MRI depiction of fetal brain abnormalities

Abstract

Intracranial abnormalities are commonly suspected findings on antenatal ultrasound that require evaluation by magnetic resonance imaging. This review depicts multiple abnormalities imaged as a means to guide clinicians in proper diagnosis.

Keywords: Congenital brain malformations; fetal magnetic resonance imaging; midline abnormalities.

Fig. 1.

MRI findings of agenesis of the corpus callosum in a 30-week, 0-day fetus. (a) Sagittal HASTE image demonstrates absence of the corpus callosum (black arrow) and radial pattern of the parasagittal gyri. (b) Coronal HASTE image shows the “longhorn” configuration of the lateral ventricles (white arrows).

Fig. 2.

MRI findings of aqueductal stenosis in a 38-week, 1-day fetus. (a) Sagittal HASTE image displays lack of a normal cerebral aqueduct and normal size of the fourth ventricle in the posterior fossa (black arrow). (b) Axial HASTE image demonstrates marked ventriculomegaly (white arrows).

Fig. 3.

MRI findings of Chiari 2 malformation in a 26-week, 5-day fetus. (a) Sagittal HASTE image reveals an open neural tube defect (black arrow) and downward translation of the cerebellar tonsils (white arrow). (b) Axial HASTE image shows enlarged ventricular atria (asterisks).

Fig. 4.

MRI findings of Dandy-Walker continuum in a 21-week, 5-day fetus. (a) Sagittal HASTE image exhibits a small vermis (white arrow) with expansion of the posterior fossa. (b) Axial HASTE image reveals communication between the fourth ventricle and prominent posterior fossa cerebrospinal fluid (black arrow).

Fig. 5.

MRI findings of encephalocele in a 35-week, 1-day fetus. (a) Sagittal HASTE image demonstrates meninges and brain tissue (white arrow) protruding through a posterior calvarial defect. (b) Axial HASTE image exhibits extension of the supratentorial brain through the occipital calvarial defect (black arrows).

Fig. 6.

MRI findings of holoprosencephaly in a 34-week, 2-day fetus. (a) Axial HASTE image reveals fusion of the frontal lobes across the midline (white arrow). (b) Coronal HASTE image also depicts fusion of the frontal lobes across the midline (white arrow).

Fig. 7.

MRI findings of hydranencephaly in a 31-week, 5-day fetus. (a) Coronal HASTE image reveals intact thalami (white arrow). (b) Axial HASTE image shows near complete absence of the cerebral hemispheres (black arrow).

Fig. 8.

MRI findings of schizencephaly in a 37-week, 0-day fetus. (a) Axial HASTE image demonstrates prominent cerebrospinal fluid within a cleft in the right cerebral hemisphere which communicates with the right lateral ventricle (white arrow). (b) Coronal HASTE image reveals that the parenchymal cleft is lined by gray matter (black arrow).