Fig. 4.

Microstructure: (A) Resolving mouse placental structures using a hybrid strategy, combining DW MRI, contrast-enhanced under SPEN acquisition. Upper panel: Estimated placental compartmental fraction. Lower panel: Corresponding ADC values in each compartment. According to this analysis, maternal, fetal, and trophoblastic contributions constitute 66%, 24%, and 10% of overall placental volume, respectively. ADC values reveal a freely diffusive maternal blood pool, a strongly perfused fetal blood flow, and intermediate behavior for the trophoblastic labyrinth cell layer [32]. (B) Human placental perfusion fraction maps in normal and IUGR pregnancies, measured using IVIM. Perfusion fraction maps overlaid on MRI images for normal pregnancy (upper panel), indicating two zones of blood movement, and for pregnancy complicated by IUGR (lower panel), in which the placenta appears far more homogenous, with its outer zone containing a significantly reduced proportion of mobile blood. Reprinted from Ref. [37], with permission from Elsevier.