Imaging characteristics of iodine-124 on animal PET.

摘要

We studied the imaging characteristics of Iodine-124 (I-124) on an animal scanner, a microPET Focus 120. The motivation was to develop I-124 applications that take advantage of the long half-life (4.2 days) of I-124 and the wide varieties of Iodine labeled, biologically active compounds.;The challenges lay in that I-124 emits high energy positrons and high energy gamma rays that degrade image quality especially on high resolution animal PET. In this work, the decay scheme of I-124 was emulated with the GATE Monte Carlo simulation package. The imaging characteristics of the microPET Focus 120 using I-124 and F-18 with equivalent settings was studied by simulations and experiments using protocols adapted from the NEMA standard and literature. Energy spectrum and spatial distribution of true, scatter, and random coincidences were obtained from simulation. Using a setting of 250-750keV energy window and 10 ns tuning window, the system sensitivity was 4.4% and 1.1%, respectively, for point sources filled with F-18 and I-124 and placed at the center of field of view (CFOV). (Abstract shortened by UMI.).