Abstract: Placenta accreta is a critical disease in obstetrics. Prenatal diagnosis depends on imaging examination and has a positive effect on treatment and prognosis of diseases. MRI can be an important supplement for B-ultrasound examination in the diagnosis of placenta accreta in middle and late pregnancy. MRI diagnosis of placenta accreta is recommended at 24-30 W gestation. The common imaging changes include the thinning of myometrium or the interruption of T 2 low signal band at the interface between uterus and placenta, heterogeneity of placental signal intensity and T2 abnormal dark interplacental bands, placental hemorrhage, abnormal uterine bulging, placental bulging, placenta recess, shortening of the uterine cervix. The role of disorganised vasculature of placenta can not be ignored. The diagnosis of the depth of placenta accreta, the accretion area and the atypical site (non-caesarean scar) are the difficult point and direction of the study.

Key words: placenta previa, magnetic resonance imaging, review, placenta accreta