González Martínez, Antonio Javier

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2011 - 2019202020 - 20234
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Autor: Moliner Martínez, Laura ×

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    A proof-of-concept of cross-luminescent metascintillators: testing results on a BGO: BaF2metapixel
    (IOP Publishing, 2023-01-21) Konstantinou, G.; Latella, Riccardo; Moliner Martínez, Laura; Zhang, L.; Benlloch Baviera, Jose María; González Martínez, Antonio Javier; Lecoq, Paul; Instituto de Instrumentación para Imagen Molecular; European Commission
    [EN] Objective: Time-of-flight positron emission tomography (PET)is the next frontier in improving the effective sensitivity. To achieve superior timing for time-of-flight PET, combined with high detection efficiency and cost-effectiveness, we have studied the applicability of BaF2 in metascintillators driven by the timing of cross-luminescence photon production. Approach: Based on previous simulation studies of energy sharing and analytic multi-exponential scintillation pulse, as well as sensitivity characteristics, we have experimentally tested a pixel of 3 × 3 × 15 mm3 based on 300 ¿m BGO and 300 ¿m BaF2 layers. To harness the deep ultraviolet cross-luminescent light component, which carries improved timing, we use the FBK VUV SiPM. Metascintillator energy sharing is addressed through a double integration approach. Main results: We reach an energy resolution of 22%, comparable to an 18% resolution of simple BGO pixels using the same readout, through the optimized use of the integrals of the metascintillator pulse in energy sharing calculation. We measure the energy sharing extent of each pulse with a resolution of 25% and demonstrate that experimental and simulation results agree well. Based on the energy sharing, a timewalk correction is applied, exhibiting significant improvements for both the coincidence time resolution (CTR) and the shape of the timing histogram. We reach 242 ps CTR for the entire photopeak, while for a subset of 13% of the most shared events, the CTR value improves to 108 ps, comparable to the 3 × 3 × 5 mm3 LYSO:Ce:Ca reference crystal. Significance: While we are considering different ways to improve further these results, this proof-ofconcept demonstrates the applicability of cross-luminescence for metascintillator designs through the application of VUV compatible SiPM coupling, and easily implementable digital algorithms. This is the first test of BaF2-based metascintillators of sufficient stoppng power to be included in a PET scanner, demonstrating the industrial applicability of such cross-luminescent metascintillators.
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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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    NEMA Performance Evaluation of CareMiBrain dedicated brain PET and Comparison with the whole-body and dedicated brain PET systems
    (Nature Publishing Group, 2019-10-29) Moliner Martínez, Laura; Rodríguez Álvarez, María José; CATRET MASCARELL, JUAN VICENTE; González Martínez, Antonio Javier; Ilisie, Victor; Benlloch Baviera, Jose María; Departamento de Matemática Aplicada; Escuela Técnica Superior de Ingeniería Informática; Instituto de Instrumentación para Imagen Molecular; European Commission; Ministerio de Economía y Competitividad
    [EN] This article presents system performance studies of the CareMiBrain dedicated brain PET according to NEMA NU 2-2012 (for whole-body PETS) and NU 4-2008 (for preclinical PETs). This scanner is based on monolithic LYSO crystals coupled to silicon photomultipliers. The results obtained for both protocols are compared with current commercial whole body PETs and dedicated brain PETs found in the literature. Spatial resolution, sensitivity, NECR and scatter-fraction are characterized with NEMA standards, as well as an image quality study. A customized image quality phantom is proposed as NEMA phantoms do not fulfil the necessities of dedicated brain PETs. The full-width half maximum of the radial/tangential/ axial spatial resolution of CareMiBrain reconstructed with FBP at 10 and 100 mm from the system center were, respectively, 1.87/1.68/1.39 mm and 1.86/1.91/1.40 mm (NU 2-2012) and 1.58/1.45/1.40 mm and 1.64/1.66/1.44 mm (NU 4-2008). Peak NECR was 49 kcps@287 MBq with a scatter fraction of 48% using NU 2-2012 phantom. The sensitivity was 13.82 cps/kBq at the center of the FOV (NU 2-2012) and 10% (NU 4-2008). Contrast recovery coefficients for customizing image quality phantom were 0.73/0.78/1.14/1.01 for the 4.5/6/9/12 mm diameter rods. The performance characteristics of CareMiBrain are at the top of the current technologies for PET systems. Dedicated brain PET systems significantly improve spatial resolution and sensitivity, but present worse results in count rate measurements and scatter-fraction tests. As for the comparison of preclinical and clinical standards, the results obtained for solid and liquid sources were similar.
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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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    Motion Correction of Multi-Frame PET Data
    (IEEE, 2019-11-02) Cañizares, Gabriel; Espinós-Morató, Héctor; Santos Blasco, Joaquín; Hernández, Ángel; Moliner Martínez, Laura; Álvarez-Gómez, Juan Manuel; González Martínez, Antonio Javier; Sánchez Martínez, Filomeno; Rodríguez Álvarez, María José; Benlloch Baviera, Jose María; Departamento de Matemática Aplicada; Escuela Técnica Superior de Ingeniería Informática; Instituto de Instrumentación para Imagen Molecular
    [EN] Motion correction algorithms are necessary in PET studies where the patient cannot remain totally static. Otherwise, artifacts appear in the final reconstructed image, degrading the spatial resolution or even misplacing the radiation distribution source. In this work we propose a new enhanced motion correction algorithm (EMAF) based on the multiple acquisition frames (MAF). This methodology can be applied to two PET system geometries (a ring and a multi-panel system). Using simulated data, the comparison of static and motion corrected profiles shows minimum differences keeping more than 99% of the events after the process, with a minimal inter-frame error (the maximum range of loss counts is around 0.6%). To measure the quality of the correction method, two error metrics as peak signal to noise ratio (PSNR) and intensity matching precision (IMP) are proposed. A Mini-Derenzo in a ring PET system reveals a remarkable improvement both for these two metrics (44.5 dB and 98.7%) when compared to the uncorrected images (41.1 dB and 56%, respectively). An equivalent analysis for a point-like source also shows a sizeable enhancement both in contrast and resolution (64 dB and 98% versus 62.5 dB and 17.9%, PSNR and IMP correspondingly). The proposed algorithm minimizes the image artifacts and its simplicity, independency of PET configuration system and rapid reconstruction and registration times, makes it a useful tool in preclinical PET studies.
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    Performance Evaluation of the Dual Ring MAMMI breast PET
    (IEEE, 2013-11-02) Soriano, A.; Sánchez Martínez, Filomeno; Carrilero, V.; Pardo, A.; Vidal San Sebastián, Luis Fernando; Vazquez, C.; Barbera, J.; Seimetz, Michael; Rodríguez Álvarez, María José; Rigla, J. P.; Moliner Martínez, Laura; Iborra, A.; Hernández, L.; González Martínez, Antonio Javier; Crespo, E.; Conde, P.; Bellido, P.; Caballero, L.; 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] MAMMI is a dedicated breast positron emission tomograph (PET) based on monolythic LYSO crystals, with a transaxial field of view (FOV) of 170 mm. It has been upgraded by adding a second ring of detectors that extends the axial FOV from 40 mm to 94.4 mm, in order to improve its sensitivity and reduce the acquisition time. In this work we present the performance evaluation of the dual ring MAMMI breast PET and a discussion about the contribution of the addition of a second ring of detectors, the compensation of the detector blur and the increase of the scintillator thickness. Experimental measurements suggested on NEMA NU 4-2008 and NEMA NU 2-2007 have been conveniently adapted to the dimensions of the MAMMI. The addition of the second ring of detectors leads to a rise of the sensitivity from 1.8% to 3.6%. The spatial resolution at one-fourth of the axial FOV (1.5 mm axial, 1.6 mm tangential, 1.7 mm radial) is slightly better than that measured at the axial center (1.9 mm axial, 1.8 mm tangential and radial), because of the 14 mm gap in between detection rings. The results obtained after the evaluation reflect a substantial performance improvement, specially in the absolute sensitivity, because of the changes introduced in the MAMMI PET.