System and method for data interpolation in a multislice x-ray computed tomography system

A system for producing a tomographic image of an object at an exact spatial position from a measured intensity of x-rays at a plurality of points in a x,y,z coordinate system, comprising:

• a detector having a plurality of rows and columns each comprising a plurality of detector cells for receiving said x-rays and providing a plurality of measured projection data corresponding to said measured x-ray intensity, where said plurality of columns extends in a z-direction and said plurality of rows extends in an x-direction;
• and
• a high order interpolator for receiving said plurality of measured projection data and for generating a first set of estimated projection data at a first projected exact spatial position for producing said image in said z-direction, said high order interpolator comprising a linear interpolator and a non-linear interpolator, where said linear interpolator provides a linear interpolation estimate between adjacent rows of said plurality of measured projection data wherein said first projected exact spatial position is located between said adjacent rows, where said non-linear interpolator provides a non-linear interpolation estimate from said plurality of measured projection data, and where said high order interpolator adds said linear interpolation estimate to said non-linear interpolation estimate to produce said first set of estimated projection data at said first projected exact spatial position.

A system for producing a tomographic image of an object at a desired position from measured projection data corresponding to a measured intensity of x-rays, comprising:

• a detector having a plurality of detector cells in a z-direction, said detector cells for receiving said x-rays and providing said measured projection data, where said z-direction is substantially parallel to a patient axis;
• an image reconstructor for receiving said measured projection data and constructing said image at said desired position, said image reconstructor comprising a high order interpolator for generating estimated projection data in a z-direction at said desired position from said measured projection data;
• and
• where said plurality of detector cells in said z-direction form adjacent columns of detector cells in said z-direction and adjacent rows of detector cells in an x-direction that is substantially perpendicular to said z-direction, where said high order interpolator comprises a linear interpolator and a non-linear interpolator, where said linear interpolator provides a linear interpolation estimate between adjacent rows of said measured projection data wherein said exact spatial position is located between said adjacent rows, where said non-linear interpolator provides a non-linear interpolation estimate from said measured projection data, and where said high order interpolator adds said linear interpolation estimate to said non-linear interpolation estimate to produce said first set of estimated projection data at said first exact spatial position.

A method of reconstructing a tomographic image of an object at a desired position from a slice of projection data corresponding to a measured intensity of x-rays, comprising:

• receiving measured projection data from a plurality of detector cells in a z-direction, where the z-direction corresponds to a thickness of the slice of the image;
• determining the location of the desired position of the image within the slice;
• performing a high order interpolation in the z-direction from the measured projection data to determine estimated projection data at the desired position;
• wherein performing the high order interpolation comprises:
• performing a linear interpolation to determine a linear estimate, wherein the linear interpolation is performed between adjacent cells from the plurality of detector cells wherein the desired position is located between the adjacent cells;
• performing a non-linear interpolation to determine a non-linear estimate, wherein the non-linear interpolation is performed utilizing the plurality of detector cells;
• and
• adding the linear estimate and the non-linear estimate to provide the estimated projection data at the desired position.