4/28/2010

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Fetal Abnormalities and Anomalies

Fetal Abnormalities Detectable by Ultrasound

• Brain • Renal• Brain– Anencephaly– Hydrocephalus– Chiari deformities– Encephalocele

• Spine

• Renal– Hydronephrosis– Renal agenesis

• Cardiac– Chambers– OrientationSpine

– Spina bifida cystica– Myelomeningocele

– Orientation• General

– Abdominal wall defects– Lung abnormalities

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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

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Normal Development of Intestinal Tract

• At 9 weeks there is physiologic herniationof 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

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Omphalocele• Axial view mid-

abdomen• Soft tissue• Soft tissue

mass extending to right

• Abdominal contents outside the fetal

bdabdomen• Note: enclosed

by a membrane(arrows)

FetalAbdomen

Gastroschisis• Defect of

anterior wallL t l t• Lateral to umbilicus

• Bowel loops float in amniotic fluid

• Cord separate

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Gastroschisis• Lobulated

echogenic AbdominalC t tmass

• Free floating loops of bowel in

FetalAbdomen

Contents

bowel in the amniotic fluid

UmbilicalCord

Normal UGI, Small Bowel

• Small bowel• Small bowel distributed throughout the abdomen primarily to the left

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Mid-gut Malrotation• Barium UGI• Stomach

normal position

• Small bowel l t lcompletely

on right side of abdomen

Normal Barium Enema

• Normal colon• Normal colon frames the margins of the abdomen

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Mid-gut Malrotation

• Barium enema• Colon located

entirely on the left side of the abdomen

• Same case as• Same case as earlier mal-rotation case

Duodenal Atresia

• Plain film upright abdomenabdomen

• “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

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Skeletal Development Long Bones

• Diaphysis ossified at birth (shaft of long b )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 boneWeak point in the bone

• Metaphysis– Active bone formation via formation and

calcification of osteoid

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Bone Growth Abnormalities

• Cartilage growth deficiency– Example: Achondroplasia

• Ossification growth deficiency– Example: Osteogenic imperfecta

• Metabolic defectE ample H pophosphatasia– Example: Hypophosphatasia

Osteogenesis Imperfecta

• Deficient peri- and endostealendostealossification

• Multiple fractures• Healing with

deformities of bones• Limb shortening

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Achondroplasia

• Dwarfism• Deficient cartilage• Deficient cartilage

growth• Lower limbs with

ruler to measure leg lengthSh t li b b• 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)y ( )

• Congenital vessel anomaly– Coarctation of aorta– Transposition of the great vessels

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Normal Cardiac Anatomy• Right heart border

– Upper portion - SVC and ascending aortaL ti i ht– Lower portion – right atrium

• Left heart border– Upper portion – aortic

arch– Mid portion – main

pulmonary arteryp y y– Lower middle portion –

left atrium– Lower portion – left

ventricle

Normal Chest Lateral

• Anterior heart border– Upper portion –pp p

aortic arch– Mid portion –

pulmonary artery– Lower portion – right

ventricle• Posterior heart borderPosterior heart border

– Upper portion – left atrium

– Lower portion – left ventricle and IVC

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Atrial Septal Defect• Increased

pulmonary vascularityvascularity

• Small aortic arch

• Large main pulmonary artery

• Right atrialand ventricular hypertrophy

Tetralogy of Fallot• “Boot-shaped” heart• Pulmonic stenosis

(i f dib l )(infundibulum)• VSD• Right ventricular

hypertrophy• Overriding aortag• Pulmonary

circulation decreased

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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 uretersureters

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Duplication of Kidney

• Both kidneys with 2 ll ti tcollecting systems

• Right and Left upper system dilated

• Lower units smaller• Lower units smaller• Ureters join before

bladder

H h

Horseshoe Kidney

• Horseshoe kidney

• Joined at inferior aspect

• Moderate hydronephrosis

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Horseshoe Kidneys• Axial images

demonstrate kid j i dkidneys joined across the midline anterior to the aorta and i f iinferior vena cava

Pelvic Kidney

• AP tomogram

• Both kidneys in the pelvis

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Polycystic Kidneys

• Axial scan with contrastwith contrast

• Enlarged lobulatedkidneys

• Multiple cysts• Varying size• Varying size

CT Multiple Cysts

MultipleRenal Cysts

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CT Renal Cysts

Ultrasound Renal Cyst

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Renal Abnormalities

• Hydronephrosis– Hypoechoic

(Dark areas)• Thinning of

renal cortex indicates long gstanding process

Hydronephrosis

M i H d h iMassive Hydronephrosis