Direct comparison of fluorodeoxyglucose positron emission tomography and arterial spin labeling magnetic resonance imaging in Alzheimer's disease.
BACKGROUND
The utility of fluorodeoxyglucose positron emission tomography (FDG-PET) imaging in Alzheimer's disease (AD) diagnosis has been well established. Recently, measurement of cerebral blood flow using arterial spin labeling magnetic resonance imaging (ASL-MRI) has shown diagnostic potential in AD, although it has never been directly compared with FDG-PET.


METHODS
We used a novel imaging protocol to obtain FDG-PET and ASL-MRI images concurrently in 17 AD patients and 19 age-matched control subjects. Paired FDG-PET and ASL-MRI images from 19 control subjects and 15 AD patients were included for qualitative analysis, and paired images from 18 control subjects and 13 AD patients were suitable for quantitative analyses.


RESULTS
The combined imaging protocol was well tolerated. Both modalities revealed similar regional abnormalities in AD, as well as comparable sensitivity and specificity for the detection of AD after visual review by two expert readers. Interobserver agreement was better for FDG-PET (κ: 0.75, standard error: 0.12) than ASL-MRI (κ: 0.51, standard error: 0.15); intermodality agreement was moderate to strong (κ: 0.45-0.61); and readers were more confident of FDG-PET reads. Simple quantitative analysis of global cerebral fluorodeoxyglucose uptake (FDG-PET) or whole-brain cerebral blood flow (ASL-MRI) showed excellent diagnostic accuracy for both modalities, with area under receiver operating characteristic curves of 0.90 for FDG-PET (95% confidence interval: 0.79-0.99) and 0.91 for ASL-MRI (95% confidence interval: 0.80-1.00).


CONCLUSIONS
Our results demonstrate that FDG-PET and ASL-MRI identify similar regional abnormalities and have comparable diagnostic accuracy in a small population of AD patients, and support the further study of ASL-MRI in dementia diagnosis.
Department of Neurology, University of Pennsylvania, Philadelphia, USA.
Erik S
ES
Musiek
Yufen
Y
Chen
Marc
M
Korczykowski
Babak
B
Saboury
Patricia M
PM
Martinez
Janet S
JS
Reddin
Abass
A
Alavi
Daniel Y
DY
Kimberg
David A
DA
Wolk
Per
P
Julin
Andrew B
AB
Newberg
Steven E
SE
Arnold
John A
JA
Detre
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D013113:Spin Labels
D013113:Spin Labels; D019788:Fluorodeoxyglucose F18