Evolution and interpretation of diagnostic reference levels for adults undergoing X-ray computed tomography in China

Abstract

The diagnostic reference level (DRL) for adults radiation dose in CT examination based on a large-scale national survey data is released in the form of national health industry standards (WS/T 637-2018) after more than ten years of exploration by radiologists, imaging technologists, radiation protection specialists and radiographers. Its principles and method are in line with international practices and the actual situation in China, which basically cover frequently-used CT examination items for adults. Compared with DRL in several other countries or organizations, radiation exposure to the patients as a whole is at a reasonably low level. The 50th percentile (achievable dosimetry levels) and 25th percentile (indicative level of unusually low dosimetry) are given as additional tools for radiation dose optimization guidance. In daily activities of radiological diagnosis, the radiation dose should be matched with image quality and clinical diagnostic tasks, and the frequency of unjustifiable high or low radiation dose should be reduced. Key words: Radiation dose; Tomography, X-ray computed; Diagnostic reference levels; Radiation dose optimization