ABSTRACT
Numerous interpolation-based methods have been described for reducing metal artifacts in CT images, but due to the limit of the interpolation methods, interpolation alone often fails to meet the clinical demands. In this paper, we describe the use of quartic polynomial interpolation in reconstruction of the images of the metal implant followed by linear interpolation to eliminate the streaks. The two interpolation methods are combined according to their given weights to achieve good results.
Subject(s)
Humans , Algorithms , Artifacts , Dental Prosthesis , Radiographic Image Interpretation, Computer-Assisted , Methods , Tomography, X-Ray Computed , MethodsABSTRACT
<p><b>OBJECTIVE</b>To study regular patterns of cone artifact resulted from interpolation algorithm of spiral CT.</p><p><b>METHODS</b>Based on the principle of interpolation algorithm and back-projection reconstruction, a mathematical model of the reconstructed image was established to clarify the relation of the scanning parameters and the characteristics of the scanned object with the cone artifact. Experiments were carried out by a set of acrylic phantoms on siemens plus 4 CT scanners.</p><p><b>RESULTS</b>The artifact in the image was directly proportional to the table increment per gantry rotation of the scanner, and was positively correlated to the tangent of half cone-angle and inversely to the radii in the reconstruction plane of the phantom. The theoretical analysis was validated by experimental results.</p><p><b>CONCLUSION</b>The cone artifact is related to the scanning parameters and the characteristics of the scanned object.</p>