The Monte Carlo code MCML(Monte Carlo modeling of light transport in multi-layered tissue)has been the gold standard for simulations of light transport in multi-layer tissue,but it is ineffective in the presence of th...The Monte Carlo code MCML(Monte Carlo modeling of light transport in multi-layered tissue)has been the gold standard for simulations of light transport in multi-layer tissue,but it is ineffective in the presence of three-dimensional(3D)heterogeneity.New techniques have been attempted to resolve this problem,such as MCLS,which is derived from MCML,and tMCimg,which draws upon image datasets.Nevertheless,these approaches are insufficient because of their low precision or simplistic modeling.We report on the development of a novel model for photon migration in voxelized media(MCVM)with 3D heterogeneity.Voxel crossing detection and refractive-index-unmatched boundaries were considered to improve the precision and eliminate dependence on refractive-index-matched tissue.Using a semi-infinite homogeneous medium,steady-state and time-resolved simulations of MCVM agreed well with MCML,with high precision(∼100%)for the total diffuse reflectance and total fractional absorption compared to those of tMCimg(<70%).Based on a refractive-index-matched heterogeneous skin model,the results of MCVM were found to coincide with those of MCLS.Finally,MCVM was applied to a two-layered sphere with multi-inclusions,which is an example of a 3D heterogeneous media with refractive-index-unmatched boundaries.MCVM provided a reliable model for simulation of photon migration in voxelized 3D heterogeneous media,and it was developed to be a flexible and simple software tool that delivers high-precision results.展开更多
To provide a computational efficient forward model with moderate accuracy for rapid 3D optical tomography in small volumes,radiative transport in the delta-P1 approximation combined with the approximation of the recip...To provide a computational efficient forward model with moderate accuracy for rapid 3D optical tomography in small volumes,radiative transport in the delta-P1 approximation combined with the approximation of the reciprocity was examined.Perturbations of optical signals caused by absorption and fluorescence heterogeneities submerged in a resin-based liquid phantom with background parameters close to rat brain tissues were measured using a recently constructed laminar optical tomography system.These measured perturbations were used to examine the theoretically calculated fluence perturbations based on the delta-P1 approximation and the reciprocity approximation.Results show that the errors between the predicted and measured data are acceptable,especially for fluorescence perturbations.展开更多
基金This research was supported by the National Natural Science Foundation of China(Grant No.30727002)the National High-Tech R&D Program of China(2006AA020801)111 project,and the Program for Changjiang Scholars and Innovative Research Team in University.
文摘The Monte Carlo code MCML(Monte Carlo modeling of light transport in multi-layered tissue)has been the gold standard for simulations of light transport in multi-layer tissue,but it is ineffective in the presence of three-dimensional(3D)heterogeneity.New techniques have been attempted to resolve this problem,such as MCLS,which is derived from MCML,and tMCimg,which draws upon image datasets.Nevertheless,these approaches are insufficient because of their low precision or simplistic modeling.We report on the development of a novel model for photon migration in voxelized media(MCVM)with 3D heterogeneity.Voxel crossing detection and refractive-index-unmatched boundaries were considered to improve the precision and eliminate dependence on refractive-index-matched tissue.Using a semi-infinite homogeneous medium,steady-state and time-resolved simulations of MCVM agreed well with MCML,with high precision(∼100%)for the total diffuse reflectance and total fractional absorption compared to those of tMCimg(<70%).Based on a refractive-index-matched heterogeneous skin model,the results of MCVM were found to coincide with those of MCLS.Finally,MCVM was applied to a two-layered sphere with multi-inclusions,which is an example of a 3D heterogeneous media with refractive-index-unmatched boundaries.MCVM provided a reliable model for simulation of photon migration in voxelized 3D heterogeneous media,and it was developed to be a flexible and simple software tool that delivers high-precision results.
文摘To provide a computational efficient forward model with moderate accuracy for rapid 3D optical tomography in small volumes,radiative transport in the delta-P1 approximation combined with the approximation of the reciprocity was examined.Perturbations of optical signals caused by absorption and fluorescence heterogeneities submerged in a resin-based liquid phantom with background parameters close to rat brain tissues were measured using a recently constructed laminar optical tomography system.These measured perturbations were used to examine the theoretically calculated fluence perturbations based on the delta-P1 approximation and the reciprocity approximation.Results show that the errors between the predicted and measured data are acceptable,especially for fluorescence perturbations.
