Which imaging region contributes a large share of the genetically significant dose (GSD) relative to its proportion of exams?

• A. Abdomen
• B. Chest
• C. Skull
• D. Pelvis

Answer: (A)

Genetically significant dose weighs the potential genetic impact of radiation on future generations, so exposure to the gonads drives most of the GSD. The abdomen is among the most commonly performed imaging regions, and its field often includes the pelvic area where the gonads reside. Because abdomen studies are frequent and the gonads receive measurable dose during those exams, this region ends up contributing a large share of GSD relative to how often it’s imaged. Chest and skull fields spare the gonads, and although pelvic exams can deliver a higher gonadal dose per study, they are not as frequent, so their total contribution to GSD is smaller.