The quantification of radiation risks associated with radiological examinations has been a subject of interest with the increased use of X-rays. Effective dose, which is a risk-weighted measure of radiation to organs in the body associated with radiological examination, is considered a good indicator of radiological risk. We have therefore investigated patient effective doses from radiological examinations. Organ and effective doses were estimated for 94 patients who underwent computed tomography examinations and for 338 patients who had conventional radiography examinations. The OrgDose (version 2) program was used for the estimation of effective doses. The tube potential ranges: 57？kVp to 138？kVp depending on the examination and patient size. The entrance surface doses have a wide range even for the same examination: 0.44–10.31？mGy (abdomen) and 0.66–16.08？mGy (lumbar spine) and the corresponding effective dose ranges 0.025–0.77？mSv and 0.025–0.95？mSv respectively. Effective dose for adult abdomen-pelvic CT examinations ranges 5.4–19.8？mSv with a mean of 13.6？mSv and for pediatrics ranges 2.1–5.5？mSv with a mean of 2.7？mSv. The mean effective dose for adult chest and head CT examinations are 7.9 and 1.8？mSv respectively and for pediatrics are 1.7 and 1.1？mSv. 1. Introduction Diagnostic radiology imaging techniques including conventional radiography, fluoroscopy, and computed tomography (CT) procedures will continue to provide tremendous benefits to modern healthcare and the benefit derived by the patient will far outweigh the small risk associated with any properly conducted imaging modality. Nonetheless, it is important to be able to quantify the risks associated with radiological examinations of patients [1–11]. Access to such information will allow physicians and their patients to better weigh the risks of radiation exposure against the benefits afforded by various radiological examinations and hence make the best informed decisions in terms of options for other diagnostic modalities. The increase in patients undergoing radiological examinations (especially in CT) has created a great deal of interest in quantifying the risk associated with radiological examinations. Effective dose which is a risk-weighted measure of radiation to organs in the body associated with an examination(s) is considered a good indicator of radiological risk [2–6]. However, it should be realized that effective dose represents a generic estimate of risk from a given procedure for a generic model of the human body [11]. Estimated effective dose from a particular examination
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