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

Concerning the importance of radiography techniques for diagnosis of disease and considering daily application and emerging new techniques in radiography from one hand and potential misuse of radiation and exposure to patients and personnel from other, it seems necessary the measure the amount of received radiation in current radiography procedures. The aim of this research is to determine the surface dose to patients in chest and skull radiography procedures in the hospitals of Mazandaran medical science university and compare those to given standards for such examinations from national and international recommendations. The study was based on the procedures, performed at six X-ray machines in six hospitals of the medical science university. Totally 120 patients with normal BMI, undergoing prescribed chest and skull examinations were involved. The exposure parameters, such as kVp - mAs product, film-screen combination and overall procedure setup at the all 6 X-ray machines were similar, thus provided unbiased evaluation of the surface dose. Surface dose was measured, using LiF thermoluminescent dosimeters (TLD). TLD after calibration was attached to the back and front skin surface of patients and after exposure TLD5 radiance was read with TLD reader. The average surface dose, measured for patients undergoing examinations of posterior - anterior view for pectoral, profile view for chest and posterior - anterior or anterior - posterior view of skull and profile view of skull where 0.51 , 3.36 , 7.25 and 7.59 mGy, respectively. These figures exceed recommended standards. To decrease patient surface dose, such measures, as periodic and continuous on-the-job education as well as supervision could increase technical and technological knowledge and rise awareness about radiation protection issues, thus improving the situation in hospitals. (author)