Imaging in hydrocephalus: Diagnosis, monitoring …...Andrea Rossi, MD Neuroradiology Unit IRCCS...

Andrea Rossi, MDNeuroradiology Unit

IRCCS Istituto Giannina Gaslini, Genoa/Italy

[email protected]

Imaging in hydrocephalus: Diagnosis, monitoring and

complications

Outline

1. Anatomy

2. CSF Flow Dynamics

3. Classification schemes

4. Clinical scenarios

5. Basic imaging signs

6. Causes of pediatric hydrocephalus

7. Monitoring

8. Imaging of treated hydrocephalus

The Ventricular System

Contains approx. 17% of total CSF (25.5: 150 mL)

Ventricular Outlets

CisternsCistern of great vein or

transverse cistern

Cisterna ambiens or

cistern of the

quadrigeminal plate

Cisterna

vermis

Cisterna magna or

cerebellomedullary

cistern

Perimedullary Cistern

Prepontine Cistern

Interpeduncolar Cistern

Chiasmatic CisternBasal

cistern

Cistern of the

lamina

terminalis

Interhemispheric

Cistern

Foramina of Monro

Cerebral aqueduct (of Sylvius)

3

4

Outline

1. Anatomy





6. Causes of adult and pediatric hydrocephalus

7. Monitoring


Mantovani G et al, 2018

THE CSF BULK FLOW THEORY© omicsonline.org

H.W. Cushing, 1869-1939

OBSTRUCTIVE

HYDROCEPHALUS

obstruction to the CSF flow inside the

ventricular system

The ventricles dilate proximal to an

intraventricular obstruction to the bulk flow

of CSF

Communicating hydrocephalus is characterized

by enlargement of the ventricles, mainly the

lateral and third ventricle, and a narrow

subarachnoid space

COMMUNICATING

HYDROCEPHALUS

obstruction to the CSF flow outside the

ventricular system

This anatomy cannot be explained by an

obstruction to the bulk flow at the arachnoid

granulations

Matsumae et al, 2016

CSFnoncirculation

model

• Fluids movements and exchanges are free among different intracranial

compartments

• Hydrostatic and osmotic forces are the main determinants

• Dynamic equilibrium among parenchyma, interstitial space, subarachnoid

space, vascular compartment, and ventricles

• Hydrocephalus is not an imbalance between CSF production and resorption, but an imbalance between interstitial fluid (decreased) and ventricular fluid (increased)

• Benign intracranial hypertension (pseudotumor cerebri) is an opposite imbalance (increased interstitial fluid and decreased ventricular fluid)

• Hydrocephalus caused by tumoral aqueduct obstruction could be due to an increased osmolarity

• Post-hemorrhagic hydrocephalus could be caused by an obstruction of interstitial fluid and/or a hyperosmolar intraventricular/subarachnoidfluid

Mantovani et al, 2018

…. The consequences ….

S D

• The algorithms used to obtain flow estimate in cine-MRI are based on the

hypothesis that there is net craniocaudal CSF flow through the aqueduct,

whose diameter is assumed to be constant during a cardiac cycle

• The evaluation of flow void is highly subjective, also depending on

acquisition parameters used Mantovani G, 2018

Outline

1. Anatomy






7. Monitoring


Agarwal et al, 2016

CONGENITAL HYDROCEPHALUSthe condition is present at birth, caused by a complex interaction of

genetic and environmental factors during fetal development.

Congenital hydrocephalus is now often diagnosed before birth

through routine ultrasound and MRI

ACQUIRED HYDROCEPHALUSdevelops after birth as a result of neurological conditions such as

head trauma, brain tumor, cyst, intraventricular hemorrhage or

infection of the central nervous system

CONGENITAL vs ACQUIRED

• Monoventricular

• (Biventricular)

• Triventricular

• Tetraventricular

POINT OF OBSTRUCTION

Outline

1. Anatomy






7. Monitoring


CLINICAL SCENARIOS

Clinical features of hydrocephalus are

influenced by the following:

• Patient's age

• Cause

• Location of obstruction

• Duration

• Rapidity of onset

NEONATES AND INFANTS

• A full or bulging fontanel

• Seizures

• Bulging eyes and persistent

downward gaze (“setting-sun” eye

phenomenon)

• Increasing head circumference!

• Prominent scalp veins

• Increased irritability

• High-pitched cry

• Poor feeding

• Sleepiness or less alert than

usual

• Developmental delays

• Projectile vomiting

• Headaches (initially in the morning)

• Vomiting (more significant in the morning)

• Blurred vision (consequence of

papilledema and later of optic atrophy)

• Double vision (unilateral or bilateral sixth

nerve palsy)

CHILDREN

• Stunted growth and sexual maturation from third ventricle

dilatation (obesity, precocious puberty or delayed onset of puberty)

• Difficulty in walking secondary to spasticity (lower limbs+++

due to stretching of periventricular pyramidal tract)

• Drowsiness

• Slowing of mental capacity

• Neck pain suggesting tonsillar herniation

Outline

1. Anatomy






7. Monitoring


Dilatation of

Temporal Horns

Dilatation of anterior

III ventricle

Overt signs: ventricular dilatation, periventricular edema,

reduced subarachnoid spaces

Optic disc protrusion, flattening posterior sclera

Disappearance of aqueductal flow-void

DDx “ex vacuo”

WM thinning

Enlarged subarachnoid spaces

Disproportionate body vs temporal horn

Outline

1. Anatomy






7. Monitoring


Case # 1

Malformative aqueductal

stenosis

8 d

T2/DRIVE

8 d 15 m

Case # 2

Low-grade tectal glioma

5 mT2

T1 T1+C

T2/DRIVE

5 mT2

T1

8 m

Malformative stenosis:

Inferior third

Neoplastic stenosis:

Superior third

Case # 3aPost-hemorrhagic hydrocephalus

T2T1 T2/DRIVE1 d

T2T1 T2/DRIVE1 d

1 y

Case # 3bPost-hemorrhagic hydrocephalus

Superficial siderosis

Case # 4a

IV ventricle outlet obstruction

14 m

* *

14 m 27 m

* *

Case # 4bIV ventricle outlet obstruction

(Post-hemorrhagic)

CT Ventriculography

Case # 4c

IV ventricle outlet obstruction

(developmental)

4 v

130 day fetus

Blake’spouch

4 v

BP

Normal 25 W

Blake’s Pouch Cyst

Mega Cisterna Magna Arachnoid Cyst

Dandy-Walker Malformation

Case # 5a

Chiari I anomaly

Chiari I

Case # 5b

Chiari II malformation

Chiari II

Case # 5a

Single ventricle dilatation →

obstruction Monro

Case # 5b

Single ventricle dilatation →

obstruction Monro

(TSC, SEGA)

3Y 2M 4Y 4M 4Y 8M 4Y 11M

(3m rapamycin th)

Case # 6a

Ventricular compression

3Y ependymoma

Case # 6b

Ventricular compression

IV ventricular obstruction

4Y pilocytic astrocytoma

Case # 7Choroid plexus papilloma

normal choroid plexus papilloma

CSF overproduction

Outline

1. Anatomy






7. Monitoring


Pros:

Reduced exposure to ionizing radiation

Cons:

• Increased costs (?)

• Suboptimal catheter visualization

• Risk of valve malfunction after repeated

exposure to high magnetic fields

• Need for reprogramming with many

types of adjustable valves

MONITORING: MRI (rapid) vs CT

Ssh/TSE

9 sec

Outline

1. Anatomy






7. Fetal hydrocephalus


Hydrocephalus: treatments

SHUNTING THIRD VENTRICULOSTOMY

Mammillary bodies

Tuber

Infundibular recess

The Liliequist membrane:

arachnoid membrane separating the chiasmatic

and interpeduncular cisterns

The tip of the basilar artery

SUBDURAL COLLECTIONS

Too rapid drainage

SLIT VENTRICLE SYNDROME

• The absence of CSF within the ventricles combined with a

growing brain leads to situation in which "the brain is too big for

the skull"

• The intracranial pressure can be very high despite small

ventricular size

• Headache, lethargy, nausea, vomiting

CHRONIC CSF OVERDRAINAGE

NOT CHIARI 1, PLEASE!

Conclusions

• The radiologist can help to identify the

causes and surgical candidates and to

follow them up after treatment

• MRI must be technically flawless and

include hi-res T2WI and CSF flow studies

• Fast MRI protocols can safely replace CT

for ventricular size monitoring

Imaging in hydrocephalus: Diagnosis, monitoring …...Andrea Rossi, MD Neuroradiology Unit IRCCS...

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Transcript of Imaging in hydrocephalus: Diagnosis, monitoring …...Andrea Rossi, MD Neuroradiology Unit IRCCS...