The current situation of dose and DRLS for radiographic and fluoroscopic examinations

Medical radiation is the largest contributor of human-made radiation exposure today and the majority of this exposure is from diagnostic X-rays (UNSCEAR 2010). Due to advancing imaging technology and increasing investments in healthcare worldwide, a continuous growth in the use of diagnostic X-rays has been recorded in recent times and raised serious concerns about higher patient doses. For effective optimization of the diagnostic exposures, the International Commission on Radiological Protection (ICRP) introduced the concept of diagnostic reference level (DRL) in 1996 which was subsequently recommended by the International Atomic Energy Agency (IAEA) (1996), European Commission (EC) (1999) and many other organizations. The objective of a DRL is to help avoid radiation dose to the patient that does not contribute to the clinical purpose of the image. It provides a means for practices to compare their radiation dose data to benchmarks derived from aggregated dose data collected on a local, regional, or national level. Patient dose for radiographic examinations is commonly expressed in units of air kerma-area product (P_KA) or entrance surface air kerma (Ka,e) or an assessment of both, whereas, the most appropriate dose descriptor for fluoroscopy examinations is P_KA. In general, the 75th percentile of the distribution of the dose quantity is considered an appropriate level for the DRL