DocumentCode :
51835
Title :
Characterization of Sensitivity Encoded Silicon Photomultiplier (SeSP) with 1-Dimensional and 2-Dimensional Encoding for High Resolution PET/MR
Author :
Omidvari, Negar ; Schulz, Volkmar
Author_Institution :
Res. Labs., Philips Technol. GmbH Innovative Technol., Aachen, Germany
Volume :
62
Issue :
3
fYear :
2015
fDate :
Jun-15
Firstpage :
679
Lastpage :
687
Abstract :
This paper evaluates the performance of a new type of PET detectors called sensitivity encoded silicon photomultiplier (SeSP), which allows a direct coupling of small-pitch crystal arrays to the detector with a reduction in the number of readout channels. Four SeSP devices with two separate encoding schemes of 1D and 2D were investigated in this study. Furthermore, both encoding schemes were manufactured in two different sizes of 4 ×4 mm2 and 7. 73 ×7. 9 mm2, in order to investigate the effect of size on detector parameters. All devices were coupled to LYSO crystal arrays with 1 mm pitch size and 10 mm height, with optical isolation between crystals. The characterization was done for the key parameters of crystal-identification, energy resolution, and time resolution as a function of triggering threshold and over-voltage (OV). Position information was archived using the center of gravity (CoG) algorithm and a least squares approach (LSQA) in combination with a mean light matrix around the photo-peak. The positioning results proved the capability of all four SeSP devices in precisely identifying all crystals coupled to the sensors. Energy resolution was measured at different bias voltages, varying from 12% to 18% (FWHM) and paired coincidence time resolution (pCTR) of 384 ps to 1.1 ns was obtained for different SeSP devices at about 18 °C room temperature. However, the best time resolution was achieved at the highest over-voltage, resulting in a noise ratio of 99.08%.
Keywords :
biomedical MRI; least squares approximations; photomultipliers; positron emission tomography; 1D encoding; 2D encoding; CoG algorithm; SeSP devices; center of gravity algorithm; high resolution PET-MR; least squares approach; optical isolation; over voltage; paired coincidence time resolution; pitch size; position information; readout channels; sensitivity encoded silicon photomultiplier; small pitch crystal arrays; Crystals; Detectors; Encoding; Noise; Sensitivity; Temperature measurement; LYSO; PET; PET/MR; SeSP; position sensitive SiPM;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2015.2422374
Filename :
7100952
Link To Document :
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