Radiation doses for barium enema and barium meal examinations in Ireland: potential diagnostic reference levels.

Abstract

Wide variations in patient dose for the same examinations have been demonstrated by several studies throughout Europe. By investigating patient dose, variations can be acknowledged, causal agents sought and the necessary adjustments made. Diagnostic reference levels (DRLs) provide a framework with which dose levels from individual hospitals are compared, and when exceeded, corrective actions can be taken where appropriate. This study aimed to establish DRLs for barium enema and barium meal examinations in Ireland. Measurements were recorded using a dose-area product meter in 12 hospitals representing 33% of relevant hospitals. Results demonstrated wide mean hospital dose variation, by up to a factor of 7.8 and 4.2 for barium enema and barium meal examinations, respectively. Minimum and maximum individual patient dose values varied by a factor of 45 for barium enemas and 90 for barium meal examinations. Reasons for dose variations were complex, but major factors for both examinations were fluoroscopy time, secondary radiation grid type and level of filtration. Some examination-specific factors were also noted. DRLs, established using the quantity dose-area product, were calculated to be 47 Gy cm(2) for barium enemas and 17 Gy cm(2) for barium meal examinations. Although the DRL value for barium meals was the same as the reference value established in the UK for that examination in 1996, the barium enema DRL in this study was 45% higher than the relevant UK value.