Attempts to understand the image reconstruction algorithms used in medical X-ray computed tomography

From our personal perspective, medical diagnostic and treatment therapy technology owes very much from the advancement of nuclear physics, thereby impacting every living species on earth. The objective of this contribution is to illustrate the efforts made to understand the basic image reconstruction algorithms employed in X-ray computed tomography modalities. In order to improve the contrast, various filter functions are attempted in frequency space. For instance, with "Ram-Lak" filter, contrast improves significantly. Results obtained with other type of filters would be presented in the symposium