Introduction Omphalocele is classified as a ventral wall defect in which there is midline herniation of abdominal viscera into the base of the umbilical cord. Before the 1950s, gastroschisis was considered a variant of omphalocele. It is now known that…
Introduction Gastroschisis, a full thickness paraumbilical defect in the abdominal wall that results in herniation of the fetal midgut, has been considered an entity embryologically distinct from omphalocele since the mid-1950s. The widespread availability of prenatal ultrasound (US) and of…
Introduction Cloaca is derived from the Latin word for sewer or drain. Anatomically, it is used to describe a confluence of the urinary, genital, and gastrointestinal (GI) tracts. While this is the norm in birds, reptiles, and amphibians, most mammals…
Introduction While not of primary focus for the medically minded sonographer or sonologist, sex determination is often the most important question for parents during a fetal ultrasound (US) examination. Sex determination, however, can be medically important in the diagnosis of…
Introduction The fetal adrenal glands can be reliably imaged on prenatal ultrasound. The adrenal glands are located in a retroperitoneal, paraspinous location, cephalad to the upper renal poles. The gland is composed of a hypoechogenic cortex and a thin echogenic…
Introduction Autosomal recessive polycystic kidney disease (ARPKD) is a chronic, progressive condition that affects the kidneys and liver, causing cystic dilatation of the renal collecting ducts and congenital hepatic fibrosis (CHF), or Caroli disease. ARPKD is also called infantile polycystic…
Introduction Multicystic dysplastic kidney (MCDK) is a form of severe renal dysplasia that typically results in a nonfunctioning kidney. The parenchyma is replaced by numerous cysts of varying size, with echogenic intervening tissue and an atretic ureter. Microscopically, undifferentiated epithelium…
Introduction Posterior urethral valves (PUV) are the most common cause of fetal lower urinary tract obstruction, also called bladder outlet obstruction. Membranous tissue in the posterior urethra results in varying degrees of obstruction. The condition occurs only in males, although…
Introduction Duplication of the renal collecting system, also termed duplex kidney, is one of the few renal anomalies more common in females. Duplex kidneys have an upper pole and a lower pole, called moieties, each drained by a ureter. Approximately…
Introduction Fetal renal pelvis dilatation (or dilation) is a common ultrasound (US) finding, identified in 1% to 5% of pregnancies. There is a strong correlation between the degree of renal pelvis dilatation and the likelihood of postnatal urinary pathology, particularly…