2018 AAPM Annual Meeting
Back to session list

Session Title: Physics Testing Gamma Cameras and PET Scanners: Reports from TG 117 and TG 126
Question 1: Compared to conventional photo-multiplier PET systems, spatial resolution of the SiPM digital photon counting PET system is least affected by
Reference:WW Moses. Fundamental Limits of Spatial Resolution in PET. Nucl Instrum Methods Phys Res A. 2011 Aug 21; 648 Supplement 1: S236–S240 Jun Zhang, Michael V Knopp etc. Effect of next generation SiPM digital photon counting PET technology on effective system spatial resolution. SNMMI 2017 June 13; Denver, USA
Choice A:Crystal size
Choice B:Positron Range
Choice C:Noncollinearity / Acollinearity
Choice D:Localization decoding
Question 2: For a 48cm diameter object, an estimated sensitivity gain and SNR improvement of the digital photon counting TOF PET (320ps, 4.8cm uncertainty) compared to nonTOF PET are about:
Reference:Karp JS. Surti S, Daube-Witherspoon ME and Muehllehner G. Advances in Time-Of-Flight PET. Phys Med, 32(1): 12-22. Budinger TF. Time-of-Flight Positron Emission Tomography - Status Relative to Conventional PET. J Nucl Med. 1983;24(1):73–76.
Choice A:5.0 and 5.0
Choice B:10.0 and 10.0
Choice C:10.0 and 3.2
Choice D:10.0 and 5.0
Question 3: The timing resolution on the digital PET/CT scanners from GE is in the range of:
Reference:Grant AM, Deller TW, Khalighi MM, Maramraju SH, Delso G, Levin CS. NEMA NU 2-2012 performance studies for the SiPM-based ToF-PET component of the GE SIGNA PET/MR system. Med Phys. 2016 May;43(5):2334.
Choice A:250-350 ps
Choice B:350-450 ps
Choice C:450-550 ps
Choice D:Depends on the number of block rings.
Question 4: The sensitivity of digital versus conventional GE PET/CT scanners that have the same number of detector rings:
Reference:Reynés-Llompart G, Gámez-Cenzano C, Romero-Zayas I, Rodríguez-Bel L, Vercher-Conejero JL, Martí-Climent JM. Performance Characteristics of the Whole-Body Discovery IQ PET/CT System. J Nucl Med. 2017 Jul;58(7):1155-1161. Grant AM, Deller TW, Khalighi MM, Maramraju SH, Delso G, Levin CS. NEMA NU 2-2012 performance studies for the SiPM-based ToF-PET component of the GE SIGNA PET/MR system. Med Phys. 2016 May;43(5):2334.
Choice A:Is higher for digital compared to conventional detectors systems.
Choice B:Is lower for digital compared to conventional detector systems.
Choice C:Is about the same for digital compared to conventional detector systems.
Choice D:Is independent of the detector system.
Question 5: Why is LSO or LYSO commonly used as a detector material in PET/CT scanners, rather than NaI(Tl), as commonly used in SPECT?
Reference:Vandenberghe et al. Time-of-flight PET: a review of different benefits and recent developments in time-of-flight PET. Euro J Nucl Med, 3: Dec 2015.
Choice A:The energy resolution is better at 511 keV to improve event characterization.
Choice B:The lower timing resolution enables TOF imaging.
Choice C:The detector can be used for PET as well as CT detectors, thereby enabling PET/CT scanners.
Choice D:It is less a less expensive scintillation material.
Question 6: Improved time-of-flight resolution primarily leads to which of the following?
Reference:Surti S. Update on Time-of-Flight PET Imaging. J Nucl Med, 56(1): 98-105, Jan 2015.
Choice A:Improved spatial resolution
Choice B:Increased scan counts
Choice C:Improved image signal-to-noise
Choice D:All of the above
Back to session list