scholarly journals Scattered and Fluorescent Photon Track Reconstruction in a Biological Tissue

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Maria N. Kholodtsova ◽  
Pavel V. Grachev ◽  
Tatiana A. Savelieva ◽  
Nina A. Kalyagina ◽  
Walter Blondel ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Biological Tissue ◽  
Tumor Location ◽  
Accurate Information ◽  
Track Reconstruction ◽  
Excitation Radiation ◽  
Probing Depth ◽  
Tissue Phantoms ◽  
Optical Probing ◽  
Fluorescent Radiation

Appropriate analysis of biological tissue deep regions is important for tumor targeting. This paper is concentrated on photons’ paths analysis in such biotissue as brain, because optical probing depth of fluorescent and excitation radiation differs. A method for photon track reconstruction was developed. Images were captured focusing on the transparent wall close and parallel to the source fibres, placed in brain tissue phantoms. The images were processed to reconstruct the photons most probable paths between two fibres. Results were compared with Monte Carlo simulations and diffusion approximation of the radiative transfer equation. It was shown that the excitation radiation optical probing depth is twice more than for the fluorescent photons. The way of fluorescent radiation spreading was discussed. Because of fluorescent and excitation radiation spreads in different ways, and the effective anisotropy factor,geff, was proposed for fluorescent radiation. For the brain tissue phantoms it were found to be0.62±0.05and0.66±0.05for the irradiation wavelengths 532 nm and 632.8 nm, respectively. These calculations give more accurate information about the tumor location in biotissue. Reconstruction of photon paths allows fluorescent and excitation probing depths determination. Thegeffcan be used as simplified parameter for calculations of fluorescence probing depth.

SIMULATION OF SINGLE CHANNEL BIOLOGICAL TISSUE SPECTROSCOPY USING COMSOL MULTIPHYSICS

2015 ◽  
Vol 77 (28) ◽  
Author(s):  
Azmi Abou Basaif ◽  
Nashrul Fazli Mohd Nasir ◽  
Zulkarnay Zakaria ◽  
Ibrahim Balkhis ◽  
Shazwani Sarkawi ◽  
...  
Keyword(s):  
Magnetic Induction ◽  
Biological Tissue ◽  
Single Channel ◽  
Medical Condition ◽  
Biological Tissues ◽  
Comsol Multiphysics ◽  
Accurate Information ◽  
Tissue Properties ◽  
Biological Soft Tissue

The enhanced ability to detect accurate location and measure the depth of a   metal inside a biological tissue is very useful in the assessment of medical condition and treatment. This manuscript proposed a solution via the measurement of the tissue properties using magnetic induction spectroscopy (MIS) method to describe the characterization of biological soft tissue. The objective of this study is to explore the viability of locating embedded metal inside a biological tissue by measuring the differences the biological tissue electrical properties using principle of Magnetic Induction Spectroscopy (MIS). Simulation is done using COMSOL Multiphysics software for accurate information on the involved parameters for both metal and biological tissues. Simulation has confirmed that MIS capable of detecting and locate embedded metal inside a biological tissue.

scholarly journals Absorption by water increases fluorescence image contrast of biological tissue in the shortwave infrared

2018 ◽  
Vol 115 (37) ◽  
pp. 9080-9085 ◽  
Author(s):  
Jessica A. Carr ◽  
Marianne Aellen ◽  
Daniel Franke ◽  
Peter T. C. So ◽  
Oliver T. Bruns ◽  
...  
Keyword(s):  
Penetration Depth ◽  
Fluorescence Imaging ◽  
Biological Tissue ◽  
Ex Vivo ◽  
Scattered Light ◽  
Image Contrast ◽  
Fluorescence Image ◽  
Tissue Phantoms ◽  
Shortwave Infrared

Recent technology developments have expanded the wavelength window for biological fluorescence imaging into the shortwave infrared. We show here a mechanistic understanding of how drastic changes in fluorescence imaging contrast can arise from slight changes of imaging wavelength in the shortwave infrared. We demonstrate, in 3D tissue phantoms and in vivo in mice, that light absorption by water within biological tissue increases image contrast due to attenuation of background and highly scattered light. Wavelengths of strong tissue absorption have conventionally been avoided in fluorescence imaging to maximize photon penetration depth and photon collection, yet we demonstrate that imaging at the peak absorbance of water (near 1,450 nm) results in the highest image contrast in the shortwave infrared. Furthermore, we show, through microscopy of highly labeled ex vivo biological tissue, that the contrast improvement from water absorption enables resolution of deeper structures, resulting in a higher imaging penetration depth. We then illustrate these findings in a theoretical model. Our results suggest that the wavelength-dependent absorptivity of water is the dominant optical property contributing to image contrast, and is therefore crucial for determining the optimal imaging window in the infrared.

Classification of Biological Spectrum Based on Principal Component Cluster Analysis

2012 ◽  
Vol 605-607 ◽  
pp. 2245-2248
Author(s):  
Lian Shun Zhang ◽  
Ai Juan Shi
Keyword(s):  
Cluster Analysis ◽  
Biological Tissue ◽  
Fiber Optic ◽  
Scatter Correction ◽  
Principal Component ◽  
Correction Method ◽  
Tissue Phantoms ◽  
Spectrum Feature ◽  
Biological Spectrum

Spectrums of 17 biological tissue phantoms were measured using the fiber-optic spectrometer. Then, the spectrum was preprocessed by multiplicative scatter correction method to devoice the spectrum. Afterwards the features of the spectrum were extracted via principal component analysis. Ultimately, we applied cluster analysis for the spectral features. The results showed that the accumulated credibility of the first 12 spectral principal components was 99.86% for the spectrum after preprocessing; indicating that this spectrum feature extraction might be done in the case of losing no key information. And the results showed that the 17 biological tissue phantoms can be divided into four main categories according their optical features.

Optical Fiber Device and Biological Tissue Phantoms for Determination of Optical Parameters in the Near‐Infrared Region

2004 ◽  
Vol 32 (5) ◽  
pp. 489-505 ◽  
Author(s):  
Omar Feix do Nascimento ◽  
Antonio Balbin Villaverde ◽  
Renato Amaro Zângaro ◽  
Marcos Tadeu Tavares Pacheco ◽  
Steven F. Durrant
Keyword(s):  
Optical Fiber ◽  
Biological Tissue ◽  
Near Infrared ◽  
Infrared Region ◽  
Optical Parameters ◽  
Tissue Phantoms ◽  
Near Infrared Region

Pre- and Postoperative Changes in Brain Tissue Surrounding a Meningioma

Neurosurgery ◽  
1988 ◽  
Vol 22 (5) ◽  
pp. 882-885 ◽  
Author(s):  
Susan Trittmacher ◽  
Horst Traupe ◽  
Anton Schmid
Keyword(s):  
Retrospective Study ◽  
Brain Tissue ◽  
Cerebral Edema ◽  
Tumor Size ◽  
Tumor Location ◽  
Intracranial Meningioma ◽  
Postoperative Changes

Abstract A retrospective study in 33 patients with intracranial meningioma demonstrates that two pathological mechanisms are involved in causing a hypodense area around the actual tumor: pressure-induced atrophy that persists after operation and true cerebral edema of unclear cause. The extent of the hypodense area is not related to tumor location or tumor size. A relationship between meningioma with a malignant tendency and the hemispheric spread of hypodensity can be observed.

Brain tissue phantoms for optical near infrared imaging

2005 ◽  
Vol 170 (4) ◽  
pp. 433-437 ◽  
Author(s):  
K. Prahlad Rao ◽  
S. Radhakrishnan ◽  
M. Ramasubba Reddy
Keyword(s):  
Brain Tissue ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Near Infrared Imaging ◽  
Tissue Phantoms

scholarly journals A composite hydrogel for brain tissue phantoms

2016 ◽  
Vol 112 ◽  
pp. 227-238 ◽  
Author(s):  
Antonio E. Forte ◽  
Stefano Galvan ◽  
Francesco Manieri ◽  
Ferdinando Rodriguez y Baena ◽  
Daniele Dini
Keyword(s):  
Brain Tissue ◽  
Composite Hydrogel ◽  
Tissue Phantoms

scholarly journals On the quantitative optical properties of Au nanoparticles embedded in biological tissue phantoms

2021 ◽  
Vol 114 ◽  
pp. 110924
Author(s):  
J.C.R. Araújo ◽  
A.F.G. Monte ◽  
R. Lora-Serrano ◽  
W. Iwamoto ◽  
A. Antunes ◽  
...  
Keyword(s):  
Optical Properties ◽  
Biological Tissue ◽  
Au Nanoparticles ◽  
Tissue Phantoms

scholarly journals Aberration correction in STED microscopy to increase imaging depth in living brain tissue

2021 ◽  
Author(s):  
Stéphane Bancelin ◽  
Luc Mercier ◽  
Emanuele Murana ◽  
Valentin Nägerl
Keyword(s):  
Brain Tissue ◽  
Adaptive Optics ◽  
Biological Tissue ◽  
Spatial Light Modulator ◽  
A Priori ◽  
Brain Slices ◽  
Fluorescent Nanoparticles ◽  
Light Modulator ◽  
Sted Microscopy ◽  
Imaging Depth

We demonstrate an approach based on adaptive optics to improve the spatial resolution of STED microscopy inside thick biological tissue by a priori correction of spherical aberrations as a function of imaging depth. We first measured the aberrations in a phantom sample of gold and fluorescent nanoparticles suspended in an agarose gel with a refractive index closely matching living brain tissue. Using a spatial light modulator to apply corrective phase shifts, we imaged neurons in living brain slices and show that the corrections can substantially increase image quality. Specifically, we could measure structures as small as 80 nm at a depth of 90 μm inside the biological tissue, and obtain a 60% signal increase after correction.

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