Motion Correction Algorithm for Cone-Beam Computed Tomography

Cone-beam computed tomography (CBCT) is one of the most frequently used tools to diagnose hard tissues such as teeth and bones. However, the CBCT scanners generally suffer from a long image acquisition time, which can result in motion artifacts in the resultant volume images. The motion artifacts mainly come from the mechanical vibration of system components and the unintended movement of the patients during data acquisition. In this study, we propose a method to reduce motion artifacts in CBCT images. The relative misalignments between the flat-panel detector and the object can be calculated by aligning two limited-angle tomography images reconstructed at the opposite sides of the circular trajectory. Finally the motion artifacts in the resultant CT images can be suppressed without pre-calibration procedures by compensating found misalignments for CT reconstruction. The proposed algorithm will be helpful for the development of real-time motion artifact reduction in CT images.