Download Fetal Chest and Heart

FETAL CHEST
FETAL HEART
FETAL CHEST
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DIAPHRAGM
◦ Assess diaphragm (thin echogenic line)
 Diaphragm hernias
 Lung and bowel similar echogenicity- Look for peristalsis
 Left easier to see than right due to gastric bubble
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LUNGS
◦ Look for pulmonary masses
 CCAM
 Sequestration
◦ Pulmonary hypoplasia
PLEURA - effusions
 MEDIASTINUM - masses
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CONGENITAL DIAPHRAGM HERNIA
 Bochdalek - 90% on left; most unilat
 All should have amniocentesis and dedicated
echo
 Secondary pulmonary hypoplasia is major cause
of mortality
 Findings
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Polyhydramnios
Stomach/bowel/liver adjacent to heart
Peristalsis in chest
Mediastinal shift
Absent gastric bubble
Reduced abdominal circumference compared to rest
of fetal biometry
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Associated anomalies
◦ Aneuploidy (T18, T21); NTD; CHD; malrotation, omphalocele
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DDX
◦ CCAM
◦ Other cystic masses such as foregut duplication cysts are rare
CCAM
 Most common fetal lung mass
 Types I-III
◦ Types I and II macroscopic cysts >5mm with good prognosis and hydrops is rare
Small risk of malignant degeneration (rhabdomyosarcoma)
 Imaging
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◦ Macroscopic types appear cystic
◦ Microscopic types appear solid (echogenic)
Pulmonary hypoplasia of normal lung - degree determines prognosis
 Mediastinal shift - cardiac compromise; polyhydramnios (impaired
swallowing)
 Associations (type II)
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Cardiac anomalies
Pulmonary sequestration
Pectus excavatum
Jejunal atresia
Renal agenesis, prune-belly syndrome
Pathology
◦ Hamartomatous proliferation of terminal bronchioles
◦ Cysts lined by respiratory epithelium and communicate with airways at
birth
CCAM
EXTRALOBAR SEQUESTRATION
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More common in males (4:1)
90% LLL or below diaphragm
Always airless as it has its own pleural envelope and no communication
with bronchial tree
Systemic arterial supply - Aorta 80%
Systemic venous drainage - IVC, azygos, portal v
Imaging Findings
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Solid hyperechogenic mass
Look for systemic arterial supply on Doppler
Polyhydramnios
Hydrops
Associations 65%
◦ CDH
◦ Cardiac
◦ GI, Renal,Vertebral anomalies
Often regress in utero
 DDX
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◦ CCAM
◦ Congential lobar emphysema (initially filled with fetal fluid)
◦ Neuroblastoma
SEQUESTRATION
PULMONARY HYPOPLASIA
 Agenesis – complete absence of one or both lungs
(airways, alveoli, and vessels)
 Aplasia – absence of lung except for a rudimentary
bronchus that ends in a blind pouch
 Hypoplasia – decrease in number and size of
airways and alveoli
◦ Primary
◦ Secondary
 Bilateral - Oligohydramnios (Potter’s sequence); Skeletal
dysplasia
 Unilateral - CCAM; Sequestration; CDH; Hydrothorax
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Imaging
◦ Reduced thoracic circumference (<2SD) is suggestive
◦ Fetal lung maturity best sssessed with
lecithin:sphingomyelin ratio in amniotic fluid
◦ Echogenic pattern unreliable marker for maturity
PLEURAL EFFUSION = abnormal
 Fetal hydrops
 Chromosomal
 Underlying mass
 Infection
 Lymphangiectasia
 Chylothorax - assoc with T21 and Turner’s
MEDIASTINAL MASSES
 Anterior Medistinum
◦ Teratoma
◦ Cystic hygroma
◦ Normal Thymus
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Posterior Mediastinum
◦ Neurogenic tumours
◦ Enteric cyst
FETAL HEART
Technique
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Abdominal situs view
◦ 4-chamber view
◦ LVOT
 Posterior/central to RVOT
 Runs left to right
◦ RVOT
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Anterior to LVOT
Runs right to left
Bifurcates early: DA and RPA
Check for antegrade flow in DA
Anatomical trifurcation: DA, RPA, LPA
◦ 3-vessel view
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amniocentesis indicated in all abnormal: 15-40% will have
chromosomal anomalies
ventricles/atria are of roughly same size as other ventricle/atria
3 in 1 rule: heart fills 1/3 of axial chest
Cardiac circumference 1/2 chest circumference
Length atrial septum: ventricular septum 1:2
Normal HR: 120-160bpm, SR
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Best seen on Four-Chamber View
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Septal defect
Endocardial cushion defect (AVSD)
Hypoplastic left heart
Ebstein’s anomaly
Critical AS
Coarctation
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Best Seen on Outflow Tract Views
◦ Tetralogy of Fallot
◦ Transposition
◦ Truncus Arteriosus
◦ Pentalogy of Cantrell
3-VESSEL VIEW
Maternal Risk Factors for CHD
 Diabetes
 Infection - rubella, CMV
 SLE
 Drugs - EtOH, Phenytoin, lithium
 FHX of heart disease, previous child with
CHD
 Arrhythmia
VSD
 Most common CHD (1:1000)
 Membranous 80% vs Muscular 10% vs Outlet
(ECD) 5%
 Don’t mistake membranous to muscular
transition for VSD
Endocardial Cushion Defect
 40% have Trisomy 21
 EC forms lower atrial septum, superior
ventricular septum, anterior MV leaflet
and septal TV leaflet
Transposition of Great Vessels
 Aorta arises from RV and pulmonary trunk from LV
 Aorta and pulmonary artery are parallel instead of
perpendicular to each other
Tetralogy of Fallot
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Tetralogy
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Infundibular RV outflow tract stenosis
Overriding aorta
VSD
Hypoplastic RV
LV and RV are symmetric due to equal pressures
 Often missed on 4-chamber view
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Ebstein’s Anomaly
 Septal and posterior leaflets of tricuspid valve prolapse
and are integrated into RV wall
 Atrialisation of RV
 Large RA due to massive regurg
 Maternal lithium is a risk factor
Pulmonary Atresia
 Hypoplastic RA and RV
 Pulmonary artery calibre may be normal
 Reversed flow in DA
Pericardial Effusion
 >2mm
 Associated with hydrops fetalis, congenital
infection and cardiac anomalies
 Look for fluid in other compartments
(hydrops)
 Look for signs of congential infections
◦ Cerebral calcification
◦ Hepatic calcifciation
◦ Echogenic bowel
Endocardial Fibroelastosis
 Increased echogenicity of endocardium
 Ventricular dilatation and poor
contractility
Ectopia Cordis
Rhabdomyoma
 Hamartoma of myocytes
 Strong association with Tuberous Sclerosis
◦ 50-85% of fetuses with it have TS
◦ 50% of TS have it
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Echogenic mass, usually intraventricular, can arise from IV septum
FETAL ARRHYTHMIAS
PAC and PVC common and benign
 SVT is the most common tachyarrhythmia CMX hydrops
 Fetal bradycardia (HR <100 for >10sec)
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◦ If persistent - consider structural cardiac defects or
maternal CVD
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Fetal heart block
◦ 40-50% have structural abnormality - usually lethal
◦ Associated with maternal SLE, RA, Scleroderma