Patient dose reduction by audit of grid usage in barium enemas

Patient dose reduction may be achieved by removal of the antiscatter grid during fluoroscopy when fine detail is not required, such as during the filling phase of barium enemas. A questionnaire revealed that none of 22 trainee radiologists routinely removed the grid for the filling phase of adult barium enemas. Following this, 100 consecutive barium enemas were observed, with assessment of patient radiation dose by means of a dose-area product meter. The grid was removed in only six examinations. Phantom measurements implied a possible 46% reduction in dose for the filling phase by correct grid usage. These data were presented at a local clinical audit meeting, resulting in a change in departmental policy to recommend routine removal of the grid for the filling phase of barium enemas. In a follow-up audit the grid was removed in 96 of 100 consecutive enemas, resulting in a significant 46.5% dose reduction for the filling phase (95% confidence interval 38-61%). Further re-audit has demonstrated continued good practice.