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: 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: A dosimeter is described that does not show differences in sensitivity over its sensitive area when the ambient pressure changes. To that purpose the measuring chamber and a pressure compensation element together form a single gas tight chamber having at least partially of slack material, wherein the pressure inside the measuring chamber is essentially equal to ambient pressure such that no mechanical distortion of the measuring chamber over its sensitive area takes place.

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: 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: There are disclosed methods for making radiographs using slit-scanning radiographic techniques wherein a measuring exposure is effected at low radiation intensity and thereafter radiation intensity is set at a value suitable for effecting and taking the actual exposure and further including a modulation of radiation intensity during actual exposure.

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: There is disclosed a dosimeter to be used in connection with slit radiography and comprised of a gas filled chamber with one side wall provided with a plurality of X-ray transparent strip-like electrodes extending substantially transversely to a longitudinal direction of the oblong-shaped casing and another side wall provided with wire electrodes extending parallel to such longitudinal direction of the oblong-shaped casing wherein each of the strip-like electrodes generates a signal representative of intensity of ionizing radiation and wherein the strip-like electrodes are divided into a number of groups, signals from the strip-like electrodes belonging to each group are combined to provide a control signal for a respective attenuation element.

Abstract: A dosimeter for ionizing radiation is of oblong shape. It comprises a gas-filled measuring chamber surrounded by a casing. THe casing is formed of two oblong frames of insulating material that are substantially similar in shape. The two frames are mounted on each other in a gas-tight manner. The anode wires are situated in the plane of separation between the frames and are secured by the frames in contact with each other. At least one of the frames is provided with a cathode over its whole length and parallel to the plane in which the anode wires are situated. Along the edge of the cathode extends a guard electrode which surrounds the cathode with a certain gap. The dosimeter is made of materials that are transparant to the ionizing radiation. It can be used particularly in slit radiography equipment in which the slitwidth can be controlled locally and independently along the length of the slit.

Abstract: A dosimeter for ionizing radiation is of oblong shape. It comprises a gas-filled measuring chamber surrounded by a casing. Two opposite side walls are manufactured of material transparent to the ionizing radiation. One of the transparent side walls is provided with a transparent plate-like electrode. The other transparent side wall is provided with a number of strip-like electrodes extending transversely to the longitudinal direction of the measuring chamber. A guard electrode surrounds the plate-like electrode. The dosimeter being transparent to X-rays can be used particularly in slit radiography equipment in which the slitwidth can be controlled locally and independently along the length of the slit.

Abstract: There is disclosed a method for forming a radiogram of an object comprising the steps of energizing an X-ray source at a low level of radiation intensity wherein the X-ray source includes a slit diaphragm, pivoting the X-ray source during a first scanning of the object, moving an elongated X-ray detector in respect to the pivoting of the X-ray source to generate an output signal of intensity of the object during the first scanning thereof, measuring the output signal during at least a portion of said first scanning, energizing the X-ray source to a higher level of radiation intensity as determined by the output signal from the X-ray detector during the first scanning, pivoting the X-ray source during a second scanning of the object, moving the X-ray detector during the second scanning to generate a second output of radiation intensity and forming a radiogram from the second output signals.

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: An apparatus for slit radiography comprising an X-ray source, an X-ray detector positioned behind a body being irradiated, said detector collecting the radiation passed through the body, and a slit diaphragm placed between the X-ray source and the body being irradiated, through which diaphragm there is formed a planar X-ray fan beam, while for obtaining a complete X-ray shadow image of the desired part of the body at least the fan beam performs a scanning movement. There are provided detection means coacting with the X-ray detector and comprising a plurality of sections juxtaposed in the longitudinal direction of the strip-like portion of the X-ray detector irradiated through the slit diaphragm, each section being adapted to produce an electric signal depending upon the radiation impinging instantaneously on the associated section of the X-ray detector.

Abstract: There is disclosed an improved control circuit for a slit radiographic apparatus wherein the slit radiographic apparatus is comprised of an X-ray source adapted to scan a body to be radiographed through a slit diaphragm with a planar fan beam wherein the slit diaphragm is divided into a plurality of attenuating sections each associated with a controllable X-ray attenuating member and wherein there is provided a detection assembly for detecting the intensity of the radiation having passed through the body and divided into sections corresponding to attenuating sections of the slit diaphragm wherein each X-ray attenuating member is controlled by the control circuit including an energizing circuit and a comparison circuit for each attenuating member of the slit diaphragm whereby the comparison circuit compares an output signal of an associated section of the detection means to a reference signal to form an output coupled to the energizing circuit to control the attenuating member of a respective attenuating secti

Abstract: An apparatus for slit radiography comprising an X-ray source by means of which a body being irradiated can be scanned through a slit diaphragm by a substantially planar, fan-shaped X-ray beam, the scanning X-ray beam passed through the body impinging upon an X-ray detector. The apparatus comprises controllable attenuation elements coacting with the slit diaphragm, each element being adapted to influence a sector of the scanning X-ray beam under the control of signals generated by a radiation detector device. The radiation detector device is disposed between the body being irradiated and the X-ray detector. The radiation detector device comprises at least one radiation detector extending at any moment into the scanning X-ray beam passed through the body and moving in synchronism with the scanning movement of the X-ray beam.

Abstract: The invention relates to a scintillating camera and in particular to an apparatus for determining the position coordinates of a light pulse emitting point on the anode of an image intensifier tube which forms part of a scintillating camera, comprising at least three photomultipliers which are positioned to receive light emitted by the anode screen on their photocathodes, circuit means for processing the output voltages of the photomultipliers to derive voltages that are representative of the position coordinates; a pulse-height discriminator circuit adapted to be fed with the sum voltage of the output voltages of the photomultipliers for gating the output of the processing circuit when the amplitude of the sum voltage of the output voltages of the photomultipliers lies in a predetermined amplitude range, and means for compensating the distortion introduced in the image on the anode screen.