Answer to Question #248 Submitted to "Ask the Experts"

Q

A pregnant patient has been referred to a local hospital's radiology department to receive a diagnostic examination of an extremity (i.e., foot/ankle/hand wrist, etc.). If the primary radiation beam is restricted to only the area of interest, is it necessary to place more than one lead shield containing >=0.25 mm Pb over the patient's pelvic region when performing the examination? (Assume that the exposure technique requires no more that 10 mAs & 70 kVp.)

A

I live in North Carolina and according to our Regulations for Protection Against Radiation, "gonad shielding of not less than 0.5 mm lead equivalent shall be used for potentially procreative patients during radiographic procedures in which the gonads are in the direct, or useful beam, except for cases in which this would interfere with the diagnostic procedures." This implies that lead shielding is required only when the gonads are in the useful beam. But note that many facilities have policies that require gonadal shielding (from primary, leakage, and scatter radiation) for children and all potentially procreative patients during all radiographic exams. Consider x rays you might have at the dentist's office. Even though the the exposure is minimal and well collimated, the staff provides you with a lead apron. Also note that, in your scenario, the patient is pregnant. Having discussed radiation risks with many patients, I would recommend using the apron. (Yes, the exposure is minimal even to the area of interest--but the apron will provide "peace of mind" to the woman.) Carmine Plott, Ph.D., CHP