Abstract: Absorption filters are positioned in an x-ray examination apparatus according to the invention by adjusting them on the basis of the posture of the carrier supporting the x-ray source and the x-ray detector. To that end adjustment curves relating carder posture to filter adjustment are employed. The posture of the carder determines the orientation of the x-ray beam path. Because there are relatively few anatomical differences among patients to be examined, the adjustment of absorption filters on the basis of the beam orientation is quite adequate. Further improvement is achieved by providing sets of adjustment curves, each set pertaining to a class of patients, such as e.g. corpulent or slender patients, or infants or adults.

Abstract: The invention is related to a soft-tissue filter apparatus for a cephalostat, said apparatus being capable of positioning the patent (P) stationary for exposing radiographic images of the skull. The apparatus comprises an x-ray source (13) whose collimated (14) x-ray beam (XR) can be directed through the skull of the patient (P) onto an x-ray film (RF) contained in a cassette (23). The apparatus further comprises a soft-tissue filter assembly (10) in which to the region of one side (a) of the x-ray beam (XR) is placed an radiation-absorbing filter element (19) movable by means of a drive motor (15) transversely (B) to the x-ray beam (XR). The apparatus incorporates a light indicator unit (20) comprising a light source (25) capable of projecting onto the side of the face of the patient (P) a light marker line (LL) which is transferrable along the adjustment direction (B) of the soft-tissue filtering assembly.

Abstract: A filter method and device for carrying out the method in conjunction with an X-ray system having a beam path for primary radiation between an X-ray source and an examination zone and a beam path for scattered radiation between the examination zone and a detector device, involve subtractive combination of first and second measurement signals produced by the detector device in response to scattered radiation received in first and second filter arrangements. For production of the first measurement signal a filter is arranged in the beam path for primary radiation and not in the beam path for scattered radiation, while for production of the second measurement signal a filter is arranged in the beam path for scattered radiation and not in the beam path for primary radiation. The latter filter consists of the same material as the filter used for the first measurement, and may be the same filter.

Abstract: An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

Abstract: A filter changer for a radiation transmitter comprises a filter which is adjusted between a first position out of the beam path of the radiation transmitter to a second position in the beam path. The changer includes guides for guiding the filter for movement along a linear path, an arm having one end engaging the filter and the other end engaging an actuating arrangement so that when the arm is rotated against a spring, the filter is moved from the first to the second position and when the arm is released from the actuating arrangement, the spring biases the arm and filter back into the first position.

Abstract: A K-edge filter whose main portion functions as a filter member and is made of a material containing at least two kinds of elements, and an X-ray apparatus is fabricated so as to include such a K-edge filter.

Abstract: A device for compensating large absorption differences when photographing the thorax by means of X-ray radiation, whereby a compensating filter is placed close to the X-ray tube in the beam of the X-ray tube perpendicular to the optical axis of the X-ray radiation, whereby a support running in the direction of the optical axis is placed on the X-ray tube housing above the optical axis at an angle of 93.degree. to 105.degree. to the vertical, at which a filter holder, which can be displaced in the direction of the support, is arranged with the compensating filter, allowing optimum matching of the compensating filter to each patient.

Abstract: A radiographic imaging combination that is capable of detecting soft tissue anomalies is described. This combination is particularly effective for neonatal radiography and comprises a source of X-radiation exhibiting a peak emission in the range of from 40 to 60 keV with a 2 mm aluminum equivalent filtration, a filter for the source which comprises tellurium and/or antimony, at least one X-radiation imaging screen.

Abstract: A K-edge filter whose main portion functions as a filter member is made of a material containing at least two kinds of elements, and an X-ray apparatus is fabricated so as to include such a K-edge filter.

Abstract: The present invention is an apparatus and method for reducing the dosage of X-rays during a fluoroscopic procedure wherein a filter member is used to selectively attenuate the X-ray radiation striking a patient's body. The filter member allows unattenuated X-rays to image an area of interest selected by a physician, thus producing a high intensity, low noise image. However, the areas surrounding the area of interest are imaged with attenuated radiation producing a less intense, more noisy image. A real-time image processing system is used to compensate the image brightness and to potentially filter the compensated region so as to reduce noise. Image quality is thus restored so that a physician can orient the location of a procedure, within a patient's body, and have perspective to the position of area of interest relative to its surroundings.

Abstract: A method and apparatus for creating image information for objects inspect with penetrating radiation which utilizes a flying spot scanner of reduced mass. Objects are scanned with penetrating radiation along curved scan lines. The flying spot scanner which effects such scanning has a stationary absorber plate having a fixed slit in it which is curved, as well as a chopper wheel having radially oriented slits. As the chopper wheel rotates, the radially oriented slits traverse the projection of the radiation passing through the fixed slit, and because this slit is curved, the radial slits may be of reduced length, and the chopper wheel may be of reduced mass. The detected radiant energy is divided into pixels, and the pixels are addressed to a utilization means such as a memory or a display in such manner that the pixels which correspond to a scan line of the object define a curved line in the utilization means which has the same shape as the curved scanning line.

Abstract: Radiation images of an object are recorded by irradiating several kinds of radiation with different energy levels to an object constituted of tissues exhibiting different levels of radiation absorptivity with respect to the several kinds of radiation with different energy levels. Image signals representing the radiation images are then detected. An image signal is selected from the image signals, or an image signal representing the mean-level image of the radiation images is generated from the image signals. Values of parameters for a subtraction process are changed in accordance with the values of the image signal, which has been selected from the image signals, or the image signal, which represents the mean-level image of the radiation images.

Abstract: A bone mineral content measuring apparatus for obtaining the bone mineral content of an object to be examined by irradiating X-rays onto the object and measuring the X-rays which have passed through the object. An X-ray generating device generates X-rays having a continuous spectrum. The X-rays generated pass through an X-ray filter before the irradiation of the object or after the transmission of the object. The X-ray filter is composed of a substance having an X-ray absorbing characteristic with the K-absorption edge at a predetermined energy value. The X-rays which have passed through the X-ray filter and the object are detected by the X-ray detector. A data analyzer inputs the detected X-ray detection data and analyzes the bone mineral content of the object on the basis of the X-ray absorbing characteristic of the X-ray filter.

Abstract: In an x-ray examination apparatus comprisinga frame (2) to which are connected an x-ray source (3) for emission of an x-ray beam and an x-ray detector (5) that is placed opposite the x-ray source, andfilter means (31) that are placed between the x-ray source (3) and the x-ray detector (5) the filter means (31) comprising an x-ray absorbing filter body (33) and drive means for positioning the filter body in the x-ray beam, the drive means comprise two disk-shaped holding members between which the filter body is placed. The filter body is in a pivot-point pivotably fixed to one holding member and is provided with a pawl that engages a curved radial groove in the second holding member. By joint rotation of the holding members the filter body is translated in the x-ray beam whereas by rotation of one of the holding members only, the curved radial groove causes the filter body to rotate in the x-ray beam.

Abstract: The invention applies to radiological apparatuses for angiographic examination. The invention lies in the fact that an X-ray attenuation filter is disposed between the X-ray source and the patient, said filter introducing attenuation on the path of each X-ray such that the total attenuation to which each X-ray is subjected on its path to the receiver is substantially the same for all of the paths in the X-ray beam, thereby homogenizing the exposure of the image-forming receiver.

Abstract: A one dimensional X-ray image sensor consists of a plurality of unit detecting devices aligned in a row and a filter which covers a portion thereof and is made of a material having an X-ray absorption coefficient equal to or nearly equal to that of a target material to be inspected. An X-ray inspection apparatus includes the one dimensional X-ray image sensor and further includes a data processor for correcting measured values using data measured in regard to the filter.

Abstract: A radiation filter for filtering radiation beams of wavelengths within a preselected range of wavelengths comprises a radiation transmissive substrate and an attenuating layer deposited on the substrate. The attenuating layer may be deposited by a sputtering process or a vacuum process. Beryllium may be used as the radiation transmissive substrate. In addition, a second radiation filter comprises an attenuating layer interposed between a pair of radiation transmissive layers.

Abstract: A lens-like X-ray filter is filled with a liquid, the filter having flexible walls, the filter being between an X-ray source and an X-ray detector in an X-ray examination apparatus. The filter obviates brightness variations in an X-ray image caused by vignetting. The filter thickness is adjustable by the supply and the discharge of a liquid, the filter preserving a quadratic thickness variation from the center to the edges.

Abstract: An energy discriminating apparatus and method is disclosed for use in connection with digital radiography and fluoroscopy. In use of the detection system and method an x-ray source is actuated to direct x-rays through a patient's body, the x-rays including both higher and lower energy radiation. A first detector element, including a plurality of segments, is positioned opposite the source to receive and respond predominantly to x-rays in a lower energy range, the remaining x-rays, being generally of higher energy, passing through the first detector element. A second detector element, also including a plurality of segments, each segment including a phosphor coating layer and a sensor, is positioned to receive and respond to the higher energy radiation passing through the first element.

Abstract: A radiographic equalization apparatus comprises a plurality of juxtaposed disks each having a plurality of unique filtration patterns annularly disposed therearound. The disks are rotated relative to one another to obtain a unique attenuation pattern for correcting for overexposures in an x-ray image.

Abstract: An X-ray detector, which is concerned with X-rays having wavelengths of less than 100 .ANG., includes an X-ray filter with a thickness smaller than a previously defined value, a semiconductor light-receiving element arranged behind the X-ray filter, and a measuring device for measuring an output produced by the semiconductor light-receiving element. This detector is provided with a grazing incidence mirror in front of the X-ray filter so that the wavelength selection and intensity measurement can be effected simultaneously. The X-ray detector has important advantages in practical use that the power source system does not come to a large scale, its periphery circuit is simple, and sensitivity is as high as one to two orders than that of a conventional X-ray diode.

Abstract: Background-reducing x-ray multilayer mirror. A multiple-layer "wavetrap" deposited over the surface of a layered, synthetic-microstructure soft x-ray mirror optimized for reflectivity at chosen wavelengths is disclosed for reducing the reflectivity of undesired, longer wavelength incident radiation incident thereon. In three separate mirror designs employing an alternating molybdenum and silicon layered, mirrored structure overlaid by two layers of a molybdenum/silicon pair anti-reflection coating, reflectivities of near normal incidence 133, 171, and 186 .ANG. wavelengths have been optimized, while that at 304 .ANG. has been minimized. The optimization process involves the choice of materials, the composition of the layer/pairs as well as the number thereof, and the distance therebetween for the mirror, and the simultaneous choice of materials, the composition of the layer/pairs, and their number and distance for the "wavetrap.

Abstract: An X-ray image pick-up method causes X-rays from an X-ray source to be irradiated on an object for picking up its image as passed through a filter capable of restricting any fluctuation of the effective X-ray energy within .+-.10%, and then the X-rays thus penetrated through the object to be picked up by an image pick-up means. Radiation dose with respect to the object and eventually to operators is thereby minimized, while the image pick-up can be realized with a high resolution.

Abstract: There is disclosed an assembly for slit radiography with image equalization, comprising an X-ray source which can scan a body for examination via a slit of a slit diaphragm with a flat, fan-shaped X-ray beam over a scanning path in a direction transverse to the lengthwise direction of the slit for forming an X-ray shadowgraph on an X-ray detector; an absorption device which under the control of control signals can influence the fan-shaped X-ray beam per sector thereof, in order to permit control of the X-ray radiation falling in each sector on the body to be examined; and detection assembly which is designed to detect the quantity of X-ray radiation transmitted by the body instantaneously per sector during a scanning movement of the X-ray beam and to convert it into corresponding signals.

Abstract: In general, it can be difficult and time consuming to mount X-ray shields or filters on an X-ray machine. An even more serious difficulty is that of effectively masking all but a specific area. A relatively effective X-ray shielding support, which can be adjusted in any direction to mask all but a specific area includes an apertured base plate for mounting on the machine to define a frame around the collimator aperture of the machine, a variety of spacers for mounting on the base plate, and filter holders for mounting on at least one of the base plate and spacers. The spacers and filter holders are magnetic to make interconnection of the elements quick and easy.

Abstract: An x-ray diagnostics installation has an x-ray source fed by a high voltage supply, an x-ray image intensifier video chain for generating stored video signals of an exposure without a patient present in the x-ray beam, and a calculating stage connected to the memories. A filter is disposed in the path of the x-ray beam. The calculating stage is connected to the video chain and to the high voltage supply and calculates actual attenuation values of an x-ray exposure with the filter inserted in the x-ray beam.

Abstract: An apparatus for slit radiography is provided with a slot diaphragm to form a fan-shaped X-ray beam with which a body can be scanned. Controllable attenuating elements interact with the slit diaphragm to influence sectors of the fan-shaped X-ray beam. They are controlled by signals representing the instantaneous transmission of the body in the corresponding sectors. The hardness of the fan-shaped X-ray beam is varied periodically in a predetermined manner. Synchronously with the periodic variation of the hardness of the X-ray beam the attenuating elements are oscillated. The oscillation of the attenuating elements is superimposed at each instant on the instantaneous position determined by the signals representing the instantaneous body transmission. The amplitude of the oscillation is less than the height of the slit of the slit diaphragm. The influence on the X-ray beam is most at the instants at which the hardness is greatest.

Abstract: In accordance with the present invention, there is provided an X-ray filter which significantly reduces low energy radiation normally absorbed by the examination object without significantly affecting the desired high energy radiation. The filter is comprised of one or more materials containing as the major component elements selected from the group consisting of aluminum and elements having atomic numbers between 26 and 50 with the filter being selected to have X-ray filtering characteristics such that the intensity of X-rays having energies of 50 keV are reduced by about 8% to about 35% of the normal radiation levels. As a result of the construction immediately above, the filter of the present invention filters energy from the X-ray beam which is usually absorbed by the examination object and does not contribute to the radiographic image of the examination object. This is achieved with little, if any, increased loading of the X-ray tube which would otherwise reduce its effective life.

Abstract: A method for the rapid and sensitive analysis of heavy metal ores, especially those of gold and uranium, uses high-engery X-ray fluorescence spectroscopy. The invention is of particular interest for the measurement of samples from gold or bodies which typically have concentrations up to 10 ppm by mass. Preferred features include the use of an X-ray tube as a source, the counting of emitted fluorescence photons in energy bands selected to correlate with the characteristic x-ray fluorescence emissions of elements of interest, the excitement of the ore sample by irradiation with high energy bremsstrahlung radiation filtered through tin, the exploitation of polarization in analysis for uranium, the interposition of a platinum-group metal filter between the sample and the detector, and the use of high-purity germanium detectors. Techniques are described for the detection and elimination of inaccuracies due to the presence of certain interfering metals and correction for variations in sample density.

Abstract: An X-ray image processing device using dual energy projection radiography method, wherein the low energy image and the high energy image are subjected to a subtraction processing to output a first image such as bone X-ray image, and the first image and the low energy image are subjected to another subtraction to output a second image such as a soft tissue X-ray image without deterioration of the X-ray image.

Abstract: A polymer attenuation filter in a CT machine is mounted at its center and allowed to expand freely at its ends to prevent cracking of the filter as it expands with temperature and after it becomes brittle with x-ray exposure. Vertical expansion of the filter at its center is accommodated by a stress relief hole cut between the center fastening points. Relatively greater horizontal expansion is accommodated by means of spring clamping. Difference in expansion between a metallic strip filter and its support is accommodated by tightly affixing the ends of the filter to the support so that the metallic strip is always under tension and cannot buckle.

Abstract: A radiographic machine in which the exposure is equalized as between different areas of the image plane so as to enhance high spatial frequency features of the image and suppress low spatial frequency features and achieve other benefits as well. A fan beam which is wide enough to encompass the object being imaged is swept across the object and segments of that beam are individually pulse width modulated at each of a number of sampling intervals during the sweep by monastable or bistable shutter pins which either completely block or completely uncover the sectors which they control. An alternate embodiment adds beam width moulation as well, by making the shutter pins either completely block their sectors of uncover them only to the degree necessary for beam width modulation.

Abstract: A lavatory chair adapted to support a patient during radioscopic imaging of defecation dysfunction of the patient. The chair comprises an open-bottomed seat portion, a support structure for supporting the seat portion, a screen having a preselected radiopacity, and a mechanism for mounting the screen to the seat portion to give the seat portion approximately the same radiopacity as an average patient. The method of using the lavatory chair is also disclosed.

Abstract: An energy discriminating apparatus and method is disclosed for use in connection with digital radiography and fluoroscopy. In use of the detection system and method an X-ray source is actuated to direct X-rays through a patient's body, the X-rays including both higher and lower energy radiation. A first detector element, including a plurality of segments each segment including a phosphor coating layer and a sensor, is positioned opposite the source to receive and respond predominantly to X-rays in a lower energy range, the remaining X-rays, being generally of higher energy, passing through the first detector element. A second detector element, also including a plurality of segments, each segment including a phosphor coating layer and a sensor, is positioned to receive and respond to the higher energy radiation passing through the first element.

Abstract: An energy subtraction image measuring system for selectively depicting any target element using X-rays includes an X-ray filter containing the target element. It measures an X-ray image by using a quasi-monoenergetic X-ray beam obtained without using the filter and having a photon energy range that extends above and below the absorption edge of the target element, as well as an X-ray image using an X-ray beam containing only the photon energy component having photon energy levels lower than the absorption edge which is obtained by using the filter. The energy subtraction image measuring system then generates an energy substraction image by the operation of the thus obtained data.

Abstract: A radiographic apparatus (10) includes an x-ray tube (16), an off-focal radiation collimator (20), a shutter (22), and a primary beam defining collimator (24) between the x-ray tube and patient receiving region (14). The off-focal collimator is mounted within a collar (48) which surrounds an x-ray port (36) of the x-ray tube. The tube port is sealed from the atmosphere by an aluminum window (46). A plate (62) of a radiation blocking material is rotatably mounted by a bearing (70) within the collar closely adjacent the aluminum window. By rotating the moveable plate, aperture or radiation passing slots or portions (62, 64) of different sizes are selectively brought into alignment between a focal spot (34) of the x-ray tube and a radiation passing region or slot (52) of a stationary plate (50) at the distal end of the collar. The aligned slots block the passage of off-focal radiation. Moreover, rotating slots of different sizes into alignment changes the size or angle of the x-ray fan beam.

Abstract: The invention relates to a fluorescence radiation source in which an anode which encloses a member is struck by electrons on its side which faces the member and in which the primary X-ray radiation generated in the anode generates fluorescence radiation in the member. The member is preferably arranged within an enclosing shield which keeps scattered electrons remote from the member.

Abstract: A high-speed image recording apparatus comprises a sheet changer for changing a stimulable phosphor sheet at an image recording position, a radiation source drive controller, and a filter changer for changing a radiation filter on a radiation passage between a radiation source and a stimulable phosphor sheet at each image recording step. The sheet changer, the radiation source drive controller and the filter changer are activated by signals sent from a controller to load the stimulable phosphor sheet to the image recording position, to change over the radiation filter, and then to emit radiation to the stimulable phosphor sheet via an object, thereby recording a high energy image and a low energy image of good energy discrimination in stimulable phosphor sheets.

Abstract: An energy substraction medical imaging system which is used for imaging a body part impregnated with a radio-opaque dye such as iodine is provided. The system includes an electron beam target having a target surface which, when excited by a high-energy electron beam, generates radiation having strong K.sub..alpha. at energy levels slightly above and slightly below the K-edge energy level of the dye. The target surface is preferably formed of a compound containing lanthanum, such as lanthanum oxide. The target may also be formed of a compound containing a material having a K.sub..alpha. line at an energy level slightly above the dye K-edge and a material with K.sub..alpha. line slightly below the dye K-edge or with separate sections containing such materials which are alternately excited. The target is excited by a high-energy electron beam from a suitable source, the electron beam having sufficient energy to provide a high photon yield at the K.sub..alpha.

Abstract: A radiation image recording and read-out apparatus comprises a circulation transfer means for transferring a stimulable phosphor sheet along a predetermined circulation path; an image recording section which is disposed in the circulation path and in which a radiation image of an object is recorded on the stimulable phosphor sheet by exposing the stimulable phosphor sheet to radiation passing through the object; an image read-out section which is disposed in the circulation path for scanning the stimulable phosphor sheet with stimulating rays and detecting light emitted from the stimulable phosphor sheet to obtain an image signal; and an erasing section which is disposed in the circulation path and releases residual radiation energy in the stimulable phosphor sheet before the stimulable phosphor sheet is returned to the image recording section. The radiation image recording and read-out apparatus further includes a radiation quality changing filter for changing the quality of the radiation.

Abstract: An alloy filter in the form of a plate made from a homogeneous alloy comprising 85-95 wt. % cadmium, 5-15 wt. % copper and up to 3 wt. % of incidental impurities is interposed between a collimator and sodium iodide crystal of a gamma camera. The alloy filter improves image resolution by allowing the passage only of emmissions which impinge substantially perpendicularly on the collimator, while filtering out others which impinge obliquely.

Abstract: A radiation imaging system is disclosed. A radiation source directs a thin spread beam of radiation toward a detector assembly which is aligned with the radiation beam. The detector assembly includes a printed circuit board having a bowed configuration and bearing board circuitry. An array of photodiode detector elements are attached to the board. The detector includes a front and a rear array of elements arranged one behind the other. The circuit board defines a slot between the front and rear arrays in which a radiation filter can be removably and slidably interposed. The detector elements are buried or recessed in outer surfaces of the circuit board to a depth sufficient to position contact fingers of the elements substantially flush with the unrecessed surface of the board. Radiation sensitive phosphor material is removably positioned over each of the respective front and rear detector element arrays.

Abstract: This invention is directed to an improvement in an x-ray lithography system having an x-ray point source of radiation, a wafer disposed in spaced relationship with respect to the source, and a mask disposed between the source and the wafer whereby radiation from the source passes through the mask to the wafer, said improvement comprising the provision of an x-ray absorbent element mounted between the source and the wafer, said element having a radial absorption gradient profile to compensate for radial flux variation of the x-rays.

Abstract: A system comprising an X-ray source (1), an elongate detector tube (3) including at least one cathode (5) extending in the longitudinal direction of the tube and at least one anode (6) located opposite to the cathode, a slit diaphragm (2), and a filter (4) mounted in the path between the X-ray source (1) and the detector tube (3). The filter (4) blocks relatively low energy X-radiation in a portion of the beam emitted by the source (1). The cathode (5) is provided with an X-ray detection layer consisting of two strips (8',8") extending in the longitudinal direction of the tube (3). One strip (8") receives the radiation passed by the filter (4) and the other strip (8') receives the unfiltered radiation. The one strip (8") is of considerably greater thickness than the other strip (8').

Abstract: A radioscopic image former comprises a slit between an X-ray source and a subject to produce an X-ray fan beam to scan the subject. The transmission of the slit is adjusted locally during the scanning depending on local absorptions in the subject. The X-ray fan beam is cyclically modulated. The local modulation frequency depends on the coordinate in the longitudinal direction of the slit. The slit comprises a number of tongues each tongue being excited at or near its resonant frequency. Each tongue has its own frequency or phase and acts as a frequency-selective element.

Abstract: Method and modifying body for influencing the effect of X-ray or gamma radiation on a target (7) sensitive to radiation, in particular for selective modification of a radiograph of an object (10). According to the invention a modifying body comprising at least two layer groups (31, . . . 3n) is arranged in front of the target, wherein each layer group (e.g., 32) emits a secondary radiation under the influence of the X-ray or gamma radiation or the secondary radiation of the previous layer group (e.g., 31), respectively, the energy of which is lying above the absorption energy level defined by the electron shell K of an element being present in the following layer group (e.g., 33) or in the target arranged behind the last layer group (3n), respectively.

Abstract: A positioning control system controls the shifting of one of a plurality of radiation filters into the ray path. Transducers provide an electric density signal which is dependent upon the density of the examination subject. The control system has an electromotor activated by a control circuit to which the density signal is applied and which activates the motor corresponding to the respective density signal for the purpose of selection of the correct filter. The transducers may be coupled with a device physically acting in compression on a body part of the patient to be examined such that the degree of resistance of the body part to compression is sensed by the transducers as a measure of patient density.

Abstract: An apparatus for slit radiography which comprises an X-ray source and a slit diaphragm through which a body to be examined can be scanned by a planar X-ray fan beam. The slit diaphragm is operatively associated with a plurality of juxtaposed tongue-shaped attenuation elements, which elements are arranged for having their free ends swung to a greater or lesser extent into the X-ray beam so as to effect a local attenuation of the beam. The tongue-shaped attenuation elements form at least one flared configuration as seen from the X-ray source.

Abstract: The present invention concerns an X-ray examination apparatus allowing to produce images of an object through the scanning of the object by at least two fan-shaped beams having different energy spectra, and obtained from a single X-ray source, thereby allowing to obtain simultaneously images of the object adapted to contain different informations.

Abstract: An X-ray image intensifier tube which includes a luminescent layer with an absorption material having a high absorption for secondary X-rays which are generated in the original luminescent material and which are intercepted to only a very small extent by the original luminescent material. The absorption material may be included in the layer of luminescent material in homogeneous form as well as in recesses in said layer. In addition to improved resolution, a higher efficiency can be achieved by ensuring that, upon interception of the secondary radiation, the absorption material generates luminescent or secondary radiation which is intercepted by the original luminescent material.