English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The possibility to separate signals caused by 511 keV photons created inannihilation of electron-positron pairs and the so-called prompt photons fromnuclei de- excitation is investigated. It could potentially be used to improvethe quality of reconstructed images in the J-PET scanner in 2+1 photontomography. Firstly, a research is conducted for several radioisotopes thatdecay via \b{eta}+ decay followed by de-excitation of an excited nucleus.Efficiency, purity and false positive rate are calculated for each isotope as afunction of energy deposited threshold, with a hypothesis that signals causedby 511 keV photons deposit smaller values of energy than 1 z 13the selectedthreshold, while prompt photons deposit larger energy than the threshold.Analysis of the results accompanied with physical properties of radioisotopessuggests using 44 Sc, which is the most promising candidate for medicalapplications. With the use of GATE and J-POS simulation software, in-phantomscattering was introduced and the best energy deposited threshold value wasestimated to be approximately 375 keV. It corresponds to almost 100% efficiencyfor 511 keV signals, 75% purity for 511 keV photons, and approximately 70%efficiency and purity for prompt photons.

Towards 2+1 photon tomography: Energy-based selection of two 511 keV photons and a prompt photon with the J-PET scanner