Bladder wall interruption

From: Collins SL, Ashcroft A, Braun T, Calda P, Langhoff-Roos J, Morel O, et al. Proposal for standardized ultrasound descriptors of abnormally invasive placenta (AIP). Ultrasound Obstet Gynecol. 2016;47(3):271-5.

Bladder Wall Interruption

Bladder wall interruption is another sign generated by the neovascularity seen on the surface of the serosa. It can appear as pairs of hyperechoic lines (sometimes referred to as the ‘= sign’) running parallel to the uterine serosa and posterior bladder wall. This is generated by the ultrasound being reflected from both walls of the vessel producing an ‘= sign’ or a scalloped appearance.