Diagnostic reference levels (DRLs) for routine X-ray examinations in Lorestan province, Iran

Background: In diagnostic radiology there are two reasons for measuring or estimating radiation doses to patients. Firstly measurements provide a means for setting and checking standards of good practice as an aid to the optimization of patient protection. Secondly estimates of the absorbed dose to tissue and organs in the patients. Material and Methods: A total of 2382 patients were studied to calculate the Entrance Surface Air Kerma (ESAK) following seven radiographic examinations including: chest (PA, Lat), lumbar spines (AP, Lat), pelvis (AP), abdomen (AP), skull (PA, Lat), thoracic spine (AP, Lat) and cervical spines (AP, Lat). The ESAKs values were measured according to x- ray tube output, optimized exposure parameters and body thickness (tp) for each technique. Results: The parameters such as, 1st quartile, mean, median, 3rd quartile, minimum, maximum and standard deviation of each ESAK values are reported and compared to NRPB guide levels. The results showed that the ESAKs values in the lumbar spines and chest X-ray examinations were 30% above the guide levels. However, for the pelvis (AP), skull (PA) and abdomen (AP) examinations, these values were below than those reported by the NRPB. Conclusion: Periodic quality control and monitoring the technical performance of radiographers might effectively improve the image quality and eventually reducing the dose received by patients.