title: Effects of point spread function-based image reconstruction on neuroreceptor binding in positron emission tomography study with [(11)C]FLB 457.
abstract: The ordered subset expectation maximization with a point spread function (OSEM-PSF) was developed to improve the spatial resolution of reconstructed positron emission tomography (PET) images and has been reported to improve the contrast of hot spots in PET studies for oncology. However, in neuroreceptor imaging, the regional radioactivity concentration changes dynamically during the scan, and the effects of the PSF may differ among various radioligands or quantification methods. In this study, we investigated the effects of the PSF on quantification in PET studies with [(11)C]FLB 457 of dopamine D2 receptors, using both phantom and human data acquired by the Siemens Biograph 16 imaging platform. In the phantom studies, we evaluated the hot contrast recovery coefficient (HCRC) for variously sized hot spheres and the linearity between the measured and true radioactivities in OSEM-PSF images. Next, in the human studies with [(11)C]FLB 457, radioactivity concentrations and binding potentials for the cerebral cortex and thalamus were compared between images reconstructed with and without PSF. In the phantom studies, the OSEM-PSF images showed a better HCRC compared to images without PSF, and they showed a good linear correlation with true radioactivity. In the human studies, the radioactivity concentration increased especially in small regions with high accumulation of [(11)C]FLB 457 when the PSF was included. However, little difference in the binding potentials was observed for the target regions between both types of reconstructed images. In conclusion, PSF-based reconstruction reduced the spill-over phenomena in small hot regions; however, it caused no increase in the binding potentials in the [(11)C]FLB 457 studies.
authors.affiliation: Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.|Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, 2 Prannok Rd., Bangkok-noi, Bangkok, 10700, Thailand.
authors.forename: Thonnapong
authors.initials: T
authors.lastname: Thongpraparn
authors.affiliation: Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. ikoma@nirs.go.jp.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ikoma
authors.affiliation: Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shiraishi
authors.affiliation: Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Taiga
authors.initials: T
authors.lastname: Yamaya
authors.affiliation: Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
mesh_terms: D000465:Algorithms; D002250:Carbon Radioisotopes; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016014:Linear Models; D008297:Male; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography; D011485:Protein Binding; D011759:Pyrrolidines / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012457:Salicylamides / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D012457:Salicylamides; C065065:FLB 457
keywords: Image reconstruction; Neuroreceptor; PET; Point spread function; [11C]FLB 457