Post on 15-Apr-2017
Imaging of Congenital Imaging of Congenital Brain MalformationsBrain Malformations
Moment of embryology
Neurulation Neurulation
Ventral induction
Man
tlM
antl
ee
ProliferationProliferation
MigrationMigration
OrganizationOrganization
Myelination PNS CNS
Normal myelinationAt birth 1 year6 month 2 years
CephalocelesCephalocelesHerniation of intracranial contents through a
congenital defect in the dura and skull- Usually located at the midline.
Occipital Meningoencephalocele
Parietal Meningoencephalocele
Atretic occipital cephalocele
Chiari malformation type I
Basilar invagination
Posterior fossa decompression
Chiari malformation type III
Prosencephalon
Mesencephalon
Rhomboencephalon
Classification of holoprosencephaly
Classification of holoprosencephaly
Septo-optic Dysplasia
DWM DWV Persistent Blake’s pouch
Mega cisterna magna
Anterior membranous area anomaly Posterior membranous area anomaly
Retro-cerebellar cyst
Vermis Hypo-plasticRotated upwards
Hypo-plastic No or mild hypoplasia
No or mild hypoplasia
4th ventricle Markedly dilated Dilated Dilated Normal
Posterior fossa Expanded Normal size Normal size Normal size
hydrocephalus 75 % of cases 25% of cases Present No
Dandy-Walker Malformation Dandy-Walker Malformation
Dandy-Walker Variant
Mega Cistern Magna
Posterior Fossa Arachnoid Cyst
Corpus callosum genesis
Corpus callosum develpment
Corpus Callosum genesis• Genu body splenium rostrum
Corpus Callosum Agenesis
Corpus Callosum Agenesis Absent cingulate gyrus
High riding 3rd ventricle
Parallel lateral ventricles
Colpocephaly
frontal horns small & pointed
Radiating medial surface gyri
Partial corpus Callosum Agenesis
Corpus Callosum Agenesis Interhemispheric cyst
Corpus Callosum Agenesis Pericallosal lipoma
Focal cortical dysplasia
Focal cortical dysplasia
Focal cortical dyspalsia
Tuberous sclerosis
• Cortical tubers.• White matte lesions.• Subependymal nodules.• SGCA.
Ganglioglioma
DNET
Type 1 lissencephaly(agyria / pachygyria complex)
Type 2 (cobblestone) lissencephaly
Heterotopia
Heterotopias
• Normal neurons at abnormal sites• Result from arrested neuronal migration from
periventricular germinal zone to the cortex.• Heterotopias are isointense to normal gray
matter in all pulse sequences and do not enhance on administration of IV contrast.
Hetertopia
• Isointense to grey matter on all pulse sequences
No enhancement. No associated mass effect.
Band hetertopia
Sucortical curvilinear nodular hetertopia
Subcortical focal nodular heterotopia
Subependymal diffuse nodular heterotopia
subependymal focal nodular hetertopia
Polymicrogyria
Polymicrogyria
Schizencephaly
• CSF cleft , lined by grey matter, between the ependymal surface of the ventricle to the pial surface of the cerebral hemisphere.
Vascular theory of Schizencephaly
Myelination disorders
Dys-myelination Vs hypo-myelination
Dys-myelination
Hypo-myelination
Delayed myelination Vs hypomyelination
• Repeat MRI after 6 months.• Delayed myelination myelination progression.• Hypomyelination no myelination progression.• DD in these 2 conditions is quite different.
Delayed myelination
• Delayed myelination is a non specific finding associated with global developmental delay.
Causes:• Chromosomal abnormalities (e.g. trisomy 21).• Metabolic disorders (e.g. phenylketonuria).• Acquired causes (e.g. HIE).
Special features
DD of leukodystrophies