Neuro -- Ventricles

Front 1

1. What is the DDX of absence of the septum pellucidum?
2. What is the spectrum of holoprosencephaly?
3. What are the imaging findings in septo-optic dysplasia?

Back 1

1. Holoprosencephaly, Septo-optic dysplasia
2. Alobar, Semilobar, and Lobar holoprosencephaly.
3. Absence of the septum pellucidum + Hypoplasia of optic chiasm.

Front 2

1. What tumors occur in the 4th ventricle of a child?
2. What are the cells of origin of ependymoma?
3. What are the imaging findings of a 4th ventricle ependymoma?
4. Are calcifications common in ependymoma?
5. What are the most common brain tumors in a child?

Back 2

1. Ependymoma and medulloblastoma. Uncommon = malignant teratoid rhabdoid tumor.
2. Ependymal cells lining the ventricles.
3. Slow growing, lobulated tumor that fills the ventricle and can extend out the exiting foramina (“plastic” lesion).
4. 50% of ependymoma calcify.
5. 1st = JPA, 2nd = medulloblastoma, 3rd = ependymoma

Front 3

1. What are the findings in agenesis of the corpus callosum?
2. What is it associated with?

Back 3

1. High-riding 3rd ventricle, C-shaped frontal horns on coronal view, colpocephaly (dilated occipital horns), parallel orientation of lateral ventricles, median bundles of Probst do not cross hemispheres, absence of the cingulate gyrus with medial sulci reaching the level of the third ventricular roof.
2. Associated w/ Chiari II malformation, Cephaloceles,
Dandy-Walker malformation, CNS lipoma

Front 4

1. What are the imaging findings in Vein of Galen malformation?
2. What are the two types of malformations?

Back 4

1.
- Prominent dilatation of Vein of Galen, straight sinus, confluence of sinuses, transverse sinuses, and sigmoid sinus.
- Turbulent flow within the malformed vessels produces a mixed signal intensity.
- Look for phase encoding artifact indicating vascular nature of the lesion.
2.
- Type 1: Due to single or multiple arteries flowing directly into the vein of Galen, resulting in a shunt that leads to high-flow CHF.
- Type 2: Due to a parenchymal AVM in the thalamus or midbrain.

Front 5

1. What is DDX of subependymal nodule?
2. How do you differentiate between the subependymal nodules of TS from gray matter heterotopia?

Back 5

1.
- Gray matter heterotopia
- Subependymal nodules of Tuberous sclerosis
- TORCH infection, particularly CMV results on periventicular calcifications.
- Metastatic disease: primary brain neoplasms that have CSF dissemination can present with subependymal nodules (GBM, pineal region tumors, Ependymoma, medulloblastoma, primary CNS lymphoma, choroid plexus tumors. Extra cranial mets like breast cancer can also have Subependymal nodules.
2. Subependymal nodules of Tuberous sclerosis are lower in SI than gray matter.

Front 6

What is DDX of intraventricular mass?

Back 6

- Adult pt with a mass within the ATRIUM of the lateral ventricles: Meningioma or Metastasis
- Adult pt with a mass within the BODY of the lateral ventricles: Astrocytoma, oligodendroglioma, central neurocytoma, subependymoma
- Choroid plexus cyst: follows CSF SI, nonenhancing.
- Choroid plexus papilloma: usually in the 4th ventricle in adults
- Xanthogranuloma of choroid plexus: contains fat.

Front 7

1. What cells give rise to central neurocytoma?
2. What are the imaging features of central neurocytoma?

Back 7

1. Central neurocytoma is a tumor of neuronal origin (as opposed to glial).
2.
- Primarily solid intraventricular mass with cysts.
- Can have a feathery appearance due to multiple cysts and thin intervening septa.
- Abuts or is attached to the septum pellucidum
- May infiltrate into adjacent brain parenchyma precluding total resection.
- Associated hydrocephalus
- Isodense to brain with fine to coarse calcifications
- Moderate enhancement

Front 8

What are the imaging features of subependymoma?

Back 8

- Classically described as an ASYMPTOMATIC 4th VENTRICLE tumor that is incidentally found in an adult.
- 2/3 of subependymoma are found in the 4th ventricle; 1/3 arise in the lateral ventricle.
- In the lateral ventricle = usually noncalcified, minimal or no enhancement; small cysts may be seen w/n the mass.
- In the 4th ventricle: frequently calcified; moderate heterogeneous enhancement.
- Note: unlike ependymoma, subependymomas tend not seed the subarachnoid space.

Front 9

1. What is the imaging appearance of choroid plexus papilloma?
2. How can you differentiate between choroid plexus papilloma from choroid plexus carcinoma?
3. Which has CSF spread?
4. What other tumors can mimic choroid plexus carcinoma?

Back 9

1.
- Cauliflower intraventricular mass in the lateral ventricle of a child and in the 4th ventricle in an adult. Choroid plexus tumors are much more common in boys.
- Associated hydrocephalus may be multifactorial from overproduction of CSF, obstruction of CSF pathways by mass effect, and obstruction of arachnoid granulations secondary to proteinaceous or hemorrhagic CSF.
2. Choroid plexus papilloma and carcinoma cannot be distinguished on the basis of imaging findings. Carcinomas may be heterogeneous and invasive and incite surrounding parenchymal edema.
3. Both papilloma and carcinoma can have CSF spread.
4.
- PNET: invades brain parenchyma and may be indistinguishable from choroid plexus CA.
- Malignant Rhabdoid tumor