Static gain calibration

Abstract

An X-ray system (1, 10) for imaging and a gain calibration method are disclosed. An assembly (4, 14) of the system is moveable to different scan coordinates to acquire X-ray projection images at a plurality of said scan coordinates in a dynamic mode while the assembly is moving. The assembly is also moveable to a predetermined reference coordinate to acquire an X-ray projection image at said reference coordinate in a static mode while the assembly is resting. At least one processing unit (5), comprised by the X-ray system, is configured for receiving a plurality of dynamic gain calibration parameters as first inputs, for obtaining a static gain calibration parameter as a second input and for determining a plurality of adjusted dynamic gain calibration parameters. Each dynamic gain calibration parameter is obtained from an X-ray projection image acquired in the dynamic mode at one of the scan coordinates. The static gain calibration parameter is obtained from an X-ray projection image acquired in the static mode at the predetermined reference coordinate.

Description

technical field [0001] The present invention relates to X-ray systems and to a gain calibration method for an X-ray system. Background technique [0002] To work accurately and reliably, complex x-ray computed tomography (CT) or cone beam computed tomography (CBCT) scanners require full calibration on an annual basis by field service engineers. Heavily used CT or CBCT scanners require even more frequent calibration, in which case an uncomplicated calibration procedure would provide the most cost-effective solution. Performing frequent calibration scans is a time-consuming procedure during which CT or CBCT scanners are not available for patient use and should therefore be scheduled well in advance. [0003] Gain calibration for image uniformity correction in flexible X-ray CT / CBCT systems has been described in document US2015 / 0103972A1, April 16, 2015 (BREDNO et al.) as system elements (among them source and detector) The necessary result of the relative movement of . Rela...

AI Technical Summary

Problems solved by technology

Furthermore, the described method for gain calibration and uniformity correction acquires X-ray projection image data at each gantry position, which makes the calibration method a time-consuming calibration method in flexible X-ray CT scanners, which is not suitable for flexible X-ray CT scanners, there are a wide variety of scan trajectories involving different arm movements and each requires a dedicated calibration scan

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