Patent ID: 8009794

Claim:
A method of operating a cone-beam CT scanning system, the system having a two-dimensional pixel array having a first dimension, a second dimension, a number Xpix of pixels in the first dimension, and number of Ypix pixels in the second dimension, Xpix being greater than one hundred and Ypix being greater than ten, the system further having a source of radiation that emits a cone-beam of radiation that normally covers all of the pixels of the pixel array, the method comprising: determining an extent of the pixel array that the cone-beam radiation will receive direct-path radiation passing through a target volume of an object during a rotational scan of the object, the rotation scan including a plurality of projections of the object taken at a corresponding plurality of relative angles between the object and the source of radiation, the extent of the angles being equal to or greater than 180 degrees, the target volume being smaller than the volume of the object; and obscuring a portion of the cone beam of radiation such that direct rays of the radiation cover at least the determined extent, but less than 85 percent of the pixel array.