Figure 1.

Transvaginal and magnetic resonance imaging during pregnancy. (a) Transvaginal ultrasonogram at 8 weeks’ gestation revealing a gestational sac located in the lower uterine segment; (b) Transvaginal ultrasonogram at 13 weeks’ gestation revealing decreased space (arrow) between the placenta and bladder; (c) Transabdominal ultrasonogram at 33 weeks’ gestation. The arrow indicates the loss of the normal hypoechoic retroplacental zone; (d) T2 magnetic resonance image at 25 weeks’ gestation. The arrow indicates the loss of the thin, dark subplacental myometrium zone.