Method for discriminating x-ray contrast image from non-contrast image and x-ray imaging system including contrast image discriminating function

摘要

To discriminate a contrast image from a non-contrast image, an X-ray imaging method is characterized by comprising the steps of: acquiring a plurality of X-ray images of a biological body under medical examination; subtracting at least two sets of the X-ray images with each other acquired at temporally different timings to obtain a subtraction image; subdividing one subtraction image into a plurality of image blocks; calculating an averaged value of image concentration with respect to each of the image blocks, thereby obtaining a plurality of averaged values for the subdivided image blocks; calculating a difference between at least two averaged values of image concentration with respect to the image blocks acquired within substantially same temporal timing period; and, judging whether or not the X-ray image is acquired under such a condition that an X-ray contrast medium appears therein based upon the difference in said two averaged values of image concentration.