Study tissue microhemodynamics in area of tumor at optical clearing by speckle-contrast imaging (Conference Presentation)

Author(s):  
Polina A. Dyachenko Timoshina ◽  
Alla B. Bucharskaya ◽  
Valery V. Tuchin ◽  
Aleksandr P. Shkurinov
2010 ◽  
Vol 03 (03) ◽  
pp. 159-167 ◽  
Author(s):  
JING WANG ◽  
DAN ZHU ◽  
MIN CHEN ◽  
XIAOJING LIU

Laser Speckle Contrast Imaging (LSCI) plays an important role in studying blood flow, but suffers from limited penetration depth of light in turbid tissue. The strong scattering of tissue obviously reduces the image contrast which decreases the sensitivity to flow velocity. Some image processing or optical clearing methods have been proposed to lessen the deficiency, but quantitative assessment of improvement is seldom given. In this study, LSCI was applied to monitor the blood flow through a capillary embedded within various tissue phantoms at depths of 0.25, 0.45, 0.65, 0.85 and 1.05 mm, and the flow velocity in capillary was controllable from 0 to 4 mm/s. Here, glycerol, a common optical clearing agent, was mixed with Intralipid at different volume ratio to make the reduced scattering coefficient of tissue phantom decrease from 13.00 to 0.50 cm-1. The quantitative analysis demonstrates that the optical clearing method can obviously enhance the image contrast, imaging depth, and sensitivity to blood flow velocity. Comparing the Laser Speckle Contrast Analysis methods and the optical clearing method, we find that for typical turbid tissue, the sensitivity to velocity estimated by the Laser Speckle Temporal Contrast Analysis (LSTCA) is twice of that by the Laser Speckle Spatial Contrast Analysis (LSSCA); while the sensitivity to velocity estimated by using the two analysis methods has a 10-fold increase, respectively, if addition of glycerol makes the reduced scattering coefficient of tissue phantom decrease by 30%. Combining the LSTCA and the optical clearing method, the sensitivity to flow velocity will be further enhanced.


2017 ◽  
Author(s):  
Polina A. Timoshina ◽  
Ekaterina M. Zinchenko ◽  
Daria K. Tuchina ◽  
Madina M. Sagatova ◽  
Oxana V. Semyachkina-Glushkovskaya ◽  
...  

2011 ◽  
Vol 300 (2) ◽  
pp. F319-F329 ◽  
Author(s):  
Niels-Henrik Holstein-Rathlou ◽  
Olga V. Sosnovtseva ◽  
Alexey N. Pavlov ◽  
William A. Cupples ◽  
Charlotte Mehlin Sorensen ◽  
...  

Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50–100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney.


2021 ◽  
Vol 66 ◽  
pp. 101793
Author(s):  
Pernilla Stenström ◽  
Rafi Sheikh ◽  
Kristine Hagelsteen ◽  
Johanna Wennström Berggren ◽  
Malin Malmsjö

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ata Chizari ◽  
Mirjam J. Schaap ◽  
Tom Knop ◽  
Yoeri E. Boink ◽  
Marieke M. B. Seyger ◽  
...  

AbstractEnabling handheld perfusion imaging would drastically improve the feasibility of perfusion imaging in clinical practice. Therefore, we examine the performance of handheld laser speckle contrast imaging (LSCI) measurements compared to mounted measurements, demonstrated in psoriatic skin. A pipeline is introduced to process, analyze and compare data of 11 measurement pairs (mounted-handheld LSCI modes) operated on 5 patients and various skin locations. The on-surface speeds (i.e. speed of light beam movements on the surface) are quantified employing mean separation (MS) segmentation and enhanced correlation coefficient maximization (ECC). The average on-surface speeds are found to be 8.5 times greater in handheld mode compared to mounted mode. Frame alignment sharpens temporally averaged perfusion maps, especially in the handheld case. The results show that after proper post-processing, the handheld measurements are in agreement with the corresponding mounted measurements on a visual basis. The absolute movement-induced difference between mounted-handheld pairs after the background correction is $$16.4\pm 9.3~\%$$ 16.4 ± 9.3 % (mean ± std, $$n=11$$ n = 11 ), with an absolute median difference of $$23.8\%$$ 23.8 % . Realization of handheld LSCI facilitates measurements on a wide range of skin areas bringing more convenience for both patients and medical staff.


2017 ◽  
Vol 111 ◽  
pp. 49-59 ◽  
Author(s):  
Mohammad Zaheer Ansari ◽  
Eun-Jeung Kang ◽  
Mioara D. Manole ◽  
Jens P. Dreier ◽  
Anne Humeau-Heurtier

2018 ◽  
Vol 12 (1) ◽  
pp. e201800100 ◽  
Author(s):  
Wenzhi Lv ◽  
Yang Wang ◽  
Xiao Chen ◽  
Xiaoxi Fu ◽  
Jinling Lu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document