scholarly journals Inside Front Cover: In vivo noninvasive visualization of retinal perfusion dysfunction in murine cerebral malaria by camera-phone laser speckle imaging (J. Biophotonics 1/2019)

2019 ◽  
Vol 12 (1) ◽  
pp. e201870176
2018 ◽  
Vol 12 (1) ◽  
pp. e201800098 ◽  
Author(s):  
Itay Remer ◽  
Lorraine F. Pierre-Destine ◽  
David Tay ◽  
Linnie M. Golightly ◽  
Alberto Bilenca

2019 ◽  
Vol 128 ◽  
pp. 02001
Author(s):  
X Sang ◽  
D Li ◽  
B Chen

Speckle simulation is a powerful protocol to investigate the properties of speckle and evaluate image processing method. However, only static speckle images can be simulated by available methods without considering time-integrated effect of CCD. A time–integrated dynamic speckle simulation method basedon coherent imaging was developed. Through the new simulation method, the effect of speckle size on LSCI was investigated. The smaller the speckle size is, the higher the spatial resolution become.But the one-dimensional speckle size should exceed two pixels to sample the speckle pattern. The characteristics of existing speckle contrast imaging methods were studied based on spatial statistics, and optimal parameters are given to obtain accurate and less noisy image. In general, the new simulation method for laser speckle imaging is a powerful tool to monitor blood flow in vivo and lay a solid foundation for the study of hemodynamics.


2019 ◽  
Author(s):  
Nami Davoodzadeh ◽  
Mildred S. Cano-Velázquez ◽  
Carrie R. Jonak ◽  
David L. Halaney ◽  
Devin K. Binder ◽  
...  

Light based techniques for imaging, diagnosing and treating the brain have become widespread clinical tools, but application of these techniques is limited by optical attenuation in the scalp and skull. This optical attenuation reduces the achievable spatial resolution, precluding the visualization of small features such as brain microvessels. The goal of this study was to assess a strategy for providing ongoing optical access to the brain without the need for repeated craniectomy or retraction of the scalp. This strategy involves the use of a transparent cranial implant and skin optical clearing agents, and was tested in mice to assess improvements in optical access which could be achieved for laser speckle imaging of cerebral microvasculature. Combined transmittance of the optically cleared scalp overlying the transparent cranial implant was as high as 89% in the NIR range, 50% in red range, 24% in green range, and 20% in blue range. In vivo laser speckle imaging experiments of mouse cerebral blood vessels showed that the proposed optical access increased signal-to-noise ratio and image resolution, allowing for visualization of microvessels through the transparent implant, which was not possible through the uncleared scalp and intact skull.


2014 ◽  
Vol 62 ◽  
pp. 87-94 ◽  
Author(s):  
Kausik Basak ◽  
Goutam Dey ◽  
Manjunatha Mahadevappa ◽  
Mahitosh Mandal ◽  
Pranab Kumar Dutta

2021 ◽  
Vol 11 (22) ◽  
pp. 10969
Author(s):  
E Du ◽  
Shuhao Shen ◽  
Anqi Qiu ◽  
Nanguang Chen

Laser speckle imaging has been an indispensable tool for visualizing blood flow in biomedical applications. We proposed a novel design of the laser speckle imaging system, which combines confocal illumination and detection with various speckle analysis methods. The system can be operated by three imaging modes. One is surface illumination laser speckle contrast imaging (SI-LSCI) and the other two are line scan temporal speckle contrast imaging (LS-TSCI) and line scan spatial speckle contrast imaging (LS-SSCI). The experimental results of flow phantoms have validated the mixture model, which combines the Lorentzian and Gaussian models to describe the simultaneous existence of both Brownian motions and ordered flow. Our experimental results of in vivo chick embryos demonstrate that LS-SSCI maintains high temporal resolution and is less affected by motion artifacts. LS-SSCI can provide better image quality for in vivo imaging blood chick embryos than LS-TSCI. Furthermore, the experiential results present that LS-SSCI can detect and quantify the blood flow change during vascular clipping, and shows great potential in diagnosing vascular diseases, such as angiosclerosis, angiostenosis, or angiemphraxis.


2019 ◽  
Vol 13 (02) ◽  
pp. 2050004
Author(s):  
D. Li ◽  
Y. Zhang ◽  
B. Chen

The effect of optical cleaning method combined with laser speckle imaging (LSI) was discussed to improve the detection depth of LSI due to high scattering characteristics of skin, which limit its clinical application. A double-layer skin tissue model embedded with a single blood vessel was established, and the Monte Carlo method was used to simulate photon propagation under the action of light-permeating agent. 808[Formula: see text]nm semiconductor and 632.8[Formula: see text]nm He–Ne lasers were selected to study the effect of optical clearing agents (OCAs) on photon deposition in tissues. Results show that the photon energy deposition density in the epidermis increases with the amount of tissue fluid replaced by OCA. Compared with glucose solution, polyethylene glycol 400 (PEG 400) and glycerol can considerably increase the average penetration depth of photons in the skin tissue, thereby raising the sampling depth of the LSI. After the action of glycerol, PEG 400, and glucose, the average photon penetration depth is increased by 51.78%, 51.06%, and 21.51% for 808nm, 68.93%, 67.94%, and 26.67% for 632.8 nm lasers, respectively. In vivo experiment by dorsal skin chamber proves that glycerol can cause a substantial decrease in blood flow rate, whereas PEG 400 can significantly improve the capability of light penetration without affecting blood velocity, which exhibits considerable potential in the monitoring of blood flow in skin tissues.


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