PET detector block with accurate 4D capabilities

[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.This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 695536). It has also been supported by the Spanish Ministerio de Economia, Industria y Competitividad under Grants No. FIS2014-62341-EXP and TEC2016-79884-C2-1-R.Lamprou, E.; Aguilar -Talens, A.; Gonzalez-Montoro, A.; Monzó Ferrer, JM.; Cañizares-Ledo, G.; Iranzo-Egea, S.; Vidal San Sebastian, LF.... (2018). PET detector block with accurate 4D capabilities. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 912:132-136. https://doi.org/10.1016/j.nima.2017.11.002S13213691

Statistical moments of scintillation light distribution analysis with dSiPMs and monolithic crystals

[Otros] Monolithic scintillation crystals offer the possibility to preserve the scintillation light distribution, specially when black painted. Furthermore, the statistical moments of that distribution can provide accurate information about the three spatial components. Nevertheless, for monolithic crystal the moments estimation has an associated error due to the symmetry truncation of the light distribution towards the crystal borders. For the 2-D impact coordinates determination, this error is called compression as it is accentuated near the edges. The computation of all centered moments is, therefore, affected by this error. Digital SiPMs (dSiPMs) can offer complete information about the light distribution, since all cells are purely digital detectors, so that other ways to obtain ¿-impact coordinates can be performed. In this work, a comparison between the statistical moments analysis and an alternative fitting the light distribution for each event to a theoretical distribution has been made. With the fitted approach, compression is avoided and an approximately constant spatial resolution is obtained for the entire photodetection area. Moreover, DOI information is improved and preserved all over the crystal.This work was supported by the Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovación Tecnologica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Conde, P.; González Martínez, AJ.; Hernández, L.; Bellido, P.; Crespo, E.; Iborra, A.; Moliner, L.... (2013). Statistical moments of scintillation light distribution analysis with dSiPMs and monolithic crystals. IEEE. 10-13. https://doi.org/10.1109/NSSMIC.2013.6829086S101

Effect of noise in CT image reconstruction using QR- Decomposition algorithm

[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 qualityThis work was supported by the Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovación Tecnológica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Iborra, A.; Rodríguez-Álvarez, MJ.; Soriano, A.; Sánchez, F.; Bellido, P.; Conde, P.; Crespo, E.... (2013). Effect of noise in CT image reconstruction using QR- Decomposition algorithm. IEEE. 5-9. http://hdl.handle.net/10251/167122S5

Time reconstruction study using tubes of response backprojectors in List Mode algorithms, applied to amonolithic crystals based breast PET

[Otros] The LM-EM algorithm has the advantage to calculate the emission probabilities needed for the reconstruction process on the fly, without the need of a pre-calculated system matrix. The reconstruction time for this algorithm strongly depends on the used backprojector and the available statistics. This algorithm when implemented in systems using monolithic crystals to detect gamma radiation allows one to extensively exploit the virtual pixilation feature, not available for systems based on pixilated crystals. In this work we present a backprojector for LM-EM, the TOR method, which achieves a tradeoff between computational efficiency and image quality. Its temporal subset algorithm optimization (LM-OS) has also been implemented in order to achieve real-time reconstructions. To evaluate the performances of LM-OS algorithm with the TOR method backprojector and only with one iteration on the datasets, studies based on the system spatial resolution, uniformity, and contrast coefficients were carried out and they were compared with those obtained with LM-EM and MLEM algorithms using twelve iteration. Finally, a study on reconstruction time using LM-OS has been performed with breast patients dataProject funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program. This work was supported by the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i) under Grant No. FIS2010-21216-CO2-01 and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Moliner, L.; Correcher, C.; González Martínez, AJ.; Conde, P.; Crespo, E.; Hernandez, L.; Rigla, JP.... (2013). Time reconstruction study using tubes of response backprojectors in List Mode algorithms, applied to amonolithic crystals based breast PET. IEEE. 14-18. https://doi.org/10.1109/NSSMIC.2013.6829372S141

Characterization of protons accelerated from a 3 TW table-top laser system

[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.This project has been funded by Centro para el Desarrollo Tecnologico Industrial (CDTI, Spain) within the INNPRONTA program, grant no. IPT-20111027, by EUROSTARS project E9113, and by the Spanish Ministry for Economy and Competitiveness within the Retos-Colaboracion 2015 initiative, ref. RTC-2015-3278-1.Bellido-Millán, PJ.; Lera, R.; Seimetz, M.; Ruiz-De La Cruz, A.; Torres Peiró, S.; Galán, M.; Mur, P.... (2017). Characterization of protons accelerated from a 3 TW table-top laser system. Journal of Instrumentation. 12:1-12. https://doi.org/10.1088/1748-0221/12/05/T05001S11212Daido, H., Nishiuchi, M., & Pirozhkov, A. S. (2012). Review of laser-driven ion sources and their applications. Reports on Progress in Physics, 75(5), 056401. doi:10.1088/0034-4885/75/5/056401Macchi, A., Borghesi, M., & Passoni, M. (2013). Ion acceleration by superintense laser-plasma interaction. Reviews of Modern Physics, 85(2), 751-793. doi:10.1103/revmodphys.85.751Ledingham, K., Bolton, P., Shikazono, N., & Ma, C.-M. (2014). Towards Laser Driven Hadron Cancer Radiotherapy: A Review of Progress. Applied Sciences, 4(3), 402-443. doi:10.3390/app4030402Kraft, S. D., Richter, C., Zeil, K., Baumann, M., Beyreuther, E., Bock, S., … Pawelke, J. (2010). Dose-dependent biological damage of tumour cells by laser-accelerated proton beams. New Journal of Physics, 12(8), 085003. doi:10.1088/1367-2630/12/8/085003Yogo, A., Sato, K., Nishikino, M., Mori, M., Teshima, T., Numasaki, H., … Daido, H. (2009). Application of laser-accelerated protons to the demonstration of DNA double-strand breaks in human cancer cells. Applied Physics Letters, 94(18), 181502. doi:10.1063/1.3126452Fritzler, S., Malka, V., Grillon, G., Rousseau, J. P., Burgy, F., Lefebvre, E., … Ledingham, K. W. D. (2003). Proton beams generated with high-intensity lasers: Applications to medical isotope production. Applied Physics Letters, 83(15), 3039-3041. doi:10.1063/1.1616661Kishimura, H., Morishita, H., Okano, Y. H., Okano, Y., Hironaka, Y., Kondo, K., … Nemoto, K. (2004). Enhanced generation of fast protons from a polymer-coated metal foil by a femtosecond intense laser field. Applied Physics Letters, 85(14), 2736-2738. doi:10.1063/1.1803915Nakamura, S., Iwashita, Y., Noda, A., Shirai, T., Tongu, H., Fukumi, A., … Wada, Y. (2006). Real-Time Optimization of Proton Production by Intense Short-Pulse Laser with Time-of-Flight Measurement. Japanese Journal of Applied Physics, 45(No. 34), L913-L916. doi:10.1143/jjap.45.l913Nishiuchi, M., Fukumi, A., Daido, H., Li, Z., Sagisaka, A., Ogura, K., … Nakamura, S. (2006). The laser proton acceleration in the strong charge separation regime. Physics Letters A, 357(4-5), 339-344. doi:10.1016/j.physleta.2006.04.053Yogo, A., Daido, H., Fukumi, A., Li, Z., Ogura, K., Sagisaka, A., … Itoh, A. (2007). Laser prepulse dependency of proton-energy distributions in ultraintense laser-foil interactions with an online time-of-flight technique. Physics of Plasmas, 14(4), 043104. doi:10.1063/1.2721066Robinson, A. P. L., Foster, P., Adams, D., Carroll, D. C., Dromey, B., Hawkes, S., … Neely, D. (2009). Spectral modification of laser-accelerated proton beams by self-generated magnetic fields. New Journal of Physics, 11(8), 083018. doi:10.1088/1367-2630/11/8/083018Nemoto, K., Maksimchuk, A., Banerjee, S., Flippo, K., Mourou, G., Umstadter, D., & Bychenkov, V. Y. (2001). Laser-triggered ion acceleration and table top isotope production. Applied Physics Letters, 78(5), 595-597. doi:10.1063/1.1343845Lee, K., Park, S. H., Cha, Y.-H., Lee, J. Y., Lee, Y. W., Yea, K.-H., & Jeong, Y. U. (2008). Generation of intense proton beams from plastic targets irradiated by an ultraintense laser pulse. Physical Review E, 78(5). doi:10.1103/physreve.78.056403Yogo, A., Daido, H., Bulanov, S. V., Nemoto, K., Oishi, Y., Nayuki, T., … Tajima, T. (2008). Laser ion acceleration via control of the near-critical density target. Physical Review E, 77(1). doi:10.1103/physreve.77.016401Lee, K., Lee, J. Y., Park, S. H., Cha, Y.-H., Lee, Y. W., Kim, K. N., & Jeong, Y. U. (2011). Dominant front-side acceleration of energetic proton beams from plastic targets irradiated by an ultraintense laser pulse. Physics of Plasmas, 18(1), 013101. doi:10.1063/1.3496058OKIHARA, S., SENTOKU, Y., SUEDA, K., SHIMIZU, S., SATO, F., MIYANAGA, N., … SAKABE, S. (2002). Energetic Proton Generation in a Thin Plastic Foil Irradiated by Intense Femtosecond Lasers. Journal of Nuclear Science and Technology, 39(1), 1-5. doi:10.1080/18811248.2002.9715150McKenna, P., Ledingham, K. W. D., Spencer, I., McCany, T., Singhal, R. P., Ziener, C., … Clark, E. L. (2002). Characterization of multiterawatt laser-solid interactions for proton acceleration. Review of Scientific Instruments, 73(12), 4176-4184. doi:10.1063/1.1516855Spencer, I., Ledingham, K. W. D., McKenna, P., McCanny, T., Singhal, R. P., Foster, P. S., … Davies, J. R. (2003). Experimental study of proton emission from 60-fs, 200-mJ high-repetition-rate tabletop-laser pulses interacting with solid targets. Physical Review E, 67(4). doi:10.1103/physreve.67.046402Kaluza, M., Schreiber, J., Santala, M. I. K., Tsakiris, G. D., Eidmann, K., Meyer-ter-Vehn, J., & Witte, K. J. (2004). Influence of the Laser Prepulse on Proton Acceleration in Thin-Foil Experiments. Physical Review Letters, 93(4). doi:10.1103/physrevlett.93.045003Ceccotti, T., Lévy, A., Popescu, H., Réau, F., D’Oliveira, P., Monot, P., … Martin, P. (2007). Proton Acceleration with High-Intensity Ultrahigh-Contrast Laser Pulses. Physical Review Letters, 99(18). doi:10.1103/physrevlett.99.185002Neely, D., Foster, P., Robinson, A., Lindau, F., Lundh, O., Persson, A., … McKenna, P. (2006). Enhanced proton beams from ultrathin targets driven by high contrast laser pulses. Applied Physics Letters, 89(2), 021502. doi:10.1063/1.2220011Steinke, S., Henig, A., Schnürer, M., Sokollik, T., Nickles, P. V., Jung, D., … Habs, D. (2010). Efficient ion acceleration by collective laser-driven electron dynamics with ultra-thin foil targets. Laser and Particle Beams, 28(1), 215-221. doi:10.1017/s0263034610000157Strickland, D., & Mourou, G. (1985). Compression of amplified chirped optical pulses. Optics Communications, 56(3), 219-221. doi:10.1016/0030-4018(85)90120-8Yogo, A., Kondo, K., Mori, M., Kiriyama, H., Ogura, K., Shimomura, T., … Bolton, P. R. (2014). Insertable pulse cleaning module with a saturable absorber pair and a compensating amplifier for high-intensity ultrashort-pulse lasers. Optics Express, 22(2), 2060. doi:10.1364/oe.22.002060Trisorio, A., Grabielle, S., Divall, M., Forget, N., & Hauri, C. P. (2012). Self-referenced spectral interferometry for ultrashort infrared pulse characterization. Optics Letters, 37(14), 2892. doi:10.1364/ol.37.002892Seimetz, M., Bellido, P., Soriano, A., Garcia Lopez, J., Jimenez-Ramos, M. C., Fernandez, B., … Benlloch, J. M. (2015). Calibration and Performance Tests of Detectors for Laser-Accelerated Protons. IEEE Transactions on Nuclear Science, 62(6), 3216-3224. doi:10.1109/tns.2015.2480682Nürnberg, F., Schollmeier, M., Brambrink, E., Blažević, A., Carroll, D. C., Flippo, K., … Roth, M. (2009). Radiochromic film imaging spectroscopy of laser-accelerated proton beams. Review of Scientific Instruments, 80(3), 033301. doi:10.1063/1.3086424Oishi, Y., Nayuki, T., Fujii, T., Takizawa, Y., Wang, X., Yamazaki, T., … Andreev, A. A. (2005). Dependence on laser intensity and pulse duration in proton acceleration by irradiation of ultrashort laser pulses on a Cu foil target. Physics of Plasmas, 12(7), 073102. doi:10.1063/1.1943436Nishiuchi, M., Daito, I., Ikegami, M., Daido, H., Mori, M., Orimo, S., … Yoshiyuki, T. (2009). Focusing and spectral enhancement of a repetition-rated, laser-driven, divergent multi-MeV proton beam using permanent quadrupole magnets. Applied Physics Letters, 94(6), 061107. doi:10.1063/1.3078291Antici, P., Fuchs, J., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Pépin, H. (2007). Energetic protons generated by ultrahigh contrast laser pulses interacting with ultrathin targets. Physics of Plasmas, 14(3), 030701. doi:10.1063/1.2480610Green, J. S., Carroll, D. C., Brenner, C., Dromey, B., Foster, P. S., Kar, S., … Zepf, M. (2010). Enhanced proton flux in the MeV range by defocused laser irradiation. New Journal of Physics, 12(8), 085012. doi:10.1088/1367-2630/12/8/085012Zeil, K., Kraft, S. D., Bock, S., Bussmann, M., Cowan, T. E., Kluge, T., … Schramm, U. (2010). The scaling of proton energies in ultrashort pulse laser plasma acceleration. New Journal of Physics, 12(4), 045015. doi:10.1088/1367-2630/12/4/045015Nishiuchi, M., Daido, H., Yogo, A., Orimo, S., Ogura, K., Ma, J., … Azuma, H. (2008). Efficient production of a collimated MeV proton beam from a polyimide target driven by an intense femtosecond laser pulse. Physics of Plasmas, 15(5), 053104. doi:10.1063/1.2928161Macchi, A., Sgattoni, A., Sinigardi, S., Borghesi, M., & Passoni, M. (2013). Advanced strategies for ion acceleration using high-power lasers. Plasma Physics and Controlled Fusion, 55(12), 124020. doi:10.1088/0741-3335/55/12/124020Fuchs, J., Antici, P., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Audebert, P. (2005). Laser-driven proton scaling laws and new paths towards energy increase. Nature Physics, 2(1), 48-54. doi:10.1038/nphys199Schwoerer, H., Pfotenhauer, S., Jäckel, O., Amthor, K.-U., Liesfeld, B., Ziegler, W., … Esirkepov, T. (2006). Laser-plasma acceleration of quasi-monoenergetic protons from microstructured targets. Nature, 439(7075), 445-448. doi:10.1038/nature04492Margarone, D., Klimo, O., Kim, I. J., Prokůpek, J., Limpouch, J., Jeong, T. M., … Korn, G. (2012). Laser-Driven Proton Acceleration Enhancement by Nanostructured Foils. Physical Review Letters, 109(23). doi:10.1103/physrevlett.109.234801Flippo, K. A., d’ Humières, E., Gaillard, S. A., Rassuchine, J., Gautier, D. C., Schollmeier, M., … Hegelich, B. M. (2008). Increased efficiency of short-pulse laser-generated proton beams from novel flat-top cone targets. Physics of Plasmas, 15(5), 056709. doi:10.1063/1.291812

Performance Evaluation of the Dual Ring MAMMI breast PET

[Otros] 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.This work was supported in part bythe Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovación Tecnologica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Soriano, A.; Sánchez, F.; Carrilero, V.; Pardo, A.; Vidal San Sebastian, LF.; Vazquez, C.; Barbera, J.... (2013). Performance Evaluation of the Dual Ring MAMMI breast PET. IEEE. 1-4. https://doi.org/10.1109/NSSMIC.2013.6829103S1

Time-of-Flight Detector for the Characterisation of Laser-Accelerated Protons

[Otros] Lasers of ultra-high intensity focused on thin targets can form plasmas and release large numbers of charged particles with kinetic energies in the MeV region. The characterization of the accelerated particles requires suitable detectors. We present a time-of-flight detector based on a plastic scintillator optimized for the spectral analysis of laser-accelerated protons. All details of the detector layout are adapted to the expected properties of the proton beam. Particle energies will be separated by the time-of-flight technique over 200 cm path length. The active area (25 mm width) corresponds to a few mrad opening angle. With 5 mm thickness the detector is capable of absorbing protons up to 22.5 MeV. A very thin, aluminized mylar foil shields the scintillator from outer light while absorbing very little particle energy. The scintillation photons are measured with a photomultiplier tube coupled through a bundle of optical fibres. The coupling of these fibres via a PMMA light guide has been previously optimized in simulations with Litrani. A critical aspect of the detection of virtually large numbers of protons emitted in femtosecond pulses is the saturation of the PMT. The latter can be avoided by use of appropriate optical filters. With these the effective dynamic range starts from single particles over several orders of magnitude. Our time-of-flight detector has been calibrated at the Spanish National Accelerator Centre at Sevilla. Proton beams from 0.46 to 5.6 MeV from a tandem accelerator have been used to measure the relation between particle energy and pulse heights. Further tests have been performed with a pulsed electron beam to simulate many-particle hits.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER¿s funds within the INNPACTO 2011 program, Grant No. IPT-2011-0862- 900000. This work was supported by the Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovacion Tecnológica (I+D+i) under Grant No. FIS2010-21216-CO2-01 and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Seimetz, M.; Bellido, P.; Soriano, A.; Huertas, C.; García Lopez, J.; Jimenez-Ramos, MC.; Fernandez, B.... (2013). Time-of-Flight Detector for the Characterisation of Laser-Accelerated Protons. IEEE. 25-28. https://doi.org/10.1109/NSSMIC.2013.6829804S252

Dosimetric Calibration of Radiochromic Film For Laser-accelerated Proton Beams

[Otros] When an ultra-intense and ultra-short laser pulse interacts with solid matter a fraction of the laser pulse can be converted into kinetic energy of a beam of charged particles. Radiochromic film (RCF), widely used as radiation detector in the field of conventional radiotherapy, can be used as detector for laser-accelerated protons. If used in stack configuration it is a useful and versatile tool to obtain 2D spatial distribution and energetic information of proton beams. In order to obtain dosimetric information from RCF it must be properly calibrated. Irradiating film pieces under well known conditions allows us to establish a relation between the optical density (OD) of the radiochromic film, which is measured through a flat bed scanner operating in transmission mode, and the deposited energy in the active layer. A calibration curve over a large dynamic range (3 orders of magnitude) has been obtained for few MeV protons. Our calibration process has been performed at the Spanish National Accelerator Center at Sevilla. We have irradiated several areas of a single RCF with a constant 50 pA beam current and fixed 4 MeV energy from a 3 MV tandem accelerator. We have calculated the deposited energy in the films under the same conditions. We demonstrate that this technique can be used to measure the spectrum and total energy of a laser-accelerated mixed-energy proton beam. This detector has been calibrated for a near future application at the Center of Pulsed, Ultra-short, Ultra-intense Lasers (CLPU) at Salamanca (Spain). We present the calibration procedure and results, the design optimization, and a comparison with similar experiments.Project funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDERs funds within the INNPACTO 2011 program. This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e InnovacionTecnologica (I+D+i) under Grant No. FIS2010-21216-CO2-01 and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013.Bellido, P.; Seimetz, M.; Soriano, A.; Huertas, C.; García Lopez, J.; Jimenez-Ramos, MC.; Fernandez, B.... (2013). Dosimetric Calibration of Radiochromic Film For Laser-accelerated Proton Beams. IEEE. 20-23. https://doi.org/10.1109/NSSMIC.2013.6829806S202

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Detector block performance based on a monolithic LYSO crystal using a novel signal multiplexing method

[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.This work was supported by the Spanish Ministerio de Economía, Industria y Competitividad under Grant Nos. FIS2014-62341-EXP and TEC2016-79884-C2-1-R. This project has also received funding from the European Union s Horizon 2020 research and innovation programme under grant agreement No. 711323. This project has received funding from the European Research Council (ERC) under the European Union s Horizon 2020 research and innovation programme (grant agreement No. 695536).González, A.; Sánchez, F.; Martí, R.; Hernández Hernández, L.; Aguilar-Talens, A.; Barbera Ballester, J.; Catret Mascarell, JV.... (2018). Detector block performance based on a monolithic LYSO crystal using a novel signal multiplexing method. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 912:372-377. https://doi.org/10.1016/j.nima.2017.10.098S37237791