A Mesh-Based Monte Carlo Study for Investigating Structural and Functional Imaging of Brain Tissue Using Optical Coherence Tomography

Optical coherence tomography (OCT) can obtain high-resolution three-dimensional (3D) structural images of biological tissues, and spectroscopic OCT, which is one of the functional extensions of OCT, can also quantify chromophores of tissues. Due to its unique features, OCT has been increasingly used for brain imaging. To support the development of the simulation and analysis tools on which OCT-based brain imaging depends, a model of mesh-based Monte Carlo for OCT (MMC-OCT) is presented in this work to study OCT signals reflecting the structural and functional activities of brain tissue. In addition, an approach to improve the quantitative accuracy of chromophores in tissue is proposed and validated by MMC-OCT simulations. Specifically, the OCT-based brain structural imaging was first simulated to illustrate and validate the MMC-OCT strategy. We then focused on the influences of different wavelengths on the measurement of hemoglobin concentration C, oxygen saturation Y, and scattering coefficient S in brain tissue. Finally, it is proposed and verified here that the measurement accuracy of C, Y, and S can be improved by selecting appropriate wavelengths for calculation, which contributes to the experimental study of brain functional sensing.

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High speed rotary system for catheter based 3-D imaging with optical coherence tomography (OCT)

10.32920/ryerson.14652363.v1 ◽

2021 ◽

Author(s):

Antonio Mauro

Keyword(s):

Optical Coherence Tomography ◽

High Speed ◽

Imaging Techniques ◽

Three Dimensional ◽

Biological Tissues ◽

Optical Coherence ◽

X Rays ◽

Sound Waves ◽

Acquisition Rate

Optical Coherence Tomography (OCT) is an addition to the other tomographic imaging techniques of x-ray computed tomography, magnetic resonance imaging, and ultrasound imaging. OCT uses optical reflections of biological tissues as opposed to x-rays, RF fields, and sound waves to obtain images. A rotary and pullback system has been developed for use with OCT. The system was developed to facilitate the three dimensional imaging of various lumens in humans and animals. The system is capable of rotating at a rate of 200 Hz. At this rate the rotary system will allow for a frame acquisition rate of 200 fps which is significantly higher than the highest published acquisition rate to date of 108 fps. The probes used with the system were modeled after the Intravascular Ultrasound (IVUS) miniature torque cable design. The probes can be sealed and sterilized between subjects without being damaged; unlike the single use IVUS probes. The rotary system was used to image the outer ear of a mouse in vivo. A lateral slice from the resulting three dimensional image was compared to the general histology of a mouse ear. The image compared well to the general anatomy as found on the histology.

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Signal degradation by multiple scattering in optical coherence tomography of dense tissue: a Monte Carlo study towards optical clearing of biotissues

Physics in Medicine and Biology ◽

10.1088/0031-9155/47/13/307 ◽

2002 ◽

Vol 47 (13) ◽

pp. 2281-2299 ◽

Cited By ~ 101

Author(s):

Ruikang K Wang

Keyword(s):

Optical Coherence Tomography ◽

Monte Carlo ◽

Multiple Scattering ◽

Monte Carlo Study ◽

Optical Coherence ◽

Optical Clearing ◽

Signal Degradation ◽

Dense Tissue

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High speed rotary system for catheter based 3-D imaging with optical coherence tomography (OCT)

10.32920/ryerson.14652363 ◽

2021 ◽

Author(s):

Antonio Mauro

Keyword(s):

Optical Coherence Tomography ◽

High Speed ◽

Imaging Techniques ◽

Three Dimensional ◽

Biological Tissues ◽

Optical Coherence ◽

X Rays ◽

Sound Waves ◽

Acquisition Rate

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Model eye tool for retinal optical coherence tomography instrument calibration

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545821500103 ◽

2021 ◽

pp. 2150010

Author(s):

Hongting Wang ◽

Wenli Liu ◽

Zhixiong Hu ◽

Xiuyu Li ◽

Fei Li ◽

...

Keyword(s):

Quality Control ◽

Optical Coherence Tomography ◽

Rear Surface ◽

Glass Plate ◽

Three Dimensional ◽

Biological Tissues ◽

Optical Coherence ◽

Axial Resolution ◽

Single Filament ◽

Practical Tool

Optical coherence tomography (OCT) has been extensively used as noninvasive tool for biological tissues owing to its three-dimensional imaging ability and high axial resolution. OCT quality assurance is vital in these occasions to keep the reliability and accuracy in medical diagnosis. It is necessary to develop a calibration tool for OCT product manufacture, calibration, and quality control. A practical tool is demanded in the OCT quality control and calibration of OCT. So far, there is no such a practical tool that can test all the key parameters of OCT. We design and fabricate a model eye tool, which has this function. The model eye comprises a doublet lens, a single filament, a piece of glass plate and the microsphere-embedded phantom. The doublets lens is bonded by two pieces of planoconvex lenses in the plane position. The first lens focuses parallel light onto the rear surface of the second lens. The rear surface marked with concentric circles serves as retina to measure the angular field of view (FOV). The small flat surface on the peak of the second lens is used to test signal to noise ratio (SNR). The single filament with 125[Formula: see text][Formula: see text]m diameter is used to check the co-alignment of preview and OCT scan. The empty chamber between the small plane of the second lens and the first surface of glass plate is used to measure the depth scaling of the OCT. The microspheres of 1[Formula: see text][Formula: see text]m diameter distributed uniformly in the phantom, which can test the lateral and the axial resolution of OCT equipment. Experimental results are presented to show the validity of the proposed tool. It is shown that the tool is able to be used in the calibration and quality control of retinal OCT.

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EFFICIENT FITTING RANGE FOR GLUCOSE MEASUREMENT WITH OPTICAL COHERENCE TOMOGRAPHY

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545809000334 ◽

2009 ◽

Vol 02 (01) ◽

pp. 107-115

Author(s):

SHU FENG ◽

KEHONG YUAN ◽

DATIAN YE

Keyword(s):

Optical Coherence Tomography ◽

Monte Carlo ◽

Biological Tissues ◽

Scattering Coefficient ◽

Glucose Measurement ◽

Optical Coherence ◽

Non Invasive ◽

Tissue Simulating Phantoms

Studies of non-invasive glucose measurement with optical coherence tomography (OCT) in tissue-simulating phantoms and biological tissues show that glucose has an effect on the OCT signal slope. Choosing an efficient fitting range to calculate the OCT signal slope is important because it helps to improve the precision of glucose measurement. In this paper, we study the problem in two ways: (1) scattering-induced change of OCT signal slope versus depth in intralipid suspensions with different concentrations based on Monte Carlo (MC) simulations and experiments and (2) efficient fitting range for glucose measurement in 3% and 10% intralipid. The results show that the OCT signal slope expresses a contrary change with scattering coefficient below a certain depth in high intralipid concentrations, so that there is an effective fitting depth. With an efficient fitting range from 100 μm to the effective fitting depth, the precision of glucose measurement can be 4.4 mM for 10% intralipid and 2.2 mM for 3% intralipid.

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