ABSTRACT
Of the many types of patients subject to medical imaging with ionizing radiation, the one that perhaps receives the most attention and concern are pregnant females whereby an absorbed dose is delivered to the developing embryo or fetus. In this chapter, we discuss the various types of imaging procedures that might be performed on the pregnant female, as well as their justifications if the pregnancy is known in advance. At younger gestational ages, the fetal exposure might occur accidentally without prior knowledge of the pregnancy. We next review the main types of radiobiological effects that might result from fetal exposures, including both tissue reactions and stochastic cancer risks. Dose thresholds for these effects are then compared to maximally expected fetal doses, as determined by various computational methods. We conclude with a review of methods of dose optimization and reduction by imaging modality.
