Development of PIMAL: Mathematical Phantom with Moving Arms and Legs

Akkurt, Hatice; Eckerman, K.F.

doi:10.2172/1339944

Cited by 21 publications

(11 citation statements)

References 7 publications

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“…The so-obtained `lung—water–bone segmentation' was the following: HU (−1000, −920), density 0.296 g cm −3 , lung; HU (−919, 156), density 1 g cm −3 , water; HU (157, 992), density 1.92 g cm −3 , bone. Lung density and composition were derived from the lung ORNL MIRD phantom (Akkurt et al 2007). Obviously in the case of patient dosimetry a correct segmentation would be implemented adequately assigning the lung properties to the correct HU range.…”

Section: Methodsmentioning

confidence: 99%

Use of the FLUKA Monte Carlo code for 3D patient-specific dosimetry on PET-CT and SPECT-CT images

et al. 2013

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Patient-specific absorbed dose calculation for nuclear medicine therapy is a topic of increasing interest. 3D dosimetry at the voxel level is one of the major improvements for the development of more accurate calculation techniques, as compared to the standard dosimetry at the organ level. This study aims to use the FLUKA Monte Carlo code to perform patient-specific 3D dosimetry through direct Monte Carlo simulation on PET-CT and SPECT-CT images. To this aim, dedicated routines were developed in the FLUKA environment. Two sets of simulations were performed on model and phantom images. Firstly, the correct handling of PET and SPECT images was tested under the assumption of homogeneous water medium by comparing FLUKA results with those obtained with the voxel kernel convolution method and with other Monte Carlo-based tools developed to the same purpose (the EGS-based 3D-RD software and the MCNP5-based MCID). Afterwards, the correct integration of the PET/SPECT and CT information was tested, performing direct simulations on PET/CT images for both homogeneous (water) and non-homogeneous (water with air, lung and bone inserts) phantoms. Comparison was performed with the other Monte Carlo tools performing direct simulation as well. The absorbed dose maps were compared at the voxel level. In the case of homogeneous water, by simulating 108 primary particles a 2% average difference with respect to the kernel convolution method was achieved; such difference was lower than the statistical uncertainty affecting the FLUKA results. The agreement with the other tools was within 3–4%, partially ascribable to the differences among the simulation algorithms. Including the CT-based density map, the average difference was always within 4% irrespective of the medium (water, air, bone), except for a maximum 6% value when comparing FLUKA and 3D-RD in air. The results confirmed that the routines were properly developed, opening the way for the use of FLUKA for patient-specific, image-based dosimetry in nuclear medicine.

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Section: Methodsmentioning

confidence: 99%

Use of the FLUKA Monte Carlo code for 3D patient-specific dosimetry on PET-CT and SPECT-CT images

et al. 2013

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“…Such methods exist presently for equation-based stylized anthropomorphic phantoms (Akkurt and Eckerman 2007; Olsher and Van Riper 2005). With hybrid phantoms, similar rearrangement of the extremities can be performed as demonstrated graphically in Fig.…”

Section: Discussionmentioning

confidence: 99%

Hybrid Computational Phantoms Representing the Reference Adult Male and Adult Female

Hurtado

Lee²,

Lodwick³

et al. 2012

Health Physics

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Currently, two classes of the computational phantoms have been developed for dosimetry calculation: (1) stylized (or mathematical) and (2) voxel (or tomographic) phantoms describing human anatomy through mathematical surface equations and 3D voxel matrices, respectively. Mathematical surface equations in stylized phantoms are flexible but the resulting anatomy is not as realistic. Voxel phantoms display far better anatomical realism, but they are limited in terms of their ability to alter organ shape, position, and depth, as well as body posture. A new class of computational phantoms - called hybrid phantoms - takes advantage of the best features of stylized and voxel phantoms - flexibility and anatomical realism, respectively. In the current study, hybrid computational phantoms representing the adult male and female reference anatomy and anthropometry are presented. These phantoms serve as the starting framework for creating patient or worker sculpted whole-body phantoms for retrospective dose reconstruction. Contours of major organs and tissues were converted or segmented from computed tomography images of a 36-year Korean volunteer and a 25-year U.S. female patient, respectively, with supplemental high-resolution CT images for the cranium. Polygon mesh models for the major organs and tissues were reconstructed and imported into Rhinoceros™ for non-uniform rational B-spline (NURBS) surface modeling. The resulting NURBS/polygon mesh models representing body contour and internal anatomy were matched to anthropometric data and reference organ mass data provided by Centers for Disease Control and Prevention (CDC) and International Commission on Radiation Protection (ICRP), respectively. Finally, two hybrid adult male and female phantoms were completed where a total of 8 anthropometric data categories were matched to standard values within 4% and organ volumes matched to ICRP data within 1% with the exception of total skin. The hybrid phantoms were voxelized from the NURBS phantoms at resolutions of 0.158 × 0.158 × 0.158 cm3 and 0.126 × 0.126 × 0.126 cm3 for the male and female, respectively. To highlight the flexibility of the hybrid phantoms, graphical displays are given of (1) underweight and overweight adult male phantoms, (2) a sitting position for the adult female phantom, and (3) extraction and higher-resolution voxelization of the small intestine for localized dosimetry of mucosal and stem cell layers. These phantoms are used to model radioactively contaminated individuals and to then assess time-dependent detector count rate thresholds corresponding to 50, 250, and 500 mSv effective dose, as might be needed during in-field radiological triage by first responders or first receivers.

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“…To simulate interactions of gamma rays with the human body, we need attenuation coefficients for each tissue. We calculated the attenuation coefficients using compositions and density of the tissues found in a web site of Life Sciences Division at Oak Ridge National Laboratory (ORNL), "Description of the mathematical phantoms" and (Akkurt H et al, 2007). Compositions and densities of soft tissue, skeleton, lung, adipose, and glandular tissue are available from "Description of the mathematical phantoms"; compositions of bone, muscle, skin, brain, eyes, thyroid, upper face, larynx, trachea, gastrointestinal tract, testes, ovaries, uterus, urinary bladder, spleen, heart, pancreas, liver, kidney, breast, and blood are available from (Akkurt H et al, 2007).…”

Section: Simulation With Numerical Human Modelmentioning

confidence: 99%

Applications to Development of PET/SPECT System by Use of Geant4

Hirano¹

2011

Applications of Monte Carlo Methods in Biology, Medicine and Other Fields of Science

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Development of PIMAL: Mathematical Phantom with Moving Arms and Legs

Cited by 21 publications

References 7 publications

Use of the FLUKA Monte Carlo code for 3D patient-specific dosimetry on PET-CT and SPECT-CT images

Use of the FLUKA Monte Carlo code for 3D patient-specific dosimetry on PET-CT and SPECT-CT images

Hybrid Computational Phantoms Representing the Reference Adult Male and Adult Female

Applications to Development of PET/SPECT System by Use of Geant4

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