A statistical approach to motion compensated cone-beam reconstruction

One of the problems arising in radiotherapy planning is the quality of CT planning data. In the following attention is giving to the cone-beam scanning geometry where reconstruction of a 3D volume based on 2D projections, using the classic Feldkamp-Davis-Kress (FDK) algorithm requires a large number of projections to be adequate. Since the patients are breathing freely during a scan, the number of projections with similar respiration may be to low. In the following we use an iterative reconstruction combined with the simultaneous estimation of the motion field, to improve reconstruction in these situations. Using a simulated dataset we demonstrate that this combination outperforms the FDK but due to ill possessedness of the motion estimation it is only on par with the sole iterative method.