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Author |
Linhart, V.; Burdette, D.; Chessi, E.; Cindro, V.; Clinthorne, N.H.; Cochran, E.; Grosicar, B.; Honscheid, K.; Kagan, H.; Lacasta, C.; Llosa, G.; Mikuz, M.; Stankova, V.; Studen, A.; Weilhammer, P.; Zontar, D. |
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Title |
Spectroscopy study of imaging devices based on silicon Pixel Array Detector coupled to VATAGP7 read-out chips |
Type |
Journal Article |
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Year |
2011 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
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Volume |
6 |
Issue |
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Pages |
C01092 - 8pp |
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Keywords |
Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA); Compton imaging |
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Abstract |
Spectroscopic and timing response studies have been conducted on a detector module consisting of a silicon Pixel Array Detector bonded on two VATAGP7 read-out chips manufactured by Gamma-Medica Ideas using laboratory gamma sources and the internal calibration facilities (the calibration system of the read-out chips). The performed tests have proven that the chips have (i) non-linear calibration curves which can be approximated by power functions, (ii) capability to measure the energy of photons with energy resolution better than 2 keV (exact range and resolution depend on experimental setup), (iii) the internal calibration facility which provides 6 out of 16 available internal calibration charges within our region of interest (spanning the Compton edge of 511 keV photons). The peaks induced by the internal calibration facility are suitable for a fit of the calibration curves. However, they are not suitable for measurements of equivalent noise charge because their full width at half maximum varies with their amplitude. These facts indicate that the VATAGP7 chips are useful and precise tools for a wide variety of spectroscopic devices. We have also explored time walk of the module and peaking time of the spectroscopy signals provided by the chips. We have observed that (iv) the time walk is caused partly by the peaking time of the signals provided by the fast shaper of the chips and partly by the timing uncertainty related to the varying position of the photon interaction, (v) the peaking time of the spectroscopy signals provided by the chips increases with increasing pulse height. |
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Address |
[Linhart, V.; Lacasta, C.; Llosa, G.; Stankova, V.] UVEG, CSIC, IFIC, Expt Phys Dept,Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: Vladimir.Linhart@ific.uv.es |
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Iop Publishing Ltd |
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English |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1748-0221 |
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Notes |
ISI:000291345600097 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial  |
645 |
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Author |
Hoeschen, C.; Mattsson, S.; Cantone, M.C.; Mikuz, M.; Lacasta, C.; Ebel, G.; Clinthorne, N.; Giussani, A. |
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Title |
Minimising activity and dose with enhanced image quality by radiopharmaceutical administrations |
Type |
Journal Article |
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Year |
2010 |
Publication |
Radiation Protection Dosimetry |
Abbreviated Journal |
Radiat. Prot. Dosim. |
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Volume |
139 |
Issue |
1-3 |
Pages |
250-253 |
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Keywords |
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Abstract |
Owing to the introduction of new diagnostic procedures, such as computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT), the individual dose caused by medical exposures has grown rapidly in the last years. This is especially a subject to radiation protection for nuclear medical diagnosis, since in this case radiopharmaceuticals are administered to the patient, meaning not only a radiation exposure to the diseased tissue but also to the healthy tissues of large parts of the body. 'Minimizing Activity and Dose with Enhanced Image quality by Radiopharmaceutical Administrations' (MADEIRA) is a project cofunded by the European Commission within the Seventh Euratom Framework Programme that aims to improve three-dimensional (3D) nuclear medical imaging technologies significantly. MADEIRA is aiming to improve the efficacy and safety of 3D PET and SPECT functional imaging by optimising the spatial resolution and the signal-to-noise ratio, improving the knowledge of the temporal variation of the radiopharmaceuticals' uptake in and clearance from tumourous and healthy tissues, and evaluation of the corresponding patient dose. Using an optimised imaging procedure that improves the information gained per unit administered dose, MADEIRA aims especially to reduce the dose to healthy tissues of the patient. In this paper, an overall summary of the current achievements will be presented. |
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Address |
[Hoeschen, C.; Giussani, A.] German Res Ctr Environm Hlth, Helmholtz Zentrum Munchen, Inst Radiat Protect, D-85764 Neuherberg, Germany, Email: christoph.hoeschen@helmholtz-muenchen.de |
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Publisher |
Oxford Univ Press |
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English |
Summary Language |
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ISSN |
0144-8420 |
ISBN |
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Conference |
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Notes |
ISI:000277738200045 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
450 |
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Author |
Studen, A.; Burdette, D.; Chesi, E.; Cindro, V.; Clinthorne, N.H.; Cochran, E.; Grosicar, B.; Kagan, H.; Lacasta, C.; Linhart, V.; Mikuz, M.; Stankova, V.; Weilhammer, P.; Zontar, D. |
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Title |
Timing performance of the silicon PET insert probe |
Type |
Journal Article |
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Year |
2010 |
Publication |
Radiation Protection Dosimetry |
Abbreviated Journal |
Radiat. Prot. Dosim. |
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Volume |
139 |
Issue |
1-3 |
Pages |
199-203 |
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Keywords |
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Abstract |
Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an Na-22 source, and a scintillator (LYSO)-PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron-hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns. |
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Address |
[Studen, A.; Cindro, V.; Grosicar, B.; Mikuz, M.; Zontar, D.] Jozef Stefan Inst, SI-1000 Ljubljana, Slovenia, Email: andrej.studen@ijs.si |
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Publisher |
Oxford Univ Press |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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ISSN |
0144-8420 |
ISBN |
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Conference |
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Notes |
ISI:000277738200035 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
449 |
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| Permanent link to this record |
