Cbct comprising a beam shaping filter
AssigneeKoninklijke Philips N.V.
InventorsDirk SCHAEFER, Peter George VAN DE HAAR, Erik HUMMEL, Petrus Johannes WITHAGEN
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Abstract
In a first aspect, the present invention relates to a beam shaping filter (1) for use in a cone beam computed tomography system. The filter comprises a radiation attenuating element for positioning between an x-ray source of the cone beam computed tomography system and an object to be imaged. The radiation attenuation as function of position in at least a part (2) of the radiation attenuating element is rotationally symmetric with respect to a point of rotational symmetry (3).
Claims20
A cone beam computed tomography system adapted to acquire a sequence of projections for tomographic reconstruction by rotating around an object to be imaged, comprising:
- an x-ray source, and
- a beam shaping filter comprising a radiation attenuator configured to be positioned between the x-ray source and the object, wherein the beam shaping filter is configured to attenuate radiation from the x-ray source based on a radiation attenuation profile of the radiation attenuator, and wherein the radiation attenuation profile of the radiation attenuator is circularly symmetric with respect to a center point of the radiation attenuator, and wherein the radiation attenuation as a function of a radial distance to the center point of the radiation attenuator is a smooth function.
A method for imaging an examination volume, the method comprising:
- positioning a radiation attenuator of a beam shaping filter between the examination volume and an x-ray source emitting an x-ray cone beam, wherein the radiation attenuation of said radiation attenuator as a function of radial position is symmetric,
- detecting a plurality of projection images of said cone beam attenuated by said radiation attenuator and said examination volume using an x-ray detector, and
- moving said x-ray source and said x-ray detector while detecting said plurality of projection images by following a substantially isocentric dual-axis trajectory.
Dependencies are inferred from the claim text.