Accepted 16^th November, 2020

Natasha Ivanova¹, Javor Ivanov², Marin Marinov³ and Miroslav Petrov<sup>4

1</sup>Medical University “Prof. Dr. ParaskevStoyanov”, Varna, Bulgaria.
²S&T Bulgaria ЕOOD, Sofia, Bulgaria.
³Clinic of Orthopedics and Traumatology, University Hospital "St Marina", Varna, Bulgaria.
⁴Radiation Therapy Clinic, University Hospital "St Marina", Varna, Bulgaria.

The present study was conducted to evaluate the dose load of people working with mobile C-arm X-ray systems and performing orthopedic procedures. A comparison of the dose load was done based on dosimetric measurements with respect to the personnel in different modes of operation of the X-ray equipment. The doses received by the doctor-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. Dose rate calculations were done for the resulting dose measurements due to the fact that different exposure modes used different exposure times. For a more accurate comparison of the dose load in the different operating modes, the time for reaching the dose limit for the personnel given in the Bulgarian legislation was calculated – 20 mSv per year. The results of all measurements and calculations showed that the dose load in the radiography mode (single shot) is several times larger than the dose that was received in the three variations of the fluoroscopy modes. The aim of the present study is to convincingly show orthopedic surgeons and traumatologists that using a fluoroscopy mode (in all its variations) of the C-arm x-ray system in the position of the tube under the patient table is best for their work, appreciating terms of work, image quality, informational value and dose load of the staff.

Key words: C-arm type X-ray equipment, dose load, staff, Orthopedics, Traumatology Clinic.