A model for predicting skin dose received by patients from an x-ray source based on a triple phase generator

Patient dosimetry has raised concern on quality assurance in hospitals. Several organisations and research groups have been advocating ways of minimising radiation dose received by patients in hospitals. In this paper we have shown that it is possible to obtain in a simple way a reasonable estimate of skin dose received by patient from an X-ray machine source before the actual dose is given to the patients. This could help X-ray machine operators know when higher doses than normal are being given to the patients. We have done this by modifying a model for predicting skin dose derived by Edmonds for a triple-phase generator. Results for 100 patients based on the triple-phase generator output show a reasonable average agreement (»1%) between our present model and the Edmonds's model. Although our earlier estimated average dose from a single-phase generator output and those presently estimated from a triple-phase generator output give doses that are less than 1mGy, the present calculated average skin dose results for the three-phase generator are roughly three times higher than those we obtained earlier with the single-phase generator output, indicating the need for careful administration of dose to patients in view of our stated philosophy for minimising doses in hospitals. It is to be noted that a simplified formula such as we have derived is more elegant and its use less time consuming than the Edmonds's formula. Key Words:Diagnostic X-rays, filtration, skin dose, radiation, radiographic Parameters. Botswana Journal of Technology Vol.13(2) 2004: 35-4