Computational Anthropomorphic Models of the Human Anatomy: The Path to Realistic Monte Carlo Modeling in Radiological Sciences

Zaidi, Habib; Xu, X. George

doi:10.1146/annurev.bioeng.9.060906.151934

Cited by 187 publications

(148 citation statements)

References 71 publications

Supporting

Mentioning

147

Contrasting

Unclassified

Order By: Relevance

“…Tomographic images reveal internal structures realistically, but time‐consuming segmentation and classification are necessary if the models are to be used for radiation transport calculations in a Monte Carlo code. Nearly 30 such tomographic models representing various ages and both sexes have been reported to date (23) . The International Commission on Radiological Protection has recommended a programmatic shift from stylized models to tomographic models in radiation protection dosimetry.…”

Section: Methodsmentioning

confidence: 99%

Development of a geometry‐based respiratory motion– simulating patient model for radiation treatment dosimetry

Zhang

Shi³

et al. 2008

J Applied Clin Med Phys

View full text Add to dashboard Cite

Temporal and spatial anatomic changes caused by respiration during radiation treatment delivery can lead to discrepancies between prescribed and actual radiation doses. The present paper documents a study to construct a respiratory‐motion‐simulating, four‐dimensional (4D) anatomic and dosimetry model for the study of the dosimetric effects of organ motion for various radiation treatment plans and delivery strategies. The non‐uniform rational B‐splines (NURBS) method has already been used to reconstruct a three‐dimensional (3D) VIP‐Man (“visible photographic man”) model that can reflect the deformation of organs during respiration by using time‐dependent equations to manipulate surface control points. The EGS4 (Electron Gamma Shower, version 4) Monte Carlo code is then used to apply the 4D model to dose simulation. We simulated two radiation therapy delivery scenarios: gating treatment and 4D image‐guided treatment. For each delivery scenario, we developed one conformal plan and one intensity‐modulated radiation therapy plan. A lesion in the left lung was modeled to investigate the effect of respiratory motion on radiation dose distributions. Based on target dose–volume histograms, the importance of using accurate gating to improve the dose distribution is demonstrated. The results also suggest that, during 4D image‐guided treatment delivery, monitoring of the patient's breathing pattern is critical. This study demonstrates the potential of using a “standard” motion‐simulating patient model for 4D treatment planning and motion management.PACS numbers: 87.53.Bn, 87.53.Kn, 87.53.Tf, 87.53.Wz, 87.57.Gg, 89.80.+h

show abstract

Section: Methodsmentioning

confidence: 99%

Development of a geometry‐based respiratory motion– simulating patient model for radiation treatment dosimetry

Zhang

Shi³

et al. 2008

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…The change in model representation methods (figure 5.1) is driven by the desire to modify and individualize phantoms while providing and maintaining anatomical accuracy. Detailed overviews of existing computational phantoms are provided by Zaidi and Xu (2007), Zaidi and Tsui (2009), and Xu and Eckerman (2009).…”

Section: Development Of Computational Phantomsmentioning

confidence: 99%

“…Many researchers have created computational phantoms over the past decades (Xu and Eckerman 2009;Zaidi and Tsui 2009;Zaidi and Xu 2007) for application in internal dosimetry, medical imaging simulation, radiotherapy and interventional radiology, and applications involving non-ionizing radiation. The main differences in computational phantoms are due to different requirements of the simulation (e.g.…”

Section: The Reference Man Paradigmmentioning

confidence: 99%

Personalised Body Counter Calibration Using Anthropometric Parameters

Pölz

Breustedt

2015

Radiat Prot Dosimetry

View full text Add to dashboard Cite

Zusammenfassung AbstractBody counting is a method for in vivo activity assessment applied to the monitoring of people with high risk of radionuclide incorporation. Energy-sensitive radiation detectors are arranged relative to the body to quantify radionuclide deposits in anatomical structures, such as lungs, liver and skeleton. This method depends on the specific detection system and is sensitive to the individual anatomy of the person. Accurate activity estimates, which are the basis for dose calculation, require extensive calibration procedures typically involving experimental measurements of anthropomorphic phantoms conforming to a reference person. Current calibration methods offer personalisation for lung and liver counting only with respect to body mass and height and do not specify uncertainties.This work revises and extends the currently applied personalisation methods using radiation transport simulation in combination with computational phantoms derived from medical imaging data. A framework was developed that allows computation of samples of calibration factors for various anatomies in standard measurement setups and anthropometric parameters quantifying anatomic properties. Those samples are applied to create statistical models to derive personalised calibration factors given specific values of anthropometric parameters measured on the person. This gives better estimates in activity assessment and, thereby, dose calculation while quantifying and reducing uncertainties.The framework was implemented in form of an abstract, modular data model, a software tool for modelling, simulation and evaluation of general body counting scenarios, and a statistical analysis method for correlating anthropometric parameters and calibration factors. This allows efficient and reproducible modelling for virtual measurement reconstruction as well as sensitivity analyses. The framework was applied to the calibration of the In Vivo Measurement Laboratory (IVM) at Karlsruhe Institute of Technology (KIT) comprising four freely arrangeable high-purity germanium detectors in lung, liver, knee and head measurement setups. Because of the interindividual anatomical variations in the applied phantoms and iv additional sensitivity analyses, it was possible to give estimates of the expected uncertainties and to reduce them through an algorithmically reproducible approach on calibration.

show abstract

“…Especially, voxel (volume pixel) phantoms have replaced the mathematical phantoms. 9) In addition, new technologies have been introduced for CT examinations to make accurate diagnosis. From these backgrounds, a new web-based system for clinical practice, named WAZA-ARI, is being developed to enable us to calculate organ doses more accurately than the previous systems and to acquire information about radiation dose to patients from CT examinations in Japan.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Organ Doses from Computed Tomography (CT) Examination by the Radiation Transport Calculation to Develop the Dosimetry System, WAZA-ARI

Takahashi

Endo

Sato

et al. 2011

Progress in Nuclear Science and Technology

View full text Add to dashboard Cite

A new dosimetry system, named WAZA-ARI, is being developed to assess organ doses of a patient in a Computed Tomography (CT) examination. A Japanese adult male voxel phantom (JM phantom) is applied to derive the basic data for dose assessment in WAZA-ARI. The JM phantom defines outer and inner configurations of the human body more precisely than mathematical human models, such as the MIRD-type phantom. The radiation transport in CT examination was simulated with the Particle and Heavy Ion Transport code System, PHITS. A subroutine in PHITS described a source model to simulate emission of photons in a CT machine. This study clarified the relationships between the organ doses and X-ray scanning on a human body with some geometrical conditions.

show abstract

Computational Anthropomorphic Models of the Human Anatomy: The Path to Realistic Monte Carlo Modeling in Radiological Sciences

Cited by 187 publications

References 71 publications

Development of a geometry‐based respiratory motion– simulating patient model for radiation treatment dosimetry

Development of a geometry‐based respiratory motion– simulating patient model for radiation treatment dosimetry

Personalised Body Counter Calibration Using Anthropometric Parameters

Analysis of Organ Doses from Computed Tomography (CT) Examination by the Radiation Transport Calculation to Develop the Dosimetry System, WAZA-ARI

Contact Info

Product

Resources

About