Positron emission tomography inter-scanner differences in dopamine D₂ receptor binding measured with [¹¹C]FLB457.
OBJECTIVE
It is well known that the positron emission tomography (PET) system is subject to inter-scanner differences of regional radioactivity distribution. In the present study, the effect of inter-scanner difference of regional radioactivity on estimated binding potential (BP(ND)) of [¹¹C]FLB457 using the simplified reference tissue model (SRTM) was investigated.


METHODS
Each of the 11 subjects was given two PET scans using [¹¹C]FLB457, one each with both SET-3000 GCT/X (Shimadzu) and with ECAT EXACT HR+ (Siemens/CTI). In order to assess regional differences between the two scanners, estimated BP(ND) values in six volumes of interest (VOIs) by SRTM method were compared in both individual PET space and anatomical template space after anatomical normalization. Statistical voxel-by-voxel paired t test of BP(ND) images between SET-3000 GCT/X and ECAT EXACT HR+ was also performed.


RESULTS
Shapes of time-activity curves of the two PET scanners were slightly different in each VOI, with estimated BP(ND) values from ECAT EXACT HR+ appearing greater in the cerebral cortical regions and thalamus than that of SET-3000 GCT/X in both individual PET space and anatomical template space after anatomical normalization. Statistical voxel-by-voxel analysis showed similar tendency to BP(ND) value estimation, with greater BP(ND) values from ECAT EXACT HR+ than from SET-3000 GCT/X.


CONCLUSIONS
We demonstrated the inter-scanner differences in dopamine D(2) receptor binding measured with [¹¹C]FLB457. In particular, statistically significant differences of BP(ND) in certain regions were observed between two PET scanners, despite the subject groups being the same. Our results suggest that we reconsider the effect of the scanner model on the measurement of receptor binding.
Kodaka
Fumitoshi
F
Clinical Neuroimaging Team, Molecular Neuroimaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
Ito
Hiroshi
H
Shidahara
Miho
M
Takano
Harumasa
H
Takahashi
Hidehiko
H
Arakawa
Ryosuke
R
Nakayama
Kazuhiko
K
Suhara
Tetsuya
T
D000328:Adult; D016477:Artifacts; D002250:Carbon Radioisotopes; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography / Q000295:instrumentation / Q000379:methods*; D011485:Protein Binding; D011759:Pyrrolidines / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012457:Salicylamides / Q000378:metabolism*; D055815:Young Adult
D002250:Carbon Radioisotopes; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D012457:Salicylamides; C065065:FLB 457