2. • Detailed exam which is usually
done around 18 weeks.. bcoz
• Most of the organogenesis is
complete.-so that it is easy to
visualize every organ clearly.
• Termination is possible medico
legally.
• Its done routinely along with
standard scan in practice
3. Target scan-DEFINITION
Specialized Examination done when,
1. anomaly is suspected on the basis of history,
2. biochemical abnormalities or clinical evaluation,
3. or suspicious results from standard, limited exam
by an operator with experience and expertise
4. Whom: Done in Women at Risk
• Risk Factors:
• Advanced Maternal Age > 35 at
Delivery
• History Chromosomal Translocation
/previous Anomaly baby
• Chromosomal Analysis (abnormal
results)
• Amniocentesis
• Chorionic Villi Sampling
Biochemical
parameters(abnormal levels)
• 1. Alpha Fetoprotein
• 2. Triple /quadruple Marker test
• When Sonographic
markers of fetal
aneuploidy was
detected.
• They are……
6. Single umblical artery(SUA)
• Ass Trisomy13,18,triploidy
• Identification of SUA should
initiate search for addl
malformations
• Odds ratio -10.4-isolated
SUA, - 16.4-ass anomalies
vein
Artery
7. Nasal bone imaging
• The image should be magnified so that the head and the
upper thorax only are included in the screen.
• A mid-sagittal view of the fetal profile should be obtained
with the ultrasound transducer held in parallel to the direction
of the nose.
• In the image of the nose there should be two distinct lines.
The top line represents the skin and the bottom one, which is
thicker and more echogenic than the overlying skin, represents
the nasal bone..
• The nasal bone is absent in 60–70% of trisomy 21 fetuses,
in about 50% of trisomy 18 fetuses and 30% of trisomy 13
fetuses
8. Nasal bone
• Absent nasal bone
• No NB ossification at 11-
14 wks
• Absent NB also may be
noted in 2nd trimester
• Normal nasal bone length
measures 3.5 mm (95 percentile)
• Nasal bone length less than 0.75
MOM is considered as nasal
bone hypoplasia
9.
10. Nuchal translucency
Nuchal translucency is the sonographic appearance of
subcutaneous accumulation of fluid behind the fetal neck
in the first trimester of pregnancy.
The term translucency is used, irrespective of whether it
is septated or not and whether it is confined to the neck or
envelopes the whole fetus.
The incidence of chromosomal and other abnormalities
is related to the size, rather than the appearance of NT.
During the second trimester, the translucency usually
resolves and, in a few cases, it evolves into either nuchal
edema or cystic hygromas with or without generalized
hydrops.
11. NUCHAL LUCENCY/
THICKENING
• • 1st trimester: measure inner to
inner margin (midsagittal neck)
>3 mm is abnormal
• • Associated with Chromosomal
abnormalities (21, 18,
13),20%Cardiac anomalies,
Skeletal dysplasia
• • Second trimester: measure
outer to outer margin
(suboccipital-bregmatic plane at
the level of the cavum septum
pellucidum, cerebellum, and
cisterna magna)>6mm is
abnormal
• Aneuploidy risk increased 2x
normal maternal age risk
12. Hyperechoic bowel
• Nonspecific /Ass with
trisomy 21(6-7 fold)
• Ass.with bowel
atresia,cong infection,
meconium ileus,
increased risk of
IUGR,fetal demise
,placenta related
complication
• Likelihood ratio is 6.7
13. Echogenic intracardiac focus(EIF)
• Common finding in II
trimester-3-4 % normal
fetus
• Resolves by III trimester. Ass
with trisomy 13 & 21)
• Higher among Asians
• Path-papillary muscle
/intramyocardial
calcification surrounded by
fibrosis
• 96% in LV, multiple ,bilateral
and right sided –inc .risk.
• False EIF were moderator
band ,endocardial cushion
and tricuspid annulus.
14. Choroid plexus cysts
• Relatively common variant during
II trimester .
• As a single findings it has no
effect on fetal development or
ass .with adverse outcome.
• CPC resolve by 20-23 wks
• Normal fetus -3%,
• Ass with trisomy 18
• Size of cyst ->10 mm ,
delayed resolution,
bilaterality of cysts –
Isolated CPC,normal triple screen
no need for karyotype
or altered OB management
16. Abnormal Amniotic fluid volume
• Polyhydramnios-primary
manifestation during III
trimester
• Increases with severity,
mostly ass with Cong
structural anomalies(GIT)
• Oligohydraminos may
associated with renal
agenesis
17. IUGR
• Early onset /Midtrimester IUGR
common manifestation - trisomy
13 & 18.
• Symmetric IUGR is more
dangerous but triploidy is ass with
asymmetrical IUGR
18. Other potential intraabdominal
markers
• Intrahepatic calcification-rare-normal outcome as an
isolated finding.
• It may be ass. with aneuploidy, hence karyotyping is
recommended when additional structural anomalies
(+).Otherwise outcome is good .
• Hepatosplenomegaly and oligoamnios-sole signs in
downs with myeloproliferative disorder
27. What to see? IN SKULL
• 1.VAULT
• PRESENT OR ABSENT
• MINERALISATION
• 2.SHAPE
• NORMAL
• MICRO OR MACROCEPHALY
• BRACHY OR DOLICHOCEPHALY
• FRONTAL BOSSING OR SLANTING
• 3.OUTPOUCHING
CEPHALOCELE
28. • 4.MIDLINE STRUCTURES(T-THALAMIC)-----CSP
• HOLOPROSENCEPHALY,
• CORPUS COLLASUM AGENESIS
• 5.VENTRICLES(T-VENTRICULAR)
• HYDROCEPHALUS
• CYSTIC LESION COMMUNICATING OR NON COMMUNICATING
WITH THE VENTRICLE
PORENCEPHALLY ARACHNOID CYST
SCHIZENCEPHALY
• 6.POSTERIOR FOSSA(CEREBELLAR PLANE)
• CISTERNA MAGNA
• CEREBLLAR VERMIS
33. •Microcephaly
•A head circumference
below 3 standard
deviations from the mean
of the gestational age is
considered a reliable
indicator of microcephaly.
IF gestational age is not
known .HC is compared
with FL.
43. HOLOPROSENCEPHALY
Failure of midline cleavage of the forebrain:
• Alobar form: no cleavage
• Semilobm' form: partial cleavage
• Lobar form: almost complete cleavage
US Features
Alobar holoprosencephaly
• Monoventricle communicates with dorsal cyst
• Thin anterior mantle of brain tissue:
"horseshoe" or "boomerang"
• Fused thalami
• No falx, corpus callosum, or septum pe llucidum
• No brain tissue around dorsal cyst
PAN CAKE
CUP
BALL
44. • Semilobar
holoprosencephaly
• • Monoventricle with
rudimentary occipital
horns
• • Posterior brain tissue is
present (no dorsal cyst).
• • Fused thalami
• • Partial falx posteriorly
• • No corpus callosum or
septum pellucidum
45. • Lobar holoprosencephaly
• • Very difficult to make specific diagnosis
• AZYGOUUS “WANDERING ” ACA
• All types have:
• • Absent septum pellucidum
and corpus callosum
• • Thalamus fusion
Pearls
• • Identification of septum pellucidum excludes all types of holoprosencephaly.
• • Fused thalami excludes severe hydrocephalus.
• • Anterior cerebral mantle (horseshoe) excludes hydranencephaly.
• • Look for midline facial abnormalities (clefts, hypotelorism, cyclopia, proboscis
(FACE PREDICTS THE BRAIN)
47. AGENESIS OF CORPUS CALLOSUM
(ACC)
• The normal development of the corpus callosum begins anterior
(genu) and progresses to posterior (splenium). Agenesis may be
partial (affects dysgenesis posterior aspects) or complete.
• US Features
• The corpus callosum is not visible in complete agenesis.
• • Colpocephaly
• • Lateral ventricles are displaced laterally (parallel lateral ventricles).
• • Enlarged 3rd ventricle expands superiorly (high riding third
ventricle).
• • Angulated frontal horns (coronal view)( U or VIKING HORN
CONFIGURATION)
• • Abnormal (sunburst) gyral pattern in interhemispheric fissure is a
late feature.
• • The presence of a cavum septum pellucidum excludes complete
Agenesis
48. • Common associations include:
• Dandy-Walker (DW) syndrome
• Holoprosencephaly
• Heterotopias
• • TVS scaning is often helpful for early diagnosis.
• • Associated with pericallosa llipoma (hyperechoic)
54. HYDROCEPHALUS
• Grouped into Categories:
• 1. Obstructive Hydrocephalus
• CSF flow is obstructed
• 2. Cerebral Atrophy
• Ex vacuo
• 3. Maldevelopment
• Agenesis of Corpus
Collosum,DW cyst,Chiairi II
• Less often with choroid
plexus papilloma
• Most Common Causes:
• 1. Chiari II Malformations
• 2. Aqueductal Stenosis
55. Ventriculomegaly
US Findings:
>10 mm diameter
> 3 mm choroid seperation
from medial wall
“dangling choroid”
Choroid plexus Hangs
independently from
ventricle
57. Destructive Cerebral Lesions• Porencephaly
• Cystic cavities that communicate with
ventricular system
• Infection or hemorrhage
• Shizencephaly(closed or open lip)
• Clefts in fetal brain connecting
• Lateral ventricles
• SA space
• Hydranencephaly
• Cerebral cortex destroyed
• Internal carotid a or mca a occlusion
• No cortical mantle
• Falx incomplete (If present at all)
• Brainstem normal
58. Entities that do Not Communicate with
4th Ventricle
• Arachnoid Cysts
• Enlarged Cisterna Magna
68. WHAT TO SEE? IN SPINE
• 1. CRANIVERTERBERAL JUNCTION ABNORMALITIES
• 2. ALIGMENT
• KYPHOSIS/SCOLIOSIS
• 3. THREE OSSEOUS ELEMENTS
• SKIN CONTUNITY
• ABSENT OR FLARING OF POSTERIOR ELEMENTS
• 4.SACRUM
• CAUDAL REGRESSION SYNDROME
• 5. NUMBER
69.
70.
71.
72. Spina Bifida
• Spectrum Abnormalities
• Failure of NT to close
• Range:
• Spina Bfida Occulta
• Non-fusion of vertebral arches
• Skin Intact
• Myelomeningocele(OPEN OR
CLOSED)
• Protruding Sac
• CSF, SC and nerve roots
• Myeloschisis
• Totally Open Defect
• Due to failure of neural tube
closure
73. Spina Bifida
• Most Common: Lumbosacral
• Can occur anywhere in spine
• US Findings:
• Outward Splaying of Laminae
• Soft Tissue Defect
• overlies bony defect
• Protruding Sac (+/- neural tissue)
• +/- Chiari II Malformation
• +/- Ventriculomegaly (75%)
• Banana Sign
• Cerebellar hemispheres squashed
into shape banana
• Cisterna Magna is small or gone
• Lemon Sign
• Bossing of frontal bones
• Lemon shaped head on axial scan
74.
75.
76. INIENCEPHALY
• Extensive open neural tube defect (ONTD) characterized
Defect in occipital bone and inion, Occipital
encephalocele
• Spinal dysgraphism, Fixed hyperextension of head leaind
to star gazer head
77. CAUDAL REGRESSION
SEQUENCE
• Varying degrees of distal neural tube disruption due
to failure of normal mesodermal development
• Spectrum includes agenesis of distal neural tube
(non formation of sacrum to thoracic spine)
80. WHAT TO SEE? IN FACE and
NECK
• 1.ORBIT
• 2.NASAL BONE
• 3.MAXILLA AND PRE MAXILLARY TRAINGLE
• 4.MANDIBLE
NECK
• 1.CYSTIC HYGROMA
• 2.OTHER SOLID OR CYSTIC MASSES
81.
82.
83. ORBIT
• Microphthalmia/anophthalmia: complete absence or severe
hypoplasia on one or both orbits
• Hypertelorism/hypotelorism: increased/reduced interocular
distance, with orbits of normal or abnormal
• Macrophthalmia: increased orbital diameter, usually Bilateral
• Cataract: partial/complete opacity of one or both lenses
• Aphakia: congenital absence of the lens
86. NOSE
• Proboscis: Fetal profile view: single midline mainly soft tissue
formation departing from the nasal root area.
• Arhinia: Fetal profile view: complete absence of the nasal
bones and soft tissues:
• Single nostril: oblique view of the lips: evidence of a single
opening.
87.
88. -I- NB associated with
aneuploidy
• Trisomy 21 (T21) most
common
• Trisomy 18 (TI8)
• Trisomy 13 (TI3)
• Turner syndrome
89.
90.
91. PALATE
Median Cleft: midline defect, associated with the
holoprosencephaly sequence
• Unilateral Cleft Lip/Palate: unilateral defect of the lip, alveolar
ridge, and hard palate
• Bilateral Cleft Lip/Palate: bilateral defect of the lip, the
alveolar ridge, and hard palate, commonly associated with
additional tissue on the philtrum
92. Cleft Palate and Cleft Lip
• 13% of all congenital anomalies
in US
• 50% Lateral clefting
• Lip and Palate
• 25% Lip alone
• 25% Palate alone
• 25% Bilateral
• 60% have additional anomalies
• Polydactyly
• Congenital Heart Dz
• Trisomy 21
95. MACROGLOSSIA
• Enlarged tongue
• Tongue exceeds 95th
percentile for gestational
age
• IIMAGING FINDINGS
• General Features
• • Persistent protrusion of
tongue through lips
• o Best seen on sagittal or
coronal images
• • Trisomy 21 fetuses also
exhibit "tongue thrusting"
• o Repetitive "in and out"
motion of tongue tip
96. EAR ABNORMALITIES
• Anotia-- Absent ear
• Microtia--Small ear
• Cephalo-caudad ear length < 1/3 of BPD
< 10th percentile for gestational age
• Malpositioned ears
• Low-set ears: Top of helix lower than inner canthi line
• Malrotated ears
• Often also dysplastic, may be large or small
