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Juste B, Miró R, Campayo JM, Diez S, Verdú G. Linear Accelerator Photon Spectra Reconstruction Using a Mixed Experimental Monte Carlo Method. NUCL TECHNOL 2017. [DOI: 10.13182/nt09-a9281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- B. Juste
- Polytechnic University of Valencia Chemical and Nuclear Engineering Department, Camí de Vera s/n, Valencia 46022, Spain
| | - R. Miró
- Polytechnic University of Valencia Chemical and Nuclear Engineering Department, Camí de Vera s/n, Valencia 46022, Spain
| | - J. M. Campayo
- Hospital Clínic Universitari de Valencia Avda. Blasco Ibáñez, 17, Valencia 46010, Spain
| | - S. Diez
- Hospital Clínic Universitari de Valencia Avda. Blasco Ibáñez, 17, Valencia 46010, Spain
| | - G. Verdú
- Polytechnic University of Valencia Chemical and Nuclear Engineering Department, Camí de Vera s/n, Valencia 46022, Spain
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2
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Juste B, Miró R, Verdú G, Díez S, Campayo JM. Bremsstrahlung Spectrum Reconstruction from Gradient Depth Dose Curves Obtained in a Water Phantom. NUCL TECHNOL 2017. [DOI: 10.13182/nt11-a12287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- B. Juste
- Universitat Politècnica de València, Institute for Industrial, Radiophysical and Environmental Safety, Camí de Vera, s/n Valencia, 46022, Spain
| | - R. Miró
- Universitat Politècnica de València, Institute for Industrial, Radiophysical and Environmental Safety, Camí de Vera, s/n Valencia, 46022, Spain
| | - G. Verdú
- Universitat Politècnica de València, Institute for Industrial, Radiophysical and Environmental Safety, Camí de Vera, s/n Valencia, 46022, Spain
| | - S. Díez
- Hospital Clínic Universitari de Valencia, Avda, Blasco Ibáñez 17, 46010, Valencia, Spain
| | - J. M. Campayo
- Hospital Clínic Universitari de Valencia, Avda, Blasco Ibáñez 17, 46010, Valencia, Spain
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Juste B, Miró R, Verdú G, Díez S, Campayo JM. Neutron activation processes simulation in an Elekta medical linear accelerator head. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:3026-8. [PMID: 25570628 DOI: 10.1109/embc.2014.6944260] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Monte Carlo estimation of the giant-dipole-resonance (GRN) photoneutrons inside the Elekta Precise LINAC head (emitting a 15 MV photon beam) were performed using the MCNP6 (general-purpose Monte Carlo N-Particle code, version 6). Each component of LINAC head geometry and materials were modelled in detail using the given manufacturer information. Primary photons generate photoneutrons and its transport across the treatment head was simulated, including the (n, γ) reactions which undergo activation products. The MCNP6 was used to develop a method for quantifying the activation of accelerator components. The approach described in this paper is useful in quantifying the origin and the amount of nuclear activation.
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Juste B, Miró R, Verdú G, Díez S, Campayo JM. Neutron distribution and induced activity inside a Linac treatment room. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2015:6896-6899. [PMID: 26737878 DOI: 10.1109/embc.2015.7319978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Induced radioactivity and photoneutron contamination inside a radiation therapy bunker of a medical linear accelerator (Linac) is investigated in this work. The Linac studied is an Elekta Precise electron accelerator which maximum treatment photon energy is 15 MeV. This energy exceeds the photonuclear reaction threshold (around 7 MeV for high atomic number metals). The Monte Carlo code MCNP6 has been used for quantifying the neutron contamination inside the treatment room for different gantry rotation configuration. Walls activation processes have also been simulated. The approach described in this paper is useful to prevent the overexposure of patients and medical staff.
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Juste B, Miró R, Jambrina A, Díez S, Campayo JM, Santos A, Verdú G. Comparison between transmission and scattering spectrum reconstruction methods based on EPID images. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2013:1640-1643. [PMID: 24110018 DOI: 10.1109/embc.2013.6609831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Numerous improved physics-based methods for Linac photon spectra reconstruction have been published; some of them are based on transmission data analysis and others on scattering data. In this work, the two spectrum unfolding approaches are compared in order to experimentally validate its robustness and to determine which is the optimal methodology for application on a clinical quality assurance routine. Both studied methods are based on EPID images generated when the incident photon beam impinges onto plastic blocks. The distribution of transmitted/scatter radiation produced by this object centered at the beam field size was measured. Measurements were performed using a 6 MeV photon beam produced by the linear accelerator. The same radiation distribution conditions were also simulated with Monte Carlo code for a series of monoenergetic identical geometry photon beams for both cases. Two systems of linear equations were generated to combine the polyenergetic EPID measurements with the monoenergetic simulation results. Regularization techniques were applied to solve the systems for obtaining the incident photon spectrum. We present a comparison between the well-known photon Spectral Reconstruction based on Transmission Data (Trans-based) technology and the Spectral Reconstruction based on Scattering Data (Scatt-based), which we both developed using EPID images. It is shown that Trans-based reconstruction results display much better agreement with photon spectrum theoretical predictions.
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Juste B, Miró R, Morera D, Díez S, Campayo JM, Verdú G. MCNP5 Monte Carlo simulation of amorphous silicon EPID dosimetry from MLC radiation therapy treatment beams. Annu Int Conf IEEE Eng Med Biol Soc 2012; 2012:5786-5789. [PMID: 23367244 DOI: 10.1109/embc.2012.6347309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The present work is focused on a MCNP Monte Carlo (MC) simulation of a multi-leaf collimator (MLC) radiation therapy treatment unit including its corresponding Electronic Portal Imaging Device (EPID). We have developed a methodology to perform a spatial calibration of the EPID signal to obtain dose distribution using MC simulations. This calibration is based on several images acquisition and simulation considering different thicknesses of solid water slabs, using a 6 MeV photon beam and a square field size of 20 cm x 20 cm. The resulting relationship between the EPID response and the MC simulated dose is markedly linear. This signal to dose EPID calibration was used as a dosimetric tool to perform the validation of the MLC linear accelerator MCNP model. Simulation results and measurements agreed within 2% of dose difference. The methodology described in this paper potentially offers an optimal verification of dose received by patients under complex multi-field conformal or intensity-modulated radiation therapy (IMRT).
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Affiliation(s)
- B Juste
- The Institute for Industrial, Radiophysical and Environmental Safety (ISIRYM), Polytechnic University of Valencia, Valencia, Spain.
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Mayo P, Rodenas F, Campayo JM, Marín B, Verdú G. Quality Assurance Applied to Digital Radiographic Equipment by Developed Software for Phantom Images. NUCL TECHNOL 2011. [DOI: 10.13182/nt11-a12268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- P. Mayo
- Titania Servicios Tecnologicos, Sorolla Center, local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - F. Rodenas
- Universidad Politécnica de Valencia, Departamento de Matemáticas Camino de Vera s/n, 46022, Valencia, Spain
| | - J. M. Campayo
- Hospital Clínico Universitario de Valencia, Avda. Blasco Ibañez, No. 17 46017, Valencia, Spain
| | - B. Marín
- Universidad Politécnica de Valencia, Departamento de Ingeniería Química y Nuclear Camino de Vera s/n, 46022, Valencia, Spain
| | - G. Verdú
- Universidad Politécnica de Valencia, Departamento de Ingeniería Química y Nuclear Camino de Vera s/n, 46022, Valencia, Spain
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Juste B, Miró R, Verdú G, Díez S, Campayo JM. 6 and 15 MeV photon spectra reconstruction using an unfolding depth dose gradient methodology. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2011:129-132. [PMID: 22254267 DOI: 10.1109/iembs.2011.6089869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An accurate knowledge of the spectral distribution emission is essential for precise dose calculations in radiotherapy treatment planning. Reconstruction of photon spectra emitted by medical accelerators from measured depth dose distributions in a water cube is an important tool for commissioning a Monte Carlo treatment planning system. However, the reconstruction problem is an inverse radiation transport function which is poorly conditioned and its solution may become unstable due to small perturbations in the input data. In this paper we present a more stable spectral reconstruction method which can be used to provide an independent confirmation of source models for a given machine without any prior knowledge of the spectral distribution. This technique involves measuring the depth dose curve in a water phantom and applying an unfolding method using Monte Carlo simulated depth dose gradient curves for consecutives mono-energetic beams. We illustrate this theory to calculate a 6 and a 15 MeV photon beam emitted from an Elekta Precise radiotherapy unit using the gradient of depth dose curves in a cube-shaped water tank.
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Affiliation(s)
- B Juste
- Chemical and Nuclear Engineering Department, Polytechnic University of Valencia, Camí de Vera, Valencia, Spain.
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Mayo P, Ródenas F, Verdu G, Campayo JM, Gallardo S. Analysis of image quality parameter of conventional and dental radiographic digital images. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2010:3174-3177. [PMID: 21096597 DOI: 10.1109/iembs.2010.5627182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The image quality obtained by a radiographic equipment is very useful to characterize the physical properties of the image radiographic chain, in a quality control of the radiographic equipment. In the radiographic technique it is necessary that the evaluation of the image can guarantee the constancy of its quality to carry out a suitable diagnosis. In this work we have designed some radiographic phantoms for different radiographic digital devices, as dental, conventional, equipments with computed radiography (phosphor plate) and direct radiography (sensor) technology. Additionally, we have developed a software to analyse the image obtained by the radiographic equipment with digital processing techniques, as edge detector, morphological operators, statistical test for the detected combinations‥ The design of these phantoms let the evaluation of a wide range of operating conditions of voltage, current and time of the digital equipments. Moreover, the image quality analysis by the automatic software, let study it with objective parameters.
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Affiliation(s)
- P Mayo
- Titania S.T. Sorolla Center, Avda. de las Cortes Valencianas, 58- 46015, Valencia, Spain
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Juste B, Miró R, Verdu G, Diez S, Campayo JM. Electron influence on the reconstruction of a linac 6 MeV photon spectra by unfolding methods. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2010:577-580. [PMID: 21095887 DOI: 10.1109/iembs.2010.5626399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Megavoltage photon sources are normally used for radiotherapy treatments. For these equipments an accurate knowledge of their spectral distribution is essential for accurate dose calculations planning. There are several ways to determine the spectrum of a clinical photon beam: direct measurement, electron source modelling or reconstruction from experimental measures. In this paper we focus on the latter type of spectral reconstruction methods which can be used to provide an independent confirmation of source models for a given machine without any prior knowledge of the spectral distribution. This technique involves measuring the depth dose curve in a water phantom and applying an unfolding method using Monte Carlo simulated depth dose curves for consecutives mono-energetic beams. We illustrate this theory to calculate a 6 MeV photon beam from an Elekta Precise radiotherapy unit using the gradient of depth dose measurements in a cube-shaped water tank.
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Affiliation(s)
- B Juste
- Chemical and Nuclear Engineering Department at the Polytechnic University of Valencia, Camí de Vera s/n 46022, Spain.
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Mayo P, Rodenas F, Campayo JM, Pascual A, Marín B, Verdú G. Image Quality Assessment of Digital Dental Radiography Systems with Specifically Developed Phantom and Software. NUCL TECHNOL 2009. [DOI: 10.13182/nt09-a9133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- P. Mayo
- Titania ST, Grupo Dominguis, Sorolla Center local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - F. Rodenas
- Universidad Politécnica de Valencia Departamento de Matemáticas, Camino de Vera s/n, 46022, Valencia, Spain
| | - J. M. Campayo
- UTPR Lainsa, Grupo Dominguis Sorolla Center, local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - A. Pascual
- UTPR Lainsa, Grupo Dominguis Sorolla Center, local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - B. Marín
- Universidad Politécnica de Valencia Departamento de Ingeniería Química y Nuclear, Camino de Vera s/n 46022, Valencia, Spain
| | - G. Verdú
- Universidad Politécnica de Valencia Departamento de Ingeniería Química y Nuclear, Camino de Vera s/n 46022, Valencia, Spain
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Mayo P, Rodenas F, Campayo JM, Pascual A, Marín B, Verdú G. Phantom Development for Constancy and Acceptance Test for Digital Radiographic Equipment. NUCL TECHNOL 2009. [DOI: 10.13182/nt09-a9132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- P. Mayo
- Titania ST, Grupo Dominguis, Sorolla Center local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - F. Rodenas
- Universidad Politécnica de Valencia, Departamento de Matemáticas Camino de Vera s/n, 46022, Valencia, Spain
| | - J. M. Campayo
- UTPR Lainsa, Grupo Dominguis Sorolla Center, local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - A. Pascual
- UTPR Lainsa, Grupo Dominguis Sorolla Center, local 10, Avda. de las Cortes Valencianas, No. 58, 46015, Valencia, Spain
| | - B. Marín
- Universidad Politécnica de Valencia Departamento de Ingeniería Quémica y Nuclear, Camino de Vera s/n 46022, Valencia, Spain
| | - G. Verdú
- Universidad Politécnica de Valencia Departamento de Ingeniería Quémica y Nuclear, Camino de Vera s/n 46022, Valencia, Spain
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Mayo P, Rodenas F, Verdú G, Campayo JM, Villaescusa JI. Analysis of digital image quality indexes for CIRS SP01 and CDMAM 3.4 mammographic phantoms. Annu Int Conf IEEE Eng Med Biol Soc 2009; 2008:418-21. [PMID: 19162682 DOI: 10.1109/iembs.2008.4649179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mammographic phantom images are usually used to study the quality of images obtained by determined mammographic equipment. The digital image treatment techniques allow carrying out an automatic analysis of the phantom image. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. In this work we apply some techniques of digital image processing to compute a specific image quality indexes for mammographic phantoms, namely CIRS SP01 and CDMAM 3.4. to study the evolution of this parameter with different varying conditions of the mammographic equipment. The indexes are calculated from a scoring system based on a designed algorithm which analyses the phantom image by means of an automatic detection of the test objects in each phantom.
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Affiliation(s)
- P Mayo
- ISIRYM, Institute for Industrial, Radiophysical and Environment Safety, Universidad Politécnica de Valencial, and Hospital Clinico de Valencia, Camino de Vera, s/n. 46022, Valencia, Spain
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Juste B, Miro R, Diez S, Campayo JM, Verdu G. Dosimetric capabilities of the Iview GT portal imager using MCNP5 Monte Carlo simulations. Annu Int Conf IEEE Eng Med Biol Soc 2009; 2009:3743-3746. [PMID: 19965234 DOI: 10.1109/iembs.2009.5334899] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This work is focused on developing a methodology to obtain portal dosimetry with an amorphous silicon Electronic Portal Image Device (a-Si EPID) used in radiotherapy by means of Monte Carlo simulations and experimental measures. Pixel intensity values from portal images have been compared with dose measured from an ionization chamber and dose calculated from Monte Carlo simulations. To this end, several images were acquired with the Elekta iView GT EPID using an attenuator phantom slab (10 cm thickness of solid water) and a 6 MeV photon energy beam with different monitor units settings (MU). The average pixel value in a region of interest (ROI) centered at the beam for each image was extracted and compared to dose measures performed with an ionization chamber. These parameters were found to be linearly related with the number of monitor units. Since MCNP5 simulations allow calculating the deposited dose in the ROI within the phosphor layer of the EPID model, we could compare the portal dose with the simulated transit dose in order to perform a treatment control.
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Affiliation(s)
- B Juste
- Chemical and Nuclear Engineering Department at the Polytechnic University of Valencia, Spain.
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Juste B, Miro R, Campayo JM, Diez S, Verdu G. Photon spectra calculation for an Elekta linac beam using experimental scatter measurements and Monte Carlo techniques. Annu Int Conf IEEE Eng Med Biol Soc 2008; 2008:3289-3292. [PMID: 19163410 DOI: 10.1109/iembs.2008.4649907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The present work is centered in reconstructing by means of a scatter analysis method the primary beam photon spectrum of a linear accelerator. This technique is based on irradiating the isocenter of a rectangular block made of methacrylate placed at 100 cm distance from surface and measuring scattered particles around the plastic at several specific positions with different scatter angles. The MCNP5 Monte Carlo code has been used to simulate the particles transport of mono-energetic beams to register the scatter measurement after contact the attenuator. Measured ionization values allow calculating the spectrum as the sum of mono-energetic individual energy bins using the Schiff Bremsstrahlung model. The measurements have been made in an Elekta Precise linac using a 6 MeV photon beam. Relative depth and profile dose curves calculated in a water phantom using the reconstructed spectrum agree with experimentally measured dose data to within 3%.
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Affiliation(s)
- B Juste
- Chemical and Nuclear Engineering Department at the Polytechnic University of Valencia, Spain.
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Mayo P, Rodenas F, Verdú G, Campayo JM, Villaescusa JI. Study of digital mammographic equipments by phantom image quality. Conf Proc IEEE Eng Med Biol Soc 2007; 2006:1994-6. [PMID: 17946081 DOI: 10.1109/iembs.2006.259245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast-detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is CDMAM 3.4. One of the most extended indexes to measure the image quality in an objective way is the image quality figure (IQF). The aim of this work is to study the image quality of different images contrast-detail phantom CDMAM 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments that facilitates the evaluation of image contrast and detail resolution.
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Affiliation(s)
- P Mayo
- Chem. & Nucl. Eng. Dept., Univ. Politecnica de Valencia
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17
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Ramos M, Ferrer S, Villaescusa JI, Verdu G, Campayo JM. Monte Carlo image reconstruction of a mammographic phantom. Conf Proc IEEE Eng Med Biol Soc 2007; 2004:1467-70. [PMID: 17271972 DOI: 10.1109/iembs.2004.1403452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The aim of this study is the development of a methodology to reconstruct via Monte Carlo techniques the radiographic image of the CIRS 11 A (MAMMO PHANTOM SP01) phantom. This phantom is used in image quality assessment during quality control tests in breast screening locations and other health centers. The mammographic phantom is comprised of a reference point, a glandular tissue step wedge, contrast and resolution targets, and groups of microcalcifications and fibers. The MCNP radiation transport code (version 4c2) has been modified and recompiled to let use of a large number of tallies and detectors per input file, and an azimuthal directional source biasing. The output surface air kerma (OSAK) delivered by the X-rays has been scored employing a rectangular matrix of point detectors (F5 tally) under the phantom, simulating the image system. Some variance reduction techniques have been implemented to ensure that photons reach the detectors and that weight fluctuations were reduced. The characteristic curve of the film-scanner imaging system combination has been obtained throughout several experimental measures with an aluminium sensitometric wedge and Monte Carlo simulations. The reconstructed images agree with the range of values, indicating that this method would be suitable for training purposes, phantom designing or dose calculations.
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Affiliation(s)
- M Ramos
- Dept. of Chem. & Nucl. Eng., Univ. Politecnica de Valencia, Spain
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Sancho M, Arnal JM, Villaescusa JI, Campayo JM, Verdú G. Declassification of radioactive liquid wastes generated in radio immune assay [corrected] (RIA) laboratories. Radiat Prot Dosimetry 2005; 116:518-20. [PMID: 16604690 DOI: 10.1093/rpd/nci076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Radioactive liquid wastes of low-medium activity level are generated in radio immune assay (RIA) laboratories, which are also potentially infectious because of the pathogens from patient blood. The most common way of managing these wastes consists of a temporal storage, for partial radioactivity decay, followed by management by an authorised company. The object of this work is to study the viability of treating radioactive liquid wastes coming from RIA using membrane techniques in order to reduce their volume, which would mean an improvement from the radiological point of view and a decrease in management costs. This paper describes the results of some experiments carried out with RIA real wastes, by means of processes such as ultrafiltration and reverse osmosis. It has been proved that waste volume can be significantly reduced, obtaining a treated liquid that is free of pathogens and organic matter and with an activity level around the environmental background.
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Affiliation(s)
- M Sancho
- Chemical and Nuclear Engineering Department, Polytechnic University of Valencia Camino de Vera, s/n, 46022 Valencia, Spain.
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Abstract
A Theratron 780 (MDS Nordion) 60Co radiotherapy unit has been simulated with the Monte Carlo code MCNP. The unit has been realistically modelled: the cylindrical source capsule and its housing, the rectangular collimator system, both the primary and secondary jaws and the air gaps between the components. Different collimator openings, ranging from 5 x 5 cm2 to 20 x 20 cm2 (narrow and broad beams) at a source-surface distance equal to 80 cm have been used during the study. In the present work, we have calculated spectra as a function of field size. A study of the variation of the electron contamination of the 60Co beam has also been performed.
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Affiliation(s)
- R Miró
- Departamento de Ingeniería Química y Nuclear, Universidad Politécnica de València, Camí de Vera, s/n, 46022 València, Spain.
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Mayo P, Rodenas F, Verdú G, Villaescusa JI, Campayo JM. A comparative study of computer assisted assessment of image quality index for mammographic phantom images. Radiat Prot Dosimetry 2005; 116:620-3. [PMID: 16604712 DOI: 10.1093/rpd/nci222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Mammographic phantom images are usually used to study the quality of images obtained by dedicated mammographic equipment. The digital image treatment techniques allow us to carry out an automatic analysis of the phantom image. In this work, some techniques of digital image processing are applied to compute a specific image quality index (IQI) for a mammographic phantom, namely CIRS model 11A version SP01. The algorithm designed analyses the phantom image by means of automatic detection of the number of microcalcifications, and the image resolution as the number of line pairs per millimetre. Then, the IQI is calculated from a scoring system. The manner in which the functioning conditions (kV and mAs) of the mammographic equipment and the preprocessing denoising method of the digital image affect the results for the IQI are also studied.
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Affiliation(s)
- P Mayo
- Chemical and Nuclear Engineering Department, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia, Spain
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Mayo P, Rodenas F, Verdú G, Villaescusa JI, Campayo JM. Automatic evaluation of the image quality of a mammographic phantom. Comput Methods Programs Biomed 2004; 73:115-128. [PMID: 14757255 DOI: 10.1016/s0169-2607(03)00023-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this work a method has been developed to analyse the digital image quality of a mammographic phantom by means of automatic process techniques. The techniques used for the digital image treatment are standard techniques as the image thresholding to detect objects, the regional growing for pixels pooling and the morphological operator application to determine the objects shape and size, etc. This study allows the obtention of information about the phantom characteristics, that due to its small size and lowly contrast can be obtained very difficultly by direct observation. The final aim of this work is to obtain one or more parameters to characterize the reference phantom quality image in an objective way. These parameters will serve to compare images obtained at different mammographic centers and also, to study the temporal evolution of the image quality produced by determined mammographic equipment.
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Affiliation(s)
- P Mayo
- Dpto. Ingenieri;a Qui;mica y Nuclear, Universidad Politécnica de Valencia, Valencia, Spain.
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