Patent Number: 
Section: claims

1. A variable stop apparatus for arrangement between an X-ray source and an object to be measured in a Computed-Tomography (CT) scanner, the variable stop apparatus comprising:a stop carrier including at least two stops and being pivotable about a pivot axis;each of the at least two stops being configured to be individually brought into a predetermined angular position by pivoting the stop carrier; andat least two of the at least two stops being arranged at different longitudinal positions in a longitudinal direction defined by the pivot axis. 2. The variable stop apparatus as claimed in claim 1, wherein the at least two stops have at least one of different stop shapes or stop dimensions, respectively. 3. The variable stop apparatus as claimed in claim 1, wherein the different longitudinal positions are selected depending on at least one of a stop shape, a stop dimension, and a focal spot size. 4. The variable stop apparatus as claimed in claim 1, wherein:the stop carrier includes at least one tube, andone of the at least two stops is arranged in a cavity of the at least one tube. 5. The variable stop apparatus as claimed in claim 1, wherein:the stop carrier includes at least two planes which are offset with respect to one another in the longitudinal direction,each of the at least two planes extends in a direction transverse to the pivot axis, andeach of the at least two planes defines an exit opening of one of the at least two stops, respectively. 6. The variable stop apparatus as claimed in claim 1, further comprising:a motor configured to drive the stop carrier and to thereby bring one of the at least two stops into the predetermined angular position. 7. The variable stop apparatus as claimed in claim 6, further comprising:a filter arrangement arranged at a distance from the stop carrier and configured to bring individual filters into the predetermined angular position by pivoting the filter arrangement about the pivot axis to permit an X-ray beam to pass through a filter in its predetermined angular position and through an aperture of a stop of the at least two stops in its predetermined angular position during operation. 8. The variable stop apparatus as claimed in claim 7, wherein the motor is configured to drive both the stop carrier and the filter arrangement. 9. A CT-scanner comprising:the variable stop apparatus as claimed in claim 1, the variable stop apparatus being arranged to permit the at least two stops positioned at the predetermined angular position to be located in the beam path between a focal spot of the X-ray source of the CT-scanner and the object to be measured.