Physical dose quantities in computed tomography - How effective for describing the patient dose and the radiation risk?

Different physical dose quantities are evaluated with regard to their efficacy for describing the patient dose and the radiation risk. Mean CTDI10cm was defined as the arithmetical average of the five CTDI values measured over 10 cm in a CTDI head and body phantom, Integral dose-length product (iDLP(10cm)) was defined as the product of the dose-length product for a single scan measured over 10 cm and the number of performed scans. Mean CTDI10cm proves to he a good approximation of the mean absorbed doses of organs localised totally within the examined body region. iDLP(10cm) is a good measure of the effective dose and can therefore be used for assessing the radiation risk associated with the CT examination.