Photoacoustic correlation spectroscopy for in vivo blood flow speed measurement

2012 ◽  
Author(s):  
Sung-Liang Chen ◽  
Zhixing Xie ◽  
Paul L. Carson ◽  
Xueding Wang ◽  
L. Jay Guo
Keyword(s):  
Blood Flow ◽  
Flow Speed ◽  
Correlation Spectroscopy ◽  
Speed Measurement

scholarly journals In vivo flow speed measurement of capillaries by photoacoustic correlation spectroscopy

2011 ◽  
Vol 36 (20) ◽  
pp. 4017 ◽  
Author(s):  
Sung-Liang Chen ◽  
Zhixing Xie ◽  
Paul L. Carson ◽  
Xueding Wang ◽  
L. Jay Guo
Keyword(s):  
Flow Speed ◽  
Correlation Spectroscopy ◽  
Speed Measurement

scholarly journals In vivo deep-brain blood flow speed measurement through third-harmonic generation imaging excited at the 1700-nm window

2020 ◽  
Vol 11 (5) ◽  
pp. 2738 ◽  
Author(s):  
Hongji Liu ◽  
Xinlin Chen ◽  
Xiangquan Deng ◽  
Ziwei Zhuang ◽  
Shen Tong ◽  
...  
Keyword(s):  
Blood Flow ◽  
Harmonic Generation ◽  
Third Harmonic Generation ◽  
Flow Speed ◽  
Brain Blood Flow ◽  
Third Harmonic ◽  
Speed Measurement ◽  
Deep Brain

In Vivo Imaging of Cerebral Circulation In Mouse Models of Polycythemia Vera

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4091-4091
Author(s):  
Thom P. Santisakultarm ◽  
Nozomi Nishimura ◽  
Claire Paduano ◽  
Radek C. Skoda ◽  
William L. Olbricht ◽  
...  
Keyword(s):  
Blood Flow ◽  
Transgenic Mice ◽  
Polycythemia Vera ◽  
Blood Viscosity ◽  
Capillary Flow ◽  
Conflicts Of Interest ◽  
Flow Speed ◽  
Leukocyte Adherence ◽  
Cerebral Microcirculation

Abstract Abstract 4091 Polycythemia vera (PV) is a myeloproliferative disease which is often associated with compromised cerebral microcirculation due to thrombotic and other rheological complications; this, in turn, may contribute to cognitive decline. Elevated blood viscosity may also lead to leukocyte adhesion, which further impacts cortical perfusion. An activating mutation, JAK2V617F, in the gene for JAK2, a cytoplasmic tyrosine kinase, is associated with PV in humans and transgenic mice carrying the same mutation have been developed. Our study aims to quantify the alterations in cerebral microcirculation in polycythemic mice and to determine the role of leukocyte adherence in disrupting blood flow, raising the possibility of a possible clinical therapeutic target for patients with PV. We used two models of PV: erythropoietin (EPO) injection (10-100 IU daily subcutaneous injections for 5 days) and a JAK2V617F transgenic mouse. Vascular topology and blood flow was imaged in anesthetized mice, through a craniotomy, using in vivo two-photon excited fluorescence microscopy. Texas-red dextran (0.05 mL of 2.5% w/v) and rhodamine 6G (0.05 mL of 0.1% w/v) were intravenously injected to label blood plasma and leukocytes, respectively. RBC flow speed was measured in arterioles, capillaries, and venules. Brain capillaries were classified as flowing or stalled by evaluating the motion of RBCs within individual vessels. We found a significant decrease in average capillary flow speed in EPO-injected mice, with an average hematocrit (Hct) of 60% (0.70±0.533 mm/s. 10 mice, 105 vessels, p<0.01) and JAK2V617F transgenic mice with Hct of 67% (0.55±0.362 mm/s. 3 mice, 47 vessels, p<0.01) compared to wild type controls with Hct of 48% (1.24±0.986 mm/s. 9 mice, 92 vessels), but not in surface arterioles or venules. In EPO-injected mice, 20% of the capillaries were stalled (12 mice, 6594 vessels, p<0.01), compared to only 3% in control mice (5 mice, 2431 vessels). In JAK2V617F transgenic mice, we found 25% of the capillaries were stalled (4 mice, 4574 vessels, p<0.01). Further, we observed firm leukocyte adherence in a large fraction of the stalled capillaries in the EPO-injected and JAK2V617F transgenic mice (see Figure). Our findings suggest that high Hct creates flow conditions which lead to leukocyte adherence, and may result in leukocyte activation. This work suggests that targeting leukocyte adherence and reducing the hematocrit may be clinically important in patients with PV and other diseases with high blood viscosity to ameliorate abnormal cerebral blood flow. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Time-domain diffuse correlation spectroscopy (TD-DCS) for noninvasive, depth-dependent blood flow quantification in human tissue in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Samaei ◽  
Piotr Sawosz ◽  
Michał Kacprzak ◽  
Żanna Pastuszak ◽  
Dawid Borycki ◽  
...  
Keyword(s):  
Blood Flow ◽  
Time Domain ◽  
Human Tissue ◽  
Correlation Spectroscopy ◽  
Flow Quantification ◽  
Flow Index ◽  
Flow Measurements ◽  
Diffuse Correlation Spectroscopy ◽  
Sensing Applications

AbstractMonitoring of human tissue hemodynamics is invaluable in clinics as the proper blood flow regulates cellular-level metabolism. Time-domain diffuse correlation spectroscopy (TD-DCS) enables noninvasive blood flow measurements by analyzing temporal intensity fluctuations of the scattered light. With time-of-flight (TOF) resolution, TD-DCS should decompose the blood flow at different sample depths. For example, in the human head, it allows us to distinguish blood flows in the scalp, skull, or cortex. However, the tissues are typically polydisperse. So photons with a similar TOF can be scattered from structures that move at different speeds. Here, we introduce a novel approach that takes this problem into account and allows us to quantify the TOF-resolved blood flow of human tissue accurately. We apply this approach to monitor the blood flow index in the human forearm in vivo during the cuff occlusion challenge. We detect depth-dependent reactive hyperemia. Finally, we applied a controllable pressure to the human forehead in vivo to demonstrate that our approach can separate superficial from the deep blood flow. Our results can be beneficial for neuroimaging sensing applications that require short interoptode separation.

scholarly journals A Compact Multi-Distance DCS and Time Domain NIRS Hybrid System for Hemodynamic and Metabolic Measurements

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 870
Author(s):  
Caterina Amendola ◽  
Michele Lacerenza ◽  
Mauro Buttafava ◽  
Alberto Tosi ◽  
Lorenzo Spinelli ◽  
...  
Keyword(s):  
Blood Flow ◽  
Hybrid System ◽  
Time Domain ◽  
Near Infrared ◽  
Correlation Spectroscopy ◽  
Optical Signals ◽  
In Vivo Experiments ◽  
Tissue Optical Properties ◽  
Depth Sensitivity

In this work, we present a new multi-distance diffuse correlation spectroscopy (DCS) device integrated with a compact state-of-the-art time domain near infrared spectroscopy (TD-NIRS) device. The hybrid DCS and TD-NIRS system allows to retrieve information on blood flow, tissue oxygenation, and oxygen metabolic rate. The DCS device performances were estimated in terms of stability, repeatability, ability in retrieving variations of diffusion coefficient, influence of the tissue optical properties, effect of varying count rates and depth sensitivity. Crosstalk between DCS and TD-NIRS optical signals was also evaluated. Finally, in vivo experiments (venous and arterial cuff occlusions on the arm) were conducted to test the ability of the hybrid system in measuring blood flow variations.

Microvascular features that suggest effectors of blood-flow regulation in the brain: Evidence by SEM of corrosion casts of intracerebral vessels

1990 ◽  
Vol 48 (3) ◽  
pp. 274-275
Author(s):  
Enrico D.F. Motti ◽  
Hans-Georg Imhof ◽  
Gazi M. Yasargil
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Corrosion Casts ◽  
Cerebral Microcirculation ◽  
Pial Arteries ◽  
Random Occurrence ◽  
Brain Arteries ◽  
Homogeneous Network ◽  
The Brain

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.

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