A Small-Animal PET System Based on LYSO Crystal Arrays, PS-PMTs and a PCI DAQ Board

作者:Alva Sanchez H*; Murrieta T; Moreno Barbosa E; Brandan M E; Ruiz Trejo C; Martinez Davalos A; Rodriguez Villafuerte M
来源:IEEE Transactions on Nuclear Science, 2010, 57(1): 85-93.
DOI:10.1109/TNS.2009.2038052

摘要

A positron emission tomography system for small animals has been designed for research purposes, and developed at Instituto de Fisica, UNAM, Mexico. Its detection modules are based on pixelated scintillator LYSO crystal arrays coupled to Hamamatsu H8500 position-sensitive photomultiplier tubes. The front-end electronics are based on nuclear instrumentation modules (NIM) and in-house built readout circuits. Peak signal digitization is performed with a commercial analogue-to-digital acquisition (DAQ) board. The system has been characterized for spatial, timing and energy resolution, system dead time, absolute sensitivity, scatter fraction and noise equivalent count rate (NEC). The results indicate that the detection modules are able to identify individual crystals (out of 400) with up to 8-to-1 peak-to-valley ratios with individual crystal energy resolution ranging from 7 to 15% at 511 keV. The timing resolution is 1.9 ns and the system dead time was found to be 16.8 mu s and 42.1 mu s for 0.5 ml and 10 ml volume sources, respectively. The measured absolute system sensitivity is 0.11% and the scatter fraction from a glass capillary inside a 2.5 cm diameter mouse phantom is 21.5%. A true NEC maximum value was not achieved with the system due to saturation of the PS-PMT output signals for activities above 0.27 mCi. Results from a Na(18)F PET bone scan of a 30 g mouse are shown.

  • 出版日期2010-2