MDCT를 이용한 복부 3-phase검사시 추적검사환자의 피폭선량 감소를 위한 Bolus triggering에 대한 고찰

Study of Bolus triggering used for reducing radiation exposure dose of follow-up patients during abdomen 3-phase examination with MDCT

Purpose In this study, number of monitoring time is examined when Bolus triggering is applied to determine examination time according to circulation of blood for 3-phase examination to reduce exposure dose during monitoring among CTDIvol to patients. Materials and Methods The research was conducted from January 2007 to May 2007 toward 339 in-patients conducted Liver, Pancreas Protocol CT examination and patients were analyzed by disease, sex and age. 16MDCT (Somatom Sensation 16, Siemens, Germany) and Auto injector(Stellant, Medrad, U.S.A) were used for as experimental equipment and contrast medium was injected through Antecubital vein(elbow). 20G(needle) was used, monitoring location was Thoracic spine 12 by 1 second interval to examine peak time of each individual. 350mg I/ml 120cc contrast medium was injected with 3cc per second and monitoring conditions were 120 kV, 20mAs, detector collimation is 16×0.75mm. Results When analyzed by disease, sex and age, regular monitoring number was unable to find but for identical tracking examination conducted toward 35 people, 17 people had identical monitored number. Among 18 unidentical people, 17 people had ±3 times and only 1 person had 6 times different due to changed IV location and Flow rate. Conclusion Monitored number analysis was applied to experiment result and average was 9.4 times CTDIvol 39.12mGy. As minimum monitored number was 2, monitoring start time was 2 seconds after enhance to reduce CTDIvol to 8.32mGy. Also in case of follow-up patients, as error range is ±3sec, monitoring number data is recorded and managed with OCS Warning System to reduce average numbers from 9.4 times to 6 times resulting reduction of 28.96mGy that is 3 time exposure dose CTDIvol of single phase examination.