Fast and efficient optical Cherenkov detector for PET
Description
Positron Emission Tomography (PET) is a nuclear imaging technique widely used in oncology and neuroscience to observe biological activity in the body. Detection of two gamma quanta with the energy 511 keV emitted by positron annihilation in tissues allows one to reconstruct the tracer activity distribution in the body of the patient. Additional measurement of the difference in time detection between the two photons lets us to improve significantly the quality of the reconstructed image (time-of-flight method). In this manuscript, we present the development of two innovative detectors, fast and efficient, used to detect Cherenkov light produced by electrons from the photo-ionization conversions of 511 keV gamma quanta. The first one, intended for use in a brain PET scanner of a high spatial resolution, uses Trimethyl-Bismuth for the detection medium. The second one, planned to be used to construct a whole-body PET scanner, enforces a PbF2 crystal as Cherenkov radiator. In both configurations a micro-channel photo-multiplier (MCP-PMT) is used to detect Cherenkov photons. We commissioned an electronic detection chain with a time resolution limited to 5 ps (RMS). Using precise MCP-PMT calibration, we were able to develop simultaneously detectors with high efficiency, up to 25 %, and time resolution as good as 200 ps (FWHM).We highlight the limitations of detectors time resolution and suggest several developments in order to improve performances of Cherenkov light detectors. (author)
Abstract (French)
La Tomographie par Emission de Positrons (TEP) est une technique d'imagerie medicale utilisee largement dans le traitement du cancer et dans la recherche neurobiologique, afin d'imager l'activite biologique des organes. Il s'agit de detecter deux photons de 511 keV produits par l'annihilation d'un positron dans les tissus, ce qui permet d'en reconstruire la carte 3D. En mesurant avec une tres bonne precision la difference de temps de detection des deux photons, il sera possible d'ameliorer la qualite d'image (technique du temps de vol). Dans ce manuscrit, nous presentons le developpement de deux detecteurs innovants, rapides et efficaces, pour la detection de la lumiere Cherenkov produite par la conversion des photons de 511 keV. Le premier, destine a un scanner clinique (cerveau) et pre-clinique a haute precision spatiale, utilise comme milieu de detection du TriMethylBismuth. Le second, pouvant etre utilise pour construire un scanner corps entier, met en oeuvre un cristal de PbF2 comme radiateur Cherenkov. Dans les deux configurations, un photomultiplicateur a micro-canaux (MCP-PMT) est utilise pour detecter les photons Cherenkov. Notre electronique de detection montre une resolution temporelle limitee a 5 ps (RMS). La chaine de detection est limitee par les performances du MCP-PMT. Apres etalonnage, nous avons mesure une efficacite de 25 % (grande pour un detecteur Cherenkov), et de resolution temporelle de 200 ps (FWHM). Nous exposons les facteurs limitant la resolution temporelle des detecteurs et proposons des developpements qui permettront d'en ameliorer les performances
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Additional details
Additional titles
- Original title (French)
- Detecteur optique Cherenkov de photons 511 keV, rapide et efficace, pour l'imagerie TEP
Publishing Information
- Imprint Pagination
- 145 p.
- Report number
- FRCEA-TH--10915
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 51056585
- Subject category
- S46: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; S62: RADIOLOGY AND NUCLEAR MEDICINE;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- BRAIN; CHERENKOV COUNTERS; PHOTOMULTIPLIERS; POSITRON COMPUTED TOMOGRAPHY; SPATIAL RESOLUTION; TIME RESOLUTION; WHOLE-BODY COUNTING
- Descriptors DEC
- BODY; CENTRAL NERVOUS SYSTEM; COMPUTERIZED TOMOGRAPHY; COUNTING TECHNIQUES; DIAGNOSTIC TECHNIQUES; EMISSION COMPUTED TOMOGRAPHY; MEASURING INSTRUMENTS; NERVOUS SYSTEM; ORGANS; PHOTOTUBES; RADIATION DETECTORS; RESOLUTION; TIMING PROPERTIES; TOMOGRAPHY
Optional Information
- Notes
- 79 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses; Also available from SCD, Domaine universitaire de Paris-Sud Batiment 407 Rue du Doyen Georges Poitou 91405 ORSAY Cedex (France)