Abdominal radiography accounts for 25% of all radiography but contributes over ______% of the genetically significant dose (GSD).

• A. 30
• B. 50
• C. 70
• D. 90

Answer: (C)

Genetically significant dose reflects the potential genetic impact of radiation on future generations by weighting the dose received by the gonads, since germ cells contribute to hereditary effects. Abdominal radiography often includes the pelvic region, where the ovaries and testes reside, so the gonadal dose per exam is relatively high compared with many other radiographic studies. Although abdominal exams make up about a quarter of procedures, the high gonadal dose and the radiosensitivity of reproductive cells mean they disproportionately drive the population genetic risk. That’s why abdominal radiography contributes a large share of the GSD—over 70%. Other exams tend to expose the gonads much less, especially with shielding and distance, so their contribution to GSD is much smaller.