X-Ray Barrier Estimation - A Case Study of the General Radiography Room of a Major Nigerian Teaching Hospital

Abstract

Background: The observation that the designing rules and calculations on shielding barrier thickness estimation for most general radiographic rooms are not being practised made the evaluation of the already existing shielding barrier of the general Radiography Room of Ahmadu Bello University Teaching Hospital, Shika - Zaria to ascertain its shielding adequacy very necessary.
Materials and Methods: The General Radiography Room with an area of 6.36m x 5m houses a Silhouette General X-ray machine; model MS-185N with serial number 0877 manufactured by General Electric (GE) Medical Systems in September, 2004. The evaluation was based on the method by NCRP Report No. 147, and used the number of patients examined in this room per week for shielding calculations.
Results: The results showed that the barrier thickness required varied from 0.10 to 0.46mm of lead for the secondary barriers and 1.36mm of lead for the primary barrier. The ratio of the calculated to the current (already contructed) barrier thickness ranged from 0.09 to 0.23 for the secondary barriers and 0.68
for the primary barrier .
Conclusion: Based on the results from this study, the shielding barrier already provided in the General Radiography Room of Ahmadu Bello University Teaching Hospital, Shika - Zaria is adequate and in the event of public access to the surrounding area, the dose rates are at acceptable limits.