Time–frequency analysis of laser speckle contrast for transcranial assessment of cerebral blood flow

Golubova, Nadezhda; Potapova, Elena; Seryogina, Evgeniya; Dremin, Viktor

doi:10.1016/j.bspc.2023.104969

Cited by 11 publications

(2 citation statements)

References 56 publications

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“…We place the tubes at 6 mm from the surface of the scattering medium, corresponding to ≈ 40 mean free paths (MFPs). We then use the same milk solution [37] to pass through the tube using a syringe pump (New Era 4041) at various flow speeds, although an intralipid solution [38] can be also used to mimic blood in tissue phantoms.…”

Section: Building a Dynamic Tissue Phantommentioning

confidence: 99%

SpeckleCam: High-resolution Computational Speckle Contrast Tomography for Deep Blood Flow Imaging

Maity,

Veeraraghavan,

Sabharwal

et al. 2023

Preprint

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Laser speckle contrast imaging is widely used in clinical studies to monitor blood flow distribution. Speckle contrast tomography, similar to diffuse optical tomography, extends speckle contrast imaging to provide deep tissue blood flow information. However, the current speckle contrast tomography techniques suffer from poor spatial resolution and involve both computation and memory intensive reconstruction algorithms. In this work, we present SpeckleCam, a camera-based system to reconstruct high resolution 3D blood flow distribution deep inside the skin. Our approach replaces the traditional forward model using diffuse approximations with Monte-Carlo simulations-based convolutional forward model, which enables us to develop an improved deep tissue blood flow reconstruction algorithm. We show that our proposed approach can recover complex structures up to 6 mm deep inside a tissue-like scattering medium in the reflection geometry. We also conduct human experiments to demonstrate that our approach can detect reduced flow in major blood vessels during vascular occlusion.

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Section: Building a Dynamic Tissue Phantommentioning

confidence: 99%

SpeckleCam: High-resolution Computational Speckle Contrast Tomography for Deep Blood Flow Imaging

Maity,

Veeraraghavan,

Sabharwal

et al. 2023

Preprint

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“…Alterations in microcirculation are associated with various pathologies, such as cancer [1], diabetes [2,3], hypertension [4], sepsis [5], and viral infections [6]. This field is still very much alive, as witnessed by the new publications on the influence of microcirculation in various pathologies [7], including Covid [8], and the renewed interest in the associated dynamic speckle technology [9][10][11]. Therefore, monitoring the peripheral microcirculation of the body holds significant diagnostic potential.…”

Section: Introductionmentioning

confidence: 99%

Standardizing Laser Speckle Orthogonal Contrast Imaging: Achieving Reproducible Measurements across Instruments

Orlik,

Colin,

Plyer

2024

Photonics

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Using two independent speckle imaging systems based on the recently published LSOCI method operating in contact mode on the skin, we assess the reproducibility of in vivo measurements and conduct an inter-instrument comparison. To this aim, we propose a calibration method to handle each imaging system as a comprehensive unit, which includes the laser source, optics, and camera. Key to our method is the introduction of a new index that quantifies the departure of the temporal contrast observed in vivo from the spatial contrast scattered from a reference static element generating a circular Gaussian speckle field. Using such near-real-time calibration method, we demonstrate that the microcirculation images produced by 2 different instruments exhibit high accuracy and stability, with microcirculation activity values in excellent agreement, thereby paving the way for clinical applications.

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Enhancing Transcranial Blood Flow Visualization with Dynamic Light Scattering Technologies: Advances in Quantitative Analysis

Zherebtsov,

Sdobnov,

Sieryi

et al. 2024

Laser & Photonics Reviews

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A comparative application of major dynamic light scattering (DLS)‐based image methodologies applied to transcranial cerebral blood flow imaging is presented. In particular, the study delves into assessing capability of Laser Doppler Flowmetry (LDF), Laser Speckle Contrast Imaging (LSCI), and Diffuse Correlation Spectroscopy (DCS) in enhancing the spatial and temporal resolution of transcranial blood flow imaging. An integral part of the study is focused on the modulation of blood flow through the administration of the vasodilator drug, Sodium Nitroprusside (SNP). This pharmacological intervention facilitated a direct observation of cerebral vasculature's responsiveness to external stimuli, illuminating the physiological adaptations within the brain's microvascular architecture. Advanced LSCI processing techniques are incorporated, notably entropy and principal component analysis (PCA). Entropy is providing a quantifiable measure of the randomness and complexity within the speckle patterns of transcranial blood flow images, revealing remarkably similar outcomes with DSC approach in terms of blood flow dynamics and its quantitative evaluation. The application of PCA approach is provided a more nuanced understanding of blood flow dynamics, facilitating the identification of subtle changes induced by drug administration. This method proved instrumental in enhancing the visualization and detection of nuanced blood flow dynamics, thereby allowing for a more detailed examination of cerebral circulation alterations induced by SNP administration. The study seeks to offer a wider‐ranging insight into comprehending the translating further the concept of DLS into transcrainial blood flow vizualization and explore its practical applications, considering hardware, advanced quantitative image processing, and data acquisition.

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Time–frequency analysis of laser speckle contrast for transcranial assessment of cerebral blood flow

Cited by 11 publications

References 56 publications

SpeckleCam: High-resolution Computational Speckle Contrast Tomography for Deep Blood Flow Imaging

SpeckleCam: High-resolution Computational Speckle Contrast Tomography for Deep Blood Flow Imaging

Standardizing Laser Speckle Orthogonal Contrast Imaging: Achieving Reproducible Measurements across Instruments

Enhancing Transcranial Blood Flow Visualization with Dynamic Light Scattering Technologies: Advances in Quantitative Analysis

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