Target scan for fetal anomalies

Fetal anomalies scan

1. TARGET SCAN K MOHAMED RAFI 29/09/2011 HEAD ,SPINE AND FACE

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, anomaly is suspected on the basis of history, biochemical abnormalities or clinical evaluation, 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……

5. Markers (SMFA) SINGLE UMBLICAL ARTERY Nasal bone Nuchal thickening Hyperechoic bowel Echogenic intracardiac focus Umblical cord cysts Choroid Plexus cyst Abnormal AFI IUGR Renal pyelectasis (>4 mm) Widened iliac angle(>90 degree) Placental abnormalities Mild ventricular dilatation Shortened limbs Other potential intraabdominal markers

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. 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 .

10. 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

11. 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

12. 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.

13. 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

14. Umblical cord cysts/pseudocysts Rare. High association. Ass with trisomy 18,13 and inversion

15. 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

16. IUGR Early onset /Midtrimester IUGR common manifestation - trisomy 13 & 18. Symmetric IUGR is more dangerous but triploidy is ass with asymmetrical IUGR

17. 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

18. HEAD

19. Development of brain

20. 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

21. 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

22. 1.VAULT ACRANIA EXENCEPHALY ANENCEPHALY

23. Anencephaly Most Common Neural Tube Defect Cerebrovasculosa Replaces Hemispheres Fatal condition US Findings: 1. Absence of Cranial Vault 2. ABSENT Cerebral Hemisphere above orbital level

24. 2.SHAPE Microcephaly(< 3 SD) Macrocephaly (>2 SD) D o licocephaly (OBLONG SHAPE) B r achycephaly (ROUND SKUL) Turricephaly (MULTIPLE SUTURES) Lemon shaped skull(SPINA BIFIDA) Strawberry shaped skull(EDWARD SYNDROME) Clover leaf shaped skull(THANATROPHIC DYSPLASIA) FRONTAL BOSSING OR SLANTING

25. •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.

26. 3.OUTPOUCHING Cephalocele Meningoceles: Encephaloceles:

27. Cephalocele Protrusion thru Bony Calvarium Defect Brain CSF filled Sac Types: 1. Meningoceles: only MENINGES AND CSF 2. Encephaloceles: WITH Brain Locations: Occipital (75 %) Frontoethmoidal (13 %) Parietal (12 %)

28. MECKEL GRUBER SYNDROME

29. 4.MIDLINE STRUCTURES HOLOPROSECCEPHALY, CORPUS COLLASUM AGENESIS

30. 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

31. 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

32. 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)

33. Holoprosencephaly

34. 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

35. Common associations include: Dandy-Walker (DW) syndrome Holoprosencephaly Heterotopias • TVS scaning is often helpful for early diagnosis. • Associated with pericallosa llipoma (hyperechoic)

36. 5.VENTRICLES HYDROCEPHALUS

37. HYDROCEPHALUS Grouped into Categories: 1. Obstructive Hydrocephalus CSF flow is obstructed 2. Cerebral Atrophy Ex vacuo 3. Maldevelopment Agenesis of Corpus Collosum,DW cyst,Chiair i II Less often with choroid plexus papilloma Most Common Causes: 1 . Chiari II Malformations 2. Aqueductal Stenosis

38. Ventriculomegaly US Findings: >10 mm diameter > 3 mm choroid seperation from medial wall “dangling choroid” Choroid plexus Hangs independently from ventricle

39. Ventriculomegaly

40. Destructive Cerebral Lesions Porencephal y 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

41. Entities that do Not Communicate with 4 th Ventricle Arachnoid Cysts Enlarged Cisterna Magna

42. 6.POTERIOR FOSSA(CEREBELLAR PLANE)

43. Dandy-Walker Roof of 4 t Ventricle IS Undeveloped Cisterna Magna abnormal Enlarged Comms 4 th ventricle No roof Post Fossa cyst Tentorium elevated Cerebellum hypoplastic Hydrocephalus

44. Chiari II Malformations See in 95% of Myelomenigoceles Abnormalities Include: 1. Caudal displacement of CEREBULLUM Pons Medulla 2. 4 th Ventricle Elongated 3. Posterior Fossa small 4. Beaking of Tectum 4. Cisterna Magna Obliterated

45. Vascular Vein of Galen Aneurysm

46. Vein of Galen Aneurysm Intracranial AV Malformation Central to posterior in location May mimick posterior fossa cyst Shunting Sequelae: CHF, Dilation of neck veins and arteries, Hydrops Prognosis poor if large or associated hydrops Steals cerebral perfusion  infarcts Ventriculomegaly Treatment Coil Emolization, Craniotomy vessel ligation

47. Vein of Galen Aneurysm Normal Circle of Willis Vein of Galen Aneurysm

48. Vein of Galen Aneurysm

49. spine

50. 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

51. 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

52. 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

53. 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

54. 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)

55. Curvature Abnormality

56. Face and neck

57. 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

58. 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

59. ORBIL DAIMETER= INTERORBITAL DISTANCE

60. CONGENITAL CATARACT

61. 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.

62. - I- NB associated with aneuploidy • Trisomy 21 (T21) most common • Trisomy 18 (TI8) • Trisomy 13 (TI3) • Turner syndrome

63. 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

64. 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

65. Cleft Palate and Cleft Lip

66. 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

67. 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

68. MICRO GNATHIA” SMALL CHIN RETROGNATHIA: POSTERIORLY DISPLACED CHIN

69. Cystic Hygroma Fluid Collection Fetal Neck Lymphatic system fails to develop Bilateral Nuchal Cystic Masses 70% have chromosomal anomalies Turners Downs syndrome

70. TCS

71. TO SUMMARIZE

72. Thank you FOR THIS OPPURTUNITY Target scan 2 part- SKELETAL DYSPLASIA ,GIT,GUT,