A system and method for ground glass nodule (GGN) segmentation is provided. The method comprises: selecting a point in a medical image, wherein the point is located in a GGN; defining a volume of interest (VOI) around the point, wherein the VOI comprises the GGN; removing a chest wall from the VOI; obtaining an initial state for a Markov random field; and segmenting the VOI, wherein the VOI is segmented using the Markov random field.