The method of controlling the output of x-ray source of the x-ray survey instrument and the x-ray survey instrument

摘要

An X-ray examination apparatus arranged with control means to control a dose of an X-ray source in accordance with a grey-level distribution of an acquired image. The X-ray examination apparatus ( 1 ) comprises the X-ray unit ( 2 ) arranged to communicate data to the control and processing means ( 10 ). The X-ray unit ( 2 ) is arranged to generate a beam of X-rays ( 1 f) propagating from an X-ray source ( 1 c). The X-ray source ( 1 c) together with the X-ray detector ( 1 b)can be rotated about an acquisition volume V about a rotation axis ( 1 e). The control and processing means ( 10 ) comprises an image processing means ( 3 ), which is arranged to compress the first image into the second image. Upon a compression of the first image with the grey-level compression function the resulting second image is forwarded to the control means ( 6 ), which is arranged to compute an average pixel value of the second image and to compare it with a pre-stored reference value. In case the computed average value substantially deviates from the pre-stored reference value a dose control signal C is sent to the X-ray source ( 1 c) in order to modify its settings. The X-ray examination apparatus further comprises a viewing station, whereto the resulting image is forwarded. The viewing station comprises a processor ( 5 ) an input device ( 5 b) and a console ( 5 a) whereon the image is displayed by means of a suitable user interface ( 5 c). After the image has been analyzed, it can be stored in a suitable database ( 7 ).