Application of optical flow algorithms to laser speckle imaging

Aminfar, AmirHessam; Davoodzadeh, Nami; Aguilar, Guillermo; Princevac, Marko

doi:10.1016/j.mvr.2018.11.001

Cited by 25 publications

(25 citation statements)

References 31 publications

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“…Laser speckle imaging has become a useful tool for brain blood flow applications as the images it produces contain functional information (i.e. relative blood velocity) in addition to showing structure of the vessel networks 13,66,67 . As we previously reported, exposure time of 6 ms gave the highest SNR for imaging through WttB implant using our optical setup 24 .…”

Section: Discussionmentioning

confidence: 99%

Theranostic cranial implant for hyperspectral light delivery and microcirculation imaging without scalp removal

Davoodzadeh¹,

Cano‐Velázquez

Jonak³

et al. 2019

Preprint

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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.

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Section: Discussionmentioning

confidence: 99%

Theranostic cranial implant for hyperspectral light delivery and microcirculation imaging without scalp removal

Davoodzadeh¹,

Cano‐Velázquez

Jonak³

et al. 2019

Preprint

Self Cite

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“…As soon as the speckle display is produced on a motion particle, for example, red blood cells, the motion of the blood in the vessels results in variations in the speckle display on the sensor. 11 In the LSCI technique, the motion of blood triggers haziness of image contrast, which results in gleaming of the intensity. The result is an instant image of the microcirculation.…”

Section: The Principles Of Lscimentioning

confidence: 99%

The use of laser speckle contrast imaging in clinical applications

2020

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<p class="abstract">Laser speckle contrast imaging (LSCI) is a useful device which is recruited for visualizing full-field microcirculatory images. The speckle pattern is produced as a consistent light illuminates a rough object, and the backscattered radiation is transformed into images and be shown on a screen. Movement within the object results in the fluctuation of patterns over time. Similar information can be attained by employing the Doppler effect, which needs to be scanned again. However, LSCI renders similar data without any further scanning procedure. Nowadays, LSCI has gained expanded consideration, in part because of its accelerated adoption for blood flow studies in the different surgical departments. Here we represent and review the application of LSCI methods of visualizing the field of microcirculation as medical applications from different clinical aspects and discuss the drawbacks that hinder its approval clinically.</p>

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“…Brain tissue was modeled as a single compartment. We assumed that blood vessels are distributed randomly, following a uniform distribution, throughout the brain tissue [8][9][10][11]. The inner sphere, which represents the ventricular system, includes the CP.…”

Section: Model Developmentmentioning

confidence: 99%

“…) . = (9) We used large values for and due to the negligible permeability barrier of the contact surfaces to sodium. Thus, the ISF sodium concentration is approximately in equilibrium with ventricular and subarachnoid sodium concentrations at the interface of brain tissue and CSF.…”

Section: Formulation Of the Modelmentioning

confidence: 99%

Regulation of CSF and brain tissue sodium levels by the blood-CSF and blood-brain barriers during migraine

Ghaffari

Grant²,

Petzold

et al. 2019

Preprint

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BackgroundCerebrospinal fluid (CSF) and brain tissue sodium levels increase during migraine. However, little is known regarding the underlying mechanisms of sodium homeostasis disturbance in the brain during the onset and propagation of migraine. Exploring the cause of sodium dysregulation in the brain is important, since correction of the altered sodium homeostasis could potentially treat migraine. Under the hypothesis that disturbances in sodium transport mechanisms at the blood-CSF barrier (BCSFB) and/or the blood-brain barrier (BBB) are the underlying cause of the elevated CSF and brain tissue sodium levels during migraines, we developed a mechanistic, differential equation model of a rat's brain to compare the significance of the BCSFB and the BBB in controlling CSF and brain tissue sodium levels. The model includes the ventricular system, subarachnoid space, brain tissue and blood. Sodium transport from blood to CSF across the BCSFB, and from blood to brain tissue across the BBB were modeled by influx permeability coefficients and , respectively, while sodium movement from CSF into blood across the BCSFB, and from brain tissue to blood across the BBB were modeled by efflux permeability coefficients ′ and ′ , respectively. We then performed a global sensitivity analysis to investigate the sensitivity of the ventricular CSF, subarachnoid CSF and brain tissue sodium concentrations to pathophysiological variations in , , ′ and ′ . Our results show that the ventricular CSF sodium concentration is highly influenced by perturbations of , and to a much lesser extent by perturbations of ′ . Brain tissue and subarachnoid CSF sodium concentrations are more sensitive to pathophysiological variations of and ′ than variations of and ′ within 30 minutes of the onset of the perturbations. However, is the most sensitive model parameter, followed by and ′ , in controlling brain tissue and subarachnoid CSF sodium levels within 2 hours of the perturbation onset.

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Application of optical flow algorithms to laser speckle imaging

Cited by 25 publications

References 31 publications

Theranostic cranial implant for hyperspectral light delivery and microcirculation imaging without scalp removal

Theranostic cranial implant for hyperspectral light delivery and microcirculation imaging without scalp removal

The use of laser speckle contrast imaging in clinical applications

Regulation of CSF and brain tissue sodium levels by the blood-CSF and blood-brain barriers during migraine

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