Entrance skin dose assessment of selected computedradiography facilities in Ghana

Background: the basic challenge with computed radiography (cr) systems isthe large dynamic range which provides an opportunity for radiographers togradually increase exposure factors and still produce good image quality, apractice that can lead to dose creep. materials and methods: the aim of thisstudy was to establish the entrance skin dose (esd) values for nine selectedexaminations in three cr facilities in ghana (chest pa, abdomen ap, lumbarpelvis ap, lumbar spine lat, cervical spine ap, cervical spine lat, skull pa andskull lat). esd was estimated by the indirect method involving the use of astandard equation. the study involved 150 females and 120 males with theaverage age of 50 ± 14 years. the average weight of the study population was69 ± 8 kg, and the average height of 162 ± 9 cm. the cr systems used at allthe hospitals were manufactured by shimadzu medical systems (kyoto,japan) and the model number was ud150l-40e. results: the average esds(mgy) for each examination were; 0.93 ± 0.7, 3.04 ± 0.4 , 4.95 ± 0.9, 0.59 ±0.3, 0.63 ± 0.4, 1.77 ± 0.3, 1.64 ± 0.3, 2.31 ± 0.4 and 3.15 ± 0.6 for chest pa,lumbar spine ap, lumber spine lat, cervical spine ap, cervical spine lat, skullpa, skull lat, pelvis ap, and abdomen ap respectively. the single factoranova t-test that was performed indicated a significant difference (p-value =5.73 x 10-15) among the esds for chest pa examination. conclusion: overexposure of patients is very possible with cr systems, it is thereforeimportant for patient dose to be audited periodically in order to achieve theprinciples of as low as reasonably achievable (alara).