Tumors are judged by a medical image diagnosis aiding apparatus that employs a computer, based on image patterns, which are obtained from the density values of images and which are inherent in medical images, in a manner approximating human visual perception. Candidate regions of patterns are extracted from medical image data. The type of pattern of the candidate regions is judged by employing characteristic amounts of an inner/outer outline image, which is an image of the vicinity of the outline of the extracted candidate region.