Measurement of Entrance Surface Air Kerma of plain abdominal radiography in some Nigerian health facilities

Abstract

 Background : Patient dose assessments in many Nigerian radiological departments have shown large inter- and intra-hospital variations for the same type of radiological examinations, hence, there is a need for regular monitoring of radiological equipment and measurement of patient dose in our health facilities. The main objective of this survey was to evaluate the Entrance Surface Dose Air Kerma (ESAK) of the patients who underwent abdominal (anteroposterior; AP) radiography in ten health facilities in Southern Nigeria.

Material and Methods: A total of ten health facilities comprising private and public health facilities were included in this investigation. A total of 223 adult patients who weighed within 70±5kg `were considered in this survey. The ESAK was calculated from the tube output of the x-ray machines and the exposure parameters utilized during examinations according to the International Atomic Energy Agency code of practice.

Results : The mean ESAK values obtained from the health centres ranged from 1.00 milligray (mGy) to 17.21mGy. The maximum/minimum ratio of individual ESAK which is the range factor (RF) varied from 1.3 to 6.1.

Conclusion and Recommendation : Variations were observed in patient dose values among radiological units. The entrance surface air kerma (ESAK) obtained in the study were comparable with the dose values in the UK- 2010 review in most cases. The intra-radiological unit patient dose variations, as revealed by the range factor show that the operation technique employed was not fully optimized and that dose reduction is possible without degrading image quality. Therefore, there is a need for regular monitoring of radiographic equipment and periodic surveys of the patient dose.