Size specific dose estimate

Last revised by Andrew Murphy on 23 Mar 2023

Size specific dose estimate (SSDE) measured in mGy, is a method of estimating CT radiation dose that takes a patient's size into account. 

CTDIvol and DLP are common methods to estimate a patient's radiation exposure from a CT procedure. The exposures are the same regardless of patient size, but the size of the patients is a factor in the overall patient's absorbed dose.

Coefficients were developed to help transform a patient's exposure to absorbed dose if the AP and lateral dimensions of the patient are provided. Various methods are discussed in the reference articles.

SSDE does not take the organs in the CT scan's field of view into account, so it is not a measure of effective dose.