Abstract: An x-ray source (20) rotates about a fixed cylinder (16) within which a subject of non-uniform cross-section is received. Radiation from the x-ray source passes through the subject and impinges on an arc of radiation detectors (28). Because the subject is of non-uniform cross-section, the average x-ray energy fluence impinging on the detectors across the arc varies with the relative angular position of the x-ray source and the subject. In one embodiment, a motor (18) which rotates the x-ray tube relative to the subject is controlled by a digital motor control (50). The digital motor control varies the rotational speed to a preselected angular velocity indicated by a look-up table (52) at each of a multiplicity of angular positions around the subject.

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: A CT apparatus reduces errors in projection data acquired in helical scanning. The imaged object moves concurrently along a translation axis and the x-ray beam is periodically translated with the imaged object so as to subtend a single predetermined volume element during the acquisition of one projection set of data for a first slice. The x-ray beam then returns to its starting position and tracks a second predetermined volume element within a next slice. The x-ray beam may be translated by moving the focal point or a collimator or a combination of both. Helical scans with a pitch requiring sweeping of the x-ray beam beyond the detector limits are accommodated by limiting the sweep to a lessor compliance distance. The angular rate of the sweep is held constant within this compliance distance during the sweep.

Abstract: A method and apparatus for radiographic techniques using an x-ray source (13). The radiographed object (M) is subjected to a beam (X) of radiation which is employed for forming a radiographic image of the object (M) onto a film (25). Between the radiographed object (M) and the film (25) is utilized a grid assembly (20) that prevents the disturbing effect of backscattered radiation or secondary radiation generated in the radiographed object on the radiographed image. The grid assembly (20) comprises a grid plate (22) having several equidistantly spaced lamellas opaque to x-rays. The x-rays can pass in the direction of the beam axis between the spaces (24) of said lamellas to the film (25). The grid plate is reciprocatingly oscillated at a varying amplitude so that the stops and changes of travel direction (K.sub.1 . . . K.sub.

Abstract: In an X-ray CT apparatus of a helical scanning scheme, a scannogram is obtained before acquiring projection data, and a range for which a tomographic image is desired, i.e., start and end positions of a helical scanning are designated on the scannogram. Helical scanning is started, not from a position of an object corresponding to the designated start position, but from a position preceding to the designated start position by a shift distance of the top plate corresponding to one cycle of helical scanning. Helical scanning is performed until a position over the designated end position by a shift distance of the top plate corresponding to one cycle of helical scanning. The projection data is acquired and is stored in correspondence with the scanning position. When reconstruction is to be performed, first, a desired slice position is designated on the scannogram.

Abstract: In an equalization radiography device an X-ray fan beam (3,4) is used to scan a body (7) under examination. The X-ray fan beam comprises a number of adjacent sectors. A modulator device (5) comprising a number of controllable beam sector modulators is present for controlling per sector the quantity of X-ray radiation transmitted. A detector (11) placed behind the body generates per sector a measurement signal representing a desired position of the beam sector modulator for that sector. During operation the instantaneous position of each beam sector modulator is continuously detected (20,21). Signals representing those positions are generated and compared with the respective measurement signals. Control signals are derived from the comparisons to control the positions of the respective beam sector modulators.

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 pencil beam of X-rays is scanned over the surface of the body of a person being examined. X-rays that are scattered or reflected from the subject's body are detected by a detector. The signal produced by this scattered X-ray detector in then used to modulate an image display device to produce an image of the subject and any concealed objects carried by the subject. The detector assembly is constructed in a configuration to automatically and uniformly enhance the image edges of low atomic number (low Z) concealed objects to facilitate their detection. A storage means is provided by which previously acquired images can be compared with the present image for analyzing variances in similarities with the present image, and provides means for creating a generic representation of the body being examined while suppressing anatomical features of the subject to minimize invasion of the subject's privacy.

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 method and apparatus for improving skin line viewing in a medical X-ray diagnostic system having an X-ray source for generating a scanning X-ray beam to image a target. In one form, the apparatus includes a first collimator positioned in the X-ray beam and having a rectangular shaped slit for passing the beam. A second collimator is positioned adjacent the first collimator and includes a plurality of spaced attenuation plates which can be moved over the slit in the first collimator. The attenuation plates are angles and tapered with respect to the slit. Control means is provided for locating the target within the slit and continuously driving the second collimator attenuation plates so as to intersect the edge of the target aligned with the slit.

Abstract: A slit radiography assembly including an X-ray source, and X-ray detector and a slit diaphragm comprised of a plurality of sections juxtaposed in the longitudinal direction of the slit and coacting with controllable attenuation elements wherein: during scanning, a detection assembly includes a plurality of response sections cooperate with the X-ray detector to provide an electric signal representative of the intensity to control the attenuation elements during scanning at initial measuring exposure and subsequent radiographical exposure of the body.

Abstract: At least one primary diaphragm comprises two elements displaceable so as to form a linear fan-shaped beam which is incident on an object to be examined. The elements form the slit-shaped aperture forming the fan beam in their normal X-ray beam forming position and are moveable to a respective, selectable limit position perpendicularly to the fan shaped beam in order to define and mark an examination zone greater in cross-section area than the fan beam with a light beam. Light incident on the examination zone is restricted by the diaphragm elements in their limit positions, thus marking the examination zone with the light beam. X-ray exposure of the object to be examined takes place only when the elements are between the two positions defining the examination zone of the primary diaphragm where its diaphragm elements occupy in their respective limit positions.

Abstract: A slit radiography device scans a body under examination with a fan-shaped x-ray beam. A number of absorption elements placed next to each other can be moved into the x-ray beam to a greater or lesser extent in order to influence the x-ray radiation incident on the body per sector of the beam. As seen in the longitudinal direction of the slit the absorption elements are designed such that a certain distance is present between them. As seen in the direction of the radiation beam the thickness of the material of the absorption elements is always the same so that there are no gaps between the elements that the x rays can shine through.

Abstract: A linear detector selectively detects successive line images from different angles while the linear detector and a radiation source are rotated about a patient. Radiation-transmission images are generated and detected and converted to computer-grabbed images by a computer which acquires, processes, stores and reconstructs the images. A visual monitor display reconstructs video images including a planar image and tomographic images representing sections orthogonal to the planar image. Selectively-positionable field-delineating lines corresponding to intersectional outlines between a simulation beam and the planar image are overlaid on the planar image. Beam-delineating lines are updated by the computer to correspond to intersectional outlines as the field-delineating lines are positioned.

Abstract: X-ray analysis apparatus and related method including a bone densitometer apparatus, in which detectors are translatable in the plane of the fan beam for each scan line position to provide enhanced signal-to-noise ratio and resolution, and detector-to-detector normalization. In this motion, the detectors move relative to an x-ray source and an object or patient. Indexing or moving from one scan line position to the next involves relative movement between the object or patient, and the x-ray source and detectors, which are fixed in relationship to each other during this indexing.

Abstract: A detector for detecting z-axis position in the plane of the fan beam of a computed tomography machine with respect to the detector array employs a pair of slotted masks over independent detector cells, the slots creating exposed widths that decrease and increase along their length. The intensity signals from the two detector cells so masked are subtracted to produce a z-axis position signal eliminating the effect of dark currents. Multiple cells may be ganged to reduce the effects of sensitivity variations among pairs of detector cells. The z-axis position signal may be used to control the z-axis position of the fan beam with respect to the detector array and to reduce the effect of the detector cell's variations in sensitivity.

Abstract: Scanning slit radiography apparatus with a radiographic grid of the invention makes possible the X-ray imaging at an enhanced primary radiation transmission, yet at a reduced scatter transmission. By orienting long axes A of radiopaque strips 12 obliquely to the sweep S of the grid 1, the strips 12 being separated by air interspaces 13 can be performed with a sufficient own stiffness that no aluminum top and bottom covers are needed. The planes of downward lateral faces 12' intersect each other in an upward decentration line D.sub.+ and the planes of upward lateral faces 12" intersect each other in a downward decentration line D.sub.-. In a preferred embodiment of the invention the grid 1 is inclined during the sweep S so that the convergent line of the grid continues to pass through the tube focus.

Abstract: A CT apparatus reduces errors in projection data acquired in helical scanning. The imaged object moves concurrently along a translation axis and the x-ray beam is periodically translated with the imaged object so as to subtend a single predetermined volume element during the acquisition of one projection set of data for a first slice. The x-ray beam then returns to its starting position and tracks a second predetermined volume element within a next slice. The x-ray beam may be translated by moving the focal point or a collimator or a combination of both.

Abstract: An equalization radiography system automatically identifies the lung field in a pre-scan and then carries out an imaging scan in which it equalizes the X-ray exposure but only outside the lung field.

Abstract: An equalization radiography system using specially shaped and arranged modulator pins which reduce artifacts by effectively smoothing variations in attenuation as between adjacent pins.

Abstract: A body is scanned by a fan-shaped X-ray beam for an X-ray shadow image. Per sector of the fan-shaped X-ray beam detection means deliver a signal which is a measure of the quantity of X-ray radiation instantaneously transmitted in the respective sector through the body. An attenuation device operates in conjunction with a slit-type diaphragm and regulates the quantity of X-ray radiation transmitted under the control of control signals per sector of the fan-shaped X-ray beam. The control signals are formed on the basis of the signals from the detection means. The attenuation device comprises one or more elastic X-ray radiation absorbing strips extending essentially parallel to the slit-type diaphragm. The attenuation device comprises controllable drive members to bring the strip or strips to an undulated state.

Abstract: A method and device for producing flux equalized x-ray images for medical radiography through the use of a scanning fan shaped x-ray beam and a feedback control system which regulates the beam intensity at a multiple number of points along the fan beam to compensate for the x-ray attenuation variations of the patient.

Abstract: A radiographic apparatus includes an X-ray generator for radiating X-rays, two slit members sequentially arranged to oppose the X-ray generator, a subject being arranged between the slit members, and each of the slit members having at least one linear slit for narrowing down X-rays to obtain a slit-like X-ray beam, a slit member moving unit for moving the slit members in such a manner that an X-ray tube focal point and the slits of the slit members are always aligned with each other, and a cassette film for two-dimensionally recording a slit-like X-ray beam obtained by causing X-rays to pass through the object and the linear slits of the slit members.

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: An x-ray analysis apparatus with an x-ray tube which generates an x-ray beam to expose an object to be analyzed. The apparatus inserts into and removes from the x-ray beam a piece of reference material such that regions of the object are exposed both to the x-ray beam and the x-ray beam obstructed by the reference material. A detector detects x-rays passing through the object and produces an indication of the object based upon the signals produced by the exposure to the x-ray beam and upon the signals produced by the exposure to the x-ray beam obstructed by the reference material.

Abstract: 1. A diagnostic x-ray machine including a reciprocating grid reduces grid lines, in the radiographic image, formed as a result of velocity variations in the reciprocation of the grid, principally at the points of grid reversal. An x-ray source produces a beam of x-ray radiation along a major axis directed through the body and to the grid. A reciprocating mechanism moves the grid within a plane perpendicular to the major axis between a first limit and a second limit and the x-ray beam is modulated synchronously with the grid motion to reduce the grid image at points of grid speed variation.

Abstract: The invention relates to an arrangement for generating an X-ray or gamma beam with small cross-section and variable direction, having an X-ray or gamma emitter, from the focus of which a bundle of rays emerges, and a diaphragm arrangement, which cuts out a beam from the bundle of rays and comprises a hollow-cylindrical first diaphragm body which is rotatable about its axis of symmetry and has two mutually offset helical slits on the circumference. In this arrangement, an X-ray beam with at least approximately square cross-section is cut out on a relatively long hollow-cylindrical body with small diameter by the slits winding around the diaphragm body in at least one turn each and being shaped in such a way that at least one straight line runs through the slits towards the focus, the position of which line can be varied by turning the diaphragm body.

Abstract: An improved system for radiographically inspecting a relatively stationary object and a related method are disclosed. A source transmits radiation toward a selected location at which the object is positioned. Radiation interactive with the object is thereafter transmitted in one embodiment to a detection area having electronic detectors and another embodiment through an atomic element filter to the detection area. En route to the detectors area or the filter and detection area, radiation is first blocked by a scanning point selection means which sequentially selects only a pencil beam portion of the radiation to be transmitted to the detection area at any given time. The pencil beams sequentially selected sweep the entire detection area over a short time, enabling use of signals generated by the electronic detectors in obtaining an image of the object or for obtaining the identity and location of atomic elements constituting the object.

Abstract: An exposure compensation apparatus for use in a radiographic equipment to modulate local intensity of radiation. The exposure compensation apparatus comprises a detecting means to detect transmittance of radiation at a location of a radiated object, right-left reversion means to reverse a location arrangement of the transmittance data on a line of a predetermined direction, an averaging means to average a pair of the original and reversed transmittance data of a location to acquire an averaged transmittance, and a local intensity control means to control a local intensity compensation means of the radiographic equipment.

Abstract: An X-ray radiography system comprising divided fan beam scanning device, feed-back the beam regulator and a silver halide photosensitive material having a covering power not less than 45 which is capable to diagnose wide range of photodensity area at one time exposure for minimizing the radiation dose is disclosed.

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: Apparatus and method for producing a digital panoramic X-ray image of an object is disclosed. The system of the invention includes an X-ray source and a digital radiation detector, which move around the object in unison in a certain time period. The radiation detector produces pixel data signals that are proportional to the incident X-rays on it. The pixel data signals are integrated over a series of varying time intervals to obtain pixel data signals which are proportional to the X-rays incident upon the radiation detector during each time interval. The integrated pixel data signals are converted into digital signals, which are then used to produce a digital X-ray image of the object.

Abstract: In a scanning equalization radiography system, a control function similar to the exposure response function of the image sensor is employed, whereby the response of the sensor will be linearly related to the x-ray attenuation of an object being radiographed thereby enabling quantitative measurements to be made directly from the radiograph.

Abstract: In a method for slit radiography a fan-shaped X-ray beam scans a body to form an X-ray shadow image. The fan-shaped beam is formed by a number of sectors situated next to each other. For each sector the transmitted X-ray radiation is controlled instantaneously during a scan by means of controllable beam sector modulators. The X-ray radiation is cyclically modulated in a predetermined manner for all the sectors taken together. The controllable beam sector modulators are individually controlled to select cyclically and in synchronism with the predetermined cyclic modulation a part of the X-ray radiation for each sector.

Abstract: A device for forming an X-ray beam or gamma beam (11) having a small cross-section and a variable direction, includes an X-ray source or gamma source (1) which supplies an X-ray beam and a diaphragm device which forms the X-ray beam from the radiation beam. The diaphragm device has a stationary diaphragm section (7) provided with a rectilinear slit (8) and a cylindrical first diaphragm body (3) which rotates about an axis of rotation (5) and which is provided with a helical slit (9) on its outer surface. In order to reduce the expenditure for manufacturing a device which is also suitable for different distances between the radiation source and the axis of rotation, the diaphragm body (3) has an at least approximately semi-circular cross-section over at least a part of its length.

Abstract: An X-ray exposure apparatus comprises an X-ray source, a reflecting mirror for deflecting an X-ray beam radiated from the X-ray source to an object, and mechanisms for rotating the reflecting mirror about an axis of rotation apart from a reflecting surface of the reflecting mirror. The reflecting mirror has such a shape that the angle of incidence remains constant relative to the X-ray beam at given angles of rotation.

Abstract: An apparatus for slit radiography comprising discrete controllable attenuation elements coacting with a slit diaphragm, each attenuation element being affixed to damping means.

Abstract: A dynamic focusing device is provided for an X-ray scanner, the device comprising at least one detector module located in a position to receive, be illuminated by, and respond to X-rays. A source of X-rays is movable toward or away from the detector module. The module comprises a plurality of crystals each having a scintillation surface located in a common plane, with a plurality of septa separating the crystals. The septa have a height which is upstanding above the surfaces of the crystals far enough to reduce lateral X-ray scatter and to cast a shadow upon the surfaces of the crystals responsive to an illumination thereof from said X-ray source. The invention dynamically positions the detector module relative to the distance between the detector module and the source of X-rays in order to reduce substantially to a minimum any shadow in the X-rays cast by the septa upon the surfaces of the crystals.

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: Method and apparatus for minimizing scatter in an X-ray imaging system of the type including a controllable source of X-ray radiation and means for collimating the X-ray radiation into a fan-shaped beam and effecting scanning of the X-ray beam across a target area. The improved system includes a grid assembly extending in a transverse direction across the target area and having a relatively narrow width in the beam scanning direction. A drive is coupled to the grid removing the grid in synchronism with the X-ray beam and an X-ray impervious belt is coupled to the grid and extends in a transverse direction across the target area and is movable with the grid for covering the target area outside the grid to prevent scatter radiation from impinging on X-ray film located beneath the grid. In one form, the grid includes a plurality of air interspersed septa to allow reduced beam energy.

Abstract: A multilayer x-ray reflector or reflectors are used with a source of radiation for narrow bandwidth or dual energy radiographic imaging applications. In one aspect, a unique multilayer design permits two distinct x-ray energies of narrow bandwidth to be reflected at the same incident angle for use in dual energy applications. In another aspect, several multilayer reflectors are employed in a slit scanning system. In yet another aspect, an elongated radiation source and a multilayer x-ray reflecting structure are combined to provide an x-ray or gamma ray source.

Abstract: A dynamic focusing device is provided for an X-ray scanner, the device comprising at least one detector module located in a position to receive, be illuminated by, and respond to X-rays. A source of X-rays is movable toward or away from the detector module. The module comprises a plurality of crystals each having a scintillation surface located in a common plane, with a plurality of septa separating the crystals. The septa have a height which is upstanding above the surfaces of the crystals far enough to reduce lateral X-ray scatter and to cast a shadow upon the surfaces of the crystals responsive to an illumination thereof from said X-ray source. The invention dynamically positions the detector module relative to the distance between the detector module and the source of X-rays in order to reduce substantially to a minimum any shadow in the X-rays cast by the septa upon the surfaces of the crystals.

Abstract: A method and device for producing flux equalized x-ray images for medical radiography through the use of a scanning fan shaped x-ray beam and a feedback control system which regulates the beam intensity at a multiple number of points along the fan beam to compensate for the x-ray attenuation variations of the patient.

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 monostable or bistable shutter pins which either completely block or completely uncover the sectors which they control. An alternate embodiment adds beam width modulation 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 scanning type radiographic imaging system is disclosed which employs novel means to produce comparable radiation intensity in the object regions being radiographed. Such result is achieved with variable radiation attenuating elements having their attenuation controlled during this scanning process with novel feedback control means. The feedback control is produced with a stationary detection unit having circuit means which generates the electrical control signals.

Abstract: A method and apparatus for detecting x-ray radiation in a radiographic imaging context is disclosed. It is particularly useful in conjunction with slit and slot scan radiography. In accordance with this invention, detectors are constructed and arranged such that substantially all of the energy from an x-ray to be detected is discharged in the detector. In this way a detector is provided which provides a direct electronic read out, high x-ray stopping power and high spatial resolution while obtaining good signal collection efficiency without the use of excessively high voltage levels. In the preferred embodiment, solid state x-ray detectors are constructed such that the thickness of the detector along the direction of incident x-rays is long enough that substantially all of the x-ray energy is discharged in the detector.

Abstract: A radiographic diagnostic apparatus including an X-ray tube for generating X-ray radiation, a line slit for shaping the X-ray radiation into a fan beam, a linear X-ray sensor array for detecting the X-ray radiation, and apparatus for driving the components is provided. The focal spot of the X-ray tube and the line slit are disposed on a straight line that connects between a specified fixed point and the center of the linear sensor array of a line extending therefrom. The X-ray tube, the line slit and the linear X-ray sensor array are driven together in a direction perpendicular to the direction of alignment of the linear X-ray sensor array so as to scan an object and thereby produce a radiographic image of the object.

Abstract: In an X-ray apparatus utilizing a fan-shaped X-ray beam the thickness of the beam is determined by a collimator of variable aperture. The X-ray beam irradiates a patient to be examined and is subsequently detected by a detector array. An image of a patient can be formed from detector signals. Using a variable aperture of the collimator, comprising two slats which are pivotable in opposite directions and a collimating side of which is provided with an X-ray absorbing material, the thickness of the X-ray beam can be varied, and hence also the thickness of the slice to be imaged.

Abstract: In a method for slit radiography a fan-shaped X-ray beam scans a body to form an X-ray shadow image. The fan-shaped beam is formed by a number of sectors situated next to each other. For each sector the transmitted X-ray radiation is controlled instantaneously during a scan by means of controllable beam sector modulators. The X-ray radiation is cyclically modulated in a predetermined manner for all the sectors taken together. The controllable beam sector modulators are individually controlled to select cyclically and in synchronism with the predetermined cyclic modulation a part of the X-ray radiation for each sector.

Abstract: Tomographic imaging with the aid of a line collimator is improved by providing for the illumination of a given linear element of the selected slice from a plurality of different directions. The line images resulting from illumination from different directions are then processed so as to minimize or eliminate spurious features of the image which result from portions of the object not lying along the slice but closer to the source of penetrating radiant energy than the slice plane.