Research on influencing factors of geometric efficiency on MDCT / 中国医学装备

ABSTRACT

Objective:To investigate the dependence of geometric efficiency (GE) on beam collimation and tube voltage.Methods: The dose profile was measured under the conditions of different collimations and tube voltages and GE was calculated.Results: GE was found to be from 11% to 68%, GE at central position and periphery were found to range from 11% to 49% and 16% to 68% respectively, and weighted GE was found to be from 17% to 58%. GE was increased with beam collimation, while it was less pronounced on tube voltages.Conclusion:The dependence of GE on collimation was significant. Therefore, operators should choose appropriate collimations to reduce the dose burden of patients in CT examinations.