Method and apparatus for detecting prospective abnormal patterns

A method of detecting a definite prospective abnormal pattern, in which an image signal representing a radiation image of a right mamma of an object and an image signal representing a radiation image of a left mamma of the object are obtained, each of the image signals being made up of a series of image signal components representing picture elements in the radiation image, and wherein a prospective abnormal pattern is detected from one of the radiation images of either one of the right and left mammae by utilizing the respective image signals, the method comprising the steps of:

• (a) detecting the prospective abnormal pattern of one of the image signals representing the radiation images of the right and left mammae,
• (b) setting a region of the detected prospective abnormal pattern in one radiation image, which is represented by the one image signal, and setting a region in the radiation image of the opposite mamma, which region corresponds to the position of said region of the detected prospective abnormal pattern in the one radiation image,
• (c) carrying out iris filter processing on image signal components, which represent picture elements located in both regions set in step (b), respective iris filter output signals being thereby obtained,
• (d) calculating a difference value between said respective iris filter output signals, which have been obtained with respect to corresponding picture elements in said both regions,
• (e) calculating a rating function value, which represents a degree of malignancy of the detected prospective abnormal pattern, in accordance with the image signal components, which represent the picture elements located in said region of the detected prospective abnormal pattern in the one radiation image, and
• (f) determining the definite prospective abnormal pattern in accordance with said rating function value and said difference value.

An apparatus for detecting a definite prospective abnormal pattern, in which an image signal representing a radiation image of a right mamma of an object and an image signal representing a radiation image of a left mamma of the object are obtained, each of the image signals being made up of a series of image signal components representing picture elements in the radiation image, and wherein a prospective abnormal pattern is detected from one of the radiation images of either one of the right and left mammae using the respective image signals, the apparatus comprising:

• (a) detection means for detecting the prospective abnormal pattern of one of the image signals representing the radiation images of the right and left mammae,
• (b) region setting means for setting a region of the detected prospective abnormal pattern in one radiation image, which is represented by the one image signal, and for setting a region in the radiation image of the opposite mamma, which region corresponds to the position of said region of the detected prospective abnormal pattern in the one radiation image,
• (c) iris filter processing means for carrying out iris filter processing on image signal components, which represent picture elements located in both regions set by said region setting means, respective iris filter output signals being thereby obtained,
• (d) difference value calculating means for calculating a difference value between said respective iris filter output signals, which have been obtained with respect to corresponding picture elements in said both regions, and
• (e) definite prospective abnormal pattern detecting means for detecting the definite prospective abnormal pattern using said difference value calculated by said difference value calculating means.

An apparatus for detecting a definite prospective abnormal pattern, in which an image signal representing a radiation image of a right mamma of an object and an image signal representing a radiation image of a left mamma of the object are obtained, each of the image signals being made up of a series of image signal components representing picture elements in the radiation image, and wherein a prospective abnormal pattern is detected from one of the radiation images of either one of the right and left mammae using the respective image signals, the apparatus comprising:

• (a) detection means for detecting the prospective abnormal pattern of one of the image signals representing the radiation images of the right and left mammae,
• (b) region setting means for setting a region of the detected prospective abnormal pattern in one radiation image, which is represented by the one image signal, and for setting a region in the radiation image of the opposite mamma, which region corresponds to the position of said region of the detected prospective abnormal pattern in the one radiation image,
• (c) iris filter processing means for carrying out iris filter processing on image signal components, which represent picture elements located in both regions set by said region setting means, respective iris filter output signals being thereby obtained,
• (d) difference value calculating means for calculating a difference value between said respective iris filter output signals, which have been obtained with respect to corresponding picture elements in said both regions,
• (e) rating function value calculating means for calculating a rating function value, which represents a degree of malignancy of the detected prospective abnormal pattern, in accordance with the image signal components, which represent the picture elements located in said region of the detected prospective abnormal pattern in the one radiation image, and
• (f) definite prospective abnormal pattern detecting means for detecting the definite prospective abnormal pattern using said rating function value, which has been calculated by said rating function value calculating means, and said difference value, which has been calculated by said difference value calculating means.

A method for detecting a definite prospective abnormal pattern in mammae, said method comprising:

• (a) obtaining a first radiation image of a first mamma and a second radiation image of a second mamma;
• (b) detecting a prospective abnormal pattern in one of the first and second radiation images;
• (c) disposing said first and second radiation images to be symmetrical about an axis of symmetry;
• (d) carrying out iris filter processing on image signal components of a region at which the prospective abnormal pattern was detected in one of the first and second radiation images at step (b), and on image signal components in a corresponding region opposite said axis of symmetry in the other one of said first and second radiation images, whereby respective iris filter output signals are obtained for each of said regions, and
• (e) determining a definite prospective abnormal pattern based upon the respective iris filter output signals.