Abstract: 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.

Abstract: A system and method of x-ray imaging includes obtaining a plurality of x-ray projection images of a patient. At least one object in the plurality of x-ray projection images is identified. A priori information of the identified at least one object is obtained. A three dimensional volume is reconstructed from the plurality of x-ray projection images. The a priori information is used to refine the acquisition of x-ray projection images or presentation of the three dimensional volume.

Abstract: 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.

Abstract: According to one embodiment, an X-ray computed tomography apparatus includes an X-ray tube, a high voltage power supply, and focus size control circuitry. The X-ray tube includes a cathode, an anode, and a deflector configured to deflect the electrons from the cathode. The high voltage power supply generates a tube voltage to be applied between the cathode and the anode. The focus size control circuitry controls a focus size formed in the anode by applying to the deflector a deflecting voltage of a deflecting voltage value based on a tube voltage value of the tube voltage and a predetermined size, in order to form a focus of the predetermined size in the anode during the period where the tube voltage is applied by the high voltage power supply.

Abstract: A method for optimizing CT scanning parameter is disclosed. A target group may be generated from a plurality of reference information samples. Each of the reference information samples may include subject information, information indicating a scanning protocol, one or more scanning parameter values and information indicating reconstructed image quality; the target group can consist of one or more reference information samples with the same subject information and the same scanning protocol. A scanning parameter optimization may be performed according to reconstructed image qualities and scanning parameter values of reference information samples in the target group, so as to acquire a target scanning parameter value of the target group. And according to the target scanning parameter value, a reference X-ray irradiation dose corresponding to the scanning protocol and the subject information of the target group may be determined.

Abstract: The present specification discloses systems for a compact and portable X-ray transmission imaging system that is used for security inspection of small items. The system includes a housing with an X-ray tunnel for receiving an article to be inspected, a conveyor for conveying the article through the tunnel, a dual source X-ray system, with a central target, for generating two overlapping cone beams, and a two-dimensional X-ray detector system for detecting the generated dual energy X-rays.

Abstract: A method and apparatus for preheating a bulb tube of medical equipment is provided. The method includes: selecting a scanning condition which satisfies an equipment calibration condition, as a preheating condition for the bulb tube, from scanning conditions used by the medical equipment; selecting a new preheating condition if an accumulated thermal capacity according to selected preheating conditions is smaller than a target thermal capacity, until the accumulated thermal capacity reaches the target thermal capacity, wherein the accumulated thermal capacity indicates a sum of a thermal capacity estimated to be generated when the bulb tube is preheated according to the selected preheating conditions, and the target thermal capacity indicates a thermal capacity required to complete the preheating of the bulb tube; preheating the bulb tube according to selected preheating conditions and executing an equipment calibration corresponding to each of the preheating conditions during the bulb tube preheating.

Abstract: A sensor panel of an electronic cassette includes detection pixels each for outputting a dose signal corresponding to a dose of X-rays, an irradiation start judging section for judging whether or not X-ray irradiation has been started based on the dose signal, and an AEC section for judging whether or not an accumulated dose of X-rays has reached a target dose based on the dose signal. A gain setting section sets a gain of an integration amplifier in the case of using the irradiation start judging section lower than that in the case of using the AEC section.

Abstract: An x-ray tube unit includes an x-ray tube unit housing, in which a vacuum housing is disposed, which includes a high-voltage component. The vacuum housing includes an insulating medium circulating in the x-ray tube unit housing flowing around it. Further, a cathode module and an anode are disposed in the vacuum housing, the cathode module lying at high voltage and including an emitter which emits electrons when heating current is fed to it. In addition, a potential difference is present between the cathode module and the anode for accelerating the emitted electrons. In accordance with an embodiment of the invention a high-voltage feed, a heating transformer and a radiation protection component are integrated into the high-voltage component, the high-voltage component being filled at least partly with an electrically-insulating encapsulation material. This produces a compact and installation-friendly x-ray tube unit which has high operational safety.

Abstract: A system and a method is disclosed for consistently and verifiably optimizing computed tomography (CT) radiation dose in the clinical setting. Mathematical models allow for estimation of patient size, image noise, size-specific radiation dose, and image quality targets based on digital image data and radiologists preferences. A prediction model estimates the scanner's tube current modulation and predicts image noise and size-specific radiation dose over a range of patient sizes. An optimization model calculates specific scanner settings needed to attain target image quality at the minimum radiation dose possible. An automated system processes the image and dose data according to the mathematical models and stores and displays the information, enabling verification and ongoing monitoring of consistent dose optimization.

Abstract: A system and method of x-ray imaging includes obtaining a plurality of x-ray projection images of a patient. At least one object in the plurality of x-ray projection images is identified. A priori information of the identified at least one object is obtained. A three dimensional volume is reconstructed from the plurality of x-ray projection images. The a priori information is used to refine the acquisition of x-ray projection images or presentation of the three dimensional volume.

Abstract: A system and method for generating X-rays are provided. The X-ray source includes an X-ray chamber including a sidewall formed of a piezoelectric material at least partially surrounding an evacuated chamber, a cathode positioned at a first end of the evacuated chamber, an anode positioned at a second opposite end of the evacuated chamber, and a window positioned at the second end, the window substantially transparent to X-ray radiation. The window includes a target layer at least partially covering a surface of the window. The target layer is configured to receive a flow of electrons from the cathode and to generate a flow of X-rays from an interaction with the flow of electrons. The X-ray source includes an actuator coaxially aligned with the X-ray chamber and configured to generate a stress in the sidewall.

Abstract: A method and an associated apparatus for controlling a heating current flowing through an emitter of a pulsed X-ray tube during pulse pauses are provided. The heating current is controlled by comparing a measured actual value of the heating current with a predefinable desired value of the heating current. A low-pass filtering of the actual value of the heating current is effected before the comparison. A time constant of the low-pass filtering is equal to a thermal time constant of the emitter. A correction of the actual value of the heating current is provided before the low-pass filtering by a first correction value. The first correction value is determined such that a tube current control during the pulses is not compensated for by the heating current control in the pulse pauses.

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: A radiographic examination apparatus improves response to fluoroscopy or continuous shooting by changing promptly the power-output of an X-ray tube. The apparatus and method, when an absolute value of variation C per fixed time interval between the filament electric current of current pulse-output calculated by the filament electric current variation calculation element is more than a setup value, a flash control between pulse conducts increases or decreases temporarily the filament electric current between pulses to become the filament electric current on flash control between pulses calculated by a filament electric current calculation element based on a radiation condition of a current pulse-output and the radiation condition of following pulse-output.

Abstract: An X-ray diagnostic system according to an embodiment includes: an X-ray tube for radiating an X-ray to the subject on the basis of a tube current for taking a scanogram of a subject; an X-ray detector for detecting the X-ray radiated by the X-ray tube and transmitted through the subject; a data collector for collecting X-ray dose distribution data, which shows the dose distribution of the X-ray; an image processor for creating the scanogram from the X-ray dose distribution data; a genuine data generator for generating genuine data showing the dose distribution of the X-ray, from the scanogram; a threshold value setting section for setting a threshold value for the genuine data; and a tube current adjustor for adjusting a tube current for taking a tomographic image of the subject in accordance with a comparison between the X-ray dose in the genuine data and the threshold value.

Abstract: A power converter is configured to include an inverter which converts a DC output into an AC voltage of a predetermined frequency, and a high voltage generator which receives an output from output terminals of the inverter and boosts the output to a desired high DC voltage. The high voltage generator includes a transformer, and the primary windings of the transformer are connected to the output terminals of the inverter in parallel by conductive wires connected to both ends of each primary winding. Further, a current sensor is provided to detect a current flowing through each of the primary windings, and a control unit determines abnormalities of a path of the inverter and the primary windings on the basis of a value of the current sensor.

Abstract: A power supply operating off a common 110/220 Volt source utilizes a number of capacitors connected in series to form a module. A number of modules are connected in series to form a bus level module. A number of bus level modules are connected in parallel to provide the voltage and power needed by an X-Ray generator.

Abstract: A flat panel detector has pixels for obtaining image signals and detective pixels for detecting the amount of incident x-rays. A signal processing circuit is of a pipeline-type, wherein first and second buffer memories are connected to the output of an A/D converter. In a dose detecting operation, the signal processing circuit repeats primary cycles alternately with secondary cycles of a shorter length than the primary cycles. In the primary cycle, a dose detection signal based on electric charges from the detective pixels is input in the first buffer memory and, simultaneously, a dummy signal is output from the second buffer memory. In secondary cycle, the dose detection signal is output from the first buffer memory and, simultaneously, a second dummy signal is input in the second buffer memory. On the basis of the dose detection signals, a start-of-radiation detector detects the start of x-ray radiation.

Abstract: An x-ray beam control system includes a feedback control loop circuit having a modulation circuit. The feedback control loop circuit generates a control signal. A x-ray tube, has a filament response profile of tube current versus filament temperature that is non-linear. A compensation circuit receives the control signal and modifies the control signal according to a compensating function that is matched to the filament response profile. The modulation circuit receives the modified control signal and generates a drive signal. The x-ray tube receives the drive signal at a filament thereof, and outputs a tube current signal having a linear response to the control signal. The feedback control loop circuit receives the tube current signal.

Abstract: Provided herein are systems and methods for operating a traveling wave linear accelerator to generate stable electron beams at two or more different intensities by varying the number of electrons injected into the accelerator structure during each pulse by varying the width of the beam pulse, i.e., pulse width. The electron beams may be used to generate x-rays having selected doses and energies, which may be used for cargo scanning or radiotherapy applications.

Abstract: A compact x-ray source can include a circuit (10) providing reliable voltage isolation between low and high voltage sides (21, 23) of the circuit while allowing AC power transfer between the low and high voltage sides of the circuit to an x-ray tube electron emitter (43). Capacitors (11, 12) can provide the isolation between the low and high voltage sides of the circuit. The x-ray source (110) can utilize capacitors of a high voltage generator (67) to provide the voltage isolation. A compact x-ray source (110) can comprise a single transformer core (101) to transfer alternating current from two alternating current sources (104a, 104b) to an electron emitter (43) and a high voltage generator (107). A compact x-ray source (120) can comprise a high voltage sensing resistor (R1) disposed on a cylinder (41) of an x-ray tube (40).

Abstract: An X-ray imaging system can include an X-ray tube, an X-ray generator, a precharging module and a triaxial cable. The X-ray tube can be configured to generate an X-ray emission and include an anode, a cathode and a filament. The X-ray generator can be coupled with the X-ray tube and include a high voltage module and a low voltage module. The high voltage module can be being configured to supply a dosing voltage across the X-ray tube and the low voltage module can be configured to supply a dosing current to the filament. The precharging module can be configured to supply a precharge voltage. The triaxial cable can electrically connect the X-ray generator to the X-ray tube. The outer shield conductor of the triaxial cable can carry a ground voltage, the inner shield conductor can carry the precharge voltage and the center conductor can carry the dosing voltage.

Abstract: A device for producing x-rays includes: a housing that includes a folded high-voltage multiplier coupled to a filament transformer, the transformer coupled to an x-ray tube for producing the x-rays. A method of fabrication and an x-ray source are disclosed.

Abstract: Discharge module which is formed by three circuits, a control and measurement circuit for X-rays, a voltage division circuit between serial switches, which is independent from the previous one, and a third circuit of the charge short circuit, which in turn is formed by a successive or slave trip circuit of the switches and another main discharge circuit through the switches; due to the established configuration, a much improved radiation control is achieved as it is not affected by unforeseen agents, the short circuit current is not restricted to the port current of the switches, and residual voltage of the switches is reduced.

Abstract: An X-ray CT apparatus is provided that generates a three-dimensional cross-section model from scanogram projection data of an examinee. An operator inputs a site of interest, an assumed displacement amount of the site and a desired image quality index value. A scan planning unit calculates an X-ray attenuation index from the three-dimensional cross-section model, and corrects the calculated X-ray attenuation index on the basis of the input site of interest, assumed displacement amount and image quality index value. The scan planning unit further determines a tube current modulating pattern (irradiation X-ray dose modulating pattern) on the basis of the corrected X-ray attenuation index. When scanning is executed, an X-ray tube is controlled according to the determined irradiation X-ray dose modulating pattern, and controlled so as to obtain an optimum X-ray dose.

Abstract: A power supply operating off a common 110/220 Volt source utilizes a number of capacitors connected in series to form a module. A number of modules are connected in series to form a bus level module.

Abstract: In order to prevent breakage of a power converter, a current which flows into an inverter (3) in the power converter is detected. The inverter (3) is equipped with two or more primary windings in parallel with each other. The current flowing through each of the primary windings is detected by current sensors (17, 6). A control unit (22) determines from the outputs of the current sensors that an abnormality occurs, when current does not flow through any of the primary windings.

Abstract: An X-ray apparatus includes a converter into which there is integrated a control logic circuit configured to regulate the supply voltage of a high-voltage power supply source of the X-ray apparatus. To this end, the intelligent voltage-voltage, converter is placed between the power battery and the capacitor bank. This intelligent converter is capable of determining the optimum voltage to be delivered to the generator for the radiology examination to be undertaken in regulating the current of the power battery at the necessary level of current.

Abstract: A weight (22) and height (24) of a patient who is to undergo a calcium screening examination in an x-ray diagnostic scanner (10) is used to calculate an appropriate x-ray dose in terms of tube current (mAs) for the calcium screening examination in accordance with the formula: mAs=c(BMI)2, where BMI is a patient's body mass index defined as: BMI=patent weight_(patient height)2.and C is a constant selected in accordance with a target required noise. In this manner, patients can be scanned with a minimum dose necessary to achieve the target noise, e.g., 20 HU. The images can be compared with earlier (and subsequent) images that have the same target noise.

Abstract: The present invention provides an X-ray CT apparatus capable of obtaining each tomographic image indicative of X-ray tube voltage dependent information of a subject with the optimum image quality by less reduced exposure. The X-ray CT apparatus includes device for setting a plurality of X-ray tube voltages and sets imaging conditions used in the photography using the respective X-ray tube voltages in such a manner that respective image noise of tomographic images photographed at the X-ray tube voltages become substantially identical to one another. The setting of the imaging conditions is the setting of X-ray tube currents. The X-ray tube currents are set based on geometrical characteristic amounts of the subject determined from each scout image in such a manner that the respective image noise of the tomographic images photographed at the plurality of X-ray tube voltages become substantially identical to one another.

Abstract: In the X-ray CT apparatus of the present invention, the setting device sets X-ray irradiation condition candidate by at least one combination of a tube current and tube voltage for power to be supplied to the X-ray source by the use of an X-ray absorption coefficient of said scanning subject site of the object, and the control device makes the display device selectably display each of the set X-ray irradiation condition candidates which is provided for a diagnosis of a requested tissue of the object, to take control such that a tomographic image of the object is taken according to the selected X-ray irradiation condition candidate. According to the X-ray CT apparatus of the present invention, it is possible to set a scanning condition in view of absorption or transmission of X-rays specific to and different among each tissue of an object.

Abstract: The present invention aims to obtain a tomographic image similar in image quality to a tomographic image obtained by executing a scan at X-ray tube current value set by an X-ray automatic exposure function even when the X-ray tube current value set by the X-ray automatic exposure function are not within a standard range of the X-ray tube current values settable at the X-ray tube (21). X-ray tube current value supplied to the X-ray tube (21) are set by the X-ray automatic exposure function. Thereafter, when the X-ray tube current value set by the X-ray automatic exposure function is not within in the standard range of the X-ray tube current value settable at the X-ray tube, the X-ray tube current value at a portion not within the standard range are changed so as to be within the standard range, and the set value of helical pitch is changed so as to correspond to the ratio between the pre-changed x-ray tube current value and the post-changed X-ray tube current value.

Abstract: An X-ray CT apparatus includes a projection data analysis part that reconstructs a tomographic image at an imaging portion of the object used for analysis from the projection data and produces a control profile by reprojecting the reconstructed tomographic image, and a tube current control part that controls value of current to be fed to the X-ray tube based on the produced control profile.

Abstract: The present invention is directed to a networked scanner environment wherein each scanner is communicatable with one or more databases configured to store data associated with previously executed imaging sessions. The one or more databases may be queried by a user to determine, based on a set of user inputs, an historical evaluation of the prior imaging sessions conducted in accordance with scan parameters similar to the scan parameters of an imminent imaging session. The present invention includes a global database that is accessible by a series of remotely located imaging systems as well as includes one or more databases particular to a specific treatment facility housing one or more imaging scanners. The present invention is also applicable with a stand-alone imaging system having a database local to that particular imaging system for storing and accessing data associated with imaging sessions conducted on that particular imaging system.

Abstract: Methods for determining and displaying x-ray radiation generated by a radiographic device may include storing in a memory a plurality of tables that correlate voltage and current values of an x-ray tube to a predicted radiation rate for a given radiographic device. Actual or approximate voltage and current values are then obtained from an operating x-ray tube. Based on these values, a predicted instant (or “dynamic”) radiation late is selected from one of the stored tables and is displayed to the practitioner. In addition, the method may approximate an accumulated radiation dose by measuring the time periods over which predicted radiation rates are generated and calculating a running total. Apparatus for conducting such methods is also disclosed.

Abstract: A system is provided for radiographic inspection of an object comprising multiple having different material properties. The system comprises a radiation source configured to generate radiation, a display unit for generating a graphical user interface (GUI) including multiple fields. A user enters input data via the fields in the GUI. The input data relates to one or more material properties for each of the regions. A processor is configured to compute a plurality of exposure parameters based on the input data.

Abstract: In an X-ray generating device of the neutral grounding system, to remove an unbalance voltage generated due to difference in impedance of parallel transformer coils of the high voltage transformer and particularly an unbalance voltage involved with difference in impedance above and below the neutral points generated in a metal X-ray tube, a plurality of currents flowing in opposite directions through primary windings of the parallel transformer coils in the high voltage transformer are passed through by or wound around a common toroidal coil or wound around an outer circumference of the toroidal coil at a predetermined ratio of winding number, and the unbalance voltage occurring to the secondary side is cancelled by changing primary current with magnetic behavior.

Abstract: Methods for determining and displaying x-ray radiation generated by a radiographic device may include storing in a memory a plurality of tables that correlate voltage and current values of an x-ray tube to a predicted radiation rate for a given radiographic device. Actual or approximate voltage and current values are then obtained from an operating x-ray tube. Based on these values, a predicted instant (or “dynamic”) radiation late is selected from one of the stored tables and is displayed to the practitioner. In addition, the method may approximate an accumulated radiation dose by measuring the time periods over which predicted radiation rates are generated and calculating a running total. Apparatus for conducting such methods is also disclosed.

Abstract: A target structure for an electron linear accelerator converts energy in an electron beam to x-rays and provides for the monitoring and control of the effective energy of the electron beam by collecting and processing a residual current in the target structure.

Abstract: Systems and methods for providing independent exposure detection, X-ray spectrum and timing compensation, and providing an exposure termination signal to an X-ray system. The system incorporates an interface for receiving exposure characteristic data such as kVp, spectral filter, and focal spot. The system through a programmed controller determines one or more control parameters based on the received exposure characteristic data and generates a control signal for controlling an X-ray source.

Abstract: An X-ray generator of this invention has an X-ray monitor that monitors a state of an X-ray emitted from a target. Hence the state of the X-ray can be monitored in real time to maintain the X-ray in a constant state. The X-ray monitor is positioned off the path on which an X-ray transmitted from a first exit window travels. Hence, when the X-ray is emitted from the first exit window to an object to be inspected, the X-ray monitor does not obstruct the approaching of the object to the first exit window. This makes it possible to acquire X-ray images of high magnification.

Abstract: A maximum tube voltage value setting module 240a, a warming-up module 240b, a limit tube voltage control module 240c, a limit tube current control module 240d and a focus grid electrode control module 240e of an operation program 240 which respectively correspond to different maximum tube voltage values are stored in storage sections 32a-e of an X-ray tube control apparatus 3. When the maximum tube voltage value of an X-ray tube 1 is changed, an extraction section 34 extracts each module of the operation program 240 which corresponds to the maximum tube voltage value after being changed from the storage sections 32a-e. A communications section 36 sends the operation program 240 comprised of each extracted module to an X-ray tube controller 2 and overwrites it in a memory section 24.

Abstract: An X-ray computed tomographic apparatus includes a gantry, a reconstructing portion, and a tube current value determining portion. The gantry acquires projection data of an arbitrary range in a body axial direction by continuously moving a tabletop on which a subject is laid down and by continuously rotating an X-ray tube about the subject. The reconstructing portion reconstructs image data from the acquired projection data according to reconstruction processing selected by an operator from plural types of reconstruction processing. The tube current value determining portion determines plural tube current values respectively corresponding to discrete, plural positions within the range, on the basis of the selected type of reconstruction processing and an image quality level specified or selected by the operator.

Abstract: An X-ray computed tomography apparatus includes an X-ray tube, a high voltage generator which generates a high voltage to be applied to the X-ray tube, an X-ray detector having a plurality of X-ray detection element lines, a scanogram generating unit which generates a scanogram on the basis of an output from the X-ray detector, a reconstructing unit which reconstructs an image on the basis of an output from the X-ray detector, a tube current determining unit which determines a tube current value on the basis of the pixel values of a plurality of pixels included in a two-dimensional partial region of the scanogram, and a control unit which controls the high voltage generator on the basis of the determined tube current value.

Abstract: A control circuit for controlling an electron-emitting device is formed to draw, with a voltage applied, an excitation current being related to a number of electrons emitted. The inventive control circuit includes a first determinator for determining whether an amount of charge transported by the excitation current has reached a predetermined charge threshold value, a second determinator for determining whether a magnitude of the excitation current has reached a predetermined current threshold value, and a switch for switching off the excitation current as soon as the first determinator determines that the amount of charge has reached a predetermined charge threshold value, or as soon as the second determinator determines that the magnitude of the excitation current is smaller than the predetermined current threshold value.

Abstract: A method for determining the heating time constant of a cathode of an X-ray tube. The value of a boost current applied during a preliminary period must be a function of both a pre-existing heating holding current and a service current to be used subsequently. A model of evolution of cathode temperature produces a minimizing tube current error between a tube current that is expected for the tube and a tube current obtained. The model requires only four parameters that need to be computed.

Abstract: For automatically controlling or adjusting the X-ray dose when scanning an examination subject in a CT apparatus, a series of reference measurements are initially made by obtaining CT images of respective phantoms having different attenuation. The tube current for each phantom that produces an image of the phantom having an acceptable noise level, and thus an acceptable image quality, is stored in a table. In a subsequent CT scan of an examination subject, the tube voltage is automatically adjusted when irradiating a region of the subject having attenuation comparable to the attenuation of one of the phantoms, so as to employ the tube current when irradiating the examination subject that produced the image of acceptable quality for the comparable phantom.

Abstract: To adjust the emission rate of radiation from an X-ray tube, the value of the current of the X-ray tube is modeled empirically by a second-order polynomial function depending on the heating current and a first-order polynomial function depending on the high voltage. A transfer function gives precision closer than 3% for the adjusting of an expected tube current. This function can also be used to take account of disparities of manufacture and of the aging of the tubes in use.

Abstract: A method and apparatus is disclosed to acquire scout scan data of a subject and analyzed to determine a peak-to-peak modulation amplitude of a normalized waveform indicative of subject size and shape. The scout scan data provides a representation of patient size and shape that is associated with an ideal tube current modulation waveform or profile. The ideal tube current modulation profile may then be sampled or approximated at various points to determine a tube current modulation profile for implementation to acquire CT data with reduced dose but without sacrificing image quality.