Contrast enhancement subsurface optical imaging with different incident polarization states

2006 ◽  
Author(s):  
Hanrong Shao ◽  
Yonghong He ◽  
Yonghong Shao ◽  
Hui Ma
Keyword(s):  
Optical Imaging ◽  
Contrast Enhancement ◽  
Polarization States ◽  
Incident Polarization

Contrast enhancement in biomedical optical imaging using ultrabright color LEDs

2007 ◽  
Author(s):  
Kevin Burton ◽  
Raphael Zelikowsky ◽  
Danny Shandling ◽  
Erik Lindsley ◽  
Daniel L. Farkas
Keyword(s):  
Optical Imaging ◽  
Contrast Enhancement ◽  
Biomedical Optical Imaging

scholarly journals Dynamic Analysis of the Blood-Brain Barrier Disruption in Experimental Stroke Using Time Domain in Vivo Fluorescence Imaging

2008 ◽  
Vol 7 (6) ◽  
pp. 7290.2008.00025 ◽  
Author(s):  
Abedelnasser Abulrob ◽  
Eric Brunette ◽  
Jacqueline Slinn ◽  
Ewa Baumann ◽  
Danica Stanimirovic
Keyword(s):  
Optical Imaging ◽  
Contrast Enhancement ◽  
Blood Brain Barrier ◽  
Time Domain ◽  
Near Infrared ◽  
Ex Vivo ◽  
Brain Barrier ◽  
Experimental Stroke ◽  
Blood Brain

The blood-brain barrier (BBB) disruption following cerebral ischemia can be exploited to deliver imaging agents and therapeutics into the brain. The aim of this study was (a) to establish novel in vivo optical imaging methods for longitudinal assessment of the BBB disruption and (b) to assess size selectivity and temporal patterns of the BBB disruption after a transient focal ischemia. The BBB permeability was assessed using in vivo time domain near-infrared optical imaging after contrast enhancement with either free Cy5.5 (1 kDa) or Cy5.5 conjugated with bovine serum albumin (BSA) (67 kDa) in mice subjected to either 60- or 20-minute transient middle cerebral artery occlusion (MCAO) and various times of reperfusion (up to 14 days). In vivo imaging observations were corroborated by ex vivo brain imaging and microscopic analyses of fluorescent tracer extravasation. The in vivo optical contrast enhancement with Cy5.5 was spatially larger than that observed with BSA-Cy5.5. Longitudinal studies after a transient 20-minute MCAO suggested a bilateral BBB disruption, more pronounced in the ipsilateral hemisphere, peaking at day 7 and resolving at day 14 after ischemia. The area differential between the BBB disruption for small and large molecules could potentially be useful as a surrogate imaging marker for assessing perinfarct tissues to which neuroprotective therapies of appropriate sizes could be delivered.

scholarly journals Image contrast enhancement in angular domain optical imaging of turbid media

2008 ◽  
Vol 16 (26) ◽  
pp. 21492 ◽  
Author(s):  
Fartash Vasefi ◽  
Bozena Kaminska ◽  
Glenn H. Chapman ◽  
Jeffrey J. Carson
Keyword(s):  
Optical Imaging ◽  
Contrast Enhancement ◽  
Image Contrast ◽  
Turbid Media ◽  
Angular Domain ◽  
Image Contrast Enhancement

scholarly journals The use of microbubbles as contrast agents in the optical imaging of tissue

2021 ◽  
Author(s):  
Homa Assadi
Keyword(s):  
Optical Properties ◽  
Contrast Agents ◽  
Optical Imaging ◽  
Contrast Enhancement ◽  
Blood Volume ◽  
Volume Fraction ◽  
Repeated Administration ◽  
Skin Tissue ◽  
Surrounding Water ◽  
Tissue Phantom

In this study, micrometer-sized (< 5μm) microbubbles (MBs) were investigated as optical contrast agents. Exogenous contrast agents in optical imaging can enhance the detection of cancerous tissue, however they are limited by their potential side effects such as organ accumulation and toxicity with repeated administration. In ultrasound imaging, microbubbles are FDA approved and used clinically as contrast agents. Microbubbles can also produce a refractive index mismatch between the gas-filled core and surrounding water media, potentially modifying optical properties of tissue when injected intravenously into tissue. Cancer detection can potentially be achieved by imaging microvasculature functionality through the blood volume fraction measurements with diffuse optical imaging (DOI). In order to study the potential application of using MBs for DOI, the effect of MBs on the bulk optical properties of a skin tissue phantom solution at various volume fraction of human blood was assessed at various injection doses of Definity® microbubble. The absorption and reduced scattering coefficients were computed and compared in the absence and presence of microbubbles. The presence of microbubbles in the blood caused a statistically significant enhancement in the reduced scattering contrast (~1.3 times) at 660 nm wavelength which increases with the dose of Definity® MBs (166 μL/kg) at 6% blood volume fraction. However, the absorption contrast enhancement remained relatively constant as microbubble dose increased. The scattering contrast enhancement confirmed the feasibility of using MBs as DOI contrast agents to improve the detection of tissue with high blood concentration conditions. Microbubbles were also investigated as optical coherence tomography (OCT) contrast agents. OCT structural and speckle variance (sv) images, as well as the speckle decorrelation times, were evaluated under no-flow and flow conditions from a skin tissue phantom with two embedded microtubes. Faster decorrelation times and greater structural and svOCT image contrasts were detected with the presence of MBs. The effects of the presence of MBs on the image contrast were maximal (2 times) at no flow in the svOCT imaging mode and reduced with blood average flow velocity from zero to 12 mm/s. This result confirmed the feasibility of using MBs to enhance svOCT visualization of microvasculature morphology.

scholarly journals The use of microbubbles as contrast agents in the optical imaging of tissue

2021 ◽  
Author(s):  
Homa Assadi
Keyword(s):  
Optical Properties ◽  
Contrast Agents ◽  
Optical Imaging ◽  
Contrast Enhancement ◽  
Blood Volume ◽  
Volume Fraction ◽  
Repeated Administration ◽  
Skin Tissue ◽  
Surrounding Water ◽  
Tissue Phantom

In this study, micrometer-sized (< 5μm) microbubbles (MBs) were investigated as optical contrast agents. Exogenous contrast agents in optical imaging can enhance the detection of cancerous tissue, however they are limited by their potential side effects such as organ accumulation and toxicity with repeated administration. In ultrasound imaging, microbubbles are FDA approved and used clinically as contrast agents. Microbubbles can also produce a refractive index mismatch between the gas-filled core and surrounding water media, potentially modifying optical properties of tissue when injected intravenously into tissue. Cancer detection can potentially be achieved by imaging microvasculature functionality through the blood volume fraction measurements with diffuse optical imaging (DOI). In order to study the potential application of using MBs for DOI, the effect of MBs on the bulk optical properties of a skin tissue phantom solution at various volume fraction of human blood was assessed at various injection doses of Definity® microbubble. The absorption and reduced scattering coefficients were computed and compared in the absence and presence of microbubbles. The presence of microbubbles in the blood caused a statistically significant enhancement in the reduced scattering contrast (~1.3 times) at 660 nm wavelength which increases with the dose of Definity® MBs (166 μL/kg) at 6% blood volume fraction. However, the absorption contrast enhancement remained relatively constant as microbubble dose increased. The scattering contrast enhancement confirmed the feasibility of using MBs as DOI contrast agents to improve the detection of tissue with high blood concentration conditions. Microbubbles were also investigated as optical coherence tomography (OCT) contrast agents. OCT structural and speckle variance (sv) images, as well as the speckle decorrelation times, were evaluated under no-flow and flow conditions from a skin tissue phantom with two embedded microtubes. Faster decorrelation times and greater structural and svOCT image contrasts were detected with the presence of MBs. The effects of the presence of MBs on the image contrast were maximal (2 times) at no flow in the svOCT imaging mode and reduced with blood average flow velocity from zero to 12 mm/s. This result confirmed the feasibility of using MBs to enhance svOCT visualization of microvasculature morphology.

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