Fetal Abnormalities and
Anomalies
Fetal Abnormalities Detectable
by Ultrasound
• Brain
–
–
–
–
Anencephaly
Hydrocephalus
Chiari deformities
Encephalocele
• Spine
– Spina bifida cystica
– Myelomeningocele
• Renal
– Hydronephrosis
– Renal agenesis
• Cardiac
– Chambers
– Orientation
• General
– Abdominal wall defects
– Lung abnormalities
Hydrocephalus
• Dilated ventricles
• Large sausage like
hypoechoic area
represents dilated
lateral ventricle
Intestinal Tract Abnormalities
Detectable by Ultrasound
• Omphalocele
• Abdominal wall defects and
gastroschisis
• Midgut malrotation
• Focal intestinal atresia
Normal Development of Intestinal Tract
• At 9 weeks there is physiologic herniation
of the small bowel into the umbilical cord
• The small bowel rotates 90 degrees
counterclockwise around the superior
mesenteric artery
• At 12 weeks the small bowel returns into
the abdominal cavity while rotating an
additional 180 degrees counterclockwise
around the superior mesenteric artery
• Total rotation of 270 degrees
Omphalocele
• Midline
defect
• Covering
membrane
• Contains
organs or
bowel
• Cord from
apex of
mass
Omphalocele
• Axial view midabdomen
• Soft tissue
mass extending
to right
• Abdominal
contents outside
the fetal
abdomen
• Note: enclosed
by a membrane
(arrows)
Fetal
Abdomen
Gastroschisis
• Defect of
anterior wall
• Lateral to
umbilicus
• Bowel loops
float in
amniotic
fluid
• Cord
separate
Gastroschisis
• Lobulated
echogenic
mass
• Free
floating
loops of
bowel in
the
amniotic
fluid
Abdominal
Contents
Fetal
Abdomen
Umbilical
Cord
Normal UGI,
Small Bowel
• Small bowel
distributed
throughout the
abdomen primarily
to the left
Mid-gut
Malrotation
• Barium UGI
• Stomach
normal
position
• Small bowel
completely
on right side
of abdomen
Normal Barium
Enema
• Normal colon
frames the
margins of the
abdomen
Mid-gut
Malrotation
• Barium enema
• Colon located
entirely on the
left side of the
abdomen
• Same case as
earlier malrotation case
Duodenal Atresia
• Plain film upright
abdomen
• “Double bubble” sign
• Air distended
stomach and proximal
duodenum
• Atresia involves
second portion of the
duodenum
Image donated by Dr.
Nancy Fitzgerald – Texas
Children’s Hospital
Houston Texas
Skeletal Development Long Bones
• Diaphysis ossified at birth (shaft of long
bone)
• Epiphysis radiolucent (cartilage) at birth
except for distal femoral epiphysis
– Develop Epiphyseal Ossification Centers
(EOC) later in life
Skeletal Development Long Bones
• Physis
– Cartilaginous plate between EOC and
metaphysis
– Responsible for growth in length
– When ossifies (closes) – longitudinal growth
stops
– Weak point in the bone
• Metaphysis
– Active bone formation via formation and
calcification of osteoid
Bone Growth Abnormalities
• Cartilage growth deficiency
– Example: Achondroplasia
• Ossification growth deficiency
– Example: Osteogenic imperfecta
• Metabolic defect
– Example: Hypophosphatasia
Osteogenesis Imperfecta
• Deficient peri- and
endosteal
ossification
• Multiple fractures
• Healing with
deformities of bones
• Limb shortening
Achondroplasia
• Dwarfism
• Deficient cartilage
growth
• Lower limbs with
ruler to measure
leg length
• Short limb bones
with flaring
metaphyses
Cardiovascular SystemDevelopmental Abnormalities
• Congenital heart disease
– Intra-cardiac septal defect (VSD, ASD)
– Patent ductus arteriosus (PDA)
– Tetralogy of Fallot (VSD, Pulmonary stenosis,
Overiding Aorta, RV hypertrophy)
– Endocardial cushion defect
– Pulmonary stenosis (PS)
• Congenital vessel anomaly
– Coarctation of aorta
– Transposition of the great vessels
Normal Cardiac Anatomy
• Right heart border
– Upper portion - SVC
and ascending aorta
– Lower portion – right
atrium
• Left heart border
– Upper portion – aortic
arch
– Mid portion – main
pulmonary artery
– Lower middle portion –
left atrium
– Lower portion – left
ventricle
Normal
Chest Lateral
• Anterior heart border
– Upper portion –
aortic arch
– Mid portion –
pulmonary artery
– Lower portion – right
ventricle
• Posterior heart border
– Upper portion – left
atrium
– Lower portion – left
ventricle and IVC
Atrial Septal Defect
• Increased
pulmonary
vascularity
• Small aortic
arch
• Large main
pulmonary
artery
• Right atrial
and ventricular
hypertrophy
Tetralogy of Fallot
• “Boot-shaped” heart
• Pulmonic stenosis
(infundibulum)
• VSD
• Right ventricular
hypertrophy
• Overriding aorta
• Pulmonary
circulation
decreased
Renal Abnormalities
• Anomalies in size and form
– Horseshoe kidney
• Anomalies in position
– Malrotation
– Ectopia
• Anomalies in structure
– Polycystic kidney
• Anomalies of drainage system
– Duplicated kidney, ureter
Normal
Kidney
• Intravenous
urogram
• Opacification of
collecting
systems and
ureters
Duplication of Kidney
• Both kidneys with 2
collecting systems
• Right and Left
upper system
dilated
• Lower units smaller
• Ureters join before
bladder
Horseshoe
Kidney
• Horseshoe
kidney
• Joined at
inferior aspect
• Moderate
hydronephrosis
Horseshoe Kidneys
• Axial images
demonstrate
kidneys joined
across the
midline
anterior to the
aorta and
inferior vena
cava
Pelvic Kidney
• AP
tomogram
• Both
kidneys in
the pelvis
Polycystic Kidneys
• Axial scan
with contrast
• Enlarged
lobulated
kidneys
• Multiple cysts
• Varying size
CT Multiple Cysts
Multiple
Renal
Cysts
CT Renal Cysts
Ultrasound Renal Cyst
Renal Abnormalities
• Hydronephrosis
– Hypoechoic
(Dark areas)
• Thinning of
renal cortex
indicates long
standing
process
Hydronephrosis
Massive Hydronephrosis