| 摘要 |
A method and apparatus for improving imaging in an X-ray mammography machine having a controllable X-ray source (50) incorporates apparatus for directing the X-ray beam (52) in a preselected configuration onto at least a portion of a target area (60). The creation intensity of the beam is detected (114) in each of a plurality of substantially equal segments (1 DIVIDED 12) of the target area and a first segment of lowest radiation intensity is identified. The X-ray source is adjusted to establish a predetermined radiation intensity in the identified first segment. Second segments are then identified each having a radiation intensity greater than a predetermined percentage of the radiation intensity in the identified first segment. The radiation intensity directed toward the identified second segments is then automatically attenuated by a control system (92, 86) responsive to the radiation intensity detected in the second segments. The attenuation is achieved by moving collimators (58,120,200) into the beam so as to reduce the radiation directed towards the second segments. The beam is scanned over the target and continuously adjusted in accordance with the radiation detected in each of the segments of the beam. In this manner, each area of the target receives just sufficient radiation to provide proper imaging without overexposing area of the target which have less attenuation than other areas. |
