Method for scanning an examination subject with a CT device
AssigneeSiemens Aktiengesellschaft
InventorThomas Von Der Haar
Life of this patent
Estimating the term…
Abstract
In a method for scanning an examination subject and a CT (computed tomography) device for implementing the method, the cross-section of the X-ray beam emanating from the X-ray source of the device is modified during the scan so that, at all times, substantially only the region of the examination subject that is used for the reconstruction of images is penetrated by the X-ray beam.
Claims19
A method for scanning an examination subject with a computed tomography device having an X-ray source with a focus from which an X-ray beam, having a beam cross section, emanates, and a detector system having a plurality of detector rows, each detector row containing a plurality of detector elements, and said computed tomography device having a system axis, said method comprising the steps of:
- disposing an examination subject between said X-ray source and said detector system;
- conducting a scan of said examination subject by displacing at least said focus of said X-ray source relative to said system axis to irradiate said examination subject with said X-ray beam from a plurality of different positions relative to said system axis;
- generating detector signals with said detector system corresponding to radiation incident on said detector system during said scan;
- supplying said signals to a computer and, in said computer, reconstructing an image of said examination subject from said detector signals;
- and
- modifying said cross section of said X-ray beam during said scan so that, at all times, substantially only a region of said examination subject which is used for reconstructing said image is penetrated by said X-ray beam.
A method as claimed in claim 11 comprising fading in a plurality of said detector rows during each complete revolution of said focus around said system axis which increases as said pitch increases.
A computed tomography device, having a system axis, for scanning an examination subject comprising:
- an X-ray source with a focus from which an X-ray beam, having a beam cross section, emanates;
- a detector system having a plurality of detector rows, each detector row containing a plurality of detector elements;
- a scanner containing said X-ray source and said detector system for conducting a scan of said examination subject by displacing at least said focus of said X-ray source relative to said system axis to irradiate said examination subject with said X-ray beam from a plurality of different positions relative to said system axis, said detector system generating detector signals corresponding to radiation incident on said detector system during said scan;
- a computer supplied with said signals for reconstructing an image of said examination subject from said detector signals;
- and
- a beam modifier for modifying said cross section of said X-ray beam during said scan so that, at all times, substantially only a region of said examination subject which is used for reconstructing said image is penetrated by said X-ray beam.
Dependencies are inferred from the claim text.