GI Tract

Question 0

What are the four layers of the bowel wall?

Answer 0

Mucosa
Submucosa
Muscularis externa
Adventitia or serosa

Question 1

How thick is the normal intestinal wall?

Answer 1

3-5 mm

Question 2

How does the bowel wall appear on ultrasound?

Answer 2

“Gut signature” or “target” or “pseudokidney” sign
Hypoechoic external rim corresponding to thickened intestinal wall and a hypoechoic center relating to a residual gut lumen or mucosal ulceration

Question 3

What is the gastroesophageal junction?

Answer 3

Segment of the esophagus between the diaphragm and the stomach

Question 4

How is pneumoperitoneum detected on ultrasound?

Answer 4

Free peritoneal air will float anteriorly with the patient in the supine position
A reverberation artifact or total sound reflection will appear after placing the transducer on the anterior abdomen

Question 5

How do patients present with acute appendicitis?

Answer 5

Periumbilical pain shifting to RLQ
Anorexia
Leukocytosis
Rebound tenderness

Question 6

What is the typical location for the appendix?

Answer 6

Posterior to the terminal ileum

Anterior to iliac vessels

Question 7

What is the cause of appendicitis?

Answer 7

Obstruction of the appendiceal lumen by a fecalith or hyperplasia of the submucosa

Question 8

What technique is used with ultrasound to displace bowel gas and decrease the distance between the transducer and the appendix?

Answer 8

Graded compression

Question 9

What is sonographic criteria for diagnosing and inflammatory appendix?

Answer 9

Non-compressible appendix
> 6 mm diameter
Appendicolith

Question 10

What does hypertrophic pyloric stenosis cause?

Answer 10

Functional gastric outlet obstruction and as a result of hypertrophy and hyperplasia of the muscular layers of the pylorus

Question 11

At what age do patients present with hypertrophic pyloric stenosis?

Answer 11

3 to 8 weeks

Question 12

What do patients with pyloric stenosis present with?

Answer 12

Vomiting (non-bloody, non-bilious)
Palpable olive shaped pylorus
Visible peristalsis

Question 13

What is the pylorus size criteria?

Answer 13

Muscle thickness > 3 mm
Channel length > 17 mm
Cross-section diameter > 15 mm

Question 14

What measurement is considered the most accurate for diagnosing a hypertrophic pylorus?

Answer 14

Muscle wall thickness

Question 15

What are symptoms of diverticulitis?

Answer 15

Left lower quadrant pain
Fever
Leukocytosis

Question 16

What are sonographic findings of diverticulitis?

Answer 16

Thickening of the bowel wall (> 4mm)
Abscess formation
Inflamed diverticula - round echogenic structures

Question 17

What are causes of mechanical small bowel obstruction?

Answer 17

Intraluminal (food bolus)
Bowel wall lesion (tumor, Crohn’s disease)
Extrinsic (adhesions, hernia) - most common

Question 18

How is ultrasound used to demonstrate small bowel obstruction?

Answer 18

Loops of distended bowel, level of obstruction, and peristalsis

Question 19

What is the most common cause of intestinal obstruction in the infant – toddler age?

Answer 19

Intussusception

Question 20

How does intussusception occur?

Answer 20

Peristalsis results in invagination of proximal bowel into lumen of more distal bowel = “telescoping” causing a bowel obstruction

Question 21

Where does intussusception typically occur?

Answer 21

Ileocolic junction

Question 22

What is the typical clinical presentation of intussusception?

Answer 22

Bloody diarrhea/currant jelly
May be post viral illness
Right-sided abdominal mass
Vomiting
Lethargy and irritability

Question 23

What is the classic sign of an intussusception?

Answer 23

Sausage-shaped mass in the right hypochondrium

Question 24

How does intussusception appear sonographically?

Answer 24

“Pseudo-kidney” mass - longitudinal plane

“Target sign” or concentric rings of folded bowel - transverse plane