FIRST EXPERIENCES WITH PULSED FLUOROSCOPY USING A MULTIFUNCTIONAL FLUOROSCOPY UNIT

Comparison of radiation doses in pulsed and continuous fluoroscopy to quantify the dose reduction by pulsed fluoroscopy. Further, the applic ability of pulsed fluoroscopy in clinical routine has been evaluated. Materials and methods: In a human pelvic phantom, the radiation dose ( skin entry dose in cGycm(2)) was measured at two pulses per second (pp s), 3 pps, 6 pps, 12 pps and continuous fluoroscopy mode, respectively , using image-intensifier entries of 38 cm, 25 cm, and 17 cm. 300 exam inations were carried out, and the results of the different fluoroscop y modes were registered. Results: Dose reduction depends on the image- intensifier entry. Compared to the radiation dose in continuous fluoro scopy, with 12 pps fluoroscopy the radiation dose can be reduced at a minimum of 51%, with 6 pps fluoroscopy to 40%, with 3 pps fluoroscopy to 20%, and with 2 pps fluoroscopy to a minimum of 14.5%. Clinical rou tine has shown that 78% of all examinations can be performed with 2 or 3 pps fluoroscopy mode. In 12.7% of the cases pulsed fluoroscopy of d iverse frequencies was used, in an additional 2% combined with continu ous fluoroscopy. Exclusively, continuous fluoroscopy has been employed in 2% of the cases. Conclusions: Using pulsed fluoroscopy, an 80% red uction of the radiation dose compared to continuous fluoroscopy is pos sible. About 96% of all examinations can be performed with pulsed fluo roscopy of different pulse rate and without using continuous fluorosco py.