| 摘要 |
<p>In an equalization radiography device an X-ray fan beam (3, 4) is used to scan a body (7) under examination. The X-ray fan beam comprises a number of adjacent sectors. A modulator device (5) comprising a number of controllable beam sector modulators is present for controlling per sector the quantity of X-ray radiation transmitted. A detector (11) placed behind the body generates per sector a measurement signal representing a desired position of the beam sector modulator for that sector. During operation the instantaneous position of each beam sector modulator is continuously detected (20, 21). Signals representing those positions are generated and compared with the respective measurement signals. Control signals are derived from the comparisons to control the positions of the respective beam sector modulators.</p> |
