BRAIN. CONGENITAL. BRAIN CONGENITAL. Agenesis of the Corpus Callosum Arachnoid Cyst Craniosynostosis Dandy-Walker Syndrome Encephalocele Hydrocephalus Neurofibromatosis (NF1) Tuberous Sclerosis. AGENESIS OF THE CORPUS CALLOSUM. Description.
Coronal T2W image shows agenesis of the corpus callosum with widely spaced lateral ventricle with continuity of third ventricle with the interhemispheric fissure.
Axial CT (A) and axial T1W MR (B) show enlarged parallel lateral ventricles with a “race car” configuration and no corpus callosum.
Sagittal T1W image shows congenital absence of the corpus callosum with radially oriented gyri and the absence of the cingulategyrus.
MRI and CT
(1) middle cranial fossa;
(2) parasellar cisterns; and
(3) subarachnoid space over the convexities.
Axial NECT shows a CSF density well circumscribed extraaxial fluid collection in the left middle cranial fossa with posterior
displacement of the left temporal lobe.
Axial T2W (A) and T1W C+ (B) images follow the signal
characteristics of the CSF.
(1) scaphocephaly (sagittal) the most
(2) plagiocephaly; and
Axial NECT shows elongation of the calvarium in the antero-posterior dimension and narrowing in the transverse dimension.
Coronal NECT shows premature complete fusion of the sagittal suture.
Lateral 3D reconstructed image (A) and above view (B) image of the skull shows complete fusion of the sagittal suture and elongation of the skull in AP dimension..
Appears as a massively dilated fourth ventricle expanding into the posterior fossa demonstrating hydrocephalus. Both CT and MRI images demonstrate a massively dilated fourth ventricle, expanded posterior fossa with an inferior hypoplasticvermis.
Axial NECT shows a large posterior fossa with a CSF density cyst, hypoplasticcerebellar hemispheres, and absence of the vermis.
Sagittal T1W image shows a massively dilated fourth ventricle, expanded posterior fossa, high-riding torcula, and hypoplastic cerebellum.
Axial T2W (A) and coronal T1W (B) show absence of the cerebellarvermis.
Axial NECT shows a small amount of brain protruding posteriorly through a midline defect in the occipital bone.
Axial T1W (A) and T2W (B) images showing herniation of the brain through a defect in the posterior skull.
In the noncommunicating type of hydrocephalus, the flow of the cerebral spinal fluid (CSF) from the ventricular system into the subarachnoid space is obstructed by a mass-occupying lesion, congenital narrowing of the aqueduct of Sylvius, or associated with a meningomyelocele.
The communicating type of hydrocephalus may result from an overproduction of CSF in the choroid plexus, or inadequate reabsorption of CSF by the arachnoidvilli.
(1) an excessive amount of CSF
(2) inadequate reabsorption of CSF by the
(3) an obstruction of the outflow of the
CSF from one or more of the ventricles.
T1-weighted axial MRI shows markedly dilated lateral ventricles with low-signal CSF.
T2-weighted axial MRI shows high-signal CSF of the markedly dilated ventricles.
Axial NECT shows markedly dilated lateral ventricles.
T2W axial image shows high-signal CSF within markedly dilated lateral ventricles as a result of a shunt malfunction (fluid leaking around shunt in right parieto-occipital soft tissue).
Axial NECT shows a soft tissue density infiltrative mass of the right orbit with moderate exophthalmos.
Coronal T1W image (A) shows low-signal-intensity mass within the right orbit which is bright on T2W images (B) consistent with a plexiformneurofibroma.