First positronium lifetime imaging with scandium-44 on a long axial field-of-view PET/CT.

DOI
Publisher DOI
PubMed ID
41357528
Abstract
Purpose
The physical properties of 44Sc, combined with its imminent clinical application, position it as a prime candidate for in vivo positronium lifetime imaging. In this study, we investigate the count statistics for ortho-positronium (oPs) measurements with 44Sc on a commercial long-axial field-of-view (LAFOV) PET/CT.Method
A NEMA image quality phantom was filled with 41.7 MBq of 44Sc dissolved in water and scanned on a LAFOV PET/CT. Three-photon events were identified using a prototype feature of the scanner and dedicated software. The lifetime of oPs was determined in the phantom spheres and in 4 mm3 voxels.Results
All measured oPs lifetimes are compatible, within the uncertainties, with the literature values for water. The oPs lifetime is 2.65 , 1.39 and 1.76 ns in the three smallest spheres of the phantom and 1.79 ns for a single voxel in the central region of the largest sphere. The relative standard deviation in the background regions of the time difference distributions, i.e., for time differences smaller than - ns, is above 20%-even for voxels inside the phantom spheres.Conclusions
Despite the favorable physical properties of 44Sc, the count statistics of three-photon events remains a challenge. The high prompt-photon energy causes a significant amount of random three-photon coincidences with the given methodology and, therefore, increases the statistical uncertainties on the measured oPs lifetime.
Date Issued
2025
Publication Type
Article
Subject(s)
Subjects
NEMA phantom
•
long axial field-of-view PET/CT
•
positronium
•
positronium lifetime imaging
•
scandium-44
Language(s)
en
Author(s)
Steinberger, William M
Grundler, Pascal V
Moiseeva, Anzhelika
Conti, Maurizio
Moskal, Paweł
Stepień, Ewa Ł
van der Meulen, Nicholas P
Additional Credits
Journal
Frontiers in Nuclear Medicine
Publisher
Frontiers Media
ISSN
2673-8880
Access(Rights)
open.access
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