Stereo tube attenuation filter
AssigneeKoninklijke Philips Electronics N.V.
InventorsPeter Forthmann, Roland Proksa, Axel Thran
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Abstract
A computed tomography apparatus (10) includes spaced radiation sources (82, 84), such as anodes, which each propagate a cone-beam of radiation (40, 50) into an examination region (14). A detector (22) detects radiation which has passed through the examination region. An attenuation system (55) interposed between the radiation sources and the examination region for cone-angle dependent filtering of the cone beams. The attenuation system allows rays which contribute little to a reconstructed image to be attenuated more than rays which contribute more.
Claims21
A computed tomography apparatus comprising:
- spaced radiation sources which each propagate a cone-beam of radiation into an examination region;
- a detector which detects radiation which has passed through the examination region;
- and
- an attenuation system interposed between the radiation sources and the examination region for cone-angle dependent filtering of the cone beams.
A method of computed tomography imaging comprising:
- projecting first and second cone beams of radiation towards an examination region;
- prior to the examination region:
- attenuating the first and second cone beams to form attenuated first and second cone-beams, the attenuation being dependent on a cone angle (α);
- and
- acquiring radiation data from the examination region.
An imaging apparatus comprising:
- a radiation source which propagates a cone-beam of radiation into an examination region;
- a detector which detects radiation which has passed through the examination region;
- and
- a filter formed of a material which attenuates the radiation, the filter being interposed between the radiation source and the examination region, the filter providing cone-angle dependent filtering of the cone beam, whereby more obliquely angled rays are filtered more than less obliquely angled rays.
Dependencies are inferred from the claim text.