基于平板探测器倾斜的锥束CT修正重建算法

在锥束工业CT系统中要求射线源焦点,物体旋转中心,平板探测器中心三点在一条直线上,但由于机械的定位误差,探测器定位后会出现一定角度的倾斜现象,如果平板探测器直接采集投影数据进行重建,重建结果将会出现偏离,产生伪影.针对该问题,使用系统标定的方法测得探测器倾斜角度,并用机械校正对其进行粗调,利用平板探测器倾斜的FDK修正算法进行微调,经过两次校正可以有效的抑制由于倾斜造成的伪影,通过实验验证了该方法的有效性和可行性.

Correction reconstruction algorithm for cone beam CT with tilted flat panel detector

The cone-beam industrial CT system requires ray source focus,object rotation center,flat panel detector center in a straight line.However,due to mechanical positioning error,the positioned detector can produce a certain tilted angle.If the flat panel detector directly collects projection data and reconstructs results,there are deviations and artifacts in reconstruction results.For this problem,tilted angle of detector is measured using the system calibration,and the tilted angle is revised using the mechanical correction,and then finely revises it using FDK correction algorithm based on tilted flat panel detector.So it can effectively control those artifacts caused by the tilt.Finally,the result proves that the method is effective and feasible by experiments.