Abstract: Systems/techniques that facilitate correction of intra-scan focal-spot displacement are provided. In various embodiments, a system can access a first gantry angle of a medical scanner. In various aspects, the system can determine a first displacement of a focal-spot of the medical scanner based on the first gantry angle, by referencing a mapping that correlates gantry angles to focal-spot displacements. In various instances, the system can compensate, via one or more focal-spot position adjusters of the medical scanner, for the first displacement.

Abstract: Methods and systems are provided for dual energy imaging. In one embodiment, a method comprises controlling an x-ray source with a first voltage to generate x-rays at a first energy, controlling the x-ray source with a second voltage to generate x-rays at a second energy lower than the first energy, and controlling a current of the x-ray source to peak above a target current when a voltage of the x-ray source is transitioning from the first voltage to the second voltage. In this way, the duration for transitioning from the first voltage to the second voltage is reduced, thereby enabling faster voltage switching of the x-ray source, improved energy separation in acquired projection data, and improved image quality.

Abstract: Methods and systems are provided for dual energy imaging. In one embodiment, a method comprises controlling an x-ray source with a first voltage to generate x-rays at a first energy, controlling the x-ray source with a second voltage to generate x-rays at a second energy lower than the first energy, and controlling a current of the x-ray source to peak above a target current when a voltage of the x-ray source is transitioning from the first voltage to the second voltage. In this way, the duration for transitioning from the first voltage to the second voltage is reduced, thereby enabling faster voltage switching of the x-ray source, improved energy separation in acquired projection data, and improved image quality.

Abstract: In the present invention, a high-voltage DC/DC converter suitable for powering x-ray tubes and the like provides control of a voltage applied to a resonant circuit at least in part according to a timing of a monitored voltage on the resonator thereby compensating for variations in the parameter stability of the resonant circuit, nonlinearity in the resonant gain curve and frequency dependencies.

Abstract: In the present invention, a high-voltage DC/DC converter suitable for powering x-ray tubes and the like provides control of a voltage applied to a resonant circuit at least in part according to a timing of a monitored voltage on the resonator thereby compensating for variations in the parameter stability of the resonant circuit, nonlinearity in the resonant gain curve and frequency dependencies.

Abstract: An imaging system includes a computed tomography (CT) acquisition unit and a processing unit. The CT acquisition unit includes an X-ray source and a CT detector. The processing unit is configured to determine a voltage delivery configuration for the X-ray source based on at least one of a patient size, a clinical task, or scan parameters. The voltage delivery configuration includes at least one of a transition configuration or a voltage threshold. The transition configuration corresponds to a transition between a high voltage and a low voltage. Portions of acquired data acquired above the voltage threshold are grouped as high energy data and portions acquired below the voltage threshold are grouped as low energy data. The processing unit is also configured to implement the voltage delivery configuration on the CT acquisition unit, and to control the CT acquisition unit to perform an imaging scan using the determined voltage delivery configuration.

Abstract: An x-ray system for simultaneously or concurrently measuring currents of multiple emitters is provided. The x-ray system includes a high voltage direct current (DC) supply configured to supply tube current to the multiple emitters and plural emitter circuits. Each of these circuits includes each comprising an alternating current (AC) voltage supply, at least one of the multiple emitters operatively coupled to the AC voltage supply and the high voltage DC supply, and a circuit coupling the AC voltage supply and the high voltage DC voltage supply to the at least one of the multiple filaments. At least one of the emitter circuits has a current measurement device between the high voltage DC supply and the emitter.

Abstract: Rise times and fall times provided by a high voltage generator are controlled to maintain image quality during such scans. The rise and fall times are controlled by first measuring rise and fall times at each transition. Then, a closed-loop controller is used to adjust control parameters of the high voltage generator, based on an error determined from the measurement, to achieve substantially constant rise and fall times. This invention may be based on the implementation of two closed-loop controllers on rise and fall time of fast-kV exposures. As a result, image quality may be improved and system calibration time may be reduced.

Abstract: The present inventors have recognized that fall times between high-kV to low-kV levels (during a “dual energy” or “fast-kV” energy scan) are linked to the discharge of HV (high voltage) capacitance. In an embodiment of the invention, a high voltage generator may be activated during fall transitions from first to second energy levels in order to substantially maintain a predetermined fall transition time. Accordingly, substantially equal energy distributions between high-kV and low-kV levels may be achieved.

Abstract: Acquisition of X-ray transmission data at three or more energy levels is described. Various implementations utilize generator waveforms that utilize fast-switching, slow-switching, or a combination of fast- and slow-switching to transition between X-ray energy levels. In addition, various sampling arrangements for sampling and/or binning three or more energy levels of X-ray transmission data are discussed. The use of these data in subsequent processing steps, such for material decomposition and/or improvement of dual-energy material decomposition processing, are also described.

Abstract: An x-ray system for simultaneously or concurrently measuring currents of multiple emitters is provided. The x-ray system includes a high voltage direct current (DC) supply configured to supply tube current to the multiple emitters and plural emitter circuits. Each of these circuits includes each comprising an alternating current (AC) voltage supply, at least one of the multiple emitters operatively coupled to the AC voltage supply and the high voltage DC supply, and a circuit coupling the AC voltage supply and the high voltage DC voltage supply to the at least one of the multiple filaments. At least one of the emitter circuits has a current measurement device between the high voltage DC supply and the emitter.

Abstract: Acquisition of X-ray transmission data at three or more energy levels is described. Various implementations utilize generator waveforms that utilize fast-switching, slow-switching, or a combination of fast- and slow-switching to transition between X-ray energy levels. In addition, various sampling arrangements for sampling and/or binning three or more energy levels of X-ray transmission data are discussed. The use of these data in subsequent processing steps, such for material decomposition and/or improvement of dual-energy material decomposition processing, are also described.

Abstract: An imaging system includes a computed tomography (CT) acquisition unit and a processing unit. The CT acquisition unit includes an X-ray source and a CT detector. The processing unit is configured to determine a voltage delivery configuration for the X-ray source based on at least one of a patient size, a clinical task, or scan parameters. The voltage delivery configuration includes at least one of a transition configuration or a voltage threshold. The transition configuration corresponds to a transition between a high and low voltage. Portions of acquired data acquired above the voltage threshold are grouped as high energy data and portions acquired below are grouped as low energy data. The processing unit is also configured to implement the voltage delivery configuration on the CT acquisition unit, and to control the CT acquisition unit to perform an imaging scan using the determined voltage delivery configuration.

Abstract: The present inventors have recognized that fall times between high-kV to low-kV levels (during a “dual energy” or “fast-kV” energy scan) are linked to the discharge of HV (high voltage) capacitance. In an embodiment of the invention, a high voltage generator may be activated during fall transitions from first to second energy levels in order to substantially maintain a predetermined fall transition time. Accordingly, substantially equal energy distributions between high-kV and low-kV levels may be achieved.

Abstract: Rise times and fall times provided by a high voltage generator are controlled to maintain image quality during such scans. The rise and fall times are controlled by first measuring rise and fall times at each transition. Then, a closed-loop controller is used to adjust control parameters of the high voltage generator, based on an error determined from the measurement, to achieve substantially constant rise and fall times. This invention may be based on the implementation of two closed-loop controllers on rise and fall time of fast-kV exposures. As a result, image quality may be improved and system calibration time may be reduced.

Abstract: Energy distribution box (1) for an electrically controlled system of a vehicle, the said energy distribution box including: a set of inputs (E1, E2) intended to be connected to sources (6, 8, 30, 31, 33, 34) for supply of electrical energy, a set of outputs (S1 to SN) intended to be connected to electrical loads (11, 12, 13, 14, 20, 21, 22, 23, 25, 26, 27, 20A, 21A, 22A, 23A) of the said system and switching means (I1 to IN) arranged between the said set of inputs and the said set of outputs, the said energy distribution box being able to communicate with a unit for control of the switching means.