Abstract: An X-ray diagnostic apparatus repeatedly radiates pulse-like X-rays, repeatedly images X-rays passing through an object to be examined at a predetermined frame period, and sequentially displays a plurality of images thus obtained repeatedly. In this invention, the exposure dose can be reduced since the number of X-ray irradiation times per unit time is set to be smaller than the number of frames to be imaged per unit time.

Abstract: A subject is positioned on a patient support (12) between an x-ray source (10) and a radiation detector assembly (14). The x-ray source is gated (36) on or open prior to triggering (38) a video camera (26) of the x-ray detector assembly to generate an electronic frame image representation. The patient support is moved to generate reference images at positions (5, 4, 3, 2, 1) and the resultant reference images are stored in a reference image memory (42). A radiopaque dye is injected adjacent a first position (1) and the x-ray source and camera are triggered at a first rate indicated by a scan program memory (50). The generated images are displayed on a video monitor until a radiologist decides that the radiopaque dye has moved downstream sufficiently that it is time to index to a second position (2). The radiologist presses an index button (68) causing the patient to be indexed.

Abstract: In an interventional radiography (IVR), for example in a percutaneous transluminal coronary angioplasty (PTCA), when the IVR includes a period in which the movement of the object is slow, a normal X-ray radiating mode (a continuous X-ray radiation or a normal rate pulse radiation of about 15-30 pulses per second) is changed to a very slow rate pulse X-ray radiation of about 1-5 pulses per second to decrease the X-ray dose of the patient. Since the movement is slow, the very slow rate pulse radiation can still trace the movement adequately. Further, the quality of the X-ray image is improved by increasing the tube current in the very slow rate pulse radiation because less heat is generated in the X-ray tube.

Abstract: A high frequency voltage generator (10) produces a high positive voltage and a high negative voltage. A parallel connected coil (26) and diode (30) are connected between the high voltage supply and a target (44) of an x-ray tube (40). A second parallel connected coil (28) and diode (32) are connected between the negative voltage and an electron source (42) of the x-ray tube. The coils are preferably a multiple pancake design (FIG. 3 ). When the tube starts to arc, the sudden increase in current flow through the coil is converted and stored in a magnetic field leaving only a small current to contribute to arcing. The coils are sized such that the current which passes to the x-ray tube is sufficiently small that the arcing is usually extinguished without an avalanche phenomenon occurring.

Abstract: The disclosure relates to devices for supplying current to X-ray tube cathode filaments. The filament of a cathode is supplied with high-frequency current pulses given by a hyporesonant type DC/AC converter, the transistors of which are controlled by a regulation circuit. This regulation circuit carries out a high-frequency regulation.

Abstract: An apparatus and method for dynamically controlling the generation of radiation pulses during pulse-type fluoroscopic imaging. Brightness of an image produced by a pulse is detected, converted to a digital value and compared to an acceptable predetermined value range. If the brightness is not acceptable, the pulse rate is reset to a predetermined, relatively fast rate and the energy level for the next pulse adjusted up or down to increase or decrease the brightness as necessary. Once the brightness is found to be acceptable, the pulse rate is returned to the original pulse rate. If it is determined that motion is occurring, the pulse rate will increase to the relatively fast predetermined pulse rate to provide substantially real-time imaging. If the brightness becomes unacceptable for a pulse during the period of motion, the energy level for the subsequent pulse will be adjusted.

Abstract: A pulsed precision x-ray source includes a miniaturized internally self-shielding x-ray tube and an integral generator contained in a hand-held housing for generating timed bursts of x-ray having regulated energy level. A control grid and focus electrode within the tube enable precise on-off control of an electron beam directed to an x-ray emitting anode. The integral generator system includes an elongated, U-shaped unitary, molded plastic block mounted in the housing and includes a high voltage transformer having primary and secondary annular windings encased in a transformer portion of the block defining a central opening outside of the block for receiving a transformer core therethrough and, a capacitor-diode voltage multiplier stack connected to the secondary winding and having a positive node connectable to the anode and a negative node connectable to the cathode.

Abstract: A discharge module positionable between a high-voltage power supply and an X-ray tube for discharging any capacitive voltage remaining on the cable connecting the same. The discharge module includes a low-voltage control portion which is optically coupled to a high-voltage portion that includes a switch for activating a discharging resistor series. The module also monitors the current through the X-ray tube to initiate a fault if the current exceeds a predetermined maximum.

Abstract: An apparatus for producing high energy, pulsed, flash X-rays which is of a useful laboratory-scale size. The apparatus includes a hydrogen thyratron coupled between a D.C. power source and a low impedance Blumlein, and a low impedance X-ray head. The thyratron is in a grounded grid configuration and provides a commutated input voltage to the Blumlein at a high repetition rate. The switching waveform output of the Blumlein is applied across a pair of spaced electrodes in the X-ray head to produce an X-ray emitting discharge therebetween. A portion of the electrode assembly is preferably cast integral in an insulating base plate of the head. A pair of foil sheet conductors are preferably cast in the base plate to respectively connect the electrodes to the Blumlein. An apertured cover plate is mounted over the base plate with a seal ring interposed between the plates around the electrodes to establish a sealable evacuatable chamber around the discharge gap between the electrodes.

Abstract: A direct-current high voltage obtained by rippling, stepping-up and rectification of a direct-current low voltage is regulated in such a manner as to ensure that the maximum value of direct-current high voltage attains a predetermined peak value at each ripple pulse of the inverter. To this end, a following pulse of the inverter is produced as soon as the high voltage of the direct-current high-voltage signal has become lower than the predetermined peak value reduced by the measurement of a variation in said direct-current high voltage during a preceding pulse.

Abstract: An X-ray imaging apparatus comprises an X-ray generator, an image intensifier for converting an X-ray image of a subject under examination to an optical image, a solid state image sensor for picking up the optical image of the image intensifier, a driver circuit for driving the solid state image sensor and a television monitor for visually displaying an image signal obtained from the solid state image sensor as an X-ray optical image. The X-ray generator is controlled such that an X-ray pulse is not emitted during an interval in which the solid state image sensor transfers charges from charge storage sections to charge transfer sections.

Abstract: An apparatus for producing high energy, pulsed, flash X-rays which is of a useful laboratory-scale size. The apparatus includes a hydrogen thyratron coupled between a D.C. power source and a low impedance Blumlein, and a low impedance X-ray head. The thyratron is in a grounded grid configuration and provides a commutated input voltage to the Blumlein at a high repetition rate. The switching waveform output of the Blumlein is applied across a pair of spaced electrodes in the X-ray head to produce an X-ray emitting discharge therebetween. A portion of the electrode assembly is preferably cast integral in an insulating base plate of the head. A pair of foil sheet conductors are preferably cast in the base plate to respectively connect the electrodes to the Blumlein. An apertured cover plate is mounted over the base plate with a seal ring interposed between the plates around the electrodes to establish a sealable evacuatable chamber around the discharge gap between the electrodes.

Abstract: A portable radiographic generator is provided with an explosive magnetic flux compression generator producing the high voltage necessary to generate a relativistic electron beam. The relativistic electron beam is provided with target materials which generates the desired radiographic pulse. The magnetic flux compression generator may require at least two conventional explosively driven generators in series to obtain a desired output voltage of at least 1 MV. The cathode and anode configuration of the diode are selected to provide a switching action wherein a high impedance load is presented to the magnetic flux compression generator when the high voltage is being generated, and thereafter switching to a low impedance load to generate the relativistic electron beam. Magnetic flux compression generators can be explosively driven and provided in a relatively compact, portable form for use with the relativistic x-ray equipment.

Abstract: An X-ray generator system has first and second switching devices such as transistors which are complementarily turned on and off to intermittently apply a DC voltage to the primary winding of a transformer for thereby inducing a high voltage across secondary windings of the transformer for enabling an X-ray tube to emit X-rays. The X-ray generator has a control mode in which the first and second switching devices are simultaneously turned on immediately before they start being complementarily turned on and off, for allowing the high voltage to have a sharply rising positive-going edge.

Abstract: A circuit for operating an X-ray tube, such as in a medical diagnostics apparatus, is connected with a high-voltage generator and a switch mechanism for connecting and disconnecting the X-ray tube to the high-voltage generator. A resistor is disposed in a circuit branch which can be connected in parallel across the X-ray tube by a switch controlled by the aforementioned switch mechanism. If the X-ray tube is disconnected from the power source, the switch closes the circuit branch and causes the resistor to be connected across the X-ray tube. As a result, the X-ray tube voltage decreases relatively quickly after the high-voltage is disconnected. The resistor across the X-ray tube may be a variable resistor, such as a high-voltage triode.

Abstract: Digital radiography apparatus uses a resonance-type high frequency inverter having a main switch in series with an auxiliary switch. An X-ray tube receives the pulsed power from the high frequency inverter, after voltage ampliflication and rectification, emitting pulsed X-rays to a patient. A TV camera obtains X-ray transmission images of the patient, and an image processor generates a visual diagnostic image by subtracting one X-ray transmission image from another. The high frequency inverter circuit is controlled synchronously with the processing operation of the image processor.

Abstract: An apparatus for supplying high voltage pulsed direct current to an X-ray tube includes a transformer, a high frequency inverter circuit and a nonlinear feedback loop. The invention uses the high frequency inverter connected in series with a DC power supply source and the primary winding of the transformer in order to generate high voltage, high frequency AC in the secondary winding. A rectifier connected to the secondary winding supplies high voltage pulsed DC to the X-ray tube. A detector, such as a voltage divider, detects the voltage supplied to the X-ray tube and supplies a representation of it to a nonlinear feedback circuit connected between the detector and the high frequency inverter. The inverter circuit includes at least one switch generated by electrical pulses.

Abstract: An X-ray generator system is provided with a high-voltage feedback loop for controlling the output of an inverter to thereby maintain a desired output voltage level. The voltage-feedback loop is provided with a phase-advance network to selectively vary the gain of the system in such a way as to provide for high gain during the initial stage so as to obtain a short rise time, while subsequently reducing the gain so as to clamp the kV overshoot at the end of the rise time. A phase-lag network is also included to effectively eliminate noise that is introduced by the phase-advance network.

Abstract: A medical imaging device employs a plurality of triggered plasma cathode flash X-ray sources, each of which has an axially extending round anode rod, a cathode, and a trigger electrode. The application of a trigger pulse between the electrode and the cathode produces a burst of plasma near the cathode, the plasma containing electrons that are accelerated toward and impact the anode in a region termed the "focal spot" for producing X-rays when a voltage source applies a predetermined voltage between the cathode and anode. According to the invention, a non-conducting surface interconnects the electrode with a cathode or a conductor held at the same potential as the cathode, the application of a trigger pulse to the electrode causing flashover across said surface for producing the burst of plasma.

Abstract: A system for generating soft X rays. This system includes valve apparatus for repetitively providing bursts of a gas of brief duration and a magnetic pulse compression power supply for providing high current pulses. The system further includes a transmission line connected to the power supply for transmitting power pulses from the supply to discharge through bursts of gas. The power supply includes a plurality of series saturable inductor magnetic switches and a plurality of shunt capacitors. Thus, upon synchronized provision of a burst of gas from the valve apparatus and a power pulse from the power supply, a high current discharge generates plasma and an intense magnetic field which radially compresses the plasma, resulting in a dense, high temperature plasma which is an intense source of soft X rays.

Abstract: A rotate/rotate type X-ray computerized tomograph system employing a single-phase transformer as a high tension voltage supply whereby the secondary voltage of the single phase transformer is rectified and applied across the anode and cathode of an X-ray tube. Such a system, advantageously, is compact and lightweight and employs components which are substantially less costly than those of the prior art.

Abstract: A power supply is switchable to apply a low kilovoltage and a relatively higher kilovoltage alternately to the anode of an X-ray tube that includes a filament and a control grid. A grid bias voltage generator uses an inverter driven in the kilohertz frequency range to feed the primary winding of a first transformer whose parasitic capacitance and inductance are used to produce a peak ac output voltage from the secondary of the first transformer at resonant frequency. The secondary output voltage is rectified and the resulting negative bias voltage is applied to the control grid synchronously with the high kilovoltage being applied to the anode so the X-ray tube current is then relatively low. A less negative or zero bias voltage is applied to the grid synchronously with the lower kilovoltage being applied to the anode so the X-ray tube current is then relatively high and substantially limited by the temperature and emissivity of the filament.

Abstract: A power supply provides high voltage for a grid controlled x-ray tube. In the supply an oscillator generates a high frequency signal which is amplified and transformed to kilovoltage. A voltage multiplier increases the kilovoltage to a potential suitable for the tube. The voltage multiplier includes a bank of series capacitors which tends to maintain a constant high voltage when the tube is not conducting.

Abstract: X-ray pulses at two different photon energy levels are produced with an x-ray tube that has an adjustable resistor element in a circuit that connects the anode and filament of the tube to a high voltage supply. Two bias voltage supplies are connected in additive fashion between a control grid element of the tube and its filament to enable control of voltage drop and current through the tube. Switch means are provided to selectively shunt either or both bias voltage supplies in a repeatable order to thereby alter the bias voltage on the control grid and enable producing x-ray pulses having energies corresponding with the voltage drop and current through the tube at a selected bias voltage in accordance with the load line on the anode characteristic curve plot of the tube as determined by the value of the adjustable resistor element.

Abstract: The energy interlock system is designed for a linear accelerator having no electron beam bending system. The accelerator emits electron pulses which are directed to a target for generation of X-ray pulses. The interlock system contains an ionization chamber, a discriminator and a switch. The ionization chamber is exposed to the X-ray pulses for measuring their intensity distribution. It comprises a control electrode and a plurality of electrode segments. The discriminator is connected for detecting energy inhomogeneities in the X-ray pulses. The switch is operated by the discriminator and connected to switch the accelerator on and off.

Abstract: A circuit having indication lights for demonstrating when a flash trigger pulse has been fed to an X-ray photographic system or the like, is provided. The invention is especially useful in noting that a false triggering pulse, or prefire had inadvertently happened to a flash unit of an X-ray system before it was intended to be used, thus triggering it to photograph, ruining its film. This invention is also useful in that it marks which in a plurality of systems had been the one that had been falsely triggered, and additionally useful in marking that all of the said units had been properly triggered when a true pulsing had been engaged for all units, or of marking which unit had failed to fire.