Ultrasound and Doppler images of placenta accreta spectrum

Placenta previa with placenta accreta spectrum (A). Transvaginal image of the lower uterine segment in a patient with placenta previa shows a thin myometrium (arrows) in the region of prior cesarean delivery scar. This is either due to thinning in the region of prior cesarean scar or due to placenta accreta spectrum. In patients with findings of a thinned myometrium we recommend measuring the extent of the thin myometrium in sagittal and transverse planes. (B) and (C) Transvaginal grey scale and color Doppler images of the lower uterine segment in a patient with placenta previa and prior cesarean birth show enlarged vascular spaces within the placenta and a focal mass invading the myometrium (dashed arrow) compatible with placenta accreta spectrum. Note the hypervascularity at the serosa-bladder interface.

Placenta previa without placenta accreta spectrum (D). For comparison, color Doppler of the lower uterine segment in a patient with placenta previa and no placenta accreta spectrum. Note the vascular structures between the placenta and the bladder wall. The flow appears normal, without turbulence, and there is no crossing of vessels into the placental tissue. Also, note there are no placental sonolucencies and no evidence of a "bulge" into the bladder wall.