Quantifying dose-creep for Skull and chest radiography using dose area product and entrance surface dose: Phantom study

Abstract

Digital radiography allows for image manipulation, giving radiographers the ability to adjust the grey level of the image using latitude-algorithm. In doing such, patients receiving unnecessary radiation-dose often goes undetected. The aim of present study has been to quantify dose-creep using dose area product (DAP) and entrance surface dose (ESD) for skull and chest exams using phantoms. Furthermore, to investigate possible correlation between DAP and ESD. Adult anthropomorphic phantoms were used to produce a series of anterior-posterior (AP) and lateral (LAT) skull and chest images varying the mAs to yield optimal and overexposed images for each projection. Thermoluminescent dosimeter (TLD) was placed at the surface of the centered phantom to measure the ESD. DAP values were gathered and correlated with ESD values using Spearman's correlation coefficient test while Wilcoxon-test was used to calculate the statistical difference. Dose-creep was calculated as the percentage difference between optimum and over exposure results. The highest estimated dose-creep of (51%) was demonstrated for chest AP projection as calculated from DAP values. Using Spearman's correlation, a significant strong positive correlation was revealed for DAP and ESD optimum (r = 0.916, p = 0.0006) and overexposure (r = 0.8992, p = 0.0009), respectively. Dose-creep can be considerably high raising the need for thorough investigations and society awareness.