Magnetic resonance imaging of the placenta in rhesus monkeys, Macaca mulatta.

Magnetic resonance imaging of the uterus of rhesus monkeys was performed at different stages of pregnancy. Spin-echo sequences localized the placental discs before and after gadolinium enhancement. Fast-scan sequences provided semiquantitative appreciation of placental hemodynamics. The paramagnetic agent enhanced the placenta, crossed into the fetal circulation, and was excreted in the fetal urinary bladder. Gd DTPA was also used to contrast the external contours of the fetus.