Automatic multiclass classification of 18FDG-PET scans for the distinction between Parkinson’s disease and atypical parkinsonian syndromes

Part of the difficulty in the early diagnosis of Parkinson’s disease (PD) is in differentiating it from atypical parkinsonian disorders (APS) that have a poorer prognosis such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). 18flurodeoxyglucose (FDG) positron emission tomography (PET) has been recommended for the early differentiation between PD and APS [1]. Here, 120 FDG PET scans (42, 31, 26 and 21 for the PD, MSA, PSP and CBS resp.) were acquired on average 3.5 years after symptoms onset (because the initial clinical features were outside the prevailing perception for PD) to look, without any a priori assumption, for cerebral FDG uptake patterns that discriminate either between the PD and APS classes, or between the four PD, MSA, PSP and CBS classes. The diagnostic used to label the scans was defined by clinical criteria on average 4.5 years after PET assessment.