Fetal dosimetry from pulmonary imaging in pregnancy. Revised estimates.

Fetal dose estimates from Tc-99m MAA and Tc-99m DTPA aerosol were calculated using two methods. These calculations show that the average fetal dose decreases as gestational age (or fetal size) increases. Although the resultant dose estimates exceed those previously reported by severalfold, the risk to mother and fetus from undiagnosed pulmonary embolism far outweighs the risk to the fetus from the radiation exposure.