Estimation of fetal radiation dose from computed tomography scanning in late pregnancy - Depth-dose data from routine examinations

RATIONALE AND OBJECTIVES. TO provide depth-dose data for estimating fetal r adiation dose from routine computed tomography (CT) examinations of the tru nk. METHODS. Doses were measured during CT examinations of the thorax, upper ab domen, abdomen, and pelvis in two anthropomorphic phantoms simulating pregn ant women in the second and third trimesters. Thermoluminescent dose meters were used for dose measurements. RESULTS. In CT examinations of the abdomen, doses of 30.0 to 43.6 mGy and o f 29.1 to 42.0 mGy were measured at the measuring points in the phantom sim ulating pregnancy in the second and third trimesters, respectively. In CT e xaminations of the upper abdomen, pelvis, and thorax, both phantoms receive d lower doses of radiation. Knowledge of the normalized weighted dose index of the CT scanner and of the kVp and mAs settings of the protocol used for examination of the pregnant woman is needed to adjust the dose data found in the present study to modified protocols and different CT equipment. CONCLUSIONS. These dosimetric data may be used to guide the management of p regnant patients undergoing CT examinations of the trunk.