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Imaging depth and multiple scattering in laser speckle contrast imaging.

Davis MA, Kazmi SM, Dunn AK - J Biomed Opt (2014)

Bottom Line: We found that 95% of the detected signal comes from the top 700 μm of tissue.Additionally, we observed that single-intravascular scattering is an accurate description of photon sampling dynamics, but that regions of interest (ROIs) in areas free of obvious surface vessels had fewer intravascular scattering events than ROI over resolved surface vessels.We performed simulations over a wide range of intravascular and extravascular scattering properties to confirm the applicability of these results to LSCI imaging over a wide range of visible and near-infrared wavelengths.

View Article: PubMed Central - PubMed

Affiliation: The University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, Texas 78712, United States.

ABSTRACT
Laser speckle contrast imaging (LSCI) is a powerful and simple method for full field imaging of blood flow. However, the depth dependence and the degree of multiple scattering have not been thoroughly investigated. We employ three-dimensional Monte Carlo simulations of photon propagation combined with high resolution vascular anatomy to investigate these two issues. We found that 95% of the detected signal comes from the top 700 μm of tissue. Additionally, we observed that single-intravascular scattering is an accurate description of photon sampling dynamics, but that regions of interest (ROIs) in areas free of obvious surface vessels had fewer intravascular scattering events than ROI over resolved surface vessels. Furthermore, we observed that the local vascular anatomy can strongly affect the depth dependence of LSCI. We performed simulations over a wide range of intravascular and extravascular scattering properties to confirm the applicability of these results to LSCI imaging over a wide range of visible and near-infrared wavelengths.

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(a) Maximum intensity projection of two-photon stack with  ROIs corresponding to the parenchyma (a) and surface vessel (d); (b) is the LSCI image with an ROI corresponding to the location of the two-photon image stack; (c and d) a log-scale color overlay of dynamic scattering in the geometry in the parenchyma (c) and the surface vessel (d) ROI using intravascular .
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f3: (a) Maximum intensity projection of two-photon stack with ROIs corresponding to the parenchyma (a) and surface vessel (d); (b) is the LSCI image with an ROI corresponding to the location of the two-photon image stack; (c and d) a log-scale color overlay of dynamic scattering in the geometry in the parenchyma (c) and the surface vessel (d) ROI using intravascular .

Mentions: Figure 3 shows the characteristics of vascular scattering for two of the ROI shown in Fig. 2. Figures 3(a) and 3(b) show the maximum intensity projection of the tissue vasculature with the ROI marked by square 15-μm boxes, as well as the corresponding LSCI. The ROI in the top left corresponds to parenchyma in the speckle contrast image from Fig. 1, whereas the bottom right ROI corresponds to a resolved surface vessel.


Imaging depth and multiple scattering in laser speckle contrast imaging.

Davis MA, Kazmi SM, Dunn AK - J Biomed Opt (2014)

(a) Maximum intensity projection of two-photon stack with  ROIs corresponding to the parenchyma (a) and surface vessel (d); (b) is the LSCI image with an ROI corresponding to the location of the two-photon image stack; (c and d) a log-scale color overlay of dynamic scattering in the geometry in the parenchyma (c) and the surface vessel (d) ROI using intravascular .
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4119427&req=5

f3: (a) Maximum intensity projection of two-photon stack with ROIs corresponding to the parenchyma (a) and surface vessel (d); (b) is the LSCI image with an ROI corresponding to the location of the two-photon image stack; (c and d) a log-scale color overlay of dynamic scattering in the geometry in the parenchyma (c) and the surface vessel (d) ROI using intravascular .
Mentions: Figure 3 shows the characteristics of vascular scattering for two of the ROI shown in Fig. 2. Figures 3(a) and 3(b) show the maximum intensity projection of the tissue vasculature with the ROI marked by square 15-μm boxes, as well as the corresponding LSCI. The ROI in the top left corresponds to parenchyma in the speckle contrast image from Fig. 1, whereas the bottom right ROI corresponds to a resolved surface vessel.

Bottom Line: We found that 95% of the detected signal comes from the top 700 μm of tissue.Additionally, we observed that single-intravascular scattering is an accurate description of photon sampling dynamics, but that regions of interest (ROIs) in areas free of obvious surface vessels had fewer intravascular scattering events than ROI over resolved surface vessels.We performed simulations over a wide range of intravascular and extravascular scattering properties to confirm the applicability of these results to LSCI imaging over a wide range of visible and near-infrared wavelengths.

View Article: PubMed Central - PubMed

Affiliation: The University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, Texas 78712, United States.

ABSTRACT
Laser speckle contrast imaging (LSCI) is a powerful and simple method for full field imaging of blood flow. However, the depth dependence and the degree of multiple scattering have not been thoroughly investigated. We employ three-dimensional Monte Carlo simulations of photon propagation combined with high resolution vascular anatomy to investigate these two issues. We found that 95% of the detected signal comes from the top 700 μm of tissue. Additionally, we observed that single-intravascular scattering is an accurate description of photon sampling dynamics, but that regions of interest (ROIs) in areas free of obvious surface vessels had fewer intravascular scattering events than ROI over resolved surface vessels. Furthermore, we observed that the local vascular anatomy can strongly affect the depth dependence of LSCI. We performed simulations over a wide range of intravascular and extravascular scattering properties to confirm the applicability of these results to LSCI imaging over a wide range of visible and near-infrared wavelengths.

Show MeSH
Related in: MedlinePlus