The effectiveness of thermoluminescent crystals for calculation of required barrier against radiation at the diagnostic X-ray units

The aim of this research was the measurement of the surface skin doses of the patients concerning examination chest and skull radiographic and the comparison of the measures with National and International organization standards. In this cross sectional study, six X-ray generators in six Mazandaran University of Medical Sciences Hospitals were studied. 120 patients who were referred to the radiology wards for radiographic examinations of chest and skull with normal BMI were chosen, (20 patients for each radiography unit). In addition, six generators were matched for mAs, kvp, type of amplifier sheets, and technical conditions as much as possible, so the amount of surface dose would not depend on the mentioned items. We used thermo luminescence dosimeters for measurement of the surface skin dose (Lif-100). Calibrated Thermo luminescence dosimeters (TLD) were placed on the back skin of patients and then the results were read by TLD readers after radiation. The results of the measurement of the surface skin dose were 0.51 milli Gray for 1PA 2CXR, 3.36 milli Gray for 3LAT CXR, 7.25 milli Gray for 4AP or PA skull X-rays, and 7.59 milli Gray for LAT skull X-rays. The measured values were higher than the National and International organization standards. The results of this research revealed that the condition of the X-ray generators have to be evaluated and modified periodically. With modifying of the X-ray generators and also the promotion of the technician's skills, the radiation exposure and its side effects would reduce in patients concerning radiographic examination. (author)