ABSTRACT
Introduction In the previous chapter, some of the magnetic resonance imaging (MRI) techniques available for examining maternal, placental, and fetal cardiovascular physiology and perinatal brain development were described. Outlined were some initial observations about normal human fetal circulatory physiology made using MRI. In this chapter, we report the preliminary findings of researchers studying abnormalities of the fetal cardiovascular system using MRI, in particular, the distribution of blood flow and oxygen saturations across the circulation in fetuses with congenital heart disease (CHD) and intrauterine growth restriction (IUGR). As noted in Chapter 15, this approach is currently limited to a small number of centers performing research in this field. The techniques we describe currently require several hours of postprocessing time to generate the data for a single case. Furthermore, due to limitations imposed by the inherent trade-off between achieving adequate signal-to-noise ratio and spatial resolution when acquiring the images quickly enough to overcome fetal motion artifacts, our approach is currently only feasible in late gestation. However, using this approach, we have been able to examine some of the concepts that have been considered by previous investigators regarding the impact of cardiac malformations and placental dysfunction on fetal circulatory physiology. In particular, we have focused on the relationship between these cardiovascular changes and delays in fetal brain development.
