Scaled subprofile modeling of resting state imaging data in Parkinson's disease: Methodological issues

► Review of the Scaled Subprofile Model (SSM/PCA) for multivariate analysis. ► Reproducibility of spatial covariance patterns in Parkinson's disease PET data. ► Parkinson's disease pattern invariance under global and regional normalization. ► Effects of logarithmic transformation and data centering on PD pattern derivation. ► Independence and viability of high (red) and low (blue) areas of the PD pattern.