographic examination on the same day. Color Doppler images were acquired in the apical 3-chamber view. The frame rate ranged was from 40 to 51 frames per minute. Data analyses were performed offline using the commercially available software (DAS-RS1 TM, Hitachi-Aloka). A data sampling area was set at the level just below the aortic valve in the LVOT. The KE-ls was computed as the sum of KE values computed in frame by frame basis during late-systole; late-systole was defined as the latter one-third of ejecting time. LV pressure wave was obtained using a catheter-tipped micromanometer, and then, the first derivative of LV pressure (dP/dt) and a time constant τ of LV pressure decay during isovolumic relaxation were calculated. From LV pressure-dP/dt relationships (phase loop), the IF was determined. Results: A significant positive correlation was observed between the KE-ls and the IF (r=0.79, p<0.0001). The log transformed KE-ls had significant correlations with both peak negative dP/dt (r=0.53, p<0.01) and the time constant τ (r=-0.67, p<0.0001). Conclusion: VFM is a new useful technique to see blood flow in the LV chamber. Noninvasively obtained KE-ls using VFM, which may be a noninvasive surrogate for the IF, has significant correlations with the parameters of LV relaxation.

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