Low Dose CT Colonography(LDCTC)를 이용한 Automatic Exposure Controll(AEC)와 Beam Collimation의 변화에 따른 유용성 평가와 Effective Dose의 평가치에 대한 연구

A study on efficiency of Effective Dose with Using Automatic Exposure Controller and Beam collimation in Low Dose CT Colonography

Purpose To considerate the efficiency of Automatic Exposure Controller(AEC) and Beam Collimation with the value of Effective Dose obtained with the alteration of Automatic Exposure Controller(AEC) and Beam Collimation. Materials and methods 50 out-patients (Male:36, Female:14, mean age:45 years) underwent Low Dose CT Colonography with 16 MDCT from 1st June 2007 to 31th July 2007 were selected. The Effective Dose was produced with the alteration of DoseRight Automatic Current Selector(ACS) & DoseRight D-Dose modulation(D-DOM), Beam Collimation in same patients. Results On the assumption that Effective Dose without AEC is 100%, 8% was decreased with only ACS, 9% was declined with D-DOM, and 16% was decreased with using ACS & D-DOM. On the same condition, 8% was decreased with the Beam Colliniation increased double. Conclusion 8%~16% of Effective Dose was decreased with AEC Program(ACS, D-DOM) and Beam Collimation. Although 30%-40% of decrease effectiveness was not obtained like the previous papers about dose, the use of Automatic Exposure Controller and Beam Collimation decrease effective dose. The use of AEC and Beam Collimation maintain the high quality of images and extend the tube life time of CT modality.