Patent ID: 7424088

Claim:
A method of determining an image data value at a point of reconstruction in a computed tomography (CT) image of a scanned object, comprising: obtaining projection data of the scanned object; filtering the obtained projection data with both a one-dimensional ramp filter and a Hilbert filter to generate filtered data; applying a backprojection operator with inverse distance weighting to said filtered data to generate the image data value at the point of reconstruction in the CT image; and displaying the generated image data value, wherein the filtering step comprises applying projection subtraction to the obtained projection data to generate subtracted data; applying the Hilbert filter to the subtracted data to generate Hilbert-filtered data; and applying projection addition to the Hilbert-filtered data and ramp-filtered data to generate the filtered data, the ramp-filtered data being generated by filtering the obtained projection data with the one-dimensional ramp filter, and wherein the step of obtaining projection data produces two-dimensional projections and the step of applying the backprojection operator is applied only to said filtered data contained within a Tam window.