X-ray position determination system for medical computer tomography system

摘要

The system, part a computer-tomography system (10), scans an object. The computer-tomography system has a X-ray source (14) with a focal point, a filter unit for forming a differential path length altering itself monotonically, which moves the focal point on the x-axis and contains at least two detection unit channels (18). The X-ray source produces a X-ray beam (16) which passes through e.g. a patient. The filter unit attenuates the beam along at least two symmetrically arranged beam paths, as in a bow-tie filter, and the X-ray beams impinge on the detection unit channels. The X-ray position detection system has a unit for identifying signal intensities at the detection unit channels. A unit adds the identifying signal intensities for each detection unit channel across the entire scanning, and a unit determines an alteration of the X-ray position using this sum.