The Radiation Hazard in Radiography of the Female Abdomen and Pelvis

Abstract

The International Commission on Radiological Protection [ICRP] (1964) has recommended that all radiological examination of the lower abdomen and pelvis in women of reproductive age be limited, where possible, to the 10-day interval following the onset of menstruation. This is not incorporated in the British Code of Practice (1964). It is also recommended by the ICRP and the British Code of Practice that for designated persons the abdominal dose should not exceed 1.3 rads in any 13-week period and that the dose to the fetus should not exceed 1 rad during the known period of pregnancy. The somatic hazard to the fetus from 1 rad can lead to a risk of 1 in 5,000 of subsequently developing cancerIllusor approximately doubles the natural risk of dying from some form of cancer at an early age The genetic hazard is much less, but 1 rad will increase the natural mutation by 3%. The actual radiation exposure given to patients in a large general hospital for various radiographic investigations of the abdomen has been measured. The gonad and fetal doses were obtained by calculation of the relevant depth doses taking the most probable position of the ovaries before and during pregnancy and of the fetus at term. The results show that in early pregnancy the embryo may receive approximately 1 rad in lateral radiographs of the lumbar spine and of the lumbo-sacral junction, in renal arteriography and similar examinations requiring multiple exposures, and in all screening examinations of the pelvis and lower abdomen. Even with a repeat radiograph, none of the other projections seems likely to lead to a serious hazard It is highly unlikely that, under existing practice, these or other abdominal examinations would be carried out on pregnant women unless there were clear-cut clinical indications. Examination of the lumbar spine, examinations requiring multiple exposures of the lower abdomen, and all screening examinations of the pelvis and lower abdomen be limited to the 10-day interval following the onset of menstruation.