Diagnostic value of brain MRI and 18F-FDG PET in the differentiation of Parkinsonian-type multiple system atrophy from Parkinson's disease.

BACKGROUND AND PURPOSE: Differentiation between parkinsonian type multiple system atrophy (MSA-P) and Parkinson's disease (PD) is important but often difficult. We investigated the diagnostic value of brain magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) in differentiating MSA-P from PD.

METHODS

Twenty-four patients with MSA-P (16 probable and 8 possible) and eight patients with PD were included in this study.

RESULTS

For analysis using the putaminal findings, the sensitivities were 58.3% by visual analysis of brain MRI, 95.8% by visual analysis of (18)F-FDG PET, and 79.2% by statistical parametric mapping (SPM) analysis of (18)F-FDG PET in differentiating MSA-P from PD; the specificity was 100% for each analysis. Using the putaminal findings, visual analysis of (18)F-FDG PET had a higher sensitivity compared with brain MRI (P = 0.004) and SPM analysis of (18)F-FDG PET revealed a tendency towards higher sensitivity compared with brain MRI (P = 0.063). For analysis using both putaminal and infratentorial findings, the sensitivities were 79.2% by visual analysis of brain MRI, 95.8% by visual analysis of (18)F-FDG PET, 95.8% by SPM analysis of (18)F-FDG PET in differentiating MSA-P from PD; the specificity was 100% for each analysis.

CONCLUSION

Both brain MRI and (18)F-FDG PET showed diagnostic usefulness in differentiating MSA-P from PD, with (18)F-FDG PET being more sensitive than brain MRI.