This paper investigates a common metal artifacts problem in X-ray computed tomography (CT). The artifacts in
reconstructed image may render image non-diagnostic because of inaccuracy beam hardening correction from high
attenuation objects, satisfactory image could not be reconstructed from projections with missing or distorted data. In
traditionally analytical metal artifact reduction (MAR) method, firstly subtract the metallic object part of projection data
from the original obtained projection, secondly complete the subtracted part in original projection by using various
interpolating method, thirdly reconstruction from the interpolated projection by filtered back-projection (FBP) algorithm.
The interpolation error occurred during the second step can make unrealistic assumptions about the missing data, leading
to DC shift artifact in the reconstructed images. We proposed a differentiated back-projection (DBP) type MAR method
by instead of FBP algorithm with DBP algorithm in third step. In FBP algorithm the interpolated projection will be
filtered on each projection view angle before back-projection, as a result the interpolation error is propagated to whole
projection. However, the property of DBP algorithm provide a chance to do filter after the back-projection in a Hilbert
filter direction, as a result the interpolation error affection would be reduce and there is expectation on improving quality
of reconstructed images. In other word, if we choose the DBP algorithm instead of the FBP algorithm, less contaminated
projection data with interpolation error would be used in reconstruction. A simulation study was performed to evaluate
the proposed method using a given phantom.