Reliability Study of Reconstruction methods in Tomosynthesis Imaging of various Geometrical Objects

摘要

The primary objective of this paper is to illustrate the applicability of reconstruction methods to objects of various geometrical shapes. Reconstruction methods are compared by evaluating the efficiency in reconstruction of individual geometric shapes. Signal difference noise ratio, artifact spread function; object extension and artifact extension are taken into consideration to determine the efficiency of the reconstruction methods. The reliability of reconstruction methods is compared qualitatively as well as quantitatively by graphically plotting the cumulative average of individual parameters against corresponding reconstruction methods. All the four parameters are found to be in good agreement with one another. Seven different filters namely Shift add filter, filtered back projection, enhanced shift add filter, enhanced filtered back projection, enhanced 2 shift add filter, enhanced 2 filtered back projection filter, enhanced 3 filtered back projection filter are compared in this paper for the quality of reconstruction and their reliability. Of all the methods, enhanced 3 filtered back projection proved to be the best one. Filtered back projection filter is found to have a clear edge over the shift add filter in viewing cylindrical as well as spherical objects. Besides, shift and add filter fails to trace minute spherical objects. Also, the histograms of average image contrast and average number of slices of both cylinder and the sphere clearly drive home the point. The more the number of slices, the greater is the image resolution. Likewise, the more the signal difference noise ratio, the better the image quality.