ABSTRACT

Diagnostic reference levels (DRL) are recommended exposure/dose indicator values used for optimization and to ensure patient/worker radiation safety in diagnostic and interventional procedures involving ionizing radiation. The value that fits 75% of the dose indicator value distribution for a certain number of patients is defined as the DRL for that procedure. There are different DRL indicators in radiography, diagnostic and interventional fluoroscopy, mammography and computed tomography, depending on the device technology and dose measurement method. It is recommended that the determination of DRL and the evaluation of these values for the optimization process be repeated at regular intervals and after the emergence of new imaging technologies or innovations in existing ones. The sole goal in the DRL creation and follow-up process is not to reduce the radiation dose applied to the patient. It should also be demonstrated that the diagnostic quality of the images obtained were protected as a result of the optimization is preserved. The DRL value should be determined primarily in frequently performed radiological procedures. Determining the DRL for rarely performed imaging is neither practical nor necessary. When DRL values are exceeded, they do not indicate malpractice and are not investigated individually for each patient.