Siemens Aktiengesellschaft

Applied Radiation Corporation

Rudolf Schittenhelm

Edgar Tschunt

Gunter Schwierz

Gunter Schmitt

Helmut Reichenberger

Klaus Klingenbeck

Leonhard Taumann

Klaus Killig

Wolfhart Lichtenberg

A computer tomography apparatus has an annular anode which surrounds a detector ring disposed coaxially relative thereto and having a cathode ring also disposed coaxially relative to the anode. The cathode ring has a series of cathodes which are respectively enabled step-by-step to emit electrons onto the anode so as to displace the focus. Each cathode has a deflector unit associated therewith which deflects the focus for that cathode along the circumference of the anode. One or more cathodes with associated deflection units, and an anode section, can be constructed in combination as a module. The number of focus positions is thereby increased, and the time for acquiring a set of image data is significantly reduced.

Computer tomography apparatus

A third generation computer tomography apparatus has a radiation detector which is so narrow that the image constructed by the computer represents only a portion of a cross-sectional slice of an examination subject. The apparatus is useful for examining smaller body regions, such as to locate a calculus to be disintegrated. The tomography apparatus can be combined with a lithotripsy apparatus, including a shock wave generator, for this purpose.

Computer tomography apparatus for generating an image of a portion of a

A shock wave source has a coil carrier, a planar or concave coil, a membrane consisting of electrically conductive material and a foil consisting of electrically non-conductive material. The membrane is disposed between the coil and the foil so as to be held tightly therebetween but having a perimeter which is capable of substantially unrestrained movement. Upon the application of a high voltage pulse to the coil, the resulting field causes the membrane to be rapidly repelled, however, only the mechanical forces of the membrane act on the foil, with no electromagnetic forces generated by the coil acting on the foil. The resulting pressure pulse is intensified to form a shock wave pulse in a transmission medium adjacent to the foil. The substantially unrestrained perimeter of the membrane disposed between the coil and the foil permits an initial pressure pulse of short duration to be generated, which provides the further advantages of a short approach path, a small focus zone, a high focusing factor, low electrical and thermal stress on the shock wave source and a low acoustic energy output into the body of a patient receiving treatment using the shock wave source.

Shock wave source for generating a short initial pressure pulse

A method and apparatus for undertaking a non-contacting measurement of the three-dimensional temperature distribution in a non-uniform examination subject direct microwave radiation at the examination subject, detect the three-dimensional phase and amplitude of microwave radiation which is attenuated and scattered by the examination subject, and calculate the three-dimensional dielectric constant distribution in the examination subject on the bases of the detected phase and amplitude values. In a separate step the characteristic thermal radiation of object is measured, too. The three-dimensional temperature distribution of the examination subject is then calculated from both the three-dimensional dielectric constant distribution data and the characteristic thermal readiation data of a selected location.

Method and apparatus for non-contacting identification of the

In the exemplary embodiments a layer is to be scanned which is generally parallel to the longitudinal axis of the patient support. For example, a radiation source and a radiation receiver may be rotated in an arc about a rotational axis which lies perpendicular to the longitudinal axis of the patient support to scan a layer area in such a way that the scanned layer within the exposure subject is traversed exclusively along beam paths each of which is crossed along its entire length in the subject by a multitude of other beam paths.

Radiation diagnostic device for generating tomographic images

In the exemplary embodiments, a radiation measuring arrangement which includes radiation source is rotated for irradiating the radiography subject from different directions. A measured value converter calculates a layer image from the output signals of the detectors of the radiation receiver. For shielding against stray radiation, two hollow cylinders of equal diameter and with a common axis and comprised of a radiation-absorbing material lie between the radiation source and the radiation receiver, a gap for the passage of the x-ray beam being left therebetween. The radiography subject is introduced into the hollow cylinders.

Tomographic apparatus for producing transverse layer images

In an exemplary embodiment, a radiation source emits a radiation beam for penetrating the layer to be examined from different directions. A radiation receiver supplies electric output signals corresponding to the transmitted radiation intensity. A computer calculates the attenuation values of specific image points of the irradiated body layer based on the output signals. Correction devices are provided in the radiation receiver with which the radiation quality (mean energy) of the radiation striking the device is determined; each correction device preferably consists of a plurality of detectors arranged behind one another in the direction of the radiation, which detectors can be separated from one another by means of absorber layers. The output signals of the correction detectors serve for determining a correction for the radiation hardening in the patient.

Radiation diagnostic apparatus for generating tomographic images

In one illustrated embodiment two detector arrays are arranged in parallel and only one detector array is impinged upon by the primary radiation beam, the second detector array detecting only the scatter radiation due to the primary beam. Preferably, the second detector array is arranged so as to receive substantially a maximum intensity essentially equal to the scatter radiation impinging on the first detector array. In one example, the output of the second detector array may be simply subtracted from the output of the first detector array so as to obtain an accurate measure of the transmitted primary radiation. In an alternative embodiment, a single detector array is shifted to a second position for detecting only scatter radiation substantially corresponding to the scatter radiation mixed with the transmitted primary radiation.

Tomographic apparatus for the production of transverse tomographic images

In radiotherapy, for example, a computer-tomogram is to be formed with a conventional relatively low dosage but with sufficient information content to enable the working out of an irradiation plan with a specific selected isodose distribution. Since the normally measured attenuation coefficients are not valid with respect to substantially harder x-radiation or gamma radiation, the present disclosure teaches the introduction of test bodies into the spacial region to be scanned in generating the computer tomograph, such test bodies having the same percentage contents of the same elements as are present in the particular body volume to be examined and having a density which is adapted as far as possible to such body volume, the density however being graduated such that graduated attenuation coefficients are recorded for the test bodies in the resultant computer tomogram. Thus it is possible to find a test body section whose attenuation coefficient is identical with that of the body tissue to be subsequently subjected to radiation therapy. Since this test body section also quantitatively manifests the same elements, the attenuation coefficient of the test body agrees with that of the body tissue to be treated even in the case of radiation energies and types of radiation used in radiotherapy. Thus, by examining the attenuation coefficients of the corresponding section of the test body with the particular type of radiation to be used for radiotherapy, the matrix of attenuation coefficients contained in the computer tomogram may be transcribed into a matrix for the type of radiation to be used for the radiation therapy. This applies not only to x-radiation or gamma radiation, but also any random type of ionizing radiation, such as, for example, electron, proton and neutron radiation. As a further development, two identical test bodies may be arranged on opposite sides of the body during scanning so that the difference between the attenuation coefficients associated with these two test bodies is a measure of the hardening of the x-radiation on passage through the body of the patient. This information enables a refinement in the precision of the remaining attenuation coefficients of the computer tomograph. As a specific example, each test body may contain several hermetically sealed samples of the body substance to be examined, the samples having a known but graduated density.

Arrangement for examining a body with ionizing radiation

In an electron accelerator having a target which is subjected to an electron beam for the production of deceleration radiation, a collimator is provided behind the target which has a passageway adapted to receive a beam cone of maximum dimensions. Adjustable x-ray aperture plates are provided behind the collimator and an electron absorber is provided behind the target. An additional electron absorber is positioned in a widened portion at one end of the passageway in the collimator. Both electron absorbers are made of a material having a relatively low atomic number as compared with electron absorbers of the prior art.

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Erlangen, Germany

Rudolf Schittenhelm