Abstract: A method for reconstructing images of a subject in a variable-angle helical-scan CT scanner including an X-ray tube, a detector array, and a bed, the method comprising: angling the translation axis and the rotation axis at an acute angle relative to one another; rotating the X-ray tube about the rotation axis while translating the bed along the translation axis through a plane of rotation of the tube, whereby the X-ray tube describes a helical path relative to the subject; acquiring first and second views of the subject at the same effective rotational angle about the axis of rotation, said views comprising X-ray attenuation data received from elements of the array; producing a planar corrected image slice by interpolation of the data in different views, wherein the data is generated by non-corresponding elements in the different views; and repeating the above steps at respective positions at a plurality of rotational angles of the X-ray tube.

Abstract: A method for adjusting radiation flux in a CT scanner, including acquiring radiation attenuation data with respect to a body being imaged by the scanner from a CT scan, in a vicinity of a first axial position along the body and determining a modulation function, depending on radial view angle, based on the data. The body is translated relative to the scanner to a second axial position along the body, and a CT scan is performed in a vicinity of the second axial position, while controlling the radiation flux impinging on the body using the modulation function.

Abstract: A method for reconstructing one or more non-axial image slices in a CT scanner, comprising: acquiring X-ray attenuation data over an axial range; and processing the attenuation data to determine CT values at a plurality of points along one or more surface corresponding respectively to each one or more non-axial image slices, wherein processing the attenuation data comprises back-projecting the data directly to the plurality of points along each of the one or more surfaces.

Abstract: A method is provided for improving visual definition in a CT X-ray image having high attenuation objects such as metal prostheses and implants. The method provides for determining extents of the high attenuation objects and reducing the artifacts that the high attenuation objects cause in the image without completely removing the high attenuation objects from the image.