Automated determination of an X-ray tube-current profile

A tube-current controller for acquiring at least one X-ray image of a region under examination of a subject under examination, comprising:

• a controller configured to
• control an X-ray radiation source for acquisition of the at least one X-ray image, and
• capture raw X-ray data from an X-ray radiation detector;
• a preview acquisition controller to control a preview acquisition of the region under examination of the subject under examination;
• an X-ray attenuation estimation unit to estimate a three-dimensionally modulated X-ray attenuation based upon the preview acquisition;
• a profile definition unit to determine initial tube-current profiles based upon the X-ray attenuation estimated;
• a band definition unit to define a tolerance band for real-time modification of tube currents, wherein, based upon the initial tube-current profiles, a maximum permitted tube-current profile is determined for which the X-ray tube does not overheat;
• a dose determination unit to determine an expected value for a potential patient dose based upon the initial tube-current profiles, and a maximum value of a potential patient dose based upon the defined tolerance band;
• an X-ray attenuation determination unit to determine an actual X-ray attenuation during acquisition of the at least one X-ray image based upon raw X-ray data acquired;
• and
• an adjustment unit to determine adjusted tube-current profiles based upon the actual X-ray attenuation and initially planned tube-current profiles,
• wherein the controller is further configured to adjust the tube current of the X-ray source in accordance with the adjusted tube-current profiles determined.