Motion is one of the most critical sources of artifacts in helical conebeam CT. By comparing opposite rays corresponding to projection data, the amount of motion may be estimated and, in the following suppression of corresponding motion artifacts may be performed according to an exemplary embodiment of the present invention. The method of motion artifact compensation may be implemented in both approximate reconstruction algorithms and exact reconstruction algorithms. Advantageously, motion during the data acquisition is detected automatically and related motion artifacts may be suppressed adaptively.