Radiation Dose Management in Computed Tomography: Introduction to the Practice at a Single Facility

Abstract

Although the clinical benefits of computed tomography (CT) are undoubtedly high, radiation doses received by patients are also relatively high; therefore, radiation dose management is mandatory to optimize CT radiation doses and prevent excessive radiation events. This article describes CT dose management practice at a single facility. Many imaging protocols are used in CT depending on the clinical indications, scan region, and CT scanner; thus, managing the protocols is the first step for optimization. The appropriateness of the radiation dose for each protocol and scanner is verified, while answering whether the dose is the minimum to obtain diagnostic-quality images. Moreover, examinations with exceptionally high doses are identified, and the cause and clinical validity of the high dose are assessed. Daily imaging practice should follow standardized procedures, avoiding operator-dependent errors, and information required for radiation dose management should be recorded at each examination. The imaging protocols and procedures are reviewed for continuous improvement based on regular dose analysis and multidisciplinary team collaboration. The participation of many staff members in the dose management process is expected to contribute to promoting radiation safety through increased staff awareness.

Relationships of Radiation Dose Indices with Body Size Indices in Adult Body Computed Tomography

“…Radiation dose management using regression equations between dose indices and body size indices has expected advantages besides evaluating the standard dose and its dependence on body size for each scanner and imaging protocol. Routine dose monitoring should be conducted to identify examinations with exceptionally high doses and investigate their validities and causes [ 11 , 18 , 26 , 27 , 30 ]. If high-dose examinations are extracted simply based on the absolute values of CTDIvol or DLP, most extracted examinations would be those performed in large patients [ 18 ].…”

“…The standard dose can be estimated for each examination using the regression equation between the dose index and body size index. By comparing the actual recorded dose with the estimated dose, the excessive dose events to be investigated can be effectively and efficiently identified [ 11 , 18 ]. In addition, when using a new scanner or new imaging protocol, it is desirable to evaluate dose adequacy early using small amounts of examination data.…”

“…Because the required radiation exposure varies depending on the body size, considering body size is critical in radiation dose management [ 11 ]. Although DRLs are established for weight- or age-based groups in pediatric CT [ 7 , 12 ], they are usually determined only for standard-sized patients in adult CT. Each facility compares the radiation dose used at the facility to the DRLs based on data from examinations performed in standard-sized patients.…”