Fig. 4

Schematic drawing of the retained placenta (cross-sectional image). The retained placenta may consist of intervillous space and decidua basalis. Endometrial arteries and veins, which are branches of uterine arteries and veins, are connected to each other through the intervillous space. Angiographic findings including dilated vascular channel and contrast blush may correspond to remnant intervillous space. Endometrial arteries and veins connecting to the intervillous space may represent low-flow AVM-like findings