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A Medley of Fetal Brain Anomalies

Ana Monteagudo, MD

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Anencephaly-Exencephaly Sequence

Abnormally shaped headAbsent calvariumCRL may be lagging dates

Echogenic amniotic fluidBest seen with increased gain

Anencephaly-Exencephaly Sequence 10 3/7 weeks

Anencephaly-Exencephaly Sequence11 2/7 weeks

Iniencephaly

19 weeksIniencephaly is an NTD.Retroflexion of the headSpinal abnormalities

Head

Spine

Retroflexion with ONTD

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Posterior Encephalocele

Cranial defectBrain protruding through defect

Posterior Encephalocele14 4/7 weeks

Parietal Encephalocele- Atretic ?

Occipital bone

Parietal boneLambdoid suture

Cephalocele

Sagittal suture

Occipital Encephalocele

Feeding Vessel

Cranial Defect

H.O. EncephaloceleAnterior cephalocele 13 weeks

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Anterior Cephalocele 13 weeks

32 wks

Anterior Encephalocele 25 wks

Anterior Encephalocele

Posterior EncephaloceleMECKEL SYNDROME, TYPE 1; MKS1

TransvaginalTransabdominal

Posterior Encephalocele 34 3/7 weeks

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34 3/7 weeks

Ventriculomegaly, Dilated 3rd & DWM

Dilated 3rd ventricle Absent vermisVentriculomegaly

Lissencephaly

Absence of Gyri & Sulci (Lissencephaly) and Ventriculomegaly

VentriculomegalyDysgenetic Corpus Callosun Pericallosal Artery

Smooth brain surface Absence of Gyri & Sulci 34 3/7 weeks

Cataract

Micrognathia

Cataract and Micrognathia

Walker-Warburg Syndrome

HARD syndrome: hydrocephalus, agyria, and retinal dysplasiaProminent 3rd ventricle

Agenesis of the Corpus Callosum- Indirect Signs

Non-visualization CSP Tear-shaped ventricles

Wide Inter-hemispheric fissure

Upwardly displaced3rd ventricle

Agenesis of the Corpus callosumParallel slit-like, crescent shape lateral ventricle

Falx Absent corpus callosum

Absent pericallosal artery

Non-Visualization of CSP•No fluid filled CSP

•Normal corpus callosum & pericallosal a.

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… this finding should elicit detailed imaging and evaluation of the CC, other cerebral structures and the remaining fetal anatomy. When isolated, such a finding may be considered a variation of normal development.

Dysgenesis Corpus callosum

•Biometry too small, thick

•Obliteration of the CSP

Suspected Septopreoptic variant HPE

Dysgenesis Corpus Callosum Mild & rare subtype of lobar HPEFindings: abnormal fornix, absent or hypoplasic anterior corpus callosum, and unpaired anterior cerebral artery

Mild & rare subtype of lobar HPEFindings: abnormal fornix, absent or hypoplasic anterior corpus callosum, and unpaired anterior cerebral artery Suspected Septopreoptic variant HPE

Dysgenesis Corpus CallosumMild & rare subtype of lobar HPEFindings: abnormal fornix, absent or hypoplasic anterior corpus callosum, and unpaired anterior cerebral artery

Mild & rare subtype of lobar HPEFindings: abnormal fornix, absent or hypoplasic anterior corpus callosum, and unpaired anterior cerebral artery

Agenesis Septi Pellucidi

visualization of the normal CSP

Fused anterior horns; communicating with the 3rd ventricle

Isolated Agenesis Septi Pellucidi vs. SOD: Tough Diagnosis

Downward pointing anterior hornsFused anterior horns; communicating with the 3rd ventricle

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Lobar HPE vs. Isolated ASP vs. SOD: Tough diagnosis

Septo-Optic-Dysplasia Lobar HPEAgenesis of septi pellucidi

Fused fornixFused anterior horns; communicating with the 3rd ventricle

Downward pointing anterior horns

Amniotic Band Syndrome 12 3/7 weeks

Abnormally shaped headAmniotic membrane: loose, free floating and sticking to the fetus

Amniotic Band Syndrome 12 3/7 weeks

Abnormally shaped head & faceAmniotic membrane: loose, free floating and sticking to the fetus

Posterior EncephaloceleSecondary to Amniotic Band Syndrome 20 5/7 weeks

Posterior encephaloceleHead tethered to the placenta by thick amniotic band.

17 3/7 weeks

Posterior EncephaloceleSecondary to Amniotic Band Syndrome

Abnormally shaped head Posterior encephaloceleHead tethered to the placenta by thick amniotic band.

Amniotic Band Syndrome 17 3/7 weeks

Abnormally shaped headLarge facial cleft Head tethered to the placenta by thick amniotic band.Rt arm with constriction bandLeft hand missing fingers

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Chiari II Malformation22 2/7 weeks

‘Banana’ shaped cerebellumObliteration of the cisterna magnaCranium with the ‘lemon sign’

Ventriculomegaly with dangling choroid plexusPointing ventricleNon-visualization of CSP – absent vs. secondary disruption due to the ventriculomegaly

Myelomeningocele

Bulge in the lumbosacral area

Neural Tube Defect

Splaying Apart of the spinal processes

Normal MASFP

Normal cerebellum and cisterna magna

Normal MASFP

Closed Neural Tube DefectSpinal dysraphism

Hemivertebrae(s)

VACTERL

Vertebral anomalies

Anal atresia

Cardiac anomalies

TE fistula

Renal anomalies

Limb anomalies

19 6/7 weeks

Mild: (10-12 mm)Moderate: (13-15 mm)Severe: (>15 mm)

Serial tomographic axial sections- TVS

Bilateral ventriculomegalyDangling choroid plexus

Ventriculomegaly

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Ventriculomegaly 19 6/7 weeks

Serial tomographic coronal sections- TVS

Ventriculomegaly19 6/7 weeks

Serial tomographic sagittal sections- TVS

Median section- TVS Color Doppler, Pericallosal artery & corpus callosum

Ventriculomegaly- Follow-up30 5/7 weeks

Massive hydrocephalus

Ventriculomegaly-Two different patients similar findings

16 3/7 weeks

Ventriculomegaly-Secondary to Intracranial Hemorrhage (Fetal Stroke)

35 weeks

MacrocephalyBilateral ventriculomegalyDilated 3rd ventricle

Ependymal lining of the ventricles is echogenicEchogenic material within the ventricles Dilated 3rd ventricle

Case #1Ventriculomegaly-Secondary to Intracranial Hemorrhage (Fetal Stroke)

35 weeks

Ependymal lining of the ventricles is echogenicChoroid plexus appears large and heterogeneous

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Ventriculomegaly- TVSSecondary to Intracranial Hemorrhage (Fetal Stroke)

35 weeks

Ependymal lining of the ventricles is echogenicChoroid plexus appears large and heterogeneous

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Ventriculomegaly-Secondary to Intracranial Hemorrhage (Fetal Stroke)

Ependymal lining of the ventricles is echogenicParenchymal involvement- moth-eaten appearance

Intracranial Hemorrhage

Choroid plexus Ependymal lining of the ventricles is echogenicAnterior to the choroid plexus there is a large and heterogeneous mass

Agenesis Septi PellucidiSchizencephaly

Anterior coronal sectionNo CSPLarge defect extending to the cranium

30 weeks

Agenesis Septi PellucidiBilateral Open-Lip Schizencephaly

Right Cerebellar Hypoplasia 19 1/7 weeks

Asymmetry of the cerebellar hemispheres

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Right Cerebellar Hypoplasia 19 1/7 weeks

Vermis rotated

Inferior vermian hypoplasia

Right Cerebellar Hypoplasia PHACESRight Cerebellar Hypoplasia PHACES

Asymmetry of the cerebellar hemispheresIrregular or asymmetric cisterna magna

P = Posterior fossa

H = Hemangioma

A = Arterial

C = Cardiac

E = Eyes

S= Sternal

Picture from Internet

Dandy-Walker Malformation20 weeks

Partial or complete vermian agenesisCerebellar hemispheres are splayed apartCisterna magna is enlargedMedian plane the vermis is small, elevated and rotated

Blake’s Pouch Cyst 21 weeks

Expansion of the 4th ventricle into the cisterna magna resulting in a unilocular, avascular cyst ‘Key-hole’ sign in the transverse cerebellar view.

Vermis: normal size with mild to moderate upward rotation.Cisterna magna: normal.

Cavum Veli Interpositi (CVI)20 5/7 weeks

Is an anatomic variation where there is dilatation of the normal cistern of the velum interpositum.If measuring > 11mm is defined as a cavum veli interpositi cyst may be associated with ventriculomegaly

Is an anatomic variation where there is dilatation of the normal cistern of the velum interpositum.If measuring > 11mm is defined as a cavum veli interpositi cyst may be associated with ventriculomegaly

Color Doppler no flow

Arachnoid Cyst16 4/7 weeks

Unilocular, avascular midline cysts that do not communicate with the ventricles

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Thrombosis in the Torcular(Dural Sinus Thrombosis)

Avascular, supratentorial, hyperechogenic mass in the posterior fossa above the cerebellum, surrounded by a triangular sonolucent area (the dilated venous sinus).

Thrombosis in the Torcular(Dural Sinus Thrombosis)

20 wksSize: 3.92 x 1.94 cm

Corpus callosum Cavum septi pellucidi

Clot

Thrombosis in the Torcular(Dural Sinus Thrombosis)

No blood flow

Power Doppler EvaluationPower Doppler Evaluation

Thrombosis at the Torcular

3D reconstruction of the median plane

Corpus Callosum

CSP

Vermis

Thrombosis in the Torcular(Dural Sinus Thrombosis)

Vein of Galen Malformation33 weeks

Supratentorial mid-line translucent elongated cyst with active arteriovenous flow within the cyst demonstrated by color Doppler.

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Straight sinus

V. Galen Malformation

Vein of Galen Malformation

Comet sign or Key-hole appearanceIn 90% of cases there is high-output heart failure with secondary hydrops.

Vein of Galen Malformation

V. Galen Malformation

Corpus callosum

V. Galen Malformation

EGA 21 weeksStraight

sinus

Cytomegalovirus infection

Intraventricular synechia

Cytomegalovirus infection

MicrocephalyVentriculomegalyIntracranial calcifications