The symbol Gy (pronounced: gorey) is a unit describing the energy of ionizing radiation. The average absorbed fetal dose for a single CT examination is estimated to be <0.0005 Gy, and fetal exposure to absorbed doses below 0.05 Gy does not increase fetal malformations or induce miscarriage; the risk of neonatal malformations is significantly increased only when the radiation dose exceeds 0.15 Gy. Since the exposure area of head CT is far away from the uterus, the radiation dose to the fetus is very small and the examination can be performed with confidence due to the risk benefit.