Probabilistic approaches for atlasing normal and disease-specific brain variability

The extreme variability in the structural conformation of the human brain p oses significant challenges for the creation of population-based atlases. T he ability to statistically and visually compare and contrast brain image d ata from multiple individuals is essential to understanding normal variabil ity within a particular population as well as differentiating normal from d iseased populations. This paper introduces the application of probabilistic atlases that describe specific subpopulations, measures their variability and characterizes the structural differences between them. Utilizing data f rom structural MRI, we have built atlases with defined coordinate systems c reating a framework for mapping data from functional, histological and othe r studies of the same population. This paper describes the basic approach a nd a brief description of the underlying mathematical constructs that enabl e the calculation of probabilistic atlases and examples of their results fr om several different normal and diseased populations.