1. A method for nodule segmentation comprising: selecting a nodule from an image; defining a volume of interest wherein said volume of interest includes said nodule; removing a chest wall from said volume of interest; selecting a predefined initial intensity model; pre-segmenting said volume of interest using a Markov random field with said selected predefined initial intensity model; adapting said intensity model based upon said volume of interest pre-segmentation; and segmenting said volume of interest using a Markov random field with said adapted intensity model.