| 摘要 |
<p>A body (6) is scanned by a fan-shaped X-ray beam (4) for an X-ray shadow image. Per sector of the fan-shaped X-ray beam detection means (8) 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 (7) operates in conjunction with a slit-type diaphragm (2) and regulates the quantity of X-ray radiation transmitted under the control (11) 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 (8). The attenuation device comprises one or more elastic X-ray radiation absorbing strips (61, 62, 63) extending essentially parallel to the slit-type diaphragm. The attenuation device comprises controllable drive members (65) to bring the strip or strips to an undulated state.</p> |
