Patent ID: 8483363

Claim:
An imaging system, including: a rotating gantry with an examination region in which a volume of interest (VOI) is positioned; a transmission X-ray source, mounted for rotation with the gantry, the X-ray beam emitted across the examination region to an X-ray detector; and a movable wedge-shaped attenuation filter comprising a first lateral portion having a first thickness exposed to the X-ray beam, a second lateral portion having a second thickness exposed to the X-ray beam wherein the first thickness is greater than the second thickness, and a middle portion extending from the first lateral portion to the second lateral portion and having a thickness exposed to the X-ray beam which continually decreases from the first thickness to the second thickness, wherein the filter is positioned between the X-ray source and the examination region, for the filter being at least laterally movable relative to the X-ray beam to adjust an attenuation of the X-ray beam across an entire lateral extent of the X-ray beam between the first lateral portion and the second lateral portion of the filter.