DocumentCode :
3607420
Title :
Crystal Identification in Positron Emission Tomography Using Probabilistic Graphical Models
Author :
Keator, David B. ; Ihler, Alexander
Author_Institution :
Depts. of Comput. Sci. & Psychiatry & Human Behavior, Univ. of California, Irvine, Irvine, CA, USA
Volume :
62
Issue :
5
fYear :
2015
Firstpage :
2102
Lastpage :
2112
Abstract :
Determining the location of crystals within detector arrays (position profile) is a crucial part of system tuning in Positron Emission Tomography (PET) scanners. It provides a basis for the mapping of detected events and the most probable crystal location to assign the event. Accurate assignments are crucial for proper coincidence event processing and reconstructed image resolution. In high resolution imaging systems, image resolution is of primary importance and proper position profiles are a critical part of system tuning. The High Resolution Research Tomograph (HRRT) PET scanner is composed of 936 detector blocks each with 64 dual layer crystals arranged in 8 ×8 grids. Significant engineer time is spent fixing errors in the automated position profile estimation software used for system tuning. We have developed a probabilistic approach to position profile estimation and applied it to the HRRT PET system. Our approach is composed of a segmentation model for crosstalk filtering, a prior over valid position profile configurations, and a grid partitioning algorithm for crystal location finding. Our model outperforms the manufacturer supplied position profile estimation software, yielding a 39% decrease in mean squared error rate as compared to a gold standard configuration in the HRRT, while being a general solution applicable to many detector array configurations.
Keywords :
Gaussian processes; Markov processes; biomedical equipment; lutetium compounds; mixture models; positron emission tomography; signal processing; solid scintillation detectors; yttrium compounds; HRRT PET scanner; High Resolution Research Tomograph; Lu2SiO5-Lu2-2xY2xSiO5; PET scanners; PET system tuning; coincidence event processing; crosstalk filtering; crystal identification; crystal location determination; crystal location finding; crystal position profile; detected event mapping; detector arrays; dual layer crystals; grid partitioning algorithm; high resolution imaging systems; positron emission tomography; probabilistic graphical models; probable crystal location; reconstructed image resolution; segmentation model; Crosstalk; Crystals; Detectors; Graphical models; Image segmentation; Positron emission tomography; Probabilistic logic; Crystal position map; Gaussian mixture model; Markov random field; graphical model; high resolution research tomograph (HRRT); max-product; mean field; positron emission tomography (PET);
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2015.2477310
Filename :
7286863
Link To Document :
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