Partial volume effect-corrected FDG PET and grey matter volume loss in patients with mild Alzheimer's disease.
OBJECTIVE
Although( 18)F-fluorodeoxyglucose (FDG) PET is an established imaging technique to assess brain glucose utilisation, accurate measurement of tracer concentration is confounded by the presence of partial volume effect (PVE) due to the limited spatial resolution of PET, which is particularly true in atrophic brains such as those encountered in patients with Alzheimer's disease (AD). Our aim was to investigate the effects of PVE correction on FDG PET in conjunction with voxel-based morphometry (VBM) in patients with mild AD.


METHODS
Thirty-nine AD patients and 73 controls underwent FDG PET and MRI. The PVE-corrected grey matter PET images were obtained using an MRI-based three-compartment method. Additionally, the results of PET were compared with grey matter loss detected by VBM.


RESULTS
Before PVE correction, reduced FDG uptake was observed in posterior cingulate gyri (PCG) and parieto-temporal lobes (PTL) in AD patients, which persisted after PVE correction. Notably, PVE correction revealed relatively preserved FDG uptake in hippocampal areas, despite the grey matter loss in medial temporal lobe (MTL) revealed by VBM.


CONCLUSIONS
FDG uptake in PCG and PTL is reduced in AD regardless of whether or not PVE correction is applied, supporting the notion that the reduced FDG uptake in these areas is not the result of atrophy. Furthermore, FDG uptake by grey matter tissue in the MTL, including hippocampal areas, is relatively preserved, suggesting that compensatory mechanisms may play a role in patients with mild AD.
Samuraki
Miharu
M
Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Matsunari
Ichiro
I
Chen
Wei-Ping
WP
Yajima
Kazuyoshi
K
Yanase
Daisuke
D
Fujikawa
Akihiko
A
Takeda
Nozomi
N
Nishimura
Shintaro
S
Matsuda
Hiroshi
H
Yamada
Masahito
M
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D016477:Artifacts; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18