X-ray CT apparatus with a filtering element exhibiting a maximum absorption at its center

摘要

An X-ray computed tomography (=CT) apparatus (10) has a filter element (2) for attenuating an X-ray beam (1). The filter element (2) has a spatially varying X-ray absorption capability along a cross direction (y) which is perpendicular to both the beam axis (z) of the X-ray beam and to a rotation axis (x) of a gantry. The spatially varying X-ray absorption capability exhibits a maximum absorption along the cross direction (y) at a zero position (y0), wherein X-rays passing through the filter element (2) at the zero position (y0) intersect the rotation axis (x). The CT apparatus allows for further reduction of the radiation dose for an object to be investigated, while simultaneously retaining high image quality.

主权项

1. An X-ray computed tomography (=CT) apparatus, the apparatus comprising:
an X-ray source emitting an X-ray beam or a divergent X-ray beam, along a beam axis; a stage for an object to be investigated with an attenuated X-ray beam; a filter element disposed between said X-ray source and said stage and attenuating said X-ray beam, said filter element having a spatially varying X-ray absorption capability along a cross direction which is perpendicular to both said beam axis and to a rotation axis, said spatially varying X-ray absorption capability exhibiting a maximum absorption along said cross direction at a zero position, wherein X-rays passing through said filter element at said zero position intersect said rotation axis; a 2D X-ray detector disposed downstream of said stage, said 2D X-ray detector having a detection area; and a gantry system structured to simultaneously rotate an entirety of said X-ray source, said filter element and said 2D X-ray detector about said rotation axis or structured to rotate said stage for the object about said rotation axis, wherein said rotation axis is perpendicular to said beam axis.