González Martínez, Antonio Javier

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2007 - 200912010 - 202020
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Autor: Vidal San Sebastián, Luis Fernando ×

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    Detector blockbased on arrays of 144 SiPMs and monolithic scintillators: A performane study
    (Elsevier, 2015-07-01) González Martínez, Antonio Javier; Conde Castellanos, Pablo Eloy; Iborra Carreres, Amadeo; Aguilar, A.; Bellido, P.; Garcia-Olcina, R.; Hernández Hernández, Liczandro; Moliner Martínez, Laura; Rigla, J. P.; Rodríguez Álvarez, María José; Sánchez, F; Seimetz, Michael; Soriano Asensi, Antonio; Torres, Jose; Vidal San Sebastián, Luis Fernando; Benlloch Baviera, Jose María; Departamento de Matemática Aplicada; Escuela Técnica Superior de Ingeniería Informática; Instituto de Instrumentación para Imagen Molecular; European Regional Development Fund; Consejo Superior de Investigaciones Científicas
    [EN] We have developed a detector block composed by a monolithic LYSO scintillator coupled to a custom made 12 12 SiPMs array. The design is mainly focused to applications such as Positron Emission Tomography. The readout electronics is based on 3 identical and scalable Application Specific Integrated Circuits (ASIC). We have determined the main performance of the detector block namely spatial, energy, and time resolution but also the system capability to determine the photon depth of interaction, for different crystal surface treatments. Intrinsic detector spatial resolution values as good as 1.7 mm FWHM and energies of 15% for black painted crystals were measured. & 2014 Elsevier B.V. All rights reserved.
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    Pilot performance of a dedicated prostate PET suitable for diagnosis and biopsy guidance
    (SpringerOpen (part of Springer Nature), 2020-06-05) Cañizares-Ledo, Gabriel; Gonzalez-Montoro, Andrea; Freire, Marta; Lamprou, Efthymios; Barrio, John; Sánchez Martínez, Filomeno; Benlloch Baviera, Jose María; Hernandez, Liczandro; Moliner Martínez, Laura; Vidal San Sebastián, Luis Fernando; Torres, Irene; Sopena, Pablo; Vera-Donoso, Cesar D.; Bello, Pilar; Barbera, Julio; González Martínez, Antonio Javier; Instituto de Instrumentación para Imagen Molecular; European Commission; Generalitat Valenciana; European Regional Development Fund; Ministerio de Economía y Competitividad
    [EN] Background: Prostate cancer (PCa) represents one of the most common types of cancers facing the male population. Nowadays, to confirm PCa, systematic or multiparametric MRI-targeted transrectal or transperineal biopsies of the prostate are required. However, due to the lack of an accurate imaging technique capable to precisely locate cancerous cells in the prostate, ultrasound biopsies sample random parts of the prostate and, therefore, it is possible to miss regions where those cancerous cells are present. In spite of the improvement with multiparametric MRI, the low reproducibility of its reading undermines the specificity of the method. Recent development of prostatespecific radiotracers has grown the interest on using positron emission tomography (PET) scanners for this purpose, but technological improvements are still required (current scanners have resolutions in the range of 4¿5 mm). Results: The main goal of this work is to improve state-of-the-art PCa imaging and diagnosis. We have focused our efforts on the design of a novel prostate-dedicated PET scanner, named ProsPET. This system has small scanner dimensions defined by a ring of just 41 cm inner diameter. In this work, we report the design, implementation, and evaluation (both through simulations and real data) of the ProsPET scanner. We have been able to achieve < 2 mm resolution in reconstructed images and high sensitivity. In addition, we have included a comparison with the Philips Gemini-TF scanner, which is used for routine imaging of PCa patients. The ProsPET exhibits better contrast, especially for rod sizes as small as 4.5 mm in diameter. Finally, we also show the first reconstructed image of a PCa patient acquired with the ProsPET. Conclusions: We have designed and built a prostate specific PET system, with a small footprint and improved spatial resolution when compared to conventional whole-body PET scanners. The gamma ray impact within each detector block includes accurate DOI determination, correcting for the parallax error. The potential role of combined organdedicated prostate-specific membrane antigen (PSMA) PET and ultrasound devices, as a prebiopsy diagnostic tool, could be used to guide sampling of the most aggressive sites in the prostate.
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    Characterization of protons accelerated from a 3 TW table-top laser system
    (IOP Publishing, 2017-05) Bellido-Millán, Pablo Jesús; Lera, Roberto; Seimetz, Michael; Ruiz-de la Cruz, Alexandro; Torres Peiró, Salvador; Galán, M.; Mur, P.; Sánchez, I.; Zaffino, R.; Vidal San Sebastián, Luis Fernando; Soriano Asensi, Antonio; Sánchez-Góez, Sebastián; Sánchez Martínez, Filomeno; Rodríguez Álvarez, María José; Rigla, J.P.; Moliner Martínez, Laura; Iborra Carreres, Amadeo; Hernández Hernández, Liczandro; Grau-Ruiz, Daniel; González Martínez, Antonio Javier; García Garrigós, Juan José; Díaz Caballero, Elena; Conde-Castellanos, Pablo Eloy; Aguilar-Talens, Albert; Roso, Luis; Benlloch Baviera, Jose María; Departamento de Matemática Aplicada; Escuela Técnica Superior de Ingeniería Informática; Instituto de Instrumentación para Imagen Molecular; Ministerio de Economía y Competitividad; Ministerio de Ciencia e Innovación
    [EN] We report on benchmark tests of a 3 TW/50 fs, table-top laser system specifically developed for proton acceleration with an intrinsic pump rate up to 100 Hz. In two series of single-shot measurements differing in pulse energy and contrast the successful operation of the diode pumped laser is demonstrated. Protons have been accelerated up to 1.6 MeV in interactions of laser pulses focused on aluminium and mylar foils between 0.8 and 25 mu m thickness. Their spectral distributions and maximum energies are consistent with former experiments under similar conditions. These results show the suitability of our system and provide a reference for studies of laser targets at high repetition rate and possible applications.
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    Calibration and Performance Tests of Detectors for Laser-Accelerated Protons
    (Institute of Electrical and Electronics Engineers (IEEE), 2015) Seimetz, Michael; Bellido, P.; Soriano Asensi, Antonio; García López, J.; Jiménez-Ramos, M.C.; Fernández, B.; Conde Castellanos, Pablo Eloy; Crespo Navarro, Efren; González Martínez, Antonio Javier; Hernández Hernández, Liczandro; Iborra Carreres, Amadeo; Moliner Martínez, Laura; Rigla Pérez, Juan Pablo; Rodríguez Álvarez, María José; Sanchez, F.; Sanchez, S.; Vidal San Sebastián, Luis Fernando; Benlloch Baviera, Jose María; Departamento de Matemática Aplicada; Escuela Técnica Superior de Ingeniería Informática; Instituto de Instrumentación para Imagen Molecular; Ministerio de Ciencia e Innovación; Generalitat Valenciana; Ministerio de Economía y Competitividad; Consejo Superior de Investigaciones Científicas; European Social Fund
    We present the calibration and performance tests carried out with two detectors for intense proton pulses accelerated by lasers. Most of the procedures were realized with proton beams of 0.46-5.60 MeV from a tandem accelerator. One approach made use of radiochromic films, for which we calibrated the relation between optical density and energy deposition over more than three orders of magnitude. The validity of these results and of our analysis algorithms has been confirmed by controlled irradiation of film stacks and reconstruction of the total beam charge for strongly non-uniform beam profiles. For the spectral analysis of protons from repeated laser shots, we have designed an online monitor based on a plastic scintillator. The resulting signal from a photomultiplier directly measured on a fast oscilloscope is especially useful for time-of-flight applications. Variable optical filters allow for suppression of saturation and an extension of the dynamic range. With pulsed proton beams we have tested the detector response to a wide range of beam intensities from single particles 3 x 10(5) to protons per 100 ns time interval.
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    Effect of noise in CT image reconstruction using QR- Decomposition algorithm
    (IEEE, 2013-11-02) Iborra, A.; Rodríguez Álvarez, María José; Soriano, A.; Sánchez Martínez, Filomeno; Bellido, P.; Conde, P.; Crespo, E.; González Martínez, Antonio Javier; Martos, F.; Moliner Martínez, Laura; Rigla, J. P.; Seimetz, Michael; Vidal San Sebastián, Luis Fernando; Benlloch Baviera, Jose María; Departamento de Matemática Aplicada; Escuela Técnica Superior de Ingeniería Informática; Instituto de Instrumentación para Imagen Molecular; Generalitat Valenciana; Ministerio de Ciencia e Innovación
    [EN] The QR-Decomposition algorithm for CT 3D image reconstruction uses a linear system of equations to model the CT system response. Linear systems have a condition number that can be used to estimate the image noise. In this work the number of projections and the number of pixels in the detector have been studied to characterize the CT and the linear system of equations. The condition number of the system is estimated for the previous parameters used to generate the CT model with the aim of characterizing how these parameters affect the condition number and therefore bound the image noise level. It is shown that the condition number mainly depends on the size of pixels of the detector rather than the number of projections and this algorithm can be applied to low dose CT 3D image reconstruction without compromising image quality
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    Innovative PET detector concept based on SiPMs and continuous crystals
    (Elsevier, 2012-12-11) González Martínez, Antonio Javier; Peiró Cloquell, Antonio; Sánchez Martínez, Filomeno; Vidal San Sebastián, Luis Fernando; Benlloch Baviera, Jose María; Instituto de Instrumentación para Imagen Molecular
    The use of Silicon Photomultipliers (SiPM) has been proposed for Positron Emission Tomography (PET) readout because they are hardly affected by magnetic fields and their time response enables Time of Flight measurements. This work proposes an array of SiPM to be coupled to a monolithic LYSO crystal by means of a series of optical devices. The emitted light distribution by the scintillation crystal will be accurately determined using an Application Specific Integrated Circuit. The described sensor block aims to determine the planar coordinates and depth of interaction of the gamma ray with sub-millimetrical precision. In this work we present the initial studies regarding edge effects due to thick monolithic crystals and how to overcome these limitations by means of optical devices namely faceplates and light concentrators. We will also discuss on the alignment of such optical devices with the SiPMs
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    PET detector block with accurate 4D capabilities
    (Elsevier, 2018-12-21) Lamprou, Efthymios; Aguilar -Talens, Albert; Gonzalez-Montoro, Andrea; Monzó Ferrer, José María; Cañizares-Ledo, Gabriel; Iranzo-Egea, Sofía; Vidal San Sebastián, Luis Fernando; Hernández Hernández, Liczandro; Conde-Castellanos, Pablo Eloy; Sánchez-Góez, Sebastián; Sánchez Martínez, Filomeno; González Martínez, Antonio Javier; Benlloch Baviera, Jose María; Departamento de Ingeniería Electrónica; Escuela Técnica Superior de Ingeniería de Telecomunicación; Instituto de Instrumentación para Imagen Molecular; European Commission; Ministerio de Economía y Competitividad
    [EN] In this contribution, large SiPM arrays (8 x 8 elements of 6 x 6 mm(2) each) are processed with an ASIC-based readout and coupled to a monolithic LYSO crystal to explore their potential use for TOF-PET applications. The aim of this work is to study the integration of this technology in the development of clinical PET systems reaching sub-300 ps coincidence resolving time (CRT). The SiPM and readout electronics have been evaluated first, using a small size 1.6 mm (6 mm height) crystal array (32 x 32 elements). All pixels were well resolved and they exhibited an energy resolution of about 20% (using Time-over-Threshold methods) for the 511 keV photons. Several parameters have been scanned to achieve the optimum readout system performance, obtaining a CRT as good as 330 +/- 5 ps FWHM. When using a black-painted monolithic block, the spatial resolution was measured to be on average 2.6 +/- 0.5 mm, without correcting for the source size. Energy resolution appears to be slightly above 20%. CRT measurements with the monolithic crystal detector were also carried out. Preliminary results as well as calibration methods specifically designed to improve timing performance, are being analyzed in the present manuscript.
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    Detector block performance based on a monolithic LYSO crystal using a novel signal multiplexing method
    (Elsevier, 2018-12-21) González, A.; Sánchez Martínez, Filomeno; Martí, Rosana; Hernández Hernández, Liczandro; Aguilar-Talens, Albert; BARBERA BALLESTER, JULIO; CATRET MASCARELL, JUAN VICENTE; Cañizares-Ledo, Gabriel; Conde-Castellanos, Pablo Eloy; Lamprou, Efthymios; Martos Pedrosa, Francisco; Sánchez-Góez, Sebastián; Vidal San Sebastián, Luis Fernando; Benlloch Baviera, Jose María; González Martínez, Antonio Javier; Instituto de Instrumentación para Imagen Molecular; Ministerio de Economía y Competitividad
    [EN] Organ dedicated PET devices provide improved imaging performance when compared to whole body systems. The present study summarizes the test carried out to study a new detector block designed for an organ dedicated PET system. This block includes three novel components namely the scintillator geometry and a retroreflector layer coupled to the entrance face, the photosensor and the readout electronics. We used arrays of 12 x 12 SiPM photosensors with 3 x 3 mm(2) active area each and a pitch of 4.2 mm. We are proposing a new readout electronics that permits to reduce the 12 row and columns signals to only 8 without significant detector performance degradation. This approach also allows for resolving radioactive sources in the whole volume of the proposed crystal, significantly reducing the edge effect that typically rejects these events. An overall spatial resolution of about 1.8 mm FWHM is obtained for the whole scintillation volume, with an average energy resolution of 13% FWHM and a photon depth of interaction resolution (FWHM) of 3.7 mm. (C) 2018 Elsevier B.V. All rights reserved.
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    Design and evaluation of the MAMMI dedicated breast PET
    (American Association of Physicists in Medicine, 2012-09) Moliner Martínez, Laura; González Martínez, Antonio Javier; Soriano Asensi, Antonio; Sánchez Martínez, Filomeno; Correcher Salvador, Carlos; Orero Palomares, Abel; Carles Fariña, Montserrat; Vidal San Sebastián, Luis Fernando; Barberá Ballester, Julio; Caballero Ontanaya, Luis; Seimetz, Michael; Vazquez Barreiros, Carlos; Benlloch Baviera, Jose María; Instituto de Instrumentación para Imagen Molecular; Ministerio de Ciencia e Innovación; Generalitat Valenciana
    Purpose: A breast dedicated positron emission tomography (PET) scanner has been developed based on monolithic LYSO crystals coupled to position sensitive photomultiplier tubes (PSPMTs). In this study, we describe the design of the PET system and report on its performance evaluation. Methods: MAMMI is a breast PET scanner based on monolithic LYSO crystals. It consists of 12 compact modules with a transaxial field of view (FOV) of 170 mm in diameter and 40 mm axial FOV that translates to cover up to 170 mm. The patient lies down in a prone position that facilitates maximum breast elongation. Quantitative performance analysis of the calculated method for the attenuation correction specifically developed for MAMMI, and based on PET image segmentation, has also been conducted in this evaluation. In order to fully determine the MAMMI prototype’s performance, we have adapted the measurements suggested for National Electrical Manufacturers Association (NEMA) NU 2-2007 and NU 4-2008 protocol tests, as they are defined for whole-body and small animal PET scanners, respectively. Results: Spatial resolutions of 1.6, 1.8, and 1.9 mm were measured in the axial, radial, and tangential directions, respectively. A scatter fraction of 20.8% was obtained and the maximum NEC was determined to be 25 kcps at 44 MBq. The average sensitivity of the system was observed to be 1% for an energy window of (250 keV–750 keV) and a maximum absolute sensitivity of 1.8% was measured at the FOV center. Conclusions: The overall performance of the MAMMI reported on this evaluation quantifies its ability to produce high quality PET images. Spatial resolution values below 3 mm were measured in most of the FOV. Only the radial component of spatial resolution exceeds the 3 mm at radial positions larger than 60 mm. This study emphasizes the need for standardized testing methodologies for dedicated breast PET systems similar to NEMA standards for whole-body and small animal PET scanners
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    Design and first results of an innovative and dedicated for hanging breast imaging PET
    (Bentham Science Publishers, 2012-05-01) González Martínez, Antonio Javier; S Aukema, T.; Barberá Ballester, Julio; Benlloch Baviera, Jose María; Correcher Salvador, Carlos; Orero Palomares, Abel; Soriano Asensi, Antonio; Vogel, W.; Vazquez Barreiros, Carlos; Vidal San Sebastián, Luis Fernando; Valdes Olmos, A.R.; Instituto de Instrumentación para Imagen Molecular
    In this work the design and preliminary clinical results obtained with an innovative and dedicated breast PET is presented. A geometrical study clearly pointed out the advantages of the prone position and the technique of hanging breast in comparison to the supine, conventionally used for other imaging modalities. Occult, multifocal and also lesions close to the pectoral muscle were depicted by means of the prone method. The measured diameters of the hanging breasts allowed us to define an optimum transaxial FOV of up to 170 mm. This was achieved by means of 12 detector heads mounted on ring geometry, each using a monolithic LYSO crystal a position sensitive photomultiplier, among other components. The detector showed up an extrinsic spatial resolution as high as 1.4 mm in the center of the FOV with a physical sensitivity of 1.2 %. A clinical trial is undergoing at the Netherlands Cancer Institute in terms of a clinical validation of the dedicated breast PET. An adequate image matching between this device and the whole-body PET was observed, even for deep chest lesions. A preliminary quantitative comparison also shows a good agreement between both systems. However, a tiny deviation to higher Standard Uptake Values is observed for the prototype.