Cohen SL, Wang JJ, Chan N, et al. - In this retrospective study of pregnant women who had a CTPA as the first primary advanced imaging test for assessment of PE in a multihospital integrated healthcare network from January 2012-April 2017, researchers ascertained the mean effective radiation dose and predictors of mean efficient radiation dose for CTPA in pregnant patients across a multihospital integrated healthcare network. The mean effective radiation dose in the 534 CTPA exams was 3.96 mSv. Bivariate analysis exhibited important variations in radiation dose by trimester, ie, 4.52 mSv, 3.73 mSv, and 3.95 mSv in first, second, and third trimester, respectively. Multivariable analysis exhibited CTPA during first trimester, increasing mAs, kVp, scan length, patient size, and use of mAs modulation and declining pitch, to be predictive of higher efficient radiation dose. Hence, mean efficient radiation dose was on the lower end of published studies. Trimester was a statistically important prognosticator of efficient radiation dose while being responsible for known predictors of radiation dose.