Quality Estimation of Filtration of Diagnostic X-Ray at Federal Medical Centre and Bishop Murray Hospital Makurdi using Half-Value Layer (HVL)

Abstract

Quality filtration of diagnostic X-rays in use at Federal Medical Centre and Bishop Murray Hospital Makurdi were checked using half-value layer (HVL) at 80kVp, 70kVp and 60kVp. A simple technique of determining HVL which is based on reducing the intensity of X-ray beam to half its original value using aluminium filters added at 2cm from the table and dose detected using DIAVOLT placed at 98cm from the centre of the X-ray tubes. Results were obtained from the plot of ln Dose (mGy) Versus Aluminium thickness (mm) where the slope gives the attenuation coefficient (m). The attenuation coefficient was then used in calculating HVL using the relationship HVL=In2/m. HVL values calculated were then compared with the minimum acceptable HVL values at the kVp setting as recommended by the international Commission on Radiological units and measurement.

Keywords: Half Value Layer, Attenuation Coefficient, X-ray, filters,Makurdi