Abstract
To investigate the diagnostic value of brain magnetic resonance image (MRI) and ^18^F‐fluorodeoxyglucose positron emission tomography (^18^F‐FDG PET) in the differentiation of multiple system atrophy (MSA) from Parkinson's disease (PD). Thirty‐five patients with MSA (23 MSA‐P and 12 MSA‐C) and 17 patients with PD were included in this study. Overall correct diagnosis rates between clinical and imaging diagnosis among MSA‐P, MSA‐C, and PD patients were 80% for visual MRI analysis, 88.5% for visual ^18^F‐FDG PET analysis, and 84.3% for SPM‐supported analysis of ^18^F‐FDG PET. The sensitivity of brain MRI, and visual and SPM analysis of ^18^F‐FDG PET in differentiating MSA from PD was 72.7%, 90.9%, and 95.5%, respectively, the specificity was 100% for each imaging analysis, the positive predictive value was 100% for each imaging analysis, and the negative predictive value was 60%, 81.8%, and 90%, respectively. Our results suggest that brain MRI and ^18^F‐FDG PET are diagnostically useful in differentiating MSA (MSA‐P and MSA‐C) from PD, and indicate that ^18^F‐FDG PET has a tendency toward higher sensitivity compared to brain MRI, but a larger longitudinal study including pathological data will be required to confirm our findings. © 2007 Movement Disorder Society