Purpose: This study was done to evaluate the appropriateness of dose indices in computed tomography (CT) by comparing the body computed tomography dose index (CTDI) and the size-specific dose estimates (SSDE) to determine which of these two parameters is more appropriate to estimate the radiation dose to both adult and paediatric patients.
Materials and methods: We analysed 150 thoracic CT and 150 abdominal CT scans, half of which from adult patients and the other half from paediatric patients. We compared the values of the CTDIvol and the SSDE reporting the average, maximum and minimum percentage difference for each body region and depending on the age of the patients.
Results: In the thoracic CT and abdominal CT scans, we found values of difference between the SSDE and the CTDIvol of 26.3 and 27.3 %, respectively, in adult patients and of 46.9 and 48.5 % in paediatric patients.
Conclusions: The SSDE is a good tool for estimating the average radiation dose for a given patient depending on the input parameters and the dimensions of the specific person in question before a CT examination.