Clínica de Diagnóstico por Imagem – CDPI, Rio de Janeiro - Brazil.

Definition

Acrania is characterized by absence of the cranial vault and protrusion of brain tissue into the amniotic cavity. The brain tissue appears disorganized and heterogeneous. The diagnosis can be made by endovaginal ultrasound in the first trimester.

Here are some of the images of early ultrasound detection of exencephaly obtained at 13 weeks of gestation.

Images 1 and 2: Transvaginal ultrasonography. Early diagnosis of acrania (13 weeks) coronal (image 1) and axial (image 2) scans of the fetal head showing missing cranial vault.

Images 3 and 4: 13 weeks of pregnancy. Image 3 shows coronal, axial and sagittal view of the fetal head with absence of the cranial vault. Image 4 shows 3D image of heterogeneous and disorganized brain tissue over the acranial skull.

Images 5 and 6: 13 weeks of pregnancy. 3D images showing heterogeneous and disorganized brain tissue over the acranial fetal skull.