The three-volume set LNCS 7510, 7511, and 7512 constitutes the refereed proceedings of the 15th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2012, held in Nice, France, in October 2012. Based on rigorous peer reviews, the program committee carefully selected 252 revised papers from 781 submissions for presentation in three volumes. The second volume includes 82 papers organized in topical sections on cardiovascular imaging: planning, intervention and simulation, image registration, neuroimage analysis, diffusion weighted imaging, image segmentation, computer-assisted interventions and robotics, and image registration: new methods and results.