Assessment of the Radiation Dose during 16 Slices CT Examinations

Abstract

In this work. Two studies were presented. The first one is an experimental study of the influence of different scan parameters (potential tube. current tube and pitch) on the radiation dose is presented. It has been demonstrated that the radiation dose increases if we increase the tube current or the potential current. Contrary to the pitch. the radiation dose is reduced when the pitch increases. The second study is a Monte Carlo validation of a CT named SOMATION emotion from Siemens using GATE. Results were carried out for different voltage 80.110.130 kVp. Results of the simulation are presented and good agreements are observed (less than 2.6% for head phantom. and less than 4.6% for body phantom for all applied voltages). The influence of changing the phantom diameter on the CTDIw was also presented. the CTDIw decreased nonlinearly with increasing the phantom diameter. Moreover. the CTDIw differences decreased if the phantom diameter increased. It was demonstrated that the CTDI100 values can be characterized as functions of the kVp. mAs and diameter of phantoms. Based on these results. it is possible to optimize the CT parameters in clinical applications. Finally the effective dose was calculated using the method dose length product and the conversion factors for four clinical protocols.