The MINDVIEW project: First results

[EN] We present the first results of the MINDVIEW project. An innovative imaging system for the human brain examination, allowing simultaneous acquisition of PET/MRI images, has been designed and constructed. It consists of a high sensitivity and high resolution PET scanner integrated in a novel, head-dedicated, radio frequency coil for a 3T MRI scanner. Preliminary measurements from the PET scanner show sensitivity 3 times higher than state-of-the-art PET systems that will allow safe repeated studies on the same patient. The achieved spatial resolution, close to 1 mm, will enable differentiation of relevant brain structures for schizophrenia. A cost-effective and simple method of radiopharmaceutical production from C-11-carbon monoxide and a mini-clean room has been demonstrated. It has been shown that C-11-raclopride has higher binding potential in a new VAAT null mutant mouse model of schizophrenia compared to wild type control animals. A significant reduction in TSPO binding has been found in gray matter in a small sample of drug-naive, first episode psychosis patients, suggesting a reduced number or an altered function of immune cells in brain at early stage schizophrenia. (c) 2018 Elsevier Masson SAS. All rights reserved.This project is funded by EU grant FP7-HEALTH-F2-2013-603002.Benlloch Baviera, JM.; González Martínez, AJ.; Pani, R.; Preziosi, E.; Jackson, C.; Murphy, J.; Barbera Ballester, J.... (2018). The MINDVIEW project: First results. European Psychiatry. 50:21-27. https://doi.org/10.1016/j.eurpsy.2018.01.002S212750Gonzalez, A. J., Gonzalez-Montoro, A., Aguilar, A., Conde, P., Canizares, G., Hernandez, L., … Benlloch, J. M. (2016). A brain PET insert MR compatible: Final design and first results. 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD). doi:10.1109/nssmic.2016.8069619Dahl, K., Schou, M., Ulin, J., Sjöberg, C.-O., Farde, L., & Halldin, C. (2015). 11C-carbonylation reactions using gas–liquid segmented microfluidics. RSC Advances, 5(108), 88886-88889. doi:10.1039/c5ra20646d[26] Långström B and Sjöberg CO, System for controlling environment in reaction box, From PCT Int. Appl. (2013), WO 2013103312 A1 20130711.Autret, A., Bert, J., Strauss, O., & Visvikis, D. (2012). Projector with realistic detector scatter modelling for PET list-mode reconstruction. 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC). doi:10.1109/nssmic.2012.6551759[10] Young JW Head and Face Antropometry of Adult U.S. Citizens, Civil Aeromedical Institute, Federal Aviation Administration, U.S. Department of Transportation, Report number DOT/FAA/AM-93/10, July 1993.Braff, D. L. (1990). Sensorimotor Gating and Schizophrenia. Archives of General Psychiatry, 47(2), 181. doi:10.1001/archpsyc.1990.01810140081011Preziosi, E., Sánchez, S., González, A. J., Pani, R., Borrazzo, C., Bettiol, M., … Benlloch, J. M. (2016). Performance study of a PET scanner based on monolithic scintillators for different DoI-dependent methods. Journal of Instrumentation, 11(12), C12076-C12076. doi:10.1088/1748-0221/11/12/c12076Howes, O., McCutcheon, R., & Stone, J. (2015). Glutamate and dopamine in schizophrenia: An update for the 21st century. Journal of Psychopharmacology, 29(2), 97-115. doi:10.1177/0269881114563634Moliner, L., Correcher, C., González, A. J., Conde, P., Hernández, L., Orero, A., … Benlloch, J. M. (2013). Implementation and analysis of list mode algorithm using tubes of response on a dedicated brain and breast PET. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 702, 129-132. doi:10.1016/j.nima.2012.08.029Zelano, J., Mikulovic, S., Patra, K., Kühnemund, M., Larhammar, M., Emilsson, L., … Kullander, K. (2013). The synaptic protein encoded by the gene Slc10A4 suppresses epileptiform activity and regulates sensitivity to cholinergic chemoconvulsants. Experimental Neurology, 239, 73-81. doi:10.1016/j.expneurol.2012.09.006Antich, P., Malakhov, N., Parkey, R., Slavin, N., & Tsyganov, E. (2002). 3D position readout from thick scintillators. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 480(2-3), 782-787. doi:10.1016/s0168-9002(01)01214-1Gonzalez-Montoro, A., Benlloch, J. M., Gonzalez, A. J., Aguilar, A., Canizares, G., Conde, P., … Sanchez, F. (2017). Performance Study of a Large Monolithic LYSO PET Detector With Accurate Photon DOI Using Retroreflector Layers. IEEE Transactions on Radiation and Plasma Medical Sciences, 1(3), 229-237. doi:10.1109/trpms.2017.2692819Rahman, O., Takano, A., Amini, N., Dahl, K., Kanegawa, N., Långström, B., … Halldin, C. (2015). Synthesis of ([11C]carbonyl)raclopride and a comparison with ([11C]methyl)raclopride in a monkey PET study. Nuclear Medicine and Biology, 42(11), 893-898. doi:10.1016/j.nucmedbio.2015.07.003Howes, O. D., Kambeitz, J., Kim, E., Stahl, D., Slifstein, M., Abi-Dargham, A., & Kapur, S. (2012). The Nature of Dopamine Dysfunction in Schizophrenia and What This Means for Treatment. Archives of General Psychiatry, 69(8). doi:10.1001/archgenpsychiatry.2012.169Ling, T., Lewellen, T. K., & Miyaoka, R. S. (2007). Depth of interaction decoding of a continuous crystal detector module. Physics in Medicine and Biology, 52(8), 2213-2228. doi:10.1088/0031-9155/52/8/012González, A. J., Majewski, S., Sánchez, F., Aussenhofer, S., Aguilar, A., Conde, P., … Benlloch, J. M. (2016). The MINDView brain PET detector, feasibility study based on SiPM arrays. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 818, 82-90. doi:10.1016/j.nima.2016.02.046Wong, D. F., Waterhouse, R., Kuwabara, H., Kim, J., Brasic, J. R., Chamroonrat, W., … Mozley, P. D. (2013). 18F-FPEB, a PET Radiopharmaceutical for Quantifying Metabotropic Glutamate 5 Receptors: A First-in-Human Study of Radiochemical Safety, Biokinetics, and Radiation Dosimetry. 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A new brain dedicated PET scanner with 4D detector information

[EN] In this article, we present the geometrical design and preliminary results of a high sensitivity organ-specific Positron Emission Tomography (PET) system dedicated to the study of the human brain. The system, called 4D-PET, will allow accurate imaging of brain studies due to its expected high sensitivity, high 3D spatial resolution and, by including precise photon time of flight (TOF) information, a boosted signal-to-noise ratio (SNR). The 4D-PET system incorporates an innovative detector design based on crystal slabs (semi-monolithic) that enables accurate 3D photon impact positioning (including photon Depth of Interaction (DOI) measurement), while providing a precise determination of the photon arrival time to the detector. The detector includes a novel readout system that reduces the number of detector signals in a ratio of 4:1 thus, alleviating complexity and cost. The analog output signals are fed to the TOFPET2 ASIC (PETsys) for scalability purposes. The present manuscript reports the evaluation of the 4D-PET detector, achieving best values 3D resolution values of <1.6 mm (pixelated axis), 2.7±0.5 mm (monolithic axis) and 3.4±1.1 (DOI axis) mm; 359 ± 7 ps coincidence time resolution (CTR); 10.2±1.5 % energy resolution; and sensitivity of 16.2% at the center of the scanner (simulated). Moreover, a comprehensive description of the 4D-PET architecture (that includes 320 detectors), some pictures of its mechanical assembly, and simulations on the expected image quality are provided.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). This work was supported in part by the Spanish Government Grants Generalitat Valenciana, APOSTD/2019/086 and APOSTD/2020/139.We thank financial support from Generalitat Valenciana through the program Equipamiento e Infraestructuras FEDER 2021-22 IDIFEDER/2021/004González-Montoro, A.; Barbera Ballester, J.; Sanchez-Gonzalo, D.; Mondejar, Á.; Freire-López-Fando, M.; Díaz González, K.; Lucero-Ruiz, A.... (2022). A new brain dedicated PET scanner with 4D detector information. Bio-Algorithms and Medical-Systems. 18(1):107-119. https://doi.org/10.2478/bioal-2022-008310711918

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