Regional HmPAO SPECT and CT measurements in the diagnosis of Alzheimer's disease.
BACKGROUND
This study investigated the hypothesis that the combination of regional CT brain atrophy measurements and semiquantitative SPECT regional blood flow ratios could produce a diagnostic test for Alzheimer's disease (AD) with an accuracy comparable to that achieved with the present clinical gold standard of the NINCDS-ADRDA criteria.


METHODS
Single proton emission computed tomography (SPECT) and CT head scans were performed on 122 subjects referred an UBC Alzheimer clinic and diagnosed as either 'not demented' (ND-37) or 'possible/probable AD' (AD-85) by the NINCDS-ADRDA criteria. Stepwise discriminant analysis (SDA) was performed on the bilateral SPECT regions of interest and compared to bilateral CT qualitative/quantitative assessment in the frontal, parietal and temporal lobes to determine which were most accurate at ND/AD distinction. Receiver operating curves (ROC) were then constructed for these variables individually and for their combined discriminant function.


RESULTS
The left temporal qualitative cortical atrophy score (CT) and left temporal perfusion ratio (SPECT) were selected in the SDA. The combined discriminant function was more specific at AD/ND distinction than either of CT or SPECT alone. The accuracy of AD/ND distinction with the combined discriminant function was below that achieved by clinical diagnosis according to the NINCDS-ADRDA criteria and was not significantly different from that achieved with SPECT or CT alone as defined by ROC curve analysis.


CONCLUSIONS
The measurements of left temporal cortical atrophy and regional cerebral blood flow were most indicative of AD; however they lacked the sensitivity and specificity to recommend their use as a diagnostic test for AD.
Mattman
A
A
Clinic for Alzheimer's Disease and Related Disorders, Vancouver Hospital and Health Sciences Center-UBC Site, Canada.
Feldman
H
H
Forster
B
B
Li
D
D
Szasz
I
I
Beattie
B L
BL
Schulzer
M
M
D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000000981:diagnostic imaging*; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime