Non-invasive mapping of placental perfusion

Background. We aim to develop a clinical technique for the non-invasive measurement of placental perfusion, to enable early detection of intrauterine growth restriction (IUGR). Pregnancies with this complication are characterised by low placental perfusion. Methods. We measured placental perfusion by means of perfusion-sensitive echoplanar imaging (EPI); a rapid method of making magnetic resonance images. Perfusion measurements were done on six healthy volunteers with normal pregnancies and nine with pregnancies complicated by IUGR. Perfusion maps were created to assess the relation between placental perfusion and fetal size at birth. Findings. Pregnancies complicated by IUGR differed significantly from normal pregnancies in patterns of perfusion within the placenta (p < 0.0001, ANOVA). Subsequent analysis showed that the proportion of placentas with low perfusion rates was higher in the IUGR group than in the normal group. A significant correlation between areas of reduced placental perfusion and fetal size was demonstrated (p = 0.041, Spearman's rank correlation). Interpretation. Non-invasive imaging of placental perfusion by means of EPI has potential as a clinical tool in assessing the dynamics of placental perfusion.