This document provides information about performing a fetal neurosonogram. It begins with basic embryology of the developing central nervous system. It then discusses the key features to evaluate in a neurosonogram, including biometric measurements and assessment of brain structures. Different imaging planes and techniques like 3D and tomographic ultrasound are described. Common central nervous system anomalies that can be detected on ultrasound are listed and briefly described. The document emphasizes the importance of understanding fetal brain development and utilizing multiple imaging planes and advanced techniques to thoroughly evaluate the fetal central nervous system.

1. {‫ون‬ُ‫ط‬ُ‫ب‬ ‫ن‬ِّ‫م‬ ُ‫ُك‬َ‫ج‬َ‫ر‬ْ‫خ‬َ‫أ‬ ُ‫هللا‬َ‫و‬َ‫ت‬ َ‫ال‬ ْ ُ‫ُك‬‫َات‬‫ه‬َّ‫م‬ُ‫أ‬‫ا‬ً‫ئ‬ْ‫ي‬ َ‫ش‬ َ‫ون‬ُ‫م‬َ‫ل‬ْ‫ع‬
‫ا‬َ‫و‬ َ‫ع‬ْ‫م‬ َّ‫س‬ْ‫ل‬‫ا‬ ُ ُ‫ُك‬َ‫ل‬ َ‫ل‬َ‫ع‬َ‫ج‬َ‫و‬َ‫د‬‫ئ‬ْ‫ف‬َ‫أل‬‫ا‬َ‫و‬ َ‫ار‬ َ‫ص‬ْ‫ب‬َ‫أل‬ْ ُ‫ُك‬َّ‫ل‬َ‫ع‬َ‫ل‬ َ‫ة‬
َ‫ون‬ُ‫ر‬ُ‫ك‬ ْ‫ش‬َ‫ت‬}
(‫النحل‬ ‫سورة‬/78)

2.  Special thanks from the heart to
PROF. DR. MOHAMED ABDEL-ALEEM NAFADY
Professor of radiodiagnosis
faculty of medicine, Al-Azhar university , Assuit
For his never end support during the conduction of this work
It is a great honor to work under his supervision.
PROF. DR. ABDEL-AZEZ GALAL ALDEN ALDARWESH
Professor of gynecology and obstetrics
faculty of medicine, Al-Azhar university , Assuit
For his never end support during the conduction of this work
It is a great honor to work under his supervision.
DR.SAAD REZK ABDEL WAHED
Assistant professor and head of radiodiagnosis department
faculty of medicine, Al-Azhar university , Assuit
For his guidance, support and perseverance.

3. Also , I would like to express my deepest thanks to
PROF. DR/ MUSTAFA THABET HUSSIN
Professor of radiodiagnosis
Faculty of medicine , Assuit university
And
PROF. DR/ MOHAMAD ABDEL SAMIE MOHAMAD
Professor of gynecology and obstetrics
Faculty of medicine , Al azhar university , Assuit.
For honoring us today to come , and for their effort in reviewing this study.

4. To my mother, my wife, my son
and my friends
.

5. By
Dr. Tarek Mohamed M.
Mansour

6. The brain is the only fetal organ that continuously
develops & changes during fetal life
The largest changes occur within the 1st 20 wks,
when most scans are done
CNS anomalies are among the most common fetal
anomalies (second after cardiac anomalies).
To do fetal ultrasound neuroscan one has to:
1. know some basic embryology
2. Know the developmental milestones
3. Have a high frequency transducer and understand
how 3D works
4. Understand the most frequent CNS anomalies

8. Graphic shows the formation, closure of the neural tube. The neural
plate (red) forms, folds, and fuses in the midline. The neural and
cutaneous ectoderm then separate. Notochord (green), neural crest
(blue) are shown.
 A. Consists of 3 layers of cells:
endoderm, mesoderm, and
ectoderm.
 B. Thickening of the ectoderm
leads to the development of the
neural plate
 C. The neural groove begins to
develop at 20 days.
 D. At 22 days the neural groove
closes along the length of the
embryo forming the neural tube.

9. The neural tube closes in a bidirectional
zipper-like manner, starting in the
middle and proceeding
toward both ends.
Development of primary vesicles is depicted.
The prosencephalon (green) gives rise to the
forebrain, the mesencephalon (purple) to
the midbrain, and the rhombencephalon
(light blue) to the hindbrain.

10. Embryonic brain at 22 weeks is mostly agyric
with shallow sylvian fissures .
Prosencephalon (green), metencephalon
(yellow), and myelencephalon (light blue)
are shown. Mesencephalic, midbrain
structures are not visible.
With advancing gestational age, multiple
secondary and tertiary gyri develop, and the
number and complexity of the cerebellar
folia increase.

11. Three orthogonal images and thick slice of three-dimensional reconstructed image
(lower right) of normal brain at the end of 8 weeks of gestation. The development of
premature ventricular system is seen.

12. Donald School Textbook of Ultrasound in
Obstetrics and Gynecology (third edition
2011).

13.  Three-dimensional (3D) sonography should be
accepted as a natural development of ultrasound
imaging technology.
 Fast computer processing is essential for 3D and 4D
sonography.
 The first 3D-capable systems were developed in the
mid-1990s.
 3D acquisition was performed by moving the
transducer over the region of interest (ROI) with the
operator’s hand at a constant speed.

14.  On reaching the ROI, the operator must keep the
transducer stable while the patient stays still, so that
the probe may continue scan.
 Images are then captured and processed by a computer
that will display them three-dimensionally.
 In the multiplanar volume mode three planes are
shown – longitudinal or sagittal (A-plane), transverse
(B-plane), and coronal (C-plane) – and an orthogonal
reconstruction is obtained, which may be rotated
around three axes (x, y, z)

23. 1- Maternal factors:
 Abdominal wall
thickness.
 Colitis.
 Mother breathing.
 Obesity.
3- Amniotic fluid
(oligohydramnios).
2- Fetal factors:
 Position (face down).
 Age of fetus.
 Movement of the fetus.
 Multiple fetuses.
4- Operator skills and
experience.
5- Machine capabilities.

25. The most useful features of 3D scanning of the fetal
CNS:
– Orthogonal planes
–Tomographic imaging
–Angiography
– Inversion mode.
–Thick slice/volume contrast imaging

26. 3D multiplanar image
analysis (normal brain at
18 weeks of gestation).
The use of three
orthogonal views is
helpful in obtaining the
orientation of the brain
structure. Coronal (A),
sagittal (B), and axial (C)
images can be visualized
on a single screen. Any
rotation of the brain
image around any (x,y,z)
axis is possible

27. Tomographic ultrasound imaging (TUI) of the fetal brain. Normal brain in coronal
section at 31 weeks of gestation. Intracranial structures, including gyral formation,
are clearly demonstrated and also compare both cerebral hemisphere

33. Normal brain at 9 weeks of gestation. Tomographic ultrasound imaging of sagittal (A),
coronal (B), and axial (C) sections. The premature ventricular system is demonstrated.
In the coronal and axial sections, the already-divided bilateral hemispheres can be
visualized

34. Normal brain at 12 weeks and 5 days of gestation. Tomographic ultrasound imaging of
sagittal (A), coronal (B), and axial (C) sections. The rate of occupation of the cerebral
hemispheres becomes larger compared with previous images. The bilateral echogenic
structure is the choroid plexus filled the lateral ventricles

35. Normal brain at 17 weeks of gestation. Tomographic ultrasound imaging of sagittal
(A), coronal (B), and axial (C) sections. The choroid plexus (echogenic part) shifts to
the posterior half of the lateral ventricles

36. Normal brain at 31 weeks of gestation. Tomographic ultrasound imaging of sagittal (A),
coronal (B), and axial (C) sections. Formation of sulci and gyri is clearly observed from
around 30 weeks of gestation. The Sylvian fissure (arrows) is formed as the lateral
sulcus

38. Sonography of the CNS
Basic examination
Axial plane Sagittal plane
Neuroscan or extended
examination

39. a: Transventricular
b: Transthalamic
C: Transcerebellar

43. A: The Mid sagittal
Plan b: Para sagittal plane

46. Biometry:
 Biparietal diameter.
 Head circumference.
 Occipito-frontal
diameter.
 Atrium of lateral
ventricle at the level of
choroid plexus.
 Transcerebellar diameter.
 Depth of cisterna magna
The brain structures:
 Head shape.
 Lateral ventricles.
 Cavum septi pellucidum.
 Thalami.
 Cerebellum.
 Cisterna magna.
 Spine.

47. The brain structures:
 Anterior horns
 Posterior horns
 3rd and 4th ventricle
 Intraventricular
foramina
 Cavum septi pellucidi
 Corpus callosum
 Pericallosal artery
 Caudate nuclei
 Thalami
 Cerebellum & vermis
 Cisterna magna
 Interhemispheric fissure
 Fissures
 Sphenoidal bone
 Ocular orbits

48.  Better demonstration of the midline structures esp.
corpus callosum and cerebellar vermis.
 Visualization of both hemispheres.
 Better identification of cerebral sulci.
 Detailed examination of fetal spine.

50.  Anencephaly.
 Hydrocephalus.
 Cephalocele.
 Iniencephaly.
 Arnold-Chiarii II malformation.
 Dandy walker malformation.
 Corpus callosum agenesis.
 Holoprosencephaly.
 Hydrancephaly.
 Porencephaly.
 Arachnoid cyst.
 Choroid plexus cyst.
 Lissencephaly.
 Vein of Galen aneurysm.

51.  1/1000, M:F = 4:1
 Anencephaly/exencephaly sequences.
 Absent cranial vault.
 Begins as exencephaly (exposed neural tissue) that
gets eroded by amniotic fluid and fetal movement.
 1st trimester: exposed brain tissue gives Mickey Mouse
appearance.
 2nd & 3rd trimester: neural tissue has resolved (frog like
appearance).

52. The three orthogonal planes and a rendered
three-dimensional image of the fetus seen in
The coronal image (C) demonstrates lack of
calvarial bon
A typical-appearing fetus with exencephaly-
anencephaly sequence is shown using the
tomographic feature. there is less visible
brain tissue.

53.  Excess CSF production or obstructed flow.
 Measures the posterior horn of lateral ventricle > 10
mm in 2nd trimester.
 Choroid plexus to medial border of lateral ventricle
wall > 3 mm.
 Maximum cortical thickness < 1o mm. denoting poor
prognosis.
 Aqua ductal stenosis lead to third ventricle dilatation.
 Time of delivery: when doppler shows increase MCA
PI which mean increase intracranial tension.

55. Hydrocephalus (left) and ventriculomegaly (right). Tomographic ultrasound imaging of
X-linked hydrocephalus at 21 weeks and ventriculomegaly at 25 weeks .

57.  Herniation of
1. Meninges = meningocele.
2. Meninges + brain tissue = cephalocele.
 75% occipital defect.
 40% neonatal death.
 Survivors 80% neurological impairment.

59.  Extensive ONTD triad of:
1. Occipital encephalocele.
2. Fixed hyperextension of the fetal head.
3. Cervical dysraphism.
 US findings:
1. Short CRL due to absent cervical spine.
2. Head fixed in hyperextension.
3. Cephalocele.
 3/10,000 F:M 9:1
 Lethal condition.

61.  Spina bifida, ONTD, spinal dysraphism.
 US findings:
1. Obliterated cisterna magna.
2. Banana sign (cerebellum raped around brain stem
90%).
3. Lemon sign (depressed frontal bone 98%).
4. Ventriculomegaly.
5. Lumbo-sacral myelo-meningocele.
 High morbidity.

64.  Dysgenesis of the cerebellar vermis.
 Dilated 4th ventricle connected with cisterna magna.
 Mortality
1. 50% when isolated.
2. 80% when associated with other anomaly.
 Karyotyping: 30% chromosomal.
 1:30 000
 Low intelligence is 80% of isolated cases.

70.  1: 20, 000
 US findings:
1. Absent cavum septum pellucidum in axial planes.
2. Lateralization of lateral ventricles.
3. Tear drop shape.
4. Mild ventriculomegaly.
 Mid sagittal plane is diagnostic.
 85% isolated.

71. Ventriculomegaly in a case of complete agenesis of the corpus callosum (frontal
horns scalloped outward)

72.  Sever brain and facial malformations.
 Incomplete cleavage of prosencephalon at 4-6 W.
 1:16,000.
 Three forms:
1. Alobar: single ventricle & fused thalami.
2. Semi lobar: Partially separated hemispheres & partially
fused thalami.
3. Lobar: separated hemispheres& thalami with absent CSP.
 Prognosis:
1. Alobar: incompatible with life.
2. Semi lobar and lobar: mental retardation

73. Alobar holoprosencephaly at 15 weeks of gestation. (A–C) Three orthogonal images of
intracranial structure showing a complete single ventricle within a single-sphered
cerebral structure

75.  Complete destruction of cerebral hemispheres with normal
cerebellum and brain stem.
 May be due to vascular occlusion or toxoplasmosis.
 Lethal.
 US findings:
1. No cerebral tissue (No MCA flow).
2. Falx cerebri may be seen.
3. Normal posterior fossa.
4. Brain stem protrude to fluid filled calvaria.

76. Hydranencephaly. The absence of brain high
in the convexities distinguishes
hydranencephaly from severe hydrocephaly.
The midbrain and posterior fossa (arrows)
are normal

77.  Arachnoid cyst is encysted CSF displaced normal brain
tissue of good prognosis if isolated.

79. Thank you

80. Thank you