The diagnostic value of SPECT with Tc 99m HMPAO in Alzheimer's disease: a population-based study.
We studied the diagnostic accuracy of single-photon emission computed tomography (SPECT) with technetium 99m-labeled hexamethylpropylene amine oxime (Tc 99m HMPAO) in 48 patients with probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria and in 60 controls recruited from a population-based study. With logistic regression, we identified decreased temporal regional cerebral blood flow as the best discriminating variable between patients and controls. Receiver-operator characteristic curves showed that the discriminative ability of SPECT improved with increasing dementia severity. With specificity set at 90%, sensitivity figures were 42% in mild, 56% in moderate, and 79% in severe AD. The diagnostic gain as a function of the prior probability of the disease being present was computed for those with mild AD. When the prior probability varied at around 50%, the diagnostic gain for mild AD patients was substantial (a maximum of 34%) for a positive test result but poor for a negative test result. The results suggest that the practical usefulness of SPECT as a diagnostic adjunct in patients suspected of having mild AD is confined to situations in which, on clinical grounds, there is considerable diagnostic doubt.
Claus
J J
JJ
Department of Neurology, University Hospital Rotterdam, Dijkzigt, The Netherlands.
van Harskamp
F
F
Breteler
M M
MM
Krenning
E P
EP
de Koning
I
I
van der Cammen
T J
TJ
Hofman
A
A
Hasan
D
D
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D012372:ROC Curve; D012680:Sensitivity and Specificity; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime