fetal gastrointestinal & genitourinary systems

The fetus scanned on has testicular hypoplasia. When the sonographer scanned up to the kidneys, this was seen. What can be assumed here?

Unilateral renal agenesis

The fetus scanned on was seen with a single umbilical artery wrapped around the bladder. That prompted the sonographer to take a look at the kidneys and this was seen.

1. What pathology can be assumed here?

2. Why can this pathology happen?

1. Unilateral renal agenesis

2. The ureteral buds failed to develop

With esophageal atresia, the fetus is (1)_________ part of the esophagus or it’s (2)__________.

1. Missing

2. Underdeveloped

With esophageal atresia, will amniotic fluid pass into the intestines for absorption?

No

List the 2 US findings of esophageal atresia.

• ½ No fluid filled stomach

• 2/3 polyhydramnios

If ½ of esophageal atresia cases have no fluid in the stomach, then the other ½ can see fluid in the stomach. Why is that?

Because of TEF

Around 90% of esophageal atresia cases have what structural variation?

Distal tracheo-esophageal fistula

The TEF variation in esophageal atresia enables amniotic fluid to pass through an _________ connection between the trachea and esophagus.

Abnormal

Esophageal atresia is associated with…

1. ________ problems

2. ________ problems

3. ________ problems

4. ____________ abnormalities

1. Cardiac

2. GI

3. GU

4. Chromosomal

What structure is seen at the arrow?

Trachea

The fetus scanned on had polyhydramnios. What can be assumed here?

Esophageal atresia

Why do fetus’ with esophageal atresia have polyhydramnios?

Amniotic fluid is unable to pass into the intestines for absorption

What is the most common cause of small bowel obstruction?

Duodenal atresia

Duodenal atresia will see 2 fluid filled structures in the (1)______ abdomen that (2)_________.

1. Upper

2. Communicate

What is the most important US finding of duodenal atresia?

Double bubble

The double bubble sign for duodenal atresia will show a dilated (1)________ and (2)________ duodenum.

1. Stomach

2. Proximal

When can the double bubble sign appear for duodenal atresia?

After 24 weeks

Duodenal atresia is associated with ______hydramnios.

Poly

Duodenal atresia is associated with what 3 pathologies?

• Trisomy 21

• Cardiac anomalies

• VACTERL complex

What does each letter of ‘VACTERL’ stand for?

• Vertebral

• Anal atresia

• Cardiac

• Trachea

• Esophagus

• Renal

• Limb defect

Based on previous lectures, what pathology is VACTERL associated with?

Caudal regression syndrome (CRS)

The sonographer found polyhydramnios. This was found.

1. What US finding is seen here?

2. What pathology is it seen with?

1. Double bubble sign

2. Duodenal atresia

The sonographer scanned a fetus that has Trisomy 21. This was seen.

1. What US finding is seen here?

2. What pathology is it seen with?

1. Double bubble sign

2. Duodenal atresia

Intestinal atresia is the (1)________ or abnormal (2)_________ of the intestines.

1. Absence

2. Narrowing

General rule for intestinal atresia is that the more (1)_______ the obstruction, the less severe the (2)____________ will be and the later it will develop.

1. Distal

2. Polyhydramnios

1. If the sonographer sees multiple fluid filled loops of bowel, what pathology should be suspected?

2. What can this pathology lead to?

1. Intestinal atresia

2. Bowel obstruction

If bowel obstruction perforates with intestinal atresia, what 4 US findings can be seen?

• Calcifications

• Ascites

• Polyhydramnios

• Meconium peritionitis

Fluid filled bowel loops were seen on US. What pathology can be asusmed here?

Intestinal atresia

What causes meconium peritonitis?

Bowel perforation

What is another term for fetal stool?

Meconium

Meconium peritonitis is when (1)_________ goes into the (2)______________ and causes (3)_________.

1. Meconium

2. Surrounding spaces

3. Inflammation

List 4 pathologies that meconium peritonitis can lead to.

• Ascites

• Fibrosis

• Calcification

• Cyst formation

Approximately 80-90% of meconium peritonitis cases have what US finding?

Intra-abdominal calcifications

Meconium peritonitis occurs due to bowel perforation. List 2 pathologies that can cause perforation.

• Intestinal atresia

• Cystic fibrosis

Bowel obstruction has occurred in the fetus, and this was seen on the scan.

1. What US finding is seen here?

2. What pathology is it an indication for?

1. Meconium cyst

2. Meconium peritonitis

Bowel obstruction has occurred in the fetus, and this was seen on the scan.

1. What US finding is seen here?

2. What pathology is it an indication for?

1. Calcification

2. Meconium peritonitis

Bowel obstruction has occurred in the fetus, and this was seen on the scan.

1. What US finding is seen here?

2. What pathology is it an indication for?

1. Calcification

2. Meconium peritonitis

When fetal bowel appears hyperechoic, what structure should the sonographer compare it to?

Fetal bone

Define hyperechoic bowel.

When fetal bowel is brighter than it should be

How is hyperechoic bowel determined?

• Turning off harmonics

• Turning down gain

The brightness and harmonics have been turned down.

The echogenicity of the bowel and bone are the same.

What can be assumed here?

Hyperechoic bowel

The brightness and harmonics have been turned down.

The bowel disappeared before the bone.

What can be assumed here?

NOT hyperechoic bowel

Hyperechoic bowel can be associated with what 3 pathologies?

• Trisomy 21

• Infections

• Cystic fibrosis

Despite having associations with various pathologies, can hyperechoic bowel still be considered a normal variant?

Yes

What is the most important pathology that can be associated with hyperechoic bowel?

Trisomy 21

1. What pathology is seen at the white arrow?

2. Name at least 1 pathology question 1’s answer can be associated with.

1. Hyperechoic bowel

2. Trisomy 21, Infections, or cystic fibrosis

1. What pathology is seen if the gain were turned down and it matched the echogenicity of the fetal bone?

2. Name at least 1 pathology question 1’s answer can be associated with.

1. Hyperechoic bowel

2. Trisomy 21, Infections, or cystic fibrosis

Both images were taken with the same fetus at the same area, just with different gains.

What can be assumed regarding what is seen here?

Fetus has hyperechoic bowel

Prenatal US is capable of diagnosing many anomalies of the urogenital system. What 2 systems make up the urogenital system?

• Urinary

• Genital

When the sonographer is scanning through the kidneys, what 2 other structures/factors should also be assessed?

• Urinary bladder

• Amount of amniotic fluid

What structure is considered a critical marker in the assessment of renal function?

Amniotic fluid

The fetal kidneys will begin to excrete urine after what week?

11

The fetal kidneys will not become the major contributor of fetal urine (amount of amniotic fluid volume) until __-__ weeks.

14 - 16

If there is a decrease in amniotic fluid prior to weeks 14-16, what pathologies should be suspected?

• Premature ruptured of membranes (PROM)

• Renal abnormalities

The observation of normal amniotic fluid volume before weeks 14-16 will not exclude the possibility of what pathology?

Renal agenesis

Renal malformations may be divided into what 2 categories?

• Congenital malformation

• Obstructive process

Recognition of urinary tract anomalies is important because several fetal conditions are (1)_________ with life and it is important to ensure appropriate (2)_________ management.

1. Incompatible

2. Clinical

Prognosis of any abnormalities of the urinary tract depend on _________ or _________ involvement of the kidneys as well as associated abnormalities.

• Unilateral

• Bilateral

What is the survival rate for fetus’ with the presence of one functioning kidney?

Excellent

Which 2 maternal factors can increase the risk for urogenital malformations?

• Cocaine use

• Maternal diabetes

How does unilateral renal agenesis occur?

When the ureteral buds fail to develop

If unilateral renal agenesis is suspected, the sonographer should carefully evaluate other fetal structures and the _______ area.

Pelvic

1. With unilateral renal agenesis, how will the one kidney appear?

2. What will this be termed?

1. Larger in size, due to compensating for the missing kidney

2. Compensatory hypertrophy

The missing side of unilateral renal agenesis will see what 2 US findings?

• ‘Lying down” adrenal gland

• No renal artery

Unilateral renal agenesis will be associated with what 4 pathologies?

• Single umbilical artery (SUA)

• Uterine anomalies

• Testicular hypoplasia

• Undescended testicles

Will unilateral renal agenesis affect AFI?

No

What is the most common cause of bilateral renal agenesis?

Severe oligohydramnios

What does ‘BRA’ stand for?

Bilateral renal agenesis

Bilateral renal agenesis is a lethal disorder due to what 2 pathologies?

• Renal insufficiency

• Hypoplasia of lungs

Bilateral renal agenesis will exhibit what syndrome?

Potter’s syndrome

What are the 5 US findings of Potter’s Syndrome (bilateral renal agenesis)?

• Flat nose

• Recessed chin

• Abnormal ears

• Wide set eyes

• Deformities of limbs (talipes)

With unilateral or bilateral agenesis, what US finding can mimic the appearance of kidneys?

‘Lying down’ of adrenal gland

When scanning for bilateral renal agenesis, how will the bladder appear?

No bladder over the course of an hour.

What arteries won’t be seen with bilateral renal agenesis?

Renal arteries

Bilateral renal agenesis will typically be seen between __-__ weeks.

16 - 28

The sonographer is scanning at the level of the kidneys and does not note them. What can be assumed here?

Bilateral renal agenesis

1. What pathology is seen here?

2. What syndrome can be seen with this pathology?

1. Bilateral renal agenesis

2. Potter’s syndrome

What is another term for Potter’s syndrome?

Potter’s sequence

Potter’s syndrome is caused by (1)_________ in utero due to (2)_____hydramnios.

1. Pressure

2. Oligo

Potter’s syndrome can also occur with other conditions that cause oligohydramnios. List 3 of them.

• VACTERL syndrome

• Blockage of the urinary tract

• PROM

1. This image can be associated with what pathology?

2. What pathology can this condition be seen with?

1. Potter’s Syndrome

2. Bilateral Renal Agenesis

Define pulmonary hypoplasia.

Underdevelopment of the lungs

What causes the limb abnormalities of Potter’s syndrome?

Lack of fluid to move around

Bladder exstrophy can be similar to what other pathology?

Ectopia cordis

Bladder exstrophy can be ______ or _______.

• Mild

• Severe

1. How does bladder exstrophy appear on US?

2. What does the US appearance represent?

1. Small, soft tissue mass

2. Exposed bladder mucosa

Bladder exstrophy can be due to a (1)______ in (2)_______ abdominal wall.

1. Defect

2. Lower

Bladder exstrophy can be accompanied by other…

Abnormalities

What pathology is seen here?

Bladder exstrophy

Cloacal exstrophy can only been seen in males or females?

Females

What are the 3 openings with cloacal exstrophy?

• Urethra

• Vagina

• Rectum

With cloacal exstrophy, instead of having (1)__ separate openings, there is only (2)___ opening where urine and stool comes out.

1. 3

2. 1

1. What other pathology does cloacal exstrophy look similar to on US?

2. What is different?

1. Bladder exstrophy

2. Small and large intestine will be in the mass

Cloacal exstrophy is where which 2 tracts meet?

• GI

• GU

Cloacal exstrophy is when there is ___ opening to the outside.

1

Cloacal exstrophy will be associated with ____hydramnios.

Oligo

Cloacal exstrophy has a ____ prognosis.

Poor

1. Is this image of the pelvis normal or abnormal?

2. If abnormal, what can be assumed here?

1. Normal

2. Normal

1. Is this image of the pelvis normal or abnormal?

2. If abnormal, what can be assumed here?

1. Abnormal

2. Cloacal exstrophy

What structure is responsible for helping the bladder develop?

Urachus