A method may include obtaining a feedback or a reference value of a tube voltage applied to a radiation source of a radiation device for generating radiation rays. The method may also include determining, based on the feedback or the reference value of the tube voltage, a specific value of a focusing parameter associated with a focusing device of the radiation device. The method may further include causing the focusing device to shape a focus of the radiation rays according to the determined value of the focusing parameter. The focus of the radiation rays may satisfy an operational constraint under the specific value of the focusing parameter.

In an X-ray generator an X-ray tube includes an anode and a cathode and is energized with at least a first high voltage potential. A dynamic damper with a frequency dependent impedance is interposed between the X-ray tube and a source of the high voltage potential. The impedance of the dynamic damper increases with an increase in frequency associated with tube-spit. In an X-ray generator with resonant switching to provide a first kV level and a second kV level to the X-ray tube, the impedance of the dynamic damper is low at the operational frequency of the resonant switch to promote energy recovery when the resonant switch operates to provide a first kV level to the X-ray tube.

The present disclosure relates to a high voltage generator including multiple high voltage generating modules configured to provide a total voltage. Each of the multiple high voltage generating modules may be configured to receive a driving pulse and generate a voltage component of the total voltage according to the driving pulse. The multiple high voltage generating modules may be in a series connection. Time points when the multiple high voltage generating modules receive driving pulses may be different, and waveforms of the driving pulses may be the same.

A radiation therapy system includes an X-ray imaging system that is configured with a combined and simplified filter and collimator positioning mechanism. In addition, an X-ray imager of the RT system is only positioned at a few discrete locations within a plane that is a fixed distance from the imaging X-ray source when generating X-ray images. As a result, for each of these discrete imaging positions, the simplified filter and collimator positioning mechanism positions a specific collimator-filter combination in a specific location between the X-ray source and the imager.

A radiation therapy system includes an X-ray imaging system that is configured with a combined and simplified filter and collimator positioning mechanism. In addition, an X-ray imager of the RT system is only positioned at a few discrete locations within a plane that is a fixed distance from the imaging X-ray source when generating X-ray images. As a result, for each of these discrete imaging positions, the simplified filter and collimator positioning mechanism positions a specific collimator-filter combination in a specific location between the X-ray source and the imager.

A method and system is disclosed for acquiring image data of a subject. The image data can be collected with an imaging system with at least two different power characteristics. The image data can be reconstructed using dynamic or enhanced reconstruction techniques.

A method and system is disclosed for acquiring image data of a subject. The image data can be collected with an imaging system with at least two different power characteristics. The image data can be reconstructed using dynamic or enhanced reconstruction techniques.

The invention relates to a system (31) for generating spectral computed tomography projection data. A spectral projection data generation device (6) comprising an energy-resolving detector generates spectral computed tomography projection databased on polychromatic radiation (4), which has been provided by a radiation device (2), after having traversed an examination zone (5), and a reference values generation device generates energy-dependent reference values based on radiation, which has not traversed the examination zone. A spectral parameter providing unit (12) provides a spectral parameter being indicative of a spectral property of the radiation device based on the energy-dependent reference values. In particular, spectral properties of the radiation device can be monitored over time, wherein this information can be used for, for instance, correcting the spectral computed tomography projection data, and/or, if undesired spectral properties of the radiation device are indicated, triggering a replacement of the radiation device.

An X-ray source for emitting an X-ray beam is proposed. The X-ray source comprises an anode and an emitter arrangement comprising a cathode for emitting an electron beam towards the anode and an electron optics for focusing the electron beam at a focal spot on the anode. The X-ray source further comprises a controller configured to determine a switching action of the emitter arrangement and to actuate the emitter arrangement to perform the switching action, the switching action being associated with a change of at least one of a position of the focal spot on the anode, a size of the focal spot, and a shape of the focal spot. The controller is further configured to predict before the switching action is performed, based on the determined switching action, the size and the shape of the focal spot expected after the switching action. Further, the controller is configured to actuate the electron optics to compensate for a change of the size and the shape of the focal spot induced by the switching action.

A method may include obtaining a feedback or a reference value of a tube voltage applied to a radiation source of a radiation device for generating radiation rays. The method may also include determining, based on the feedback or the reference value of the tube voltage, a specific value of a focusing parameter associated with a focusing device of the radiation device. The method may further include causing the focusing device to shape a focus of the radiation rays according to the determined value of the focusing parameter. The focus of the radiation rays may satisfy an operational constraint under the specific value of the focusing parameter.