关键词: 锥束CT, FDK重建算法, 探测器

Abstract: In the system of cone beam CT, it is required to have source focus, the center of objects and the center of flat detector collinear. The line should be vertical to the flat detector. However, due to a positioning error of the machines, the detector might be tilted with a few angles. If directly using the data collected from a tilted flat detector to reconstruction, the result will be wrong, and an artifact might be brought out. In solving this problem, the method measures tilt angle of detector by system calibration and roughly adjusts the angle by mechanical correction, and uses the proposed FDK-based detector tilt correction algorithm to fine-tune, and after two correction can effectively suppress the flat probe due to artifacts. Through the experimental results this method is verified the feasibility.

Key words: cone beam CT, FDK reconstruction algorithm, tilted detector