Evaluation of Size-Specific Dose Estimates in Pediatric Abdominal CT

In pediatric abdominal CT examinations, the conventional CT dose index (CTDIvol) has limitations as it does not account for the patient’s body size. To address this issue, the American Association of Physicists in Medicine (AAPM) introduced the concept of size-specific dose estimate (SSDE), which considers individual patient body size. This study retrospectively analyzed the SSDE of pediatric patients aged 1 to 5 years and compared it with the CTDIvol provided by the CT equipment. The results showed that SSDE values were 2.16 to 2.34 times those of CTDIvol, indicating the potential underestimation of actual radiation exposure in pediatric patients. Additionally, among the four SSDE conversion methods proposed by the AAPM, the method using only the anteroposterior diameter was found to be statistically insignificant.(p>0.05) In contrast, the method incorporating both anteroposterior (AP) and lateral diameters was recommended. This is likely because the lateral diameter in pediatric patients increases linearly with age, whereas the AP diameter does not show a linear trend. Currently, there is an international movement to establish SSDE as the new standard for dose estimation, as it more accurately reflects actual radiation exposure. Therefore, SSDE should be actively incorporated alongside CTDI in CT examinations for more effective radiation dose management.