A re-binning algorithm for cardiac CT

The z-sharp modulation technique of the source (focal spot) allows doubling the longitudinal sampling rate of cone beam CT scans, without reducing the geometrical efficiency of the detector (T. Flohr et al, presented at the RSNA meeting 2003). Due to the small anode angle, this technique implies a large movement of the source in the radial direction. In order not to let this movement to degrade the transversal resolution, it is preferable to modulate the source between four positions. However, due to the limited number of integration times allowed within the fast gantry rotation time of cardiac acquisitions, modulating the source between four positions requires reducing the angular sampling. Motivated to avoid image degradation due to the low angular sampling, we have developed a new re-binning algorithm