Abstract

Strategies for radiation dose optimization in medical radiation exposure

Lee Jungeun, Kim Hyunji, Lee Hyunkoo
Division of Medical Radiation, Center for Disease Prevention, KCDC
Do Kyung-Hyun
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul

Following the rapid development of medical equipment including CT and PET-CT, radiation doses from medical exposure are now the largest source of human-made radiation exposure. General principles of radiation protection from the hazards of ionizing radiation are summarized in three keywords; justification, optimization, and dose limit. Because medical radiation exposure possesses unique considerations, the diagnostic reference level (DRL) is generally used as a reference value, instead of dose limits. Justification means that the examination must be medically indicated and useful. Optimization means that the imaging should be performed using doses that are ‘as low as reasonably achievable’ (ALARA), consistent with the diagnostic task. Optimization further includes understanding and changing protocols to perform the same diagnostic task with a minimal amount of radiation exposure while maintaining diagnostic accuracy. Protocols and guidelines are important tools for radiation dose reduction. Understanding the parameters and dose information is essential for optimization. If the exam is justified, then the parameters must be optimized to the imaging indication, scan area, body size, age, and weight of the patient. Furthermore, the physician should always assess the radiation risk-benefit ratio for each patient before ordering an examination that uses radiation. 

Keywords: Medical radiation, Man-made radiation, Radiation protection, Justification, Optimization,  Reference values, Risk assessment, Radiation exposure