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: A circuit assembly and method use a breakover device that changes states in response to a change in electric energy in a helper circuit that supplies current from a power source to a powered system. The helper circuit includes an inductive element connected with the powered system. The breakover device is in a non-conducting state prior to a discharge event from the powered system to prevent the current from the power source from being conducted through the resistive element. The breakover device changes to a conducting state responsive to the powered system discharging current into the helper circuit. The breakover device conducts the current that is discharged from the powered system through the resistive element to reduce the electric energy in the helper circuit from the current that is discharged.

Abstract: A digital X-ray detector is provided. The digital X-ray detector includes multiple pixels, each pixel including a pinned photodiode, and multiple readout channels coupled to each pinned photodiode, wherein each readout channel includes at least one charge-storage capacitor, an amplifier, and a transfer gate. The digital X-ray detector also includes control circuitry coupled to each pixel of the multiple pixels and configured to selectively control a flow of photocharge generated by each pinned photodiode to a respective at least one charge-storage capacitor of each respective readout channel via control of each respective transfer gate of each respective readout channel.

Abstract: In accordance with one aspect of the present system, an X-ray detector of an X-ray imaging system includes a communication module configured to receive a pre-shot image from a detection circuitry and receive one or more pre-shot parameters from a source controller of the X-ray imaging system. The X-ray detector further includes an analysis module configured to determine one or more image characteristics of the pre-shot image. The X-ray detector further includes a determination module configured to calculate one or more main-shot parameters based on the one or more pre-shot parameters and the one or more image characteristics. The determination module is further configured to send the one or more main-shot parameters to the source controller of the X-ray imaging system.

Abstract: A flat emitter configured for use in an X-ray tube is presented. The X-ray tube includes a first conductive section including a first terminal. Further, the X-ray tube includes a second conductive section including a second terminal. Also, the X-ray tube includes a third conductive section disposed between the first conductive section and the second conductive section, wherein the third conductive section is configured to emit electrons toward a determined focal spot, and wherein the third conductive section includes a plurality of slits subdividing the third conductive section into a winding track coupled to the first conductive section and the second conductive section, wherein at least two of the plurality of slits are interwound spirally to compose the winding track, and wherein the winding track is configured to expand and contract based on heat provided to the third conductive section.

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: Systems and methods for measuring current with shielded conductors are provided. One system includes a first wire within shielding, wherein the first wire is connected between a high voltage source and a filament of an x-ray system. The system also includes a second wire within shielding, wherein the second wire is connected between the high voltage source and the x-ray system and the shielding of the first and second wires is at a high voltage potential of the x-ray system. The system further includes a measurement resistor at a high voltage potential, wherein the measurement resistor is connected between the shielding and one of the first or second wires.

Abstract: A digital X-ray detector is provided. The digital X-ray detector includes multiple pixels, each pixel including a pinned photodiode, and multiple readout channels coupled to each pinned photodiode, wherein each readout channel includes at least one charge-storage capacitor, an amplifier, and a transfer gate. The digital X-ray detector also includes control circuitry coupled to each pixel of the multiple pixels and configured to selectively control a flow of photocharge generated by each pinned photodiode to a respective at least one charge-storage capacitor of each respective readout channel via control of each respective transfer gate of each respective readout channel.

Abstract: An imaging method includes executing a low-dose preparatory scan to an object by applying tube voltages and tube currents in an x-ray source, and generating a first image of the object corresponding to the low-dose preparatory scan. The method further includes generating image quality estimates and dose estimates view by view at least based on the first image. The method includes optimizing the tube voltages and the tube currents to generate optimal profiles for the tube voltage and the tube current. At least one of the optimal profiles for the tube voltage and the tube current is generated based on the image quality estimates and the dose estimates. The method includes executing an acquisition scan by applying the tube voltages and the tube currents based on the optimal profiles and generating a second image of the object corresponding to the acquisition scan. An imaging system is also provided.

Abstract: Use of a reference detector to characterize an X-ray emission focal spot is disclosed. In certain embodiments, the reference detector may contain one or more openings or apertures that may be used to acquire localized X-ray intensity information used to derive the focal spot characteristics. In certain embodiments, the reference detector is on the source-side of the imaged volume.

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: Apparatus and methods to control an electron beam of an x-ray tube are provided. One apparatus includes at least one of (i) a first switching unit having a voltage source and a pair of switches connected in series and configured to switch between open and closed positions to change an output voltage to engage or bypass the voltage source or (ii) a second switching unit connected to a voltage source and having a first pair of switches connected in series and a second pair of switches connected in series, wherein the first and second pair of switches are connected in parallel, and wherein the first and second pairs of switches are configured to switch between open and closed position to change an output voltage generated from the voltage source. The first and second switching units are connected in series and a third switching unit provided that is amplitude controllable.

Abstract: In accordance with one aspect of the present system, an X-ray detector of an X-ray imaging system includes a communication module configured to receive a pre-shot image from a detection circuitry and receive one or more pre-shot parameters from a source controller of the X-ray imaging system. The X-ray detector further includes an analysis module configured to determine one or more image characteristics of the pre-shot image. The X-ray detector further includes a determination module configured to calculate one or more main-shot parameters based on the one or more pre-shot parameters and the one or more image characteristics. The determination module is further configured to send the one or more main-shot parameters to the source controller of the X-ray imaging system.

Abstract: A medical imaging method comprising generating a radiation at a first energy level by a radiation source, generating a radiation at a second energy level different from the first energy level by the radiation source, emitting the generated radiations at an output of the radiation source towards a detector, and blocking or diverting the emitted radiations during at least one intermediate phase during which the radiation source switches in a transient way from one of the first energy level and the second energy level to the other of the first energy level and the second energy level.

Abstract: Issues related to maintaining the size of a focal spot on the target material of an X-ray source are addressed by linking the currents used in a magnetic focusing system employed in the X-ray source. The size of the focal spot on the target is less sensitive to current changes applied to the magnetic focusing system due to this linkage.

Abstract: Systems and methods for measuring current with shielded conductors are provided. One system includes a first wire within shielding, wherein the first wire is connected between a high voltage source and a filament of an x-ray system. The system also includes a second wire within shielding, wherein the second wire is connected between the high voltage source and the x-ray system and the shielding of the first and second wires is at a high voltage potential of the x-ray system. The system further includes a measurement resistor at a high voltage potential, wherein the measurement resistor is connected between the shielding and one of the first or second wires.

Abstract: Issues related to maintaining the size of a focal spot on the target material of an X-ray source are addressed by linking the currents used in a magnetic focusing system employed in the X-ray source. The size of the focal spot on the target is less sensitive to current changes applied to the magnetic focusing system due to this linkage.

Abstract: Apparatus and methods to control an electron beam of an x-ray tube are provided. One apparatus includes at least one of (i) a first switching unit having a voltage source and a pair of switches connected in series and configured to switch between open and closed positions to change an output voltage to engage or bypass the voltage source or (ii) a second switching unit connected to a voltage source and having a first pair of switches connected in series and a second pair of switches connected in series, wherein the first and second pair of switches are connected in parallel, and wherein the first and second pairs of switches are configured to switch between open and closed position to change an output voltage generated from the voltage source. The first and second switching units are connected in series and a third switching unit provided that is amplitude controllable.