| 摘要 |
PURPOSE:To obtain a good subtraction image by using an X-ray photographic film-fluorescent intensifying screen laminate wherein plural sets of X-ray photographic film-fluorescent intensifying screen combined matter are disposed in a laminated state thereby obtaining image information. CONSTITUTION:An X-ray 6 transmits an object 7 contg. a specific structure differing in an X-ray energy absorption characteristic from the other and an X-ray image is recorded in X-ray photographic films A, B. The phosphor layers 1b, 1c of fluorescent intensifying screens b, c absorb more the lower energy component of the X-ray and the image information in the part of the object 7 corresponding to the specific structure is simultaneously recorded in the two different films A, B. The X-ray image is read out by a readout system, and an image signal logSB is subtracted from a digital image signal logSA between the corresponding picture images in an arithmetic device 17, whereby the image signal of the subtraction of the specific structure desired to be extracted is obtd. The generation of a time difference in forming the two images is obviated and the image of the specific structure of a human body changing momentarily is improved. |
