PROBLEM TO BE SOLVED: To evaluate the progress of a liver lesion only using a routine inspection image without attaching a special device to a subject.SOLUTION: An image processing method comprises the steps of: calculating a standard index for at least one of the shape of a liver region and the image quality of the liver region in an image which includes the liver and onto which the roughness of the liver surface is reflected and determining the progress of a liver lesion on the basis of the calculated standard index. The index should be, for example, a degree of incoincidence between the contour of the standard liver, or a model of the standard liver shape, and the contour of the evaluation object liver fitted to the standard liver. The degree of incoincidence between contours should be represented by, for example, mean square values determined by calculating, in the two livers, distances from the center of gravity to outer peripheries in a plurality of angle directions and taking a mean square value for corresponding distances.
