Placenta accreta - dark intraplacental T2 bands
Placenta Accreta was confirmed at surgery and hysterectomy was done.
Placenta accreta is a life-threatening condition with increasing incidence in the previous years due to the increase in cesarean section deliveries. The pathogenesis is mostly related to deficient decidua at the cesarean section site.
The two most important predisposing factors are previous cesarean section and placenta previa.
Placenta accreta is a general term describing abnormal placentation and includes three subtypes;
- placenta accreta vera: adherent to the myometrium.
- placenta increta: invasion of the myometrium.
- placenta percreta: perforation of the myometrium and invading the perimetrium
Radiological manifestations of placenta previa include:
Main diagnostic signs:
- dark T2 intraplacental bands: are areas of fibrin deposition within the placenta; they appear as thick T2-WI nodular or linear areas of low signal intensity extending within the placenta from the placenta-myometrium interface with random distribution.
- heterogeneity of the placenta.
- abnormal placental vascularity with disorganization.
Less reliable signs:
- focal interruptions or indistinctness of the myometrial wall: it might be subtle with placenta accreta vera, yet with high specificity for placenta increta and percreta)
- focal uterine bulging.
- tenting of urinary bladder or invasion of the adjacent pelvic structures (highly specific for percreta rather than increta or accreta)