Determination of Effective Dose and Fetus Dose Conversion Factors for CT Scans in Pregnant Patients: A Simulation Study Using the NCICT Program.

Computed tomography (CT) imaging is an essential tool for diagnostic purposes but exposes patients, including those who are pregnant, to ionizing radiation, potentially impacting fetal health. Accurate dose estimation is necessary to manage these risks effectively. This study aimed to determine conversion factors for effective dose and uterus dose for CT imaging in pregnant patients, adjusted for gestational stages and various scan regions. The National Cancer Institute dosimetry system for computed tomography (NCICT) simulated photon interactions in hybrid phantoms representing pregnant patients at different gestational stages. A CT scanner model was used across eight gestational stages and for seven different scan regions. Dose length product, effective dose, and uterus dose values were recorded, and conversion factors were calculated for estimating effective dose and fetus dose. The study generated gestational age-specific conversion factors, which varied based on CT scan region. The results reveal a reduction in radiation dose with advancing gestational age, particularly in abdomen and pelvis scans, emphasizing the importance of gestation-specific dose adjustments. The study offers valuable conversion factors for improved radiation dose management in pregnant patients, reducing unnecessary exposure risks, and improving diagnostic practices in CT imaging.