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Improving the accuracy of the diffusion model in highly absorbing media.

Cong AX, Shen H, Cong W, Wang G - Int J Biomed Imaging (2007)

Bottom Line: It produces satisfactory results in weakly absorbing and highly scattering media, but the accuracy lessens with the decreasing albedo.The diffusion model behaves more closely to the physical model with the actual optical parameters substituted by the optimized optical parameters.The effectiveness of the proposed technique was demonstrated by the numerical experiments using the Monte Carlo simulation data as measurements.

View Article: PubMed Central - PubMed

Affiliation: Biomedical Imaging Division, School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, 1880 Pratt Drive, Blacksburg, VA 24061, USA.

ABSTRACT
The diffusion approximation of the Boltzmann transport equation is most commonly used for describing the photon propagation in turbid media. It produces satisfactory results in weakly absorbing and highly scattering media, but the accuracy lessens with the decreasing albedo. In this paper, we presented a method to improve the accuracy of the diffusion model in strongly absorbing media by adjusting the optical parameters. Genetic algorithm-based optimization tool is used to find the optimal optical parameters. The diffusion model behaves more closely to the physical model with the actual optical parameters substituted by the optimized optical parameters. The effectiveness of the proposed technique was demonstrated by the numerical experiments using the Monte Carlo simulation data as measurements.

No MeSH data available.


The finite element model of the heterogeneous phantom.
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Related In: Results  -  Collection


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fig4: The finite element model of the heterogeneous phantom.

Mentions: To further test the effectiveness of the proposed method, we constructed aheterogeneous phantom, as in Figure 4. The outer cylinder had a height of 20 mm and a radius of 10 mm. Thegeometrical center of the cylinder was at the origin. The inner sphere had a radius of 4 mm and its geometrical center was 2 mm away fromthe origin along the -axis. The absorption coefficient of the cylinder and the sphere were 0.2 and 0.35 mm−1, respectively. The reduced scattering coefficients were 1.05 mm−1 and the refractive indices were 1.37 for both media. The light source was placed at the center of the sphere. Using the optimized optical parameter in Table 2, the error wasreduced from 0.3951 to 0.2201.


Improving the accuracy of the diffusion model in highly absorbing media.

Cong AX, Shen H, Cong W, Wang G - Int J Biomed Imaging (2007)

The finite element model of the heterogeneous phantom.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2194801&req=5

fig4: The finite element model of the heterogeneous phantom.
Mentions: To further test the effectiveness of the proposed method, we constructed aheterogeneous phantom, as in Figure 4. The outer cylinder had a height of 20 mm and a radius of 10 mm. Thegeometrical center of the cylinder was at the origin. The inner sphere had a radius of 4 mm and its geometrical center was 2 mm away fromthe origin along the -axis. The absorption coefficient of the cylinder and the sphere were 0.2 and 0.35 mm−1, respectively. The reduced scattering coefficients were 1.05 mm−1 and the refractive indices were 1.37 for both media. The light source was placed at the center of the sphere. Using the optimized optical parameter in Table 2, the error wasreduced from 0.3951 to 0.2201.

Bottom Line: It produces satisfactory results in weakly absorbing and highly scattering media, but the accuracy lessens with the decreasing albedo.The diffusion model behaves more closely to the physical model with the actual optical parameters substituted by the optimized optical parameters.The effectiveness of the proposed technique was demonstrated by the numerical experiments using the Monte Carlo simulation data as measurements.

View Article: PubMed Central - PubMed

Affiliation: Biomedical Imaging Division, School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, 1880 Pratt Drive, Blacksburg, VA 24061, USA.

ABSTRACT
The diffusion approximation of the Boltzmann transport equation is most commonly used for describing the photon propagation in turbid media. It produces satisfactory results in weakly absorbing and highly scattering media, but the accuracy lessens with the decreasing albedo. In this paper, we presented a method to improve the accuracy of the diffusion model in strongly absorbing media by adjusting the optical parameters. Genetic algorithm-based optimization tool is used to find the optimal optical parameters. The diffusion model behaves more closely to the physical model with the actual optical parameters substituted by the optimized optical parameters. The effectiveness of the proposed technique was demonstrated by the numerical experiments using the Monte Carlo simulation data as measurements.

No MeSH data available.