Computed tomography scanners, x-ray filters and methods thereof

An x-ray filter assembly for use in a computed tomography scanner comprising an x-ray filter and an x-ray shield component, wherein:

• the x-ray filter comprises:
• a first filter element,
• a second filter element,
• a filter enclosure defining a recess and a filter lid,
• the filter lid is coupled to the filter enclosure and comprises a corresponding opening that is aligned with an opening of the x-ray shield component and a filter opening when the filter lid is coupled to the filter enclosure,
• the first and second filter elements are slidably positioned within the recess such that a size of the filter opening is defined by a distance of the first filter element from the second filter element, and
• the x-ray shield component is positioned within the recess in a plane in front of or behind the first and second filter elements;
• the x-ray shield component comprises an x-ray absorbing material that prevents passage of x-ray photons and defines an opening through which x-ray photons may pass such that the x-ray shield component shapes an x-ray beam comprising the x-ray photons that pass through the opening;
• the x-ray filter comprises the filter opening and a filter portion, and is positioned in front of or behind the x-ray shield component along a path of the x-ray beam;
• and
• the x-ray filter is configured to allow x-ray photons propagating toward a detector assembly to pass through the filter opening to form a high dose portion of the x-ray beam, and reduce a number of x-ray photons propagating toward the detector assembly through the filter portion to form one or more low dose portions of the x-ray beam.

A method of generating a computed tomography image of an object comprising:

• generating an x-ray beam with an x-ray tube, wherein the x-ray beam comprises a plurality of x-ray photons propagating toward a detector assembly;
• filtering the x-ray beam with a filter assembly such that the x-ray beam comprises at least one high dose portion and at least one low dose portion, wherein the high dose portion propagates toward the detector assembly through a high interest region within the object, and the low dose portion has a lower a number of x-ray photons than the high dose portion and propagates toward the detector assembly through a low interest region within the object, the filter assembly comprising:
• a first filter element,
• a second filter element,
• a filter enclosure defining a recess and a filter lid,
• the first and second filter elements are slidably positioned within the recess such that a size of a filter opening is defined by a distance of the first filter element from the second filter element,
• an x-ray shield component is positioned within the recess in a plane in front of or behind the first and second filter elements, and
• the filter lid is coupled to the filter enclosure and comprises a corresponding opening that is aligned with an opening of the x-ray shield component and the filter opening when the filter lid is coupled to the filter enclosure;
• rotating the x-ray tube and the detector assembly about the object;
• detecting x-ray photons of the high dose portion of the x-ray beam in a high resolution region of the detector assembly and detecting x-ray photons of the low dose portion of the x-ray beam in a low resolution region of the detector assembly;
• and
• constructing the computed tomography image from the detected x-ray photons of the detector assembly.