Patent ID: 7283606

Claim:
A method for reconstructing an incomplete projection data set in computed tomography, comprising the steps of: conducting a spiral scan along a z-axis of a subject on a table by moving said table along said z-axis while rotating a radiation source around the subject and emitting a penetrating radiation beam from the source to irradiate the subject from different rotational angles, at a pitch greater than or equal to one, and detecting penetrating radiation from said beam attenuated by the subject with a multi-row detector to obtain a plurality of projection data sets respectively for a plurality of z-positions along said z-axis; selectively reducing a radiation dose associated with said penetrating radiation beam when said radiation source is at at least one of said rotational angles, thereby causing at least one of said projection data sets to be an incomplete projection data set; completing said incomplete data set using completion data in said incomplete projection data set obtained from other rows of said multi-row detector or using completion data from a projection data set preceding said incomplete projection data set in said spiral scan or using completion data from a projection data set following said incomplete projection data set in said spiral scan; and reconstructing a multi-dimensional image of the subject from said projection data sets, including said completed incomplete projection data set.