This application disclosures a method for calibrating filament current data of an X-ray tube. The method includes obtaining a first value of tube current to be calibrated and a value of filament current to be calibrated, the tube current to be calibrated and the filament current to be calibrated corresponding to a first calibration point; performing an emission operation based on the first value of the tube current to be calibrated and the value of the filament current to be calibrated; determining an actual value of the tube current during the emission operation; determining a difference between the actual value of the tube current and the first value of the tube current to be calibrated; and calibrating, based on the difference, the first calibration point.

This application disclosures a method for calibrating filament current data of an X-ray tube. The method includes obtaining a first value of tube current to be calibrated and a value of filament current to be calibrated, the tube current to be calibrated and the filament current to be calibrated corresponding to a first calibration point; performing an emission operation based on the first value of the tube current to be calibrated and the value of the filament current to be calibrated; determining an actual value of the tube current during the emission operation; determining a difference between the actual value of the tube current and the first value of the tube current to be calibrated; and calibrating, based on the difference, the first calibration point.

The present application discloses a method for controlling filament current and apparatus. The method comprises: acquiring a current filament current value (S11); determining a current range within which the current filament current value falls (S12); determining a correspondence between a filament current and a control current according to the current range (S13); and determining the current control current according to the current filament current value and the correspondence (S14). The problem of large errors in the control of filament current caused by nonlinear characteristics of a filament transformer can be solved.

The present application discloses a method for controlling filament current and apparatus. The method comprises: acquiring a current filament current value (S11); determining a current range within which the current filament current value falls (S12); determining a correspondence between a filament current and a control current according to the current range (S13); and determining the current control current according to the current filament current value and the correspondence (S14). The problem of large errors in the control of filament current caused by nonlinear characteristics of a filament transformer can be solved.

An X-ray device includes a degree-of-wear detection unit for detecting a degree-of-wear of an emitter, an adhesion amount estimation unit for estimating an adhesion amount of a conductive material onto an envelope based on the degree-of-wear of the emitter and a relation between the degree-of-wear of the emitter and an adhesive amount of the conductive material onto the envelope stored in a storage unit.

An X-ray device includes a degree-of-wear detection unit for detecting a degree-of-wear of an emitter, an adhesion amount estimation unit for estimating an adhesion amount of a conductive material onto an envelope based on the degree-of-wear of the emitter and a relation between the degree-of-wear of the emitter and an adhesive amount of the conductive material onto the envelope stored in a storage unit.

According to one embodiment, an X-ray CT apparatus includes processing circuitry. The processing circuitry is configured to acquire set tube current waveform, and specify, based on the set tube current waveform, a period of a first tube current and a period of a second tube current lower than the first tube current. The processing circuitry is further configured to determine a waveform of a grid voltage such that a first grid voltage is applied during a period corresponding to the period of the first tube current and a second grid voltage, which is higher than the first grid voltage, is applied during a period corresponding to the period of the second tube current.

According to one embodiment, an X-ray CT apparatus includes processing circuitry. The processing circuitry is configured to acquire set tube current waveform, and specify, based on the set tube current waveform, a period of a first tube current and a period of a second tube current lower than the first tube current. The processing circuitry is further configured to determine a waveform of a grid voltage such that a first grid voltage is applied during a period corresponding to the period of the first tube current and a second grid voltage, which is higher than the first grid voltage, is applied during a period corresponding to the period of the second tube current.

A radiation tube that is used in a radiation source for radiography includes: an electron emitting unit that includes a cathode unit having an emitter electrode which emits electrons and a gate electrode; an anode unit that has an anode surface facing the cathode unit and collides with the electrons to generate radiation; a constant voltage supply unit that supplies a constant driving voltage to the gate electrode; and a vacuum tube that accommodates the constant voltage supply unit, the electron emitting unit, and the anode unit.

A method is described for controlling a tube current for acquiring at least one X-ray image. The method includes performing a preview acquisition of the region under examination; determining a three-dimensionally modulated X-ray attenuation of the region based upon the preview acquisition; determining initial tube-current profiles based upon the X-ray attenuation; defining a tolerance band for subsequent real-time modification of tube currents, a maximum permitted tube-current profile being determined for which an X-ray tube of the X-ray imaging apparatus does not overheat; determining an expected value and a maximum value of a potential patient dose based upon the initial tube-current profiles and the tolerance band; measuring an actual X-ray attenuation during acquisition of the at least one X-ray image; determining adjusted tube-current profiles based upon the actual X-ray attenuation and the initial tube-current profiles; and adjusting the tube current in accordance with the adjusted tube-current profiles determined.