Comparison of dose rate when working with a C-arm X-ray system

Introduction: During working with sources of ionizing radiation, it is of special importance to take into account the dose load of the personnel working with such equipment. Aim: The aim of this article is to discuss the dose load of people working with mobile X-ray systems with a C-arm, who perform orthopedic procedures in the Clinic of Orthopedics and Traumatology of the St. Marina University Hospital, Varna. This research tries to convincingly show orthopedic surgeons and traumatologists that using a fluoroscopy mode (in all its variations) of the C-arm X-ray system when the tube is positioned under the patient table is best for their work when it comes to the working conditions, the image quality, the information value and the dose exposure of the staff. Materials and Methods: In the article a comparison of the dose load (effective dose) was made based on dosimetric measurements with respect to the personnel in different modes of operation of the X-ray equipment—roentgenoscopy (single shot) and fluoroscopy. The doses received by the surgeon-operator and his assistant were measured at three points of the body—head, gonads and feet, in radiography mode (single shot) and in three sub-modes of the fluoroscopy mode—continuous fluoroscopy, ½ dose fluoroscopy, and pulse fluoroscopy. For a more accurate comparison of the dose load in the respective operating modes, the time for reaching the dose limit for the personnel, determined by the Bulgarian legislation, was calculated—namely 20mSv per year. Results: The results of all measurements and calculations showed that the dose load in the radiography mode (single shot) was several times larger than the dose that was received in the three variations of the fluoroscopy mode at the same operating time. Conclusion: The results suggest that when using the fluoroscopy mode, even in the sub-mode with the highest dose load, it gives a lower dose than using the mode roentgenography, at the same time of operation of the X-ray tube.