Balci, Serdar KGolland, PolinaShenton, MarthaWells, William2016-09-262007Balci SK, Golland P, Shenton M, Wells WM. 2007. Free-Form B-spline Deformation Model for Groupwise Registration. Med Image Comput Comput Assist Interv 10:23-30. doi: 10.1901/jaba.2007.10-23http://nrs.harvard.edu/urn-3:HUL.InstRepos:28552589In this work, we extend a previously demonstrated entropy based groupwise registration method to include a free-form deformation model based on B-splines. We provide an efficient implementation using stochastic gradient descents in a multi-resolution setting. We demonstrate the method in application to a set of 50 MRI brain scans and compare the results to a pairwise approach using segmentation labels to evaluate the quality of alignment. Our results indicate that increasing the complexity of the deformation model improves registration accuracy significantly, especially at cortical regions.en-USJournal Article2016-09-2610.1901/jaba.2007.10-23