Objectives
The purpose of this study was to clarify the concordance of diagnostic abilities and interobserver agreement between 18F‐fluorodeoxyglucose (FDG) positron emission tomography (PET) and brain perfusion single photon‐emission computed tomography (SPECT) in patients with Alzheimer's disease (AD) who were diagnosed according to the research criteria of the National Institute of Aging‐Alzheimer's Association Workshop.
Methods
Fifty‐five patients with “AD and mild cognitive impairment (MCI)” (n = 40) and “non‐AD” (n = 15) were evaluated with 18F‐FDG PET and 99mTc‐ethyl cysteinate dimer (ECD) SPECT during an 8‐week period. Three radiologists independently graded the regional uptake in the frontal, temporal, parietal, and occipital lobes as well as the precuneus/posterior cingulate cortex in both images. Kappa values were used to determine the interobserver reliability regarding regional uptake.
Results
The regions with better interobserver reliability between 18F‐FDG PET and 99mTc‐ECD SPECT were the frontal, parietal, and temporal lobes. The 99mTc‐ECD SPECT agreement in the occipital lobes was not significant. The frontal, temporal, and parietal lobes showed good correlations between 18F‐FDG PET and 99mTc‐ECD SPECT in the degree of uptake, but the occipital lobe and precuneus/posterior cingulate cortex did not show good correlations. The diagnostic accuracy rates of “AD and MCI” ranged from 60% to 70% in both of the techniques.
Conclusions
The degree of uptake on 18F‐FDG PET and 99mTc‐ECD SPECT showed significant correlations in the frontal, temporal, and parietal lobes. The diagnostic abilities of 18F‐FDG PET and 99mTc‐ECD SPECT for “AD and MCI,” when diagnosed according to the National Institute of Aging‐Alzheimer's Association Workshop criteria, were nearly identical. Copyright © 2014 John Wiley & Sons, Ltd.