Advancement in PET quantification using 3D-OP-OSEM point spread function reconstruction with the HRRT.
OBJECTIVE
Image reconstruction including the modelling of the point spread function (PSF) is an approach improving the resolution of the PET images. This study assessed the quantitative improvements provided by the implementation of the PSF modelling in the reconstruction of the PET data using the High Resolution Research Tomograph (HRRT).


METHODS
Measurements were performed on the NEMA-IEC/2001 (Image Quality) phantom for image quality and on an anthropomorphic brain phantom (STEPBRAIN). PSF reconstruction was also applied to PET measurements in two cynomolgus monkeys examined with [(18)F]FE-PE2I (dopamine transporter) and with [11C]MNPA (D2 receptor), and in one human subject examined with [11C]raclopride (D2 receptor).


RESULTS
PSF reconstruction increased the recovery coefficient (RC) in the NEMA phantom by 11-40% and the grey to white matter ratio in the STEPBRAIN phantom by 17%. PSF reconstruction increased binding potential (BP (ND)) in the striatum and midbrain by 14 and 18% in the [18F]FE-PE2I study, and striatal BP (ND) by 6 and 10% in the [11C]MNPA and [11C]raclopride studies.


CONCLUSIONS
PSF reconstruction improved quantification by increasing the RC and thus reducing the partial volume effect. This method provides improved conditions for PET quantification in clinical studies with the HRRT system, particularly when targeting receptor populations in small brain structures.
Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section and Stockholm Brain Institute, R5:02, Karolinska Hospital, 17176, Stockholm, Sweden. andrea.varrone@ki.se
Andrea
A
Varrone
Nils
N
Sjöholm
Lars
L
Eriksson
Balazs
B
Gulyás
Christer
C
Halldin
Lars
L
Farde
D000465:Algorithms; D000818:Animals; D001058:Apomorphine / Q000031:analogs & derivatives; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002250:Carbon Radioisotopes; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D005462:Fluorine Radioisotopes; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data*; D008252:Macaca fascicularis; D015233:Models, Statistical; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D020891:Raclopride; D019275:Radiopharmaceuticals
D002250:Carbon Radioisotopes; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D020891:Raclopride; C009074:N-n-propylnorapomorphine; D001058:Apomorphine