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Development and characterization of tissue-mimicking phantom materials for photoacoustic imaging

Xu, Chen LU (2019) FYSM60 20191
Atomic Physics
Department of Physics
Abstract
Tissue-mimicking phantoms are of great interest in the development of bio-medical applications. Instead of applying to biological tissues directly, phantoms enable stable and easy accessibility to validate spectroscopy systems and measuring processes. This thesis project is centered on the development and characterization of phantoms.

The interaction between light and biological tissue is mainly characterized by the absorption and scattering coefficients. The propagation of light inside tissue can be described by the diffusion theory and Monte Carlo (MC) simulations. Spectroscopy methods such as the collimated transmission spectroscopy (CTS) and the photon time of flight spectroscopy (pToFs) were used to measure the optical properties... (More)
Tissue-mimicking phantoms are of great interest in the development of bio-medical applications. Instead of applying to biological tissues directly, phantoms enable stable and easy accessibility to validate spectroscopy systems and measuring processes. This thesis project is centered on the development and characterization of phantoms.

The interaction between light and biological tissue is mainly characterized by the absorption and scattering coefficients. The propagation of light inside tissue can be described by the diffusion theory and Monte Carlo (MC) simulations. Spectroscopy methods such as the collimated transmission spectroscopy (CTS) and the photon time of flight spectroscopy (pToFs) were used to measure the optical properties of the phantoms.

Previous research on phantom materials will be summarized. In particular, the styrene-ethylene/butylene-styrene (SEBS) copolymer was studied and used to produce oil-based phantoms for photoacoustic imaging (PAI). By adding oil-based colored ink and TiO2 to the gel mixture made with SEBS powder and paraffin oil, oil-based SEBS phantoms with tunable absorption and scattering coefficients were manufactured. Together with good time stability and easy reproducibility, test results from PAI showed that these SEBS phantoms were able to provide good image quality and depth resolution within the near infrared wavelength range. (Less)
Popular Abstract
Are you curious about why ink is black? Do you really know what the word "black" means? Have your ever thought of the reason why the sky looks blue? To answer all the questions from the aspect of optical spectroscopy, these phenomena can be explained by the interaction between light and matter. More specifically, ink is black because it has a high absorption coefficient over a broad wavelength band, so we see it as "black". The sky looks blue because it scatters the blue light more than the red light, since blue light has a shorter wavelength. The absorption process describes the ability to absorb light, while the scattering process describes how much light is scattered into other directions. Similar to these phenomena, the absorption and... (More)
Are you curious about why ink is black? Do you really know what the word "black" means? Have your ever thought of the reason why the sky looks blue? To answer all the questions from the aspect of optical spectroscopy, these phenomena can be explained by the interaction between light and matter. More specifically, ink is black because it has a high absorption coefficient over a broad wavelength band, so we see it as "black". The sky looks blue because it scatters the blue light more than the red light, since blue light has a shorter wavelength. The absorption process describes the ability to absorb light, while the scattering process describes how much light is scattered into other directions. Similar to these phenomena, the absorption and scattering processes of biological tissue are also of great interest. This thesis project, derived from the absorption and scattering processes, extends to many applications in bio-medical imaging.

Various spectroscopy techniques using optical light, ultrasound and other methods, have been developed for medical imaging. Before utilizing these imaging systems in real biological tissue, there should be standards for system control. Thus, phantoms are made to validate a imaging system. Rather than the phantoms in the opera, the word "phantom" refers to the artificial model mimicking the properties of real biological tissue. They are much safer and more economically and environmentally friendly than using real biological tissue in laboratory tryouts. This thesis project gives a summary of materials for phantoms with similar optical and acoustic properties as those of real tissue.

Another part of the thesis is centered on photoacoustic effects. When biological tissue is illuminated by laser light, the absorbed energy causes temperature rise and results in volume expansion and pressure change. However, the tissue will then be cooled down by exchanging heat with the surroundings and the pressure variation results in ultrasound emission. This ultrasound signal contains information of the tissue and can be collected and analyzed to reconstruct photoacoustic images. Photoacoustic imaging (PAI) is a promising method among medical imaging applications.

This thesis aims to make a deeper dive into medical imaging applications and pre-clinical diagnosis. Hopefully, a wide range of knowledge of bio-medical phantoms can be learned from this master thesis. (Less)
Please use this url to cite or link to this publication:
author
Xu, Chen LU
supervisor
organization
course
FYSM60 20191
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8981144
date added to LUP
2019-06-12 09:21:59
date last changed
2019-06-12 09:21:59
@misc{8981144,
  abstract     = {Tissue-mimicking phantoms are of great interest in the development of bio-medical applications. Instead of applying to biological tissues directly, phantoms enable stable and easy accessibility to validate spectroscopy systems and measuring processes. This thesis project is centered on the development and characterization of phantoms.

The interaction between light and biological tissue is mainly characterized by the absorption and scattering coefficients. The propagation of light inside tissue can be described by the diffusion theory and Monte Carlo (MC) simulations. Spectroscopy methods such as the collimated transmission spectroscopy (CTS) and the photon time of flight spectroscopy (pToFs) were used to measure the optical properties of the phantoms.

Previous research on phantom materials will be summarized. In particular, the styrene-ethylene/butylene-styrene (SEBS) copolymer was studied and used to produce oil-based phantoms for photoacoustic imaging (PAI). By adding oil-based colored ink and TiO2 to the gel mixture made with SEBS powder and paraffin oil, oil-based SEBS phantoms with tunable absorption and scattering coefficients were manufactured. Together with good time stability and easy reproducibility, test results from PAI showed that these SEBS phantoms were able to provide good image quality and depth resolution within the near infrared wavelength range.},
  author       = {Xu, Chen},
  language     = {eng},
  note         = {Student Paper},
  title        = {Development and characterization of tissue-mimicking phantom materials for photoacoustic imaging},
  year         = {2019},
}