Fetal Abnormalities and Anomalies

Fetal Abnormalities Detectable by Ultrasound

• Brain– Anencephaly– Hydrocephalus– Chiari deformities– Encephalocele

• Spine– Spina bifida

cystica– Myelomeningocel

e

• 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 AbnormalitiesDetectable 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 mid-

abdomen• Soft tissue

mass extending to right

• Abdominal contents outside the fetal abdomen

• Note: enclosed by a membrane (arrows)

FetalAbdomen

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

FetalAbdomen

UmbilicalCord

AbdominalContents

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 mal-rotation 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 System- Developmental 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

• Joined at inferior aspect

• Moderate hydronephrosis

Horseshoe Kidney

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

MultipleRenal Cysts

CT Renal Cysts

Ultrasound Renal Cyst

Renal Abnormalities

• Hydronephrosis– Hypoechoic

(Dark areas)• Thinning of

renal cortex indicates long standing process

Hydronephrosis

Massive Hydronephrosis