Measurement of coincidence timing resolution with CdTe detectors

2000 ◽  
Author(s):  
Yiping Shao ◽  
H. Bradford Barber ◽  
Stephen J. Balzer ◽  
Simon R. Cherry
Keyword(s):  
Timing Resolution ◽  
Coincidence Timing

Comparison of Lu3Al5O12:Ce and LaBr3:Ce Scintillators in Gamma-Ray Spectrometry

2011 ◽  
Vol 418-420 ◽  
pp. 922-927
Author(s):  
Weerapong Chewpraditkul ◽  
Chalerm Wanarak ◽  
Marek Moszynski ◽  
Lukasz Swiderski
Keyword(s):  
Energy Resolution ◽  
Gamma Ray ◽  
Light Yield ◽  
Gamma Ray Spectrometry ◽  
Timing Resolution ◽  
Intrinsic Resolution ◽  
Γ Rays ◽  
Γ Ray ◽  
Coincidence Timing ◽  
Better Than

The performances of Ce-doped Lu3Al5O12(LuAG:Ce) and LaBr3(LaBr3:Ce) scintillators were compared for γ-ray detection using photomultiplier tube ( XP5500B PMT) readout. For 662 keV γ-rays (137Cs source), an energy resolution of 3.5% obtained for LaBr3:Ce is much better than that of 6.7% obtained for LuAG:Ce, while the estimated photofraction of 28.0% for LuAG:Ce is higher than that of 16.2% for LaBr3:Ce. The light yield non-proportionality and energy resolution versus γ-ray energy were measured and the intrinsic resolution of the crystals was calculated. The coincidence timing resolution, obtained in this work for 511 keV annihilation quanta, was 583 ps and 204 ps, respectively, for LuAG:Ce –BaF2and LaBr3:Ce – BaF2detectors.

scholarly journals A Simple Contrast Matching Rule for OSEM Reconstructed PET Images with Different Time of Flight Resolution

2021 ◽  
Vol 11 (16) ◽  
pp. 7548
Author(s):  
Luca Presotto ◽  
Valentino Bettinardi ◽  
Elisabetta De Bernardi
Keyword(s):  
Technological Development ◽  
Time Of Flight ◽  
Simulated Data ◽  
Matching Rule ◽  
Timing Resolution ◽  
Positron Emission ◽  
Contrast Matching ◽  
Coincidence Timing ◽  
Digital Simulations ◽  
Pet Scanners

Background: Time-of-Flight (TOF) is a leading technological development of Positron Emission Tomography (PET) scanners. It reduces noise at the Maximum-Likelihood solution, depending on the coincidence–timing–resolution (CTR). However, in clinical applications, it is still not clear how to best exploit TOF information, as early stopped reconstructions are generally used. Methods: A contrast-recovery (CR) matching rule for systems with different CTRs and non-TOF systems is theoretically derived and validated using (1) digital simulations of objects with different contrasts and background diameters, (2) realistic phantoms of different sizes acquired on two scanners with different CTRs. Results: With TOF, the CR matching rule prescribes modifying the iterations number by the CTRs ratio. Without TOF, the number of iterations depends on the background dimension. CR matching was confirmed by simulated and experimental data. With TOF, image noise followed the square root of the CTR when the rule was applied on simulated data, while a significant reduction was obtained on phantom data. Without TOF, preserving the CR on larger objects significantly increased the noise. Conclusions: TOF makes PET reconstructions less dependent on background dimensions, thus, improving the quantification robustness. Better CTRs allows performing fewer updates, thus, maintaining accuracy while minimizing noise.

A method for coincidence timing resolution enhancement

2016 ◽  
Vol 87 (5) ◽  
pp. 053504 ◽  
Author(s):  
E. E. Ermis ◽  
C. Celiktas ◽  
E. Pilicer
Keyword(s):  
Resolution Enhancement ◽  
Timing Resolution ◽  
Coincidence Timing

How to meet the 10 ps Coincidence Timing Resolution PET challenge

2020 ◽  
Author(s):  
Eric S. Harmon ◽  
Michael O. Thompson ◽  
Charles Ross Schmidtlein ◽  
James N. Turner ◽  
Andrzej Krol
Keyword(s):  
Timing Resolution ◽  
Coincidence Timing

Lu1.8Y0.2SiO5:Ce and LaCl3:Ce Scintillators for Gamma-Ray Detection

2011 ◽  
Vol 284-286 ◽  
pp. 2064-2069
Author(s):  
Weerapong Chewpraditkul ◽  
Chalerm Wanarak ◽  
Marek Moszynski ◽  
Tomasz Szczesniak ◽  
Lukasz Swiderski
Keyword(s):  
Energy Resolution ◽  
Gamma Ray ◽  
Light Yield ◽  
Timing Resolution ◽  
Intrinsic Resolution ◽  
Coincidence Timing ◽  
Better Than

The scintillation properties of Lu1.8Y0.2SiO5:Ce (LYSO:Ce) and LaCl3:Ce scintillators were studied under g-ray excitation. For 662 keV g-rays (137Cs source), energy resolution of 4.5% obtained for LaCl3:Ce coupled to XP5200B PMT is much better than that of 8.2% for LYSO:Ce. The estimated photofraction of 26.1% at 662 keV for LYSO:Ce is higher than that of 15.7 % for LaCl3:Ce. The non-proportionality of the light yield and energy resolution versus g-ray energy were measured and the intrinsic resolution of the crystals was calculated. The coincidence timing resolution, obtained in this work for 511 keV annihilation quanta, was 222 and 229 ps, respectively, for LYSO:Ce – and LaCl3:Ce – based detectors in coincidence with a BaF2detector.

scholarly journals Fully digital PET is unaffected by any deterioration in TOF resolution and TOF image quality in the wide range of routine PET count rates

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Julien Salvadori ◽  
Freddy Odille ◽  
Gilles Karcher ◽  
Pierre-Yves Marie ◽  
Laetitia Imbert
Keyword(s):  
Image Quality ◽  
Dead Time ◽  
Silicon Photomultipliers ◽  
Timing Resolution ◽  
Upper Limits ◽  
Wide Range ◽  
Pile Up ◽  
Digital Pet ◽  
Trigger Circuit

Abstract Purpose Digital PET involving silicon photomultipliers (SiPM) provides an enhanced time-of-flight (TOF) resolution as compared with photomultiplier (PMT)-based PET, but also a better prevention of the count-related rises in dead time and pile-up effects mainly due to smaller trigger domains (i.e., the detection surfaces associated with each trigger circuit). This study aimed to determine whether this latter property could help prevent against deteriorations in TOF resolution and TOF image quality in the wide range of PET count rates documented in clinical routine. Methods Variations, according to count rates, in timing resolution and in TOF-related enhancement of the quality of phantom images were compared between the first fully digital PET (Vereos) and a PMT-based PET (Ingenuity). Single-count rate values were additionally extracted from the list-mode data of routine analog- and digital-PET exams at each 500-ms interval, in order to determine the ranges of routine PET count rates. Results Routine PET count rates were lower for the Vereos than for the Ingenuity. For Ingenuity, the upper limits were estimated at approximately 21.7 and 33.2 Mcps after injection of respectively 3 and 5 MBq.kg-1 of current 18F-labeled tracers. At 5.8 Mcps, corresponding to the lower limit of the routine count rates documented with the Ingenuity, timing resolutions provided by the scatter phantom were 326 and 621 ps for Vereos and Ingenuity, respectively. At higher count rates, timing resolution was remarkably stable for Vereos but exhibited a progressive deterioration for Ingenuity, respectively reaching 732 and 847 ps at the upper limits of 21.7 and 33.2 Mcps. The averaged TOF-related gain in signal/noise ratio was stable at approximately 2 for Vereos but decreased from 1.36 at 5.8 Mcps to 1.14 and 1.00 at respectively 21.7 and 33.2 Mcps for Ingenuity. Conclusion Contrary to the Ingenuity PMT-based PET, the Vereos fully digital PET is unaffected by any deterioration in TOF resolution and consequently, in the quality of TOF images, in the wide range of routine PET count rates. This advantage is even more striking with higher count-rates for which the preferential use of digital PET should be further recommended (i.e., dynamic PET recording, higher injected activities).

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