Chiari II malformation

Case contributed by Naim Qaqish
Diagnosis certain


Known to have spinal defect to evaluate for other congenital abnormalities.

Patient Data

Age: Day 1
Gender: Female



Widely separated bodies of the lateral ventricles appear parallel to each other, with dilated trigons, occipital horns (colpocephaly), and temporal horns of the lateral ventricles. Dilated high riding third ventricle consistent with dysgenesis of the corpus callosum. (On the sagittal views only part of the splenium is present)

Cavum septum pellucidum and vergae are seen.

Chiari II malformation features are depicted by a small posterior fossa with low attachment of the tentorium. Caudally displaced slit-like fourth ventricle and brain stem, as well tonsillar herniation through an enlarged foramen magnum.

The tectum is beaked and hydrocephalus is present. 

Cervico-medullary kink is also noted.

Batwing configuration of the frontal horns pointing inferiorly on coronal view secondary to enlarged caudate nucleus bilaterally.

No shift of midline structures or signs of space-occupying mass lesions could be seen.

Whole spine


There is a syringohydromyelia in the cervical and upper dorsal spinal cord with expansion of the cervical spinal cord seen.

There is a large defect seen in the posterior bony elements of the lumbar spine from L1–L5 with the meninges and CSF protruding through the defect (myelomeningocele).

There is evidence of diastematomyelia and tethering of the spinal cord.

Case Discussion

This case illustrates typical appearances of Chiari II malformation. Supratentorial abnormalities are common which is not limited to corpus callosum dysgenesis and absent septum pellucidum. Spinal anomalies are extremely common including lumbar meningomyelocele and syringohydromyelia.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.