Expanding Applications, Accuracy, and Interpretation of Laser Speckle Contrast Imaging of Cerebral Blood Flow

Kazmi, SM Shams; Richards, Lisa; Schrandt, Christian J.; Davis, Mitchell A.; Dunn, Andrew K.

doi:10.1038/jcbfm.2015.84

Cited by 87 publications

(81 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is a reliable method for microcirculation research [32]. In previous studies, LPI was used for the clinical detection of local tissue perfusion, such as foot perfusion [33], cerebral blood flow [34], and skin perfusion [35]. In the present study, LPI was combined with a microscope to detect the changes of blood perfusion in the MSAs of living DS rats and was a useful device to observe the function and blood perfusion of small arteries in vivo.…”

Section: Discussionmentioning

confidence: 99%

High Sodium Intake Impairs Small Artery Vasoreactivity in vivo in Dahl Salt-Sensitive Rats

Wang

Chen

et al. 2019

J Vasc Res

View full text Add to dashboard Cite

The effects of high sodium intake on the functionality of resistance arteries have been repeatedly studied in vitro, but no study has focused on salt-sensitive hypertension in vivo. We studied the in vivo reactivity of mesenteric small arteries (MSAs) to vasoactive agents in Dahl salt-sensitive (DS) rats with various sodium diets. Twenty-four male DS rats were randomized into 3 groups: LS (0.3% NaCl diet), NS (0.6% NaCl diet), and HS (8% NaCl diet). After a 12-week intervention, the diameter changes of the MSAs after noradrenaline (NA) and acetylcholine (ACh) exposure were detected by a microscope, and changes in blood perfusion through the MSAs were measured by full-field laser perfusion imaging. HS enhanced the constrictive response of the MSAs to NA and attenuated the relaxing response to ACh. Low sodium intake reduced the response of the MSAs to NA and promoted ACh-induced vasodilatation. HS also aggravated NA-induced blood perfusion reduction and impaired ACh-induced hyperperfusion of the MSAs. Pathologically, HS was associated with arteriolar structural damage and fibrosis of the MSAs. We conclude that sodium intake affects the responsiveness of the MSAs to vasoactive agents in DS rats and might play important roles in modulating blood pressure in hypertensive individuals.

show abstract

Section: Discussionmentioning

confidence: 99%

High Sodium Intake Impairs Small Artery Vasoreactivity in vivo in Dahl Salt-Sensitive Rats

Wang

Chen

et al. 2019

J Vasc Res

View full text Add to dashboard Cite

show abstract

“…(9). Using the ordered motion, single scattering assumption; or g 1 (t) = exp (−( t /τ c ) 2 ), results in the following speckle contrast relation [23]:…”

Section: Simulation Of G 1 (T)mentioning

confidence: 99%

“…LSCI has been heavily adopted for neuroscience applications such as blood flow imaging of neurovascular pathologies [1,2], functional activation [3], and even human cortical blood flow imaging during neurosurgery [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Sensitivity of laser speckle contrast imaging to flow perturbations in the cortex

Davis

Gagnon

Boas

et al. 2016

Biomed. Opt. Express

View full text Add to dashboard Cite

Laser speckle contrast imaging has become a ubiquitous tool for imaging blood flow in a variety of tissues. However, due to its widefield imaging nature, the measured speckle contrast is a depth integrated quantity and interpretation of baseline values and the depth dependent sensitivity of those values to changes in underlying flow has not been thoroughly evaluated. Using dynamic light scattering Monte Carlo simulations, the sensitivity of the autocorrelation function and speckle contrast to flow changes in the cerebral cortex was extensively examined. These simulations demonstrate that the sensitivity of the inverse autocorrelation time, 1 /τ c , varies across the field of view: directly over surface vessels 1 /τ c is strongly localized to the single vessel, while parenchymal ROIs have a larger sensitivity to flow changes at depths up to 500 µm into the tissue and up to 200 µm lateral to the ROI. It is also shown that utilizing the commonly used models the relate 1 /τ c to flow resulted in nearly the same sensitivity to the underlying flow, but fail to accurately relate speckle contrast values to absolute 1 /τ c . Mandeville, J. Cohen-Adad et al., "Quantifying the microvascular origin of bold-fmri from first principles with two-photon microscopy and an oxygen-sensitive nanoprobe," J. Neurosci. 35, 3663-3675 (2015). 26. P. S. Tsai, J. P. Kaufhold, P. Blinder, B. Friedman, P. J. Drew, H. J. Karten, P. D. Lyden, and D. Kleinfeld, "Correlations of neuronal and microvascular densities in murine cortex revealed by direct counting and colocalization of nuclei and vessels,"

show abstract

“…On the other hand, the exact relationship between the speckle contrast and the underlying blood flow is nonlinear and is currently an active area of research as speckle contrast-based mapping only provides qualitative estimates of blood flow. There has been better understanding to link the speckle contrast value to the characteristic correlation time of the speckles via improved quantitative modeling as the correlation time is known to be inversely proportional to the blood flow [10,17,18]. A threshold below 3% was regarded as random noises to be eliminated in the image of changes in contrast as the noise levels of ex-vivo and in-vivo samples are 2-3% in our experimental system.…”

Section: Methodsmentioning

confidence: 99%

Laser Speckle Contrast Imaging for Measuring Cerebral Blood Flow Changes Caused by Electrical Sensory Stimulation

Cho

Yeon

Kim

et al. 2016

Journal of the Optical Society of Korea

View full text Add to dashboard Cite

Recently laser speckle contrast (LSC) imaging has become a widely used optical method for in vivo assessment of blood flow in the animal brain. LSC imaging is useful for monitoring brain hemodynamics with relatively high spatio-temporal resolution. A speckle contrast imaging system has been implemented with electrical sensory stimulation apparatus. LSC imaging is combined with optical intrinsic signal imaging in order to measure changes in cerebral blood flow as well as neural activity in response to electrical sensory stimulation applied to the hindlimb region of the mouse brain. We found that blood flow and oxygen consumption are correlated and both sides of hindlimb activation regions are symmetrically located. This apparatus could be used to monitor spatial or temporal responses of cerebral blood flow in animal disease models such as ischemic stroke or cortical spreading depression.

show abstract

Expanding Applications, Accuracy, and Interpretation of Laser Speckle Contrast Imaging of Cerebral Blood Flow

Cited by 87 publications

References 79 publications

High Sodium Intake Impairs Small Artery Vasoreactivity in vivo in Dahl Salt-Sensitive Rats

High Sodium Intake Impairs Small Artery Vasoreactivity in vivo in Dahl Salt-Sensitive Rats

Sensitivity of laser speckle contrast imaging to flow perturbations in the cortex

Laser Speckle Contrast Imaging for Measuring Cerebral Blood Flow Changes Caused by Electrical Sensory Stimulation

Contact Info

Product

Resources

About