New advances in fetal cardiovascular magnetic resonance imaging for quantifying the distribution of blood flow and oxygen transport: Potential applications in fetal cardiovascular disease diagnosis and therapy.

Until recently, our modern understanding of fetal circulatory physiology has been largely based on invasive measurements made in fetal sheep. However, new MRI technology developed by our group has provided equivalent information about the distribution of blood flow and oxygen transport noninvasively. The initial findings largely confirm prior estimates about the human fetal circulation extrapolated from fetal sheep data and human ultrasound data. Here we describe the hemodynamics of the normal late gestation human fetal circulation by MRI and speculate about what the advent of this technology might mean in terms of the management of fetuses affected by placental insufficiency and congenital heart disease.