| 摘要 |
PCT No. PCT/EP88/00784 Sec. 371 Date Feb. 27, 1990 Sec. 102(e) Date Feb. 27, 1990 PCT Filed Aug. 24, 1988 PCT Pub. No. WO89/02645 PCT Pub. Date Mar. 23, 1989.A body is scanned by a fan-shaped X-ray beam for an X-ray shadow image. Per sector of the fan-shaped X-ray beam detection means deliver a signal which is a measure of the quantity of X-ray radiation instantaneously transmitted in the respective sector through the body. An attenuation device operates in conjunction with a slit-type diaphragm and regulates the quantity of X-ray radiation transmitted under the control of control signals per sector of the fan-shaped X-ray beam. The control signals are formed on the basis of the signals from the detection means. The attenuation device comprises one or more elastic X-ray radiation absorbing strips extending essentially parallel to the slit-type diaphragm. The attenuation device comprises controllable drive members to bring the strip or strips to an undulated state.
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