Direct Comparison of FDG-PET and ASL-MRI in Alzheimer’s Disease Erik S. Musiek 1 , Yufen Chen 2 , Marc Korczykowski 2 , Babak Saboury 3 , Patricia M. Martinez 4 , Janet S. Reddin 3 , Abass Alavi 3 , Daniel Y. Kimberg 2 , David A. Wolk 1 , Per Julin 5 , Andrew B. Newberg 3 , Steven E. Arnold 4 , and John A. Detre 1,2,3 1 Department of Neurology, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104 2 Center for Functional Neuroimaging, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104 3 Department of Radiology, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104 4 Department of Psychiatry, University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104 5 AstraZeneca R&D, Västra Mälarehamnen 9, Södertälje, Sweden, SE-151 85 Abstract BACKGROUND—The utility flourodeoxyglucose PET (FDG-PET) imaging in Alzheimer’s Disease (AD) diagnosis is well established. Recently, measurement of cerebral blood flow using arterial spin labeling MRI (ASL-MRI) has shown diagnostic potential in AD, though it has never been directly compared to FDG-PET. METHODS—We employed a novel imaging protocol to obtain FDG-PET and ASL-MRI images concurrently in 17 AD patients and 19 age-matched controls. Paired FDG-PET and ASL-MRI images from 19 controls and 15 AD patients were included for qualitative analysis, while paired images 18 controls and 13 AD patients were suitable for quantitative analyses. RESULTS—The combined imaging protocol was well tolerated. Both modalities revealed very similar regional abnormalities in AD, as well as comparable sensitivity and specificity for the detection of AD following visual review by two expert readers. Interobserver agreement was better for FDG-PET (kappa 0.75, SE 0.12) than ASL-MRI (kappa 0.51, SE 0.15), intermodality agreement was moderate to strong (kappa 0.45-0.61), and readers were more confident of FDG- PET reads. Simple quantitative analysis of global cerebral FDG uptake (FDG-PET) or whole brain cerebral blood flow (ASL-MRI) showed excellent diagnostic accuracy for both modalities, with area under ROC curves of 0.90 for FDG-PET (95% CI 0.79-0.99) and 0.91 for ASL-MRI (95% CI 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. © 2011 Elsevier Inc. All rights reserved. Corresponding Author: Dr. John Detre, Center for Functional Neuroimaging, Univ. of Pennsylvania, 3 Gates, 3400 Spruce St., Philadelphia, PA, 19104. detre@mail.med.upenn.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The other authors report no conflicts of interest and have nothing to disclose. NIH Public Access Author Manuscript Alzheimers Dement. Author manuscript; available in PMC 2013 January 01. Published in final edited form as: Alzheimers Dement. 2012 January ; 8(1): 51–59. doi:10.1016/j.jalz.2011.06.003. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript