Siemens Aktiengesellschaft

Christoph Suess

Stefan Popescu

Willi A Kalender

Herbert Bruder

Heiko Wolf

Guenter Schmitt

Dietmar Hentschel

Arkadiusz Polacin

A method and an X-ray CT system are disclosed for producing tomographic pictures with the aid of an X-ray CT system including at least two X-ray sources arranged on a gantry with an angular offset to scan an examination object. In at least one embodiment of the method, in order to determine the scattered radiation distribution, pre-scanning is carried out in which the X-ray sources rotate about the examination object and the dose rate is modulated as a function of the rotation angle, no radiation dose is output over the majority of the revolution, at specific pre-scan angles a dose rate is produced briefly and individually in each case by the X-ray sources of the focus/detector systems, and the received scattered radiation is measured simultaneously by the detectors of the at least one other focus/detector system.

Method for producing tomographic pictures with the aid of an X-ray computed tomography system with scattered radiation correction

In a computed tomography apparatus and a method for automatic exposure control in computed tomography scanning, an exposure controller, during a first half of a revolution of an X-ray focus around a subject, calculates an actual attenuation profile of a slice of the subject from electrical signals generated by the radiation detector in the first half of the revolution, and calculates an extrapolated attenuation profile of the slice for a second half of the revolution from the actual attenuation profile, and adjusts an operating parameter of the X-ray source, such as the tube current, to modify the radiation dose emitted by the X-ray source during the second half of the revolution dependent on the extrapolated attenuation profile.

Method and apparatus for automatic exposure control in CT scanning

A phantom for measuring slice thicknesses, slice sensitivity profiles and the axial modulation transfer function in an X-ray computed tomography apparatus contains a foil of a material that highly attenuates X-radiation that is arranged parallel to the image plane of the X-ray computed tomography apparatus given employment of the phantom and which had an axial expanse that is small compared to the thinnest slice to be measured. The expanse of the foil in the direction of the image plane is on the order of magnitude of a few millimeters.

Phantom for measuring slice thicknesses, slice sensitivity profiles and the axial modulation transfer function in an X-ray computed tomography apparatus

A spiral scan computed tomography apparatus has multiple x-ray sources with their respective foci symmetrically arranged on a circle concentric with a measurement field around which the x-ray sources are rotated in order to spirally scan an examination subject while a relative motion between the x-ray sources and a patient support is produced along a longitudinal direction of the patient support. X-rays attenuated by the examination subject are detected by a stationary detector ring, or by a number of detector arrays which co-rotate with the x-ray sources on the gantry. The scan time can thereby be decreased in comparison to known systems or, within the same scan time a higher x-ray power can be achieved.

Spiral scan computed tomography apparatus with multiple x-ray sources

Patient support elements, such as pillows, are disposed on opposite sides of an examination subject lying on a supporting bed in a tomographic apparatus. The patient support bodies include one or more reference elements having known composition and characteristics which are reproduced in the image at a display unit. Standardization of the measured values is thereby achieved in a manner which is independent of the apparatus itself.

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Erlangen, Germany

Christoph Suess