Dual Source CT와 Multi Detector CT에서 Coronary 검사의 방사선량 분석

A Study on Radiation dose of Dual Source CT and Multi Detecter CT in Coronary study

Purpose This study compared an exposure dose of DSCT with MDCT in cardiac CT and we analyzed how much the radiation dose increased or decreased. Materials and Methods For an experiment, CT device for the human body was used by 16 channel MDCT(Multi Detecter CT) manufactured by siemens and DSCT(Dual Source CT) called by SIEMENS Somatom Definition CT. It is available for supplying two source with each different kVp and mAs, processing and gathering the data at the same time. we used ECG Simulator(Marquette Electronics. USA) for examining a change of Heart Rate. An experiment method compares CTDIvol and CTDIDLP of DSCT with MDCT and is to measure. it was performed by using ECG Simulator in DSCT Coronary study, giving Heart Rate with a variety of numerical value, such as 50bpm, 55bpm, 60bpm, 65bpm, 70bpm, 75bpm, 80bpm, 85bpm, 90bpm, 95bpm, 100bpm, 105bpm, 110bpm, according to high or low of each heart rate, comparing and measuring CTDIvol and CTDIDLP, we can know whether there is some differences. Results 1. The Coronary study protocol of MDCT is 120kVp, 600mAs, Rotation time 0.37sec, Scan Time 18~20sec. CTDIvol and CTDIDLP measured each 46.80mGy, 936mGy. The Coronary study protocol of DSCT is 120kVp, 300mAs, Rotation time 0.33sec, Scan Time 8~10sec. CTDIvol and CTDIDLP measured each 47.45mGy, 427.05mGy. As a result, CTDIDLP was reduced about 55% in DSCT compared with Multi Detecter CT though CTDIvol is similar. 2. Heat rate of Coronary Study used ECG Simulator in DSCT is 50bpm, 55bpm, 60bpm, 65bpm, 70bpm, 75bpm, 80bpm, 85bpm, 90bpm, 95bpm, 100bpm, 105bpm, 110bpm. according to high or low of each heart rate, CTDIvol is measured to 60.81mGy in 50bpm and 29.llmGy in 110bpm. 3. CTDIvol and CTDIDLP of MDCT used Coronary study protocol is measured to 46.80mGy and 936mGy. measured CTDIvol of DSCT is 29.11~60.81mGy in 50bpm ~110bpm heart rate and CTDIDLP is measured to 261.99~547.29mGy. Conclusion The Dual Source CT is increased 29.9%~0.1% of CTDIvol in 50bpm ~ 110bpm compared with the Multi Detecter CT. And the CTDIvol in 70bpm ~ 110bpm was reduced by 9%~37.8. In the Single Source the Table speed came to be late as a heart rate increase. On the other hand, The Table speed of DSCT did fast according to the increase of the Heart Rate and The Scan time is reduced. When heart rate is slow, CTDIDLP of Dual Source CT is reduced by 41.6 % compared with Multi Detecter CT and When heart rate is fast, CTDim.P of Dual Source CT is reduced by 72.1% compared with Multi Detecter CT.