Siemens Aktiengesellschaft

Horst Aichinger

Karlheinz Koehler

Hans-Juergen Gerlach

Sigrid Joite-Barfuss

Heinz E Kranberg

Kurt Franke

Thomas Schmitt

Manfred Pfeiler

Siegfried Wach

Udo Heinze

Helmuth Schramm

Gerd Seifert

Hans Ebersberger

Paul Marhoff

Heinz-Erik Kranberg

Albert Moosmann

Walter Sladek

An X-ray diagnostic installation includes an X-ray source and a radiation receiver and a digital imaging processing system, the digital imaging processing system including a computer which evaluates an X-ray image of a phantom by identifying visible details in the X-ray image of the phantom. The computer employs these identified visible details to automatically construct a contrast-detail graph of the phantom. The computer thus undertakes an automatic judgment of the imaging quality, without the need for a trained observer.

Diagnostic installation having a digital imaging system with

An x-ray examination installation includes an x-ray source for irradiating an examination subject with x-rays, and an automatic exposure unit having a radiation detector composed of a matrix of detector elements. Only the output signals of specified detector elements, which define the measuring field within which an optimum exposure should ensue, are utilized for generating a signal which is then supplied to the x-ray source for controlling the exposure dose. The automatic exposure unit is operated according to a method wherein a distribution of the grayscale values in a test image is first calculated, and subsequently the main image is produced with the previously-calculated distribution of grayscale values superimposed in the main image.

Method for the operation of an automatic x-ray exposure unit

An x-ray apparatus includes an x-ray tube having a focus, the x-ray tube being contained in a housing and the housing having a mechanical distance-measuring device attache thereto. The mechanical distance-measuring device is suitable for obtaining a measured value which exactly corresponds to the focus-to-skin distance for all types of examinations. The mechanical distance-measuring device, which may be a tape measure, is connected to an electrical signal generator which converts the mechanically measured value into a corresponding electrical signal.

X-ray apparatus with mechanical distance-measuring device

In an x-ray diagnostics installation for mammography, an automatic setting of the optimum beam quality ensues in combination with transparency matching. A set of exposure parameters corresponding to different thicknesses of the examination subject is stored in a memory (reference values). At the beginning of an x-ray exposure, a comparator compares the transparency signal (actual value) to the exposure parameters (reference value) interrogated from the memory dependent on the current thickness of the examination subject, and influences the x-ray tube voltage for the purpose of a rated/actual value comparison without interrupting the exposure.

X-ray diagnostics installation having means for forming a transparency

An automatic x-ray exposure unit for mammography permits a correction of the mAs product dependent on the subject thickness without the need for obtaining a transparency signal, and thus without the need for the double detector normally needed for that purpose. The automatic x-ray exposure unit permits the correction to be undertaken on site, prior to conducting an actual examination, and thus can be used for film/foil systems, such as customized systems for which no previous transparency data has been obtained. This is accomplished in an automatic x-ray exposure unit where the mAs product is obtained for a fraction (1/n) of the total exposure, and a total exposure value is then obtained by multiplying the fractional value by n. These values are used to generate a characteristic curve, which is stored, for the film/foil system being used. If it is then necessary to switch (adjust) the mAs value due to the subject thickness, this can be done using the stored curve.

Automatic x-ray exposure unit for mammography

A detector for the image brightness which is present at the output screen of an x-ray image intensifier is formed by a combination of individual detector elements, the detector elements having different shapes and/or sizes. The detector elements in combination form a matrix which enables an optimum selection of a desired measurement field by selecting defined combinations of individual detector elements.

Matrix of image brightness detector's elements formed by different

An x-ray diagnostics installation for mammography exposures has a radiation detector for making a radiation measurement used to calculate the average parenchyma dose. The radiation detector is disposed on the support table next to the measurement field in which the mammary gland is disposed, and supplies a signal to a computer corresponding to the measured radiation dose at the detector location. The computer is programmed with the dependency of the average parenchyma dose, with respect to the radiation dose at the location of the radiation detector, and thus the computer generates a value corresponding to the average parenchyma dose, obtained by direct measurement rather than by calculation.

X-Ray diagnostics installation for mammography

An automatic x-ray exposure unit has first and second radiation detectors disposed sequentially and in registry in the direction of radiation propagation following the examination space. Each radiation detector is formed by a matrix of detector elements, also in registry. The detector elements are connected to a computer which calculates the quotient of the signals of each pair of detector elements in the first and second radiation detectors which are in registry. Those pairs of detector elements having a signal quotient which is above a predetermined threshold are automatically taken into consideration for selecting the measuring field for an x-ray exposure.

Automatic x-ray exposure unit

An x-ray diagnostics generator which includes a rotating anode x-ray tube includes circuitry for setting the speed of rotation of the anode dependent on exposure parameters. At particular rotational speeds, the motor bearing for the rotating anode is subject to mechanical resonances, causing vibrations which can damage the bearing. A vibration detector is provided in mechanical contact with the x-ray tube, and when vibrations due to such mechanical resonances are sensed, a signal is provided from the detector to a processor which automatically slightly alters the rotational speed.

X-ray diagnostics generator having a rotating anode x-ray tube

An x-ray diagnostics installation has an image intensifier/video chain for generating a television image of an examination subject. A portion of the light generated by the output screen of the x-ray image intensifier is directed to a semiconductor detector which monitors the average brightness of the output luminescent screen so that the x-ray dose can be accordingly controlled. The detector has a surface on which the entire output image of the x-ray image intensifier can be imaged, and is connected to a control unit which selects a portion of the semiconductor detector surface which will be used to generate the control signal. The detector includes a diaphragm in the form of a liquid crystal matrix, the matrix being controllable by the control unit to selectively admit or block light to the surface of the semiconductor detector, thereby controlling the regions which will be used to generate the control signal.

X-ray diagnostics installation

An x-ray diagnostics installation having an image intensifier video chain which back-projects a region of primary medical interest within an x-ray image into the overall video image is provided with fiber optics and opto-electronic transducers which are actuated by a switching bank in accordance with the desired shape and position of the region of primary interest. The transducers and switching arrangment can be removed, so that the output image from the x-ray image intensifier can be viewed at the output side of the fiber optics.

X-ray diagnostics installation having an image intensifier video chain

A medical examination system includes components for generating an internal image of a patient, such as an x-ray image, and components for generating an image of the external surface of at least a portion of the patient. The signals obtained from the surface scan of the patient are used to control the positioning of other components, such as the patient support and/or the primary radiation diaphragm. The internal and surface images can be compared to achieve precise positioning of the patient and/or a setting of the primary radiation diaphragm to avoid blooming.

Medical examination system with generation of the internal patient image

An x-ray diagnostics installation, of the type suitable for mammography, includes a calculator, such as a computer, which calculates the mean parenchyma dose based on a prescribed relationship from exposure values. The mean parenchyma dose can be read from the computer by a printer to obtain a permanent record.

X-ray diagnostics installation with mean parenchyma dose calculator

The invention relates to a diagnostic radiology setup with means for suppressing stray radiation and with an image intensifier television chain with image storing means. There is provided a perforated diaphragm of radiation-absorbing material near the tube, which diaphragm can be introduced into the ray path selectively. Two image memories for an X-ray picture with a diaphragm and an X-ray picture without a diaphragm and an image processing system serve for comparing the image information of the two X-ray pictures to determine and eliminate the stray radiation component.

Diagnostic radiology setup with means for suppressing stray radiation

In an exemplary embodiment, two radiation detectors are arranged behind the radiography subject. One of the detectors is covered by a radiation filter. A different radiation attenuation along the radiation paths of the respective detectors thereby takes place, so that, through division of the output signals of the detectors, a quotient signal can be obtained which corresponds to the radiation transparency of the radiography subject.

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Fuerth, Germany

Horst Aichinger