Comparing with cross-sectional studies, a longitudinal design can significantly reduce the confounding effect of inter-individual morphological variability by using each subject as his or her own control. As a result, longitudinal imaging studies are getting increased interest and popularity in various aspects of neuroscience.

The standard FreeSurfer pipeline is designed for the processing of individual data set, and thus not optimal for the processing of longitudinal data. How to take into account the subject-wise and temporal correlation in a longitudinal data series and get more robust and reliable cortical and subcortical morphological measurements is an active research area in NMR center.

As an initial attempt, a longitudinal processing pipeline has been designed in parallel to the original FreeSurfer procedure. The basic idea is to