Diffuse light reflectance signals as potential indicators of loss of viability in brain tissue due to hypoxia: charge-coupled-device-based imaging and fiber-based measurement

Kawauchi, Satoko; Nishidate, Izumi; Uozumi, Yoichi; Nawashiro, Hiroshi; Ashida, Hiroshi; Sato, Shunichi

doi:10.1117/1.jbo.18.1.015003

Cited by 39 publications

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References 23 publications

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“…4e). In our previous study, an increase in the NIR diffuse reflectance, i.e., an increase in the light scattering, was shown to be associated with the irreversible cell damage after hypoxia 8 . Thus, the reflectance increase within the region with reduced blood flow in Fig.…”

Section: Pixels Of Area With Increased Nir Reflectancementioning

confidence: 99%

“…In the nearinfrared (NIR) spectral region, the reduced scattering coefficient of the gray matter is two orders of magnitude larger than the absorption coefficient 7 , and the use of light scattering signal therefore enables sensitive monitoring of the events associated with spreading depolarization, as well as irreversible cell damage. We previously observed an occurrence of AD by NIR diffuse reflectance measurement in the rat global hypoxic brain model 8 . In that study, we found that AD was able to be detected as a wave-like reflectance change and the irreversible light-scattering increase after the AD was associated with irreversible cell damage.…”

Section: Introductionmentioning

confidence: 99%

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Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

et al. 2014

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To understand the pathophysiology of ischemic stroke, in vivo imaging of the brain tissue viability and related spreading depolarization is crucial. In the infarct core, impairment of energy metabolism causes anoxic depolarization (AD), which considerably increases energy consumption, accelerating irreversible neuronal damage. In the peri-infarct penumbra region, where tissue is still reversible despite limited blood flow, peri-infarct depolarization (PID) occurs, exacerbating energy deficit and hence expanding the infarct area. We previously showed that light-scattering signal, which is sensitive to cellular/subcellular structural integrity, was correlated with AD and brain tissue viability in a rat hypoxia-reoxygenation model. In the present study, we performed transcranial NIR diffuse reflectance imaging of the rat brain during middle cerebral artery (MCA) occlusion and examined whether the infarct core and PIDs can be detected. Immediately after occluding the left MCA, light scattering started to increase focally in the occlusion site and a bright region was generated near the occlusion site and spread over the left entire cortex, which was followed by a dark region, showing the occurrence of PID. The PID was generated repetitively and the number of times of occurrence in a rat ranged from four to ten within 1 hour after occlusion (n=4). The scattering increase in the occlusion site was irreversible and the area with increased scattering expanded with increasing the number of PIDs, indicating an expansion of the infarct core. These results suggest the usefulness of NIR diffuse reflectance signal to visualize spatiotemporal changes in the infarct area and PIDs.

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Section: Pixels Of Area With Increased Nir Reflectancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

et al. 2014

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“…Thus, our results are an average of signals from different head tissue layers (partial volume effect), which may impact hemodynamics imaging. In future studies, simultaneous imaging and diffuse reflectance based source-detector fiber optics configuration [57] is highly recommended to validate drugs' effects on hemodynamics.…”

Section: Discussionmentioning

confidence: 99%

Exploring diazepam’s effect on hemodynamic responses of mouse brain tissue by optical spectroscopic imaging

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et al. 2014

Biomed. Opt. Express

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Abstract:In this study, a simple duel-optical spectroscopic imaging apparatus capable of simultaneously determining relative changes in brain oxy-and deoxy-hemoglobin concentrations was used following administration of the anxiolytic compound diazepam in mice with strong dominant (Dom) and submissive (Sub) behavioral traits. Three month old mice (n = 30) were anesthetized and after 10 min of baseline imaging, diazepam (1.5 mg/kg) was administered and measurements were taken for 80 min. The mouse head was illuminated by white light based LED's and diffused reflected light passing through different channels, consisting of a bandpass filter and a CCD camera, respectively, was collected and analyzed to measure the hemodynamic response. This work's major findings are threefold: first, Dom and Sub animals showed statistically significant differences in hemodynamic response to diazepam administration. Secondly, diazepam was found to more strongly affect the Sub group. Thirdly, different time-series profiles were observed post-injection, which can serve as a possible marker for the groups' differentiation. To the best of our knowledge, this is the first report on the effects of an anxiolytic drug on brain hemodynamic responses in mice using diffused light optical imaging. References and links1. R. C. Kessler, P. Berglund, O. Demler, R. Jin, K. R. Merikangas, and E. E. Walters, "Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication," Arch. Gen. Psychiatry 62(6), 593-602 (2005 894-902 (2008). 4. M. T. Berlim, M. P. Fleck, and G. Turecki, "Current trends in the assessment and somatic treatment of resistant/refractory major depression: an overview," Ann. Med. 40(2), 149-159 (2008). 5. C. J. Harmer, G. M. Goodwin, and P. J. Cowen, "Why do antidepressants take so long to work? A cognitive neuropsychological model of antidepressant drug action," Br. Ntziachristos, and B. Chance, "Non-invasive and quantitative near-infrared haemoglobin spectrometry in the piglet brain during hypoxic stress, using a frequency-domain multidistance instrument," Phys. Med. Biol. 46(1), 41-62 (2001).

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“…Diffuse reflectance spectroscopy (DRS) is one of most promising technique for evaluating optical properties of in vivo brain tissue. Several imaging techniques based on the diffuse optical spectroscopy have been used to investigate the cortical hemodynamics [3][4][5] and tissue viability 6 .…”

Section: Introductionmentioning

confidence: 99%

In vivoimaging of scattering and absorption properties of exposed brain using a digital red-green-blue camera

et al. 2014

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We investigate a method to estimate the spectral images of reduced scattering coefficients and the absorption coefficients of in vivo exposed brain tissues in the range from visible to near-infrared wavelength (500-760 nm) based on diffuse reflectance spectroscopy using a digital RGB camera. In the proposed method, the multi-spectral reflectance images of in vivo exposed brain are reconstructed from the digital red, green blue images using the Wiener estimation algorithm. The Monte Carlo simulation-based multiple regression analysis for the absorbance spectra is then used to specify the absorption and scattering parameters of brain tissue. In this analysis, the concentration of oxygenated hemoglobin and that of deoxygenated hemoglobin are estimated as the absorption parameters whereas the scattering amplitude a and the scattering power b in the expression of μ s '=aλ -b as the scattering parameters, respectively. The spectra of absorption and reduced scattering coefficients are reconstructed from the absorption and scattering parameters, and finally, the spectral images of absorption and reduced scattering coefficients are estimated. The estimated images of absorption coefficients were dominated by the spectral characteristics of hemoglobin. The estimated spectral images of reduced scattering coefficients showed a broad scattering spectrum, exhibiting larger magnitude at shorter wavelengths, corresponding to the typical spectrum of brain tissue published in the literature. In vivo experiments with exposed brain of rats during CSD confirmed the possibility of the method to evaluate both hemodynamics and changes in tissue morphology due to electrical depolarization.

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Diffuse light reflectance signals as potential indicators of loss of viability in brain tissue due to hypoxia: charge-coupled-device-based imaging and fiber-based measurement

Cited by 39 publications

References 23 publications

Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

Exploring diazepam’s effect on hemodynamic responses of mouse brain tissue by optical spectroscopic imaging

In vivoimaging of scattering and absorption properties of exposed brain using a digital red-green-blue camera

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