High-resolution technetium-99m-HMPAO SPECT in patients with probable Alzheimer's disease: comparison with fluorine-18-FDG PET.
SPECT studies of regional cerebral perfusion with a high-resolution system were compared to PET studies of regional cerebral glucose utilization (rCMRglc) in 21 patients with probable Alzheimer's disease (AD). Ten normal subjects were also evaluated with SPECT and 10 with PET.


METHODS
rCMRglc (for PET) and counts (for SPECT) in the associative cortices were normalized to the average rCMRglc, and counts in the calcarine cortex and basal ganglia were considered as a "reference area" to obtain a ratio. The ratio differences between patients and controls were tested with ANOVA performed separately for PET and SPECT.


RESULTS
The difference between probable AD patients and controls was significant for both PET (p < 0.00001) and SPECT (p < 0.005); this difference was significant for the frontal, temporal and parietal cortices (p < 0.0001) for PET, and for the temporal (p < 0.005) and parietal (p < 0.001) cortices for SPECT. Temporo-parietal defects were detected in all subjects with PET and in 90% with SPECT.


CONCLUSIONS
PET and SPECT are able to detect characteristic temporo-parietal abnormalities in probable AD. However, the presence of abnormalities in other associative areas is better evaluated with PET.
Messa
C
C
INB-CNR, University of Milano, Institute H.S. Raffaele, Italy.
Perani
D
D
Lucignani
G
G
Zenorini
A
A
Zito
F
F
Rizzo
G
G
Grassi
F
F
Del Sole
A
A
Franceschi
M
M
Gilardi
M C
MC
D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D010091:Oximes; D019788:Fluorodeoxyglucose F18; D019690:Technetium Tc 99m Exametazime; D003847:Deoxyglucose