**7. Patient doses measurement**

When performing radiographic examinations, patient doses can be evaluated as entrance surface air kerma (ESAK), the dose administered to the skin, where an X-ray beam enters the body, which includes the incident air kerma and backscattered radiation from exposed tissue. ESAK is measured using dosimeters or through calculations from the applied exposure factors and measurements of X-ray tube output [13]. Another method is the kerma-area product (KAP), defined as the product of the dose in air (air kerma) within the X-ray beam and the beam area, which enables the measurement of overall radiation entering a patient. KAP can be measured using an ionization chamber fitted to the X-ray tube. The two methods can be applied to calculate and monitor radiation doses for the various radiological examinations compared to guidance and diagnostic reference levels (DRLs). Many research bodies have been active in the area of DRL, including the International Atomic Energy Authority (IAEA) and International Commission on Radiological Protection (ICRP). The objective of DRLs is to aid in preventing the administration of unnecessary radiation doses to patients that do not support the clinical purpose of a radiographic exam. Each X-ray facility should set up DRLs following international guidelines with regular assessments and applications of corrective action in cases where these levels are exceeded.
