In situ or intraplacental
choriocarcinoma has been well documented to occur in full-term placentas.
Doppler ultrasonography represents an additional diagnostic instrument to characterize blood flow in the pregnant mare and provides an insight on fetal (umbilical and carotid arteries), maternal (uterine arteries), and placental circulations (intraplacental
Findings diagnostic of placenta accreta include abnormal uterine bulging, heterogenous signal intensity, and T2 dark intraplacental
(18) The presence of hypointense, irregular intraplacental
bands on T2-weighted sequences, analogous to the vascularized lacuna seen on ultrasound, is strongly associated with abnormalities of placentation.
signal, due to hemorrhage or vascular lacunae (9);
Transabdominal 3D power Doppler was used to map the vascularization of the intraplacental
and uterine serosa-bladder interface.
choriocarcinoma is a focal neoplastic proliferation of the chorionic villous trophoblast.
 ultrasonographic diagnosis of placental implantation: (1) loss/irregularity of the echolucent area between the uterus and placenta; (2) thinning or interruption of the hyperechoic interface between the uterine serosa and bladder wall; (3) presence of turbulent placental lacunae with high-velocity flow (>15 cm/s); (4) hypervascularity of the uterine serosa-bladder wall interface; and (5) irregular intraplacental
vascularization characterized by tortuous confluent vessels across the placental width.
The paired umbilical arteries connect with each other inside the placenta and subsequently branch into chorionic arteries or intraplacental
The common MRI features suggesting placenta accreta are as follows:[sup] (1) Uterine bulging, especially into the region of the scar or bladder; (2) heterogeneous signal intensity within the placenta; and (3) dark intraplacental
bands on T2-weighted imaging.
These are: abnormal uterine bulging of the normal pear-shaped gravid uterus, heterogeneity of the signal intensity of the placenta on T2-weighted images and the presence of T2-weighted dark linear bands in intraplacental
signal intensity, extending from the basilar plate to the placental surface.
"Essential role of platelet--derived growth factor receptor Alpha in the development of the intraplacental
yolk sac sinus of Duval in mouse placenta," BiolReprod, Vol.58(1), pp.65-72, http://dx.doi.org/10.1095/biolreprod58.1.65