X-ray examinations of the abdomen account for 25% of all radiography yet contribute over what percentage of the gonad dose (GSD)?

• A. 50%
• B. 60%
• C. 70%
• D. 80%

Answer: (C)

Gonad dose depends on how much of the reproductive organs are exposed to the x-ray beam and to scatter. When imaging the abdomen, the gonads lie very close to or inside the exposure field, including the pelvic organs. Even with careful collimation and shielding, a large portion of the gonads ends up in or near the primary beam, and the exposure factors needed for abdominal imaging produce more scatter that reaches the gonads. Because of this proximity and the resulting scatter, abdominal exams contribute a disproportionately large share of the gonad dose, often cited as over 70%, even though they account for about a quarter of all radiographic exams. In contrast, chest or extremity exams tend to expose the gonads far less, since those regions are outside the field or easier to shield.