1. A method for classifying tissue type from MRI image data of an object including at least a first type and a second type of tissue, by processing a first set of MRI image data representing substantially the first type of tissue, and a combined set of MRI image data representing at least the first and the second type of tissue, comprising using a processor to: create a segmentation from the combined set of MRI image data; and determine a first correlation value between the segmentation and the first set of MRI image data.