1
|
Francken N, Sanctorum J, Renders J, Paramonov P, Sijbers J, De Beenhouwer J. A Condensed History Approach to X-Ray Dark Field Effects in Edge Illumination Phase Contrast Simulations. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083284 DOI: 10.1109/embc40787.2023.10340826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
X-ray dark field signals, measurable in many x-ray phase contrast imaging (XPCI) setups, stem from unresolvable microstructures in the scanned sample. This makes them ideally suited for the detection of certain pathologies, which correlate with changes in the microstructure of a sample. Simulations of x-ray dark field signals can aid in the design and optimization of XPCI setups, and the development of new reconstruction techniques. Current simulation tools, however, require explicit modelling of the sample microstructures according to their size and spatial distribution. This process is cumbersome, does not translate well between different samples, and considerably slows down simulations. In this work, a condensed history approach to modelling x-ray dark field effects is presented, under the assumption of an isotropic distribution of microstructures, and applied to edge illumination phase contrast simulations. It substantially simplifies the sample model, can be easily ported between samples, and is two orders of magnitude faster than conventional dark field simulations, while showing equivalent results.Clinical relevance- Dark field signal provides information on the microstructure distribution within the investigated sample, which can be applied in areas such as histology and lung x-ray imaging. Efficient simulation tools for this dark field signal aid in optimizing scanning setups, acquisition schemes and reconstruction techniques.
Collapse
|
4
|
Sakata D, Kyriakou I, Okada S, Tran HN, Lampe N, Guatelli S, Bordage MC, Ivanchenko V, Murakami K, Sasaki T, Emfietzoglou D, Incerti S. Geant4-DNA track-structure simulations for gold nanoparticles: The importance of electron discrete models in nanometer volumes. Med Phys 2018; 45:2230-2242. [PMID: 29480947 DOI: 10.1002/mp.12827] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 01/17/2018] [Accepted: 02/03/2018] [Indexed: 01/15/2023] Open
Abstract
PURPOSE Gold nanoparticles (GNPs) are known to enhance the absorbed dose in their vicinity following photon-based irradiation. To investigate the therapeutic effectiveness of GNPs, previous Monte Carlo simulation studies have explored GNP dose enhancement using mostly condensed-history models. However, in general, such models are suitable for macroscopic volumes and for electron energies above a few hundred electron volts. We have recently developed, for the Geant4-DNA extension of the Geant4 Monte Carlo simulation toolkit, discrete physics models for electron transport in gold which include the description of the full atomic de-excitation cascade. These models allow event-by-event simulation of electron tracks in gold down to 10 eV. The present work describes how such specialized physics models impact simulation-based studies on GNP-radioenhancement in a context of x-ray radiotherapy. METHODS The new discrete physics models are compared to the Geant4 Penelope and Livermore condensed-history models, which are being widely used for simulation-based NP radioenhancement studies. An ad hoc Geant4 simulation application has been developed to calculate the absorbed dose in liquid water around a GNP and its radioenhancement, caused by secondary particles emitted from the GNP itself, when irradiated with a monoenergetic electron beam. The effect of the new physics models is also quantified in the calculation of secondary particle spectra, when originating in the GNP and when exiting from it. RESULTS The new physics models show similar backscattering coefficients with the existing Geant4 Livermore and Penelope models in large volumes for 100 keV incident electrons. However, in submicron sized volumes, only the discrete models describe the high backscattering that should still be present around GNPs at these length scales. Sizeable differences (mostly above a factor of 2) are also found in the radial distribution of absorbed dose and secondary particles between the new and the existing Geant4 models. The degree to which these differences are due to intrinsic limitations of the condensed-history models or to differences in the underling scattering cross sections requires further investigation. CONCLUSIONS Improved physics models for gold are necessary to better model the impact of GNPs in radiotherapy via Monte Carlo simulations. We implemented discrete electron transport models for gold in Geant4 that is applicable down to 10 eV including the modeling of the full de-excitation cascade. It is demonstrated that the new model has a significant positive impact on particle transport simulations in gold volumes with submicron dimensions compared to the existing Livermore and Penelope condensed-history models of Geant4.
Collapse
Affiliation(s)
- Dousatsu Sakata
- Univ. Bordeaux, CENBG, UMR 5797, Gradignan, France.,CNRS, IN2P3, CENBG, UMR 5797, Gradignan, France
| | - Ioanna Kyriakou
- Medical Physics Laboratory, University of Ioannina Medical School, Ioannina, Greece
| | - Shogo Okada
- Organization for Advanced and Integrated Research, Kobe University, Kobe, Japan
| | - Hoang N Tran
- Irfu, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
| | | | - Susanna Guatelli
- University of Wollongong, Centre For Medical Radiation Physics, Wollongong, Australia
| | - Marie-Claude Bordage
- INSERM, UMR1037 CRCT, Toulouse, France.,Université Toulouse III-Paul Sabatier, UMR1037 CRCT, Toulouse, France
| | - Vladimir Ivanchenko
- Geant4 Associates International Ltd, Hebden Bridge, UK.,Tomsk State University, Tomsk, Russia
| | | | | | | | - Sebastien Incerti
- Univ. Bordeaux, CENBG, UMR 5797, Gradignan, France.,CNRS, IN2P3, CENBG, UMR 5797, Gradignan, France
| |
Collapse
|
5
|
Vinckenbosch L, Lacaux C, Tindel S, Thomassin M, Obara T. Monte Carlo methods for light propagation in biological tissues. Math Biosci 2015; 269:48-60. [PMID: 26362232 DOI: 10.1016/j.mbs.2015.08.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 07/09/2015] [Accepted: 08/28/2015] [Indexed: 11/15/2022]
Affiliation(s)
- Laura Vinckenbosch
- Inria, BIGS, Villers-lès-Nancy, F-54600, France; Université de Fribourg, Département de Mathématiques, chemin du Musée 23, Fribourg CH-1700, Switzerland.
| | - Céline Lacaux
- Inria, BIGS, Villers-lès-Nancy, F-54600, France; Université de Lorraine, Institut Élie Cartan de Lorraine, UMR 7502, Vandœuvre-lès-Nancy, F-54506, France
| | - Samy Tindel
- Inria, BIGS, Villers-lès-Nancy, F-54600, France; Université de Lorraine, Institut Élie Cartan de Lorraine, UMR 7502, Vandœuvre-lès-Nancy, F-54506, France
| | - Magalie Thomassin
- Université de Lorraine, CRAN, UMR 7039, 9, avenue de la forêt de Haye, Vandœuvre-lès-Nancy, F-54516, France
| | - Tiphaine Obara
- Université de Lorraine, CRAN, UMR 7039, 9, avenue de la forêt de Haye, Vandœuvre-lès-Nancy, F-54516, France
| |
Collapse
|
6
|
Li D, Chen B, Ran WY, Wang GX, Wu WJ. Selection of voxel size and photon number in voxel-based Monte Carlo method: criteria and applications. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:095014. [PMID: 26417866 DOI: 10.1117/1.jbo.20.9.095014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 08/31/2015] [Indexed: 05/27/2023]
Abstract
The voxel-based Monte Carlo method (VMC) is now a gold standard in the simulation of light propagation in turbid media. For complex tissue structures, however, the computational cost will be higher when small voxels are used to improve smoothness of tissue interface and a large number of photons are used to obtain accurate results. To reduce computational cost, criteria were proposed to determine the voxel size and photon number in 3-dimensional VMC simulations with acceptable accuracy and computation time. The selection of the voxel size can be expressed as a function of tissue geometry and optical properties. The photon number should be at least 5 times the total voxel number. These criteria are further applied in developing a photon ray splitting scheme of local grid refinement technique to reduce computational cost of a nonuniform tissue structure with significantly varying optical properties. In the proposed technique, a nonuniform refined grid system is used, where fine grids are used for the tissue with high absorption and complex geometry, and coarse grids are used for the other part. In this technique, the total photon number is selected based on the voxel size of the coarse grid. Furthermore, the photon-splitting scheme is developed to satisfy the statistical accuracy requirement for the dense grid area. Result shows that local grid refinement technique photon ray splitting scheme can accelerate the computation by 7.6 times (reduce time consumption from 17.5 to 2.3 h) in the simulation of laser light energy deposition in skin tissue that contains port wine stain lesions.
Collapse
Affiliation(s)
- Dong Li
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| | - Bin Chen
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| | - Wei Yu Ran
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| | - Guo Xiang Wang
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, ChinabUniversity of Akron, Department of Mechanical Engineering, Akron, Ohio 44325-3903, United States
| | - Wen Juan Wu
- Xi'an Jiaotong University, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an 710049, China
| |
Collapse
|
7
|
Kalantzis G, Tachibana H. Accelerated event-by-event Monte Carlo microdosimetric calculations of electrons and protons tracks on a multi-core CPU and a CUDA-enabled GPU. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2013; 113:116-125. [PMID: 24113420 DOI: 10.1016/j.cmpb.2013.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 09/11/2013] [Accepted: 09/11/2013] [Indexed: 06/02/2023]
Abstract
For microdosimetric calculations event-by-event Monte Carlo (MC) methods are considered the most accurate. The main shortcoming of those methods is the extensive requirement for computational time. In this work we present an event-by-event MC code of low projectile energy electron and proton tracks for accelerated microdosimetric MC simulations on a graphic processing unit (GPU). Additionally, a hybrid implementation scheme was realized by employing OpenMP and CUDA in such a way that both GPU and multi-core CPU were utilized simultaneously. The two implementation schemes have been tested and compared with the sequential single threaded MC code on the CPU. Performance comparison was established on the speed-up for a set of benchmarking cases of electron and proton tracks. A maximum speedup of 67.2 was achieved for the GPU-based MC code, while a further improvement of the speedup up to 20% was achieved for the hybrid approach. The results indicate the capability of our CPU-GPU implementation for accelerated MC microdosimetric calculations of both electron and proton tracks without loss of accuracy.
Collapse
Affiliation(s)
- Georgios Kalantzis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, United States.
| | | |
Collapse
|