Apparatus for radiographic projection tomography
AssigneeGeneral Electric Company
InventorsHenri Souchay, Remy Klausz, Matti Jouhikainen
Life of this patent
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Abstract
In an apparatus for radiographic projection tomography, particularly mammography, an X-ray tube is mounted at the end of a swiveling arm, with a relative movement mechanism. The relative movement mechanism is such that it enables the tube to follow a path of a cycloid. Images or exposures taken only during the time when the tube, in its path, follows cusp points such that it is possible to keep a constant speed of movement of the arm while at the same time increasing the useful duration of an image. Vibration or oscillation effects inherent in the apparatus are compensated by the positioning, if necessary, of a counterweight.
Claims91
A tomography apparatus comprising:
- means for support of an object to be subjected to tomography;
- means for providing a source of radiation having a focal spot;
- means for detecting the radiation;
- and
- means for shifting the means for providing a source of radiation along a path relative to the means for support, the means for shifting comprising means for varying the speed of the focal spot as a function of the position of the focal spot relative to the means for support, wherein the means for shifting provides for the acceleration of the focal spot relative to the means for support is continuous and provides for the speed of the focal spot relative to the means for support is continuous and provides for a multiplicity of positions distributed on the path, the number of which is greater than or equal to three, and provides for the speed passing each time through a minimum value at a point, and provides for each exposure of the object to the radiation is made for a duration in which the speed of the focal spot is minimal.
A tomography apparatus comprising:
- means for support of an object to be subjected to tomography;
- means for providing a source of radiation having a focal spot;
- and
- means for detecting the radiation;
- and
- means for carrying the focal spot along a path relative to the means for support during a tomography operation, wherein the means for carrying comprises means for prompting a relative shift of the focal spot with respect to one end of the means for carrying.
A tomography apparatus comprising:
- means for support of an object to be subjected to tomography;
- means for providing a source of radiation having a focal spot;
- and
- means for detecting the radiation;
- and
- means for modifying a mean orientation of irradiation of the means for providing a source of radiation relative to a housing of the means for providing a source of radiation, during the tomography operation.
Dependencies are inferred from the claim text.