A protocol for setting dose reference level for medical radiography in Nigeria: a review

Abstract

Patients' dose audit reports in some Nigerian hospitals had shown large inter-and intra-hospital variations for the same radiological examinations. They have thus presented the need, to have a national standard for radiological diagnostic procedures and set dose limits for individual x-ray examination centers in Nigeria. These will go a long way in reducing inter-and intra-hospital dose range factors, thus reducing doses to as low as reasonably achievable and consistent with clinical objectives of the examinations. In establishing a national dose limit for medical radiological examinations, there is a need to have a national dose survey. This paper suggests a reasonable and easy procedure for achieving a national radiological dose survey. Due to its simplicity of measurement, the use of entrance surface dose as the dose parameter to be used for setting the dose limit as recommended by the European Union and the International Atomic Energy Agency (IAEA) is also suggested. ESD can be measured directly through the use of solid state detectors, or indirectly by measuring free air exposure which can later be converted to ESD using standard formula. The methods of measuring the entrance surface dose and how to derive the dose limit from them are also highlighted.

Diagnostic Reference Levels for Common X-ray Procedures in Peru

“…Research has shown that the difference between the minimum dose in one diagnostic center and the maximum dose in another can be up to 50 times as much [ 3 ]. Taking into account the principle of optimization, and having found these inconsistencies, the term "Diagnostic Reference Value" was proposed in 1990 [ 4 ].…”

Rationale for Implementing Dose Reference Level as a Quality Assurance Tool in Medical Radiography in Nigeria

“…However the FAE at the point where the X-ray central beam measures strike the body may be measured using ionization chamber. [4], [20], [26], [27].…”

Assessment of Entrance Skin Dose and Image Quality of Chest X-Rays in Two University Teaching Hospitals, North East Nigeria

“…Despite the attractive nature of the calculation methods of patient dose, one should make sure that the used x-ray equipment has an adequate QC protocol that ensures the accuracy of the measured factors [16,17,20] . Although, ESD may be sufficient for quality control measurements where the stability of the x-ray equipment is often of concern, the entrance dose is not sufficient for comparison or evaluation of actual patient dose and associated risk [16,25] . The objective of this study is to estimate and assess ESD and image quality of chest x-ray examinations and to use it as a standard in determining an easier method in assessing reference dose compliance criteria of patient's radiation exposure to medical x-rays in the hospitals within this region.…”