A Review of Diagnostic Reference Levels in Computed Tomography

Computed Tomography (CT) scanning generates 3-D images of the inside structures of the body by delivering a comparative radiation dose to the patient. This requires great concern of optimization via establishing Diagnostic Reference Level (DRL). DRL values can be estimated based on reference patient percentiles (such as 90th, 75th, and 50th) dose distribution. DRL has significant uses in professional judgments by generating harmonized evidence about the radiation dose received by the patient. The primary goal of this review is to assess the practical application of DRL in CT procedures internationally. The main objective of establishing DRLs is to optimize the patient dose without compromising the image quality in order to obtain adequate diagnostic information. That means the inescapability of DRL for a country in medical diagnosis is to reduce the limitation of dose dispersion, to harmonize and expand the good practice, to narrow large dispersion of doses, and to create systematic supervision for unwanted radiological doses. The review presents that international records have a wide range of mean dose distributions due to the variation of exam protocols and technical parameters in use. Hence, this review recommends that each CT health facility are required to exercise careful dose reduction strategies by accounting for adequate image quality with sufficient diagnostic information via follow-up of concerned bodies.