risk factors and types of placenta accreta.
To understand the correct placental development.
To comprehend the pathophysiology of placental accretism.
To know the signs of the different types of placental accretism in MRI.
The first thing is to understand how placentation occurs in a normal pregnancy,
to comprehend the pathological alternatives that exist.
Placentation will develop in the place where the implantation of the blastocyst takes place,
around day 8 post-fertilization.
Factors that can cause the implantation not to be in a suitable place are also risk factors for an abnormal placentation,
not only by alterations of the location (previous,
ectopic) but by alterations in the penetration (accretism).
These risk factorsare: previous surgeries (caesarean section as...
Findings and procedure details
PATHOPHYSIOLOGY OF INVASIVE PLACENTATION:
Placental accretism is thought to be due to an absence or deficiency of the Nitabuch layer,
which is a layer of fibrin that lies between the deciduous basal and the frondosum chorion.
Benirschke and Kaufmansuggest that this situation is the result of a failure in the reconstitution of the endometrium / decidua basalis,
especially after the repair of a cesarean section.
MR IMAGING PROTOCOL Fig. 3
Different protocols are used depending on the institution.
There are two essential sequences to assess...
MRI is a tool that helps us diagnose and differentiate between different types of abnormal placentation.
Due to the great morbidity and mortality that accompanies this pathology,
and to the multidisciplinary approach prior to the surgery that it requires,
the fact of being able to define the type of placentation,
the affectation and the location as well as the possible invasion of neighboring structures is going to affect directly in the survivorship and morbidity of the patient and the fetus.
As radiologists we must know,...
Guillermo García Galarraga:
- Deparment of radiology,
Hospital 12 de Octubre.
P.Pathology of the Human Placenta.
Baughman WC et all.
Placenta accreta: Spectrum of ultraound and MR imaging findings.
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Elsayes KM et all.
Imaging of the placenta: A multimodality pictorial review.
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Horowitz JM et all.
When timing is everything: Are placental MRI examinations permormed before 24 week's gestational age reliable?.
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