This document discusses fetal lateral ventriculomegaly seen on prenatal sonograms. It defines mild ventriculomegaly as lateral ventricle width of 10-15mm and overt or frank hydrocephalus as over 15mm. For mild cases, further evaluation with fetal MRI, ECG, karyotyping and corpus callosum assessment is recommended. Unilateral ventriculomegaly is usually benign while bilateral may be associated with neural tube defects or midline anomalies. Signs like dangling choroid plexus or anomalies of the posterior fossa/central canal can also be seen.

1. CONGENITAL LATERAL CEREBRAL
VENTRICULOMEGALY
FETAL SONOGRAM ASSESMENT
FREE LANCE RADIOLOGY
CONTINUATION OF
EDUCATION IN BASIC
DIAGNOSTIC RADIOLOGY

2. FETAL CEREBRAL LATERAL
VENTRICULOMEGALY AN OVERVIEW
• Ventriculomegaly : 0.3 to 0.5/
1000 births .
• Frank hydrocephalus is
synonymous to overt lateral
ventriculomegaly
• Ventricles have three dimensional
architecture &Variable degree of
enlargement is appreciated in
different trimesters
• Initially assessment was done
with
– RATIO OF
– MIDLINE to LATERAL WALL OF
Case of fetal cerebral Lateral
THE VENTRICLE
MIDLINE TO IPSILATTERAL ventriculomegaly .
CALVARIUM
Both the lateral ventricles
show significant and near
symmetrical dilatation.

3. MILD LATERAL CEREBRAL
VENTRICULOMEGALY
• Mild lateral cerebral ventriculomegaly ( 10 to 15 mm )
• Isolated ventriculomegaly ( No consequence) . It could
be earliest manifestation of brain damage .
• CNS and NON CNS anomalies may be associated with
it .
– Primary cerebral maldevelopment ( obstructive
hydrocephalus )
– Agyria
– Destructive lesions
– Periventricular leukomalacia
– Hypoxia

4. MILD LATERAL CEREBRAL
VENTRICULOMEGALY
• NRA : NEAR CALVARIUM REVERBATION
ARTEFACT LIMITS THE SONIC WINDOW
HENCE
– Transverse diameter of the
ventricular atrium is taken at level
of glomus of choroid .
– Measurement is taken in the axial
plane along the atrium distal to
transducer . Inside echoes are
measured
• Values are
– Mid trimester ( 6 to 7mm +_ 1mm) .
– 14 to 40 wks ( 7mm +_ 1mm) .
• Some degree of asymmetry in either side
ventricles is noted .
• Male fetus have larger measurements than
the female ones.

5. MILD LATERAL CEREBRAL
VENTRICULOMEGALY
• Mild lateral cerebral ventriculomegaly
( 10 to 15mm inclusive).
• If unilateral - benign.
• Consider
– Fetal MRI
– Fetal ECG .
– Fetal corpus callosum assessment
– Fetal karyotyping.
– First trimester screening.
• To note :
– X linked variety of hydrocephalus develops in
lateral gestation.
• Caesarean section may have to be opted due to
associated macrocrania.
• Cephalocentesis /Ventriculoamniotic shunting
are also options

6. OVERT LATERAL CEREBRAL
VENTRICULOMEGALY
• Overt cerebral lateral ventriculomegaly
or hydrocephalus .
– Atrial width >15mm
– ( 2 to third trimester) .
– Associations
• Neural tube defects .
• Mid line anomalies .
• Either aqueductal stenosis / communicating
hydrocephalus .
• Dangling choroid sign ( choroid away
from transducer touches the ventricular
wall and one near to the choroid abuts
the interventricular septum ) .

7. CONSIDER
FETAL MRI
FETAL ECG
KARYOTYPING
ASSESS FETAL
CORPUS CALLOSUM
UNILATERAL FETAL
VENTRICULOMEGALY
USUALLY BENIGN

8. MEASURES THE
AXIAL IMAGE OF THE
VENTRICLE AWAY
FROM THE
TRANSDUCER AT THE
LEVEL OF GLOMUS OF
CHOROID.
AVOID
MEASUREMENT OF
THE VENTRICLE
NEAR TO THE
TRANSDUCER DUE TO
NRA : NEAR
CALVARIUM
REVERBATION
ARTEFACT
UNILATERAL FETAL CEREBRAL
VENTRICULOMEGALY.

9. ASSESEMENT OF
CORPUS CALLOSUM
SHOULD BE DONE
3D / 4D IMAGING IS
OF HELP .
NORMAL CORPUS CALLOSUM IN
CASE OF UNILATERAL
VENTRICULOMEGALY ( USUALLY
BENIGN)

10. DANGLING CHOROID
SIGN
CHOROID PLEXUS OF
THE VENTRICLE
AWAY FROM THE
TRANSDUCER ABUTS
THE LATERAL
VENTRICULAR WALL
AND OTHER CHOROID
PLEXUS ABUTS THE
SEPTUM.
DANGLING CHOROID SIGN IN
CASE OF BILATERAL FETAL
VENTRICULOMEGALY

11. SMALL POSTERIOR
FOSSA
DILATED CENTRAL
CANAL
POSSIBLE ARNOLD
CHIARI
MALFORMATION IN
CASE OF
VENTRICULOMEGALY.
FETAL MR CAN BE OF
HELP.
CNS ANOMALIES ASSOCIATED
WITH VENTRICULOMEGALY