VIPPIX: A readout ASIC for the next generation of human brain PET scanners

[eng] Positron emission tomography (PET) is a molecular imaging technique used for several decades in nuclear medicine that provides precise physiological information of the human body, what is crucial in oncology, cardiology, and neuropsychiatry. Due to physical, the best spatial resolution of PET...

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Autor: Macías Montero, José Gabriel
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/125318
Acceso en línea:https://hdl.handle.net/2445/125318
http://hdl.handle.net/10803/663182
Access Level:acceso abierto
Palabra clave:Tomografia per emissió de positrons
Circuits integrats d'aplicació específica
Positron emission tomography
Application-specific integrated circuits
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oai_identifier_str oai:diposit.ub.edu:2445/125318
network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv VIPPIX: A readout ASIC for the next generation of human brain PET scanners
title VIPPIX: A readout ASIC for the next generation of human brain PET scanners
spellingShingle VIPPIX: A readout ASIC for the next generation of human brain PET scanners
Macías Montero, José Gabriel
Tomografia per emissió de positrons
Circuits integrats d'aplicació específica
Positron emission tomography
Application-specific integrated circuits
title_short VIPPIX: A readout ASIC for the next generation of human brain PET scanners
title_full VIPPIX: A readout ASIC for the next generation of human brain PET scanners
title_fullStr VIPPIX: A readout ASIC for the next generation of human brain PET scanners
title_full_unstemmed VIPPIX: A readout ASIC for the next generation of human brain PET scanners
title_sort VIPPIX: A readout ASIC for the next generation of human brain PET scanners
dc.creator.none.fl_str_mv Macías Montero, José Gabriel
author Macías Montero, José Gabriel
author_facet Macías Montero, José Gabriel
author_role author
dc.contributor.none.fl_str_mv Chmeissani Raad, Mokhtar
Diéguez Barrientos, Àngel
Universitat de Barcelona. Departament d'Enginyeria Electrònica i Biomèdica
dc.subject.none.fl_str_mv Tomografia per emissió de positrons
Circuits integrats d'aplicació específica
Positron emission tomography
Application-specific integrated circuits
topic Tomografia per emissió de positrons
Circuits integrats d'aplicació específica
Positron emission tomography
Application-specific integrated circuits
description [eng] Positron emission tomography (PET) is a molecular imaging technique used for several decades in nuclear medicine that provides precise physiological information of the human body, what is crucial in oncology, cardiology, and neuropsychiatry. Due to physical, the best spatial resolution of PET is approximately 1 mm for human brain scanners. Unfortunately, the minimum resolution of the best commercial PET scanners for humans is 4-5 mm due to technological limitations. In this thesis, an application specific integrated circuit (ASIC) to readout the energy and the time stamp of a high-density and highly-granulated Cadmium Telluride detector for a novel PET scanner design is presented. The research presented here was realized within the framework of Voxel Imaging PET pathfinder ERC project to develop detector modules for positron emission tomography applications and reach their actual physical limits. The VIP PET scanner is based on the stacking of 2-mm thickness pixelated hybrid detectors. Every CdTe detector is pixelated into an array of 10 x 10 voxels of 1 mm x 1 mm x 2 mm size and is connected to a pixelated ASIC to readout independently the energy and the time stamp of every photon interaction. The VIP PET is based on more than 6 million voxels with independent energy and timing readout to reach the physical limits of PET. The simulated performance based on the properties of CdTe detectors shows a scatter fraction of approximately 4 % due to an excellent energy resolution of 1.6 % FWHM of the CdTe detectors. By simulation, the VIP PET is able to distinguish 1 mm size radioactive point-like source. The characterization of 2-mm thickness CdTe detectors using commercially available single-channel readout electronics is reported. Using a Sodium-22 radioactive source, the 511 keV photopeak resolution and the coincidence time resolution of back-to-back photons were measured with – 1000 V/mm detector bias voltage at -8 Celsius degree. An energy resolution of 1.6 % FWHM and a time coincidence resolution of 6 ns FWHM were obtained for photoelectric interactions. The architecture of the VIPPIX ASIC, i.e. the ASIC developed for VIP project, is based on an array of 10 x 10 independent pixel electronics controlled by a global controller and a common time to digital converter (TDC). Additional voltage and current references are generated in the ASIC’s back-end with a temperature sensor and a chip-ID cell. Every pixel electronics composes of a programmable gain preamplifier with detector’s leakage dynamic compensation, a tuneable peak-time pulse shaper connected to a peak-and-detect circuit, a 10-bit analog-to- digital converter (ADC), a pulse discriminator with adjustable offset, and a local pixel digital controller. The measured equivalent noise charge (ENC) of the pixel is 150 e- RMS and the trigger time jitter is approximately 1 ns for energy depositions larger than 200 keV. The time resolution of the integrated TDC is 600 ps FWHM. Twelve wafers of VIPPIX ASIC has been fabricated and characterized. Best quality ASICs have been mounted on 720 CdTe detectors and stacked in 18 detector modules with 40 hybrid detectors each to build the VIP PET prototype. Five modules have been characterized with a Sodium-22 radioactive source. The performance of approximately 18000 pixels shows a resolution of 2.2 % FWHM and a coincidence time resolution of 60 ns FWHM for 511 keV photopeak at -250 V/mm detector bias. Therefore, the main goal of the research has been accomplished. A new PET design based on pixelated Cadmium Telluride detectors using dedicated readout ASICs has been successfully fabricated, partly characterized, and is ready for image acquisition.
publishDate 2018
dc.date.none.fl_str_mv 2018
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
info:eu-repo/semantics/publishedVersion
format doctoralThesis
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/125318
http://hdl.handle.net/10803/663182
url https://hdl.handle.net/2445/125318
http://hdl.handle.net/10803/663182
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv (c) Macías, 2018
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) Macías, 2018
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universitat de Barcelona
publisher.none.fl_str_mv Universitat de Barcelona
dc.source.none.fl_str_mv Tesis Doctorals - Departament - Enginyeria Electrònica i Biomèdica
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling VIPPIX: A readout ASIC for the next generation of human brain PET scannersMacías Montero, José GabrielTomografia per emissió de positronsCircuits integrats d'aplicació específicaPositron emission tomographyApplication-specific integrated circuits[eng] Positron emission tomography (PET) is a molecular imaging technique used for several decades in nuclear medicine that provides precise physiological information of the human body, what is crucial in oncology, cardiology, and neuropsychiatry. Due to physical, the best spatial resolution of PET is approximately 1 mm for human brain scanners. Unfortunately, the minimum resolution of the best commercial PET scanners for humans is 4-5 mm due to technological limitations. In this thesis, an application specific integrated circuit (ASIC) to readout the energy and the time stamp of a high-density and highly-granulated Cadmium Telluride detector for a novel PET scanner design is presented. The research presented here was realized within the framework of Voxel Imaging PET pathfinder ERC project to develop detector modules for positron emission tomography applications and reach their actual physical limits. The VIP PET scanner is based on the stacking of 2-mm thickness pixelated hybrid detectors. Every CdTe detector is pixelated into an array of 10 x 10 voxels of 1 mm x 1 mm x 2 mm size and is connected to a pixelated ASIC to readout independently the energy and the time stamp of every photon interaction. The VIP PET is based on more than 6 million voxels with independent energy and timing readout to reach the physical limits of PET. The simulated performance based on the properties of CdTe detectors shows a scatter fraction of approximately 4 % due to an excellent energy resolution of 1.6 % FWHM of the CdTe detectors. By simulation, the VIP PET is able to distinguish 1 mm size radioactive point-like source. The characterization of 2-mm thickness CdTe detectors using commercially available single-channel readout electronics is reported. Using a Sodium-22 radioactive source, the 511 keV photopeak resolution and the coincidence time resolution of back-to-back photons were measured with – 1000 V/mm detector bias voltage at -8 Celsius degree. An energy resolution of 1.6 % FWHM and a time coincidence resolution of 6 ns FWHM were obtained for photoelectric interactions. The architecture of the VIPPIX ASIC, i.e. the ASIC developed for VIP project, is based on an array of 10 x 10 independent pixel electronics controlled by a global controller and a common time to digital converter (TDC). Additional voltage and current references are generated in the ASIC’s back-end with a temperature sensor and a chip-ID cell. Every pixel electronics composes of a programmable gain preamplifier with detector’s leakage dynamic compensation, a tuneable peak-time pulse shaper connected to a peak-and-detect circuit, a 10-bit analog-to- digital converter (ADC), a pulse discriminator with adjustable offset, and a local pixel digital controller. The measured equivalent noise charge (ENC) of the pixel is 150 e- RMS and the trigger time jitter is approximately 1 ns for energy depositions larger than 200 keV. The time resolution of the integrated TDC is 600 ps FWHM. Twelve wafers of VIPPIX ASIC has been fabricated and characterized. Best quality ASICs have been mounted on 720 CdTe detectors and stacked in 18 detector modules with 40 hybrid detectors each to build the VIP PET prototype. Five modules have been characterized with a Sodium-22 radioactive source. The performance of approximately 18000 pixels shows a resolution of 2.2 % FWHM and a coincidence time resolution of 60 ns FWHM for 511 keV photopeak at -250 V/mm detector bias. Therefore, the main goal of the research has been accomplished. A new PET design based on pixelated Cadmium Telluride detectors using dedicated readout ASICs has been successfully fabricated, partly characterized, and is ready for image acquisition.Universitat de BarcelonaChmeissani Raad, MokhtarDiéguez Barrientos, ÀngelUniversitat de Barcelona. Departament d'Enginyeria Electrònica i Biomèdica2018info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/125318http://hdl.handle.net/10803/663182Tesis Doctorals - Departament - Enginyeria Electrònica i Biomèdicareponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglés(c) Macías, 2018info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1253182026-05-27T06:46:51Z
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