Survey of radiological techniques and doses of children undergoing some common x-ray examinations in three hospitals in Nigeria.

A dosimetric survey has been carried out in order to investigate typical radiation doses for children undergoing a number of common x-ray examinations in Nigeria. The results presented in this work are derived from the data of 226 children from three different hospitals included in the survey. Assuming the sample is representative of national practice patterns, pediatric chest examinations are the most frequent radiological examinations. Doses were measured by attaching thermoluminescent dosimeters to the patient's skin to determine entrance surface dose (ESD). The mean and standard deviation of the individual ESD values are reported. Comparisons were made between these doses and diagnostic reference levels, and also between the doses and those from other countries. The mean ESD values in the present work are found to be generally higher than those found in an UNSCEAR document and the NRPB diagnostic reference levels. The ratio of maximum ESD to minimum ESD, a parameter that characterizes ESD variation, was found to be less than 10 in each of the hospitals, while across the three hospitals the ratio was found to be greater than 10. The reasons for the high mean ESD and the variations in patients' ESD values have been discussed in terms of regulatory control, personnel, difference in radiological techniques, performance of x-ray facility, film processing condition, and the type of film-screen combination used. The results presented in this work will form part of the baseline data needed for deriving national guidance levels of pediatric radiological examination. In addition, it will also serve as a source of additional information on pediatric patient dosimetry. Suggestions are given on how to reduce doses to pediatric patients during x-ray examinations, especially in developing countries.