MRI-guided SPECT perfusion measures and volumetric MRI in prodromal Alzheimer disease.
OBJECTIVE
To identify group differences in the prodromal phase of Alzheimer disease (AD) using quantitative single-photon emission computed tomography (SPECT) perfusion and magnetic resonance imaging (MRI) volume measures within specific volumes of interest.


METHODS
Gerontology research unit.


METHODS
There were 17 healthy controls, 56 nondemented patients with memory problems who did not develop AD during 3 to 5 years of follow-up (questionables), and 27 nondemented patients with memory problems who developed AD during follow-up (converters).


METHODS
A Tc 99m hexamethylpropyleneamine oxime SPECT study and an MRI were performed in each participant at baseline. Mean SPECT activity concentration and MRI volume were estimated within 9 structures: rostral anterior cingulate, caudal anterior cingulate, posterior cingulate, hippocampus, entorhinal cortex, basal forebrain, temporal horn, amygdala, and the banks of the superior temporal sulcus. Data were analyzed using overall and pairwise discriminant analysis, and performance in pairwise group discrimination was measured using correlated receiver operating characteristic curve analysis.


RESULTS
The overall (3-group) discriminant function was significant for SPECT (F test, P<.001) and MRI (F test, P<.0001). For the SPECT analysis, the ranking of structures for discriminating among the 3 groups was, in order of decreasing discriminating power, caudal anterior cingulate, temporal horn, superior temporal sulcus, entorhinal cortex, hippocampus, rostral anterior cingulate, amygdala, basal forebrain, and posterior cingulate. For the MRI analysis, this ranking was entorhinal cortex, superior temporal sulcus, temporal horn, hippocampus, amygdala, caudal anterior cingulate, rostral anterior cingulate, basal forebrain, and posterior cingulate. Combining the 2 modalities yielded significantly better discrimination performance than did either alone. Furthermore, the correlation between SPECT and MRI measures was low.


CONCLUSIONS
Measures of structure activity concentration and volume carry independent information; both reveal group differences in prodromal AD.
El Fakhri
Georges
G
Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. elfakhri@bwh.harvard.edu
Kijewski
Marie Foley
MF
Johnson
Keith A
KA
Syrkin
Grigoriy
G
Killiany
Ronald J
RJ
Becker
J Alex
JA
Zimmerman
Robert E
RE
Albert
Marilyn S
MS
D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000473:pathology; D011237:Predictive Value of Tests; D011859:Radiography; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D019690:Technetium Tc 99m Exametazime