Patent ID: 7792241

Claim:
A CT system comprising: a rotatable gantry having an opening for receiving an object to be scanned; an x-ray source coupled to the gantry and configured to project x-rays through the opening, the x-ray source comprising: a target; a first cathode configured to emit a first beam of electrons toward the target; a first gridding electrode coupled to the first cathode; a second cathode configured to emit a second beam of electrons toward the target; and a second gridding electrode coupled to the second cathode; a generator configured to energize the first cathode to a first kVp and to energize the second cathode to a second kVp; a detector attached to the gantry and positioned to receive x-rays that pass through the opening; and a controller configured to: apply a gridding voltage to the first gridding electrode to block emission of the first beam of electrons toward the target; apply the gridding voltage to the second gridding electrode to block emission of the second beam of electrons toward the target; and acquire dual energy imaging data from the detector.