Fetal Abnormalities and Anomalies Fetal Abnormalities Detectable by

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 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 • 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