A wavelet method for metal artifact reduction with multiple metallic objects in the field of view

Abstract

Image artifacts induced by multiple metallic objects pose a persistent problem in X-ray computed tomography (CT). Among existing CT methods for metal artifact reduction, the wavelet-based approach we recently developed is very promising in practice. In this paper, we report a major refinement to our earlier work. The key component of this refinement is a novel weighting scheme for wavelet multiresolution interpolation. This weighting scheme is designed specifically to take into account multiple metallic implants in the field of view. In contrast to commonly used noniterative algorithms, our algorithm identifies and corrects most seriously corrupted projection data based on wavelet multiresolution analysis. Experimental results indicate that the proposed algorithm significantly improves the image quality, and clearly reveals anatomic details in the immediate vicinity of multiple metallic implants.