To understand the different types of morbidly adherent placenta
To illustrate the MR imaging findings of normal and abnormal placentation
To demonstrate the emerging role of MRI in the diagnosis of these placental abnormalities
Morbidly adherent placenta is a serious condition which can be life threatening and a potential cause of maternal morbidity and mortality with increasing incidence over the past years (1).
The two most important risk factors are previous caesarian scar and placenta previa (2).
The spectrum is thought to occur when there is a defect at the maternal portion of the placenta; the decidua,
allowing abnormal adherence of the placenta directly onto the myometrium; placenta accreta,
extension into the myometrium; placenta increta,
or invasion beyond the...
Findings and procedure details
MRI Appearance of Normal Placenta
The placenta appears pear shaped with uniform outer contour and maximum thickness of 2 – 4 cm,
attached to anterior or posterior uterine wall and display different appearances during gestation (1,
It shows homogenous intermediate T2 signal,
particularly if imaged between 19 – 23 weeks of gestation (1).
In more advanced pregnancy,
placenta becomes more lobulated with internal T2 hypointense septa running into myometrium.
These septa are uniformly thin and evenly spaced (2).
The myometrium becomes thinner as the...
Abnormal placentation can lead to life threatening bleeding.
Though US remains the primary tool of placental evaluation; MRI,
owing to its lack of ionizing radiation,
large field of view,
high spatial resolution and soft tissue contrast,
plays a crucial role in diagnosis of morbidly adherent placenta and management of high risk patients.
Placental evaluation with magnetic resonance.
Radiol Clin North Am (2013); 51:955-66.
Placenta accreta: spectrum of US and MR imaging findings.
Radiographics (2008); 28:1905-16.
MRI of placenta accreta: a new imaging perspective.
AJR Am J Roentgenol (2011); 197:1514-21.
Placental Imaging: Normal Appearance with Review of Pathologic Findings.
Radiographics (2017); 37:979-998.