Purpose: To investigate the effect of a new device for predialing the number of cinegraphic frames before each coronary angiogaphy, with the objective of reducing the patient dose area product (DAP) from coronary angiography, which typically requires 1000 to 2350 cinegraphic frames. That DAP is high and stated to be between 15.6 to 106.3 Gy x cm (2). Applying the accepted DAP-to-ED conversion factors, for the thoracic region of approximately 0.20 mSv/Gy x cm (2), this corresponds to a mean effective dose (ED) in the range of 3.1 to 21.3 mSv.
Material and methods: For patients undergoing elective coronary angiography, we compared various parameters of radiation exposure obtained with judicious radiation reducing standard techniques (n = 106) and with an additional new rotary switch for predialing the number of cinegraphic frames (n = 106).
Results: The patient radiation dose was significantly lower with the new device, with the mean DAP reduced to 5.5 from 9.1 Gy x cm (2). The corresponding reducation of the mean DAP for left ventriculography and coronary angiography was 1.3 from 1.7, and 4.2 from 7.4 Gy x cm (2), respectively. The number of cinegraphic frames was 98 vs. 184, whereas the number of cinegraphic runs and the fluoroscopy time were comparable.
Conclusion: Predialing the cinegraphic frame number before each cinegraphic run enables a reduction of the patients effective dose from coronary angiography to 0.8 mSv, i. e. to 57 % of the baseline value and far below typically reported values.