| 摘要 |
Auxiliary positioning apparatus is provided for use with a linear scanning X-ray system of the kind having a radiation source for generating an imaging beam, a detector responsive to the imaging beam to generate an output signal, and a drive arranged to move at least one of the radiation source and the detector relative to a subject in a scanning direction. In the X-ray system, a drive control system controls the operation of the drive, and at least one sensor is provided, having an output to which the drive control system is responsive to limit the scanning travel of the X-ray system. The auxiliary positioning apparatus includes an X-ray translucent panel or screen defining a scanning area of reduced size compared to a maximum scanning area of the linear scanning X-ray system, and a location arrangement to locate the positioning member relative to the radiation source and the detector in at least one predetermined position. When the screen is so located, the sensor is operated, and the drive control system responds to the sensor output to limit travel of the radiation source and/or the detector so as to scan a subject or portion of a subject within the scanning area defined by the screen. This allows the X-ray system to be used in conventional radiography applications as well as for whole-body scanning. |
