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Simulation of triple coincidences in PET
J Cal-González1, E Lage, E Herranz
1Grupo de Física Nuclear, Dpto. de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, CEI Moncloa, Spain.
Physics in Medicine and Biology
|December 6, 2014
Summary
Triple coincidences in PET scans, often discarded, can improve sensitivity and differentiate radiotracers. This study quantifies their impact, revealing significant contributions from inter-detector scatter and non-pure positron emitters.
Area of Science:
- Medical Imaging
- Nuclear Physics
- Computational Science
Background:
- Current PET scanners primarily detect double coincidence events.
- Triple coincidences, arising from scatter, random events, or beta-gamma decays, are often discarded or introduce noise.
- Novel applications for triple coincidence events are being explored to enhance PET capabilities.
Purpose of the Study:
- To extend the PeneloPET Monte Carlo simulator to assess triple coincidence proportions in PET.
- To evaluate the potential applications of triple coincidence events in PET imaging.
- To validate simulation results against experimental data from a modified preclinical PET/CT scanner.
Main Methods:
- Utilized the PeneloPET Monte Carlo simulator to model triple coincidence events.
- Validated simulation predictions against experimental data from a preclinical PET/CT scanner capable of triple coincidence acquisition.
- Analyzed energy spectra and triples-to-doubles ratios across various energy windows and radionuclides.
Main Results:
- Simulations showed good agreement with experimental data (differences <10%).
- Triple coincidences constitute ~10% of processed double events for pure positron emitters in clinical scanners.
- For non-pure emitters like Iodine-124 and Yttrium-86, this ratio increases significantly (>25% and >50%, respectively).
- Inter-detector scatter (IDS) accounts for ~18% of events in preclinical and 14-22% in clinical scanners for Fluorine-18.
Conclusions:
- Triple coincidence events are a significant factor in PET acquisitions, impacting image quality and information content.
- The validated PeneloPET simulator can accurately predict triple coincidence behavior.
- Leveraging triple coincidence data offers potential for improved PET sensitivity and advanced radiotracer differentiation.
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