Radiation dose considerations in digital radiography with an anti‐scatter grid: A study using adult and pediatric phantoms

BACKGROUND: When using an anti‐scatter grid, a decrease in receptor dose caused by its X‐ray absorption seems to lead to the misperception that radiation dose needs to be increased even in digital radiography (DR). OBJECTIVE: To demonstrate that there is no need to increase radiation dose in DR with a grid, based on a visual evaluation using an adult and a pediatric abdomen phantom (P(AD) and P(PD), respectively). MATERIALS AND METHODS: Phantom images with and without a grid were obtained with exposure parameters determined based on a preliminarily measured signal‐to‐noise ratio improvement factor (SIF), an index for potential dose reduction when using a grid. In visual evaluation, four radiologists compared phantom images with a grid applied at different dose reduction rates (0% [no reduction], 18%, 36%, and 59% for P(AD) and 0% and 11% for P(PD)) against an image without a grid at the baseline dose (as the reference). They graded the overall image quality of the former relative to that of the latter (reference) on a 3‐point scale (3 = better, 2 = almost equal, 1 = worse). RESULTS: The mean scores for dose reduction rates of 0%, 18%, 36%, and 59% were 3.00, 3.00, 2.75, and 1.00, respectively, for P(AD); those for 0% and 11% were 2.13 and 1.63, respectively, for P(PD). These results support the validity of our view that no dose increase is necessary when using an anti‐scatter grid. Actually, there is even a potential for improvement in image quality with dose reduction rates of ≤36% for P(AD). CONCLUSION: It is worth reconsidering the necessity of increasing radiation dose in the DR imaging of the adult and pediatric abdomens with an anti‐scatter grid.