Accidental embryo irradiation during barium enema examinations. An estimation of absorbed dose.

RATIONALE AND

OBJECTIVES

To investigate the possibility of an embryo to receive a dose of more than 10 cGy, the threshold of malformations induction in embryos reported by the International Commission on Radiological Protection, during barium enema examinations.

METHODS

Thermoluminescent dosimeters were placed in a phantom to calculate the depth-to-skin conversion coefficient needed for dose estimation at the average embryo depth in patients. Barium enema examinations were performed in 20 women of childbearing age with diagnostic problems demanding longer fluoroscopy times. Doses at 6 cm, the average embryo depth, were determined by measurements at the patients' skin followed by dose calculation at the site of interest.

RESULTS

The range of doses estimated at embryo depth for patients was 1.9 to 8.1 cGy. The dose always exceeded 5 cGy when fluoroscopy time was longer than 7 minutes.

CONCLUSION

The dose at the embryo depth never exceeded 10 cGy. This study indicates that fluoroscopy time should not exceed 7 minutes in childbearing-age female patients undergoing barium enema examinations.