Evaluating mass attenuation and mass energy-absorbtion coefficients of body tissues/ organ using computer software.

This study formulated an appropriate fitting model; carried out segmented least-square multifit on the attenuation data; derived optimum parameters of the fitting model for each of the energy segment and wrote a Java code. This was with a view to produce a computer program that will evaluate the mass attenuation and mass energy-absorption coefficients of body tissues/organs or any phantom material with excellent accuracy. Linear least-square curve-fitting method was employed to fit the existing attenuation data to a justified, fifth-order, inverse polynomial model by segmented multifit technique. The derived best-fit parameters, the polynomial model and the mixture additive rules were incorporated into Java codes which were packaged into a computer software application called UCOM. The results showed that the uncertainty of UCOM is 0.01% on the average. Comparative results also showed that UCOM gives better speed optimization (~150 milliseconds) and less memory utilization (~1 megabyte). Further comparisons show that UCOM offers more compatibility with computer Operating Systems such as WINDOW, UNIX and LINUX. UCOM gives some degree of freedom to user in the areas of energy grid input and input of number of elements composed in a tissue or substitute. Additionally, the software is user-friendly with a robust educative package.
This study concluded that the polynomial fitting and model used in this software provided a better and easier parameterization scheme for attenuation data than the arduous log-log and linear cubic spline fitting methods adopted in other similar parameterization studies.