The functional processing of the human brain occurs on the highly fold surface, called the gray matter. Neuroscientists are interested in developing 2D, surface-based analysis methods for analyzing the location of functional processing and studying disease and aging. Our group was the first group to propose using conformal-based methods for unfolding and flattening the cortical surface. We compute our quasi-conformal maps using circle packings and since then, a number of other conformal-based approaches have been suggested. I will discuss the method of circle packings, how we are applying it to brain imaging and open questions which need to be investigated.