Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Biophysics

Background: CT imaging is increasingly used in the field of medical diagnosis because of its advantages in the diagnosis, but the patient is given a high dose of radiation that does not match his weight and age because there is no optimal radiation dose source. Aim of the study: The aim of the present study is to make a comparative study for the measured radiation doses of the CT scans for pediatric head examinations. Materials and methods: Data obtained from 6 Egyptian hospitals is compared with the international dose reference levels, upon which, an optimization of the radiation doses can be deduced. The total sample size of this study is 295 patients having different CT scan examinations. The dose length product (DLP) and the volume CT dose index (CTDIvol) are calculated for each examination using the main parameters collected from the CT scanner, and by multiplying DLP by a conversion factor; the effective dose was also calculated. Results: The present results of DLP and CTDIvol show that sometimes the dose in Egypt CT examinations was lower and sometimes higher than published results from other countries. The present data from Egyptian CT scans indicated that the average DLP values for head examinations for pediatric patients aged {u2264} 5 are higher than the international dose reference levels

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