Policy limits fetal radiation exposure in emergency scans. (Four Scenarios Described).

ATLANTA -- A model policy intended to minimize the likelihood that pregnant women will be exposed to dangerous levels of ionizing radiation during emergency imaging studies has been developed by the radiology department of the University of Iowa Hospitals and Clinics, Iowa City.

The availability of sophisticated helical and multislice CT has led to wider application of this high-dose modality in recent years. "Some 400-450 CT scans are performed at the university each week, and although CT accounts for only 4% of all imaging studies, it accounts for 35% of total delivered radiation dose," Meghan E. Blake of the university said at the annual meeting of the Roentgen Ray Society.

Encountering pregnant or possibly pregnant patients in the emergency setting is more common than is widely appreciated, she said. A survey of patients presenting to the emergency department at Cook County Hospital in Chicago found that 30% were women of childbearing age, and 15% of these were pregnant or possibly pregnant at the time of injury. "The question is how to best handle these patients and if it is appropriate to withhold imaging studies that may alter their care," Ms. Blake said.

In the acute trauma setting, when the mother's life is in immediate danger, "essentially you must manage her as if she were not pregnant," she said. This is in the best interest of both mother and fetus, she added.

Otherwise, following the course of action advised in each of these four possible scenarios can help minimize risk:

* For examinations above the abdomen or below the hips, the patient should be assured ...