Pediatrics GIT Flashcards

Question 1

Q

Which of the following is most likely to be a feature of an enteric duplication cyst?

A. Multilocular nature

B. Hypoechoic internal layer

C. Echogenic outer layer

D. Layered echogenic debris within cyst

E. Dense calcification

Answer

A

D. Layered echogenic debris within cyst

Often an incidental finding on antenatal/postnatal US, most present in childhood. May become symptomatic due to compression effect on adjacent structures. Complications include ulceration, bleeding, volvulus and small bowel obstruction.

Question 2

Q

@# 35. Which is the most common location for enteric duplication cysts?

A. Ileum

B. Oesophagus

C. Colon

D. Jejunum

E. Stomach

Answer

A

A. Ileum

75% are abdominal. Synchronous lesions occur in 10-20%.

Question 3

Q

Which is the most common type of transition between affected aganglionic and normal gangionic bowel in Hirschsprung’s disease?

A. Long segment

B. Short segment

C. Ultra short segment

D. Total intestinal aganglionosis

E. Total colonic

Answer

A

B. Short segment

Short segment accounts for 70-80%. Long segment accounts for 15-25%.

Question 4

Q

Which of the following is the most common type of tracheoesophageal fistula (TOF)?

A. Oesophageal atresia and proximal atretic portion and location of fistulas

B. Pure oesophageal atresia without TOF

C. Isolated TOF (H type) without oesophageal atresia

D. Oesophageal atresia with proximal and distal TOF

E. Oesophageal atresia with proximal TOF and distal atretic portion

Answer

A

A. Oesophageal atresia and proximal atretic portion and location of fistulas

82% are of this type

Question 5

Q

A 6-week-old boy with persistent non-bilious vomiting undergoes ultrasound of the abdomen. Which of the following is an ultrasound feature of pyloric stenosis?

A. Elongated pyloric channel > 16mm

B. Elongated pyloric channel > 12mm

C. Thickened pyloric muscle > 2mm

D. Increased pyloric diameter > 6mm

E. Increased pyloric diameter > 10mm

Answer

A

A. Elongated pyloric channel > 16mm

US features include gastric hyperperistalsis, failure to open pyloric channel or dynamic study and the echogenic mucosal layer may also look hypertrophied.

Question 6

Q

Which is the most specific radiologic sign in the investigation of intususception in a 6-month-old?

A. Paucity of bowel gas in the right lower quadrant

B. Soft tissue mass in the right upper quadrant obscuring the liver

C. Non-visualisation of the air filled caecum

D. Soft tissue mass with concentric lucencies

E. Small bowel obstruction

Answer

A

D. Soft tissue mass with concentric lucencies

Target sign also seen on US as a mass with alternating rings of hyper and hypechogenicity in TS and layered or pseudokidney appearance on LS

Question 7

Q

In biliary atresia on US:

A. The liver is almost always of abnormal echogenicity

B. GB is present in 75% of cases

C. Extrahepatic ducts are visible

D. An echogenic triangular cord sign represents a fibrotic remnant of the common duct

E. Lack of excretion of 99mT labelled studies into small bowel by 24 hours is diagnostic

Answer

A

D. An echogenic triangular cord sign represents a fibrotic remnant of the common duct

E is highly suggestive but not diagnostic. The gallbladder is present in 25% of cases. The liver may be enlarged but is usually of normal echogenicity.

Question 8

Q

Which of the following occurs with Caroli’s disease to form Caroli’s syndrome?

A. Hepatosplenomegaly

B. Hepatic fibrosis

C. Portal hypertension

D. Cholangiocarcinoma

E. Renal cystic abnormalities

Answer

A

B. Hepatic fibrosis

Hepatosplenomegaly and portal hypertension are consequences. There is an increased risk of cholangiocarcinoma and renal cystic abnormalities.

Question 9

Q

A 6-year-old girl with a large abdominal mass in the right upper quadrant and with an elevated AFP undergoes ultrasound assessment. This shows a 10cm mass in the right lobe of the liver, of heterogeneous echotexture, but predominantly solid. A spoke-wheel appearance is seen due to fibrous septa radiating from a central hub. Which is the most likely diagnosis?

A. Haemangioendothelioma

B. Hepatoblastoma

C. Mesenchymal hamartoma

D. Hepatocellular carcinoma

E. Metastasis from neuroblastoma

Answer

A

B. Hepatoblastoma

Haemangioendotheliomas have normal Alpha fetoprotein (AFP).

Mesenchymal hamartomas are usually more cystic.

Question 10

Q

47 Regarding the normal anatomy of the umbilical cord, there is:

(a) 1 umbilical artery, 1 umbilical vein

(b) 1 umbilical artery, 2 umbilical veins

(c) 2 umbilical arteries, 1 umbilical vein

(d) 2 umbilical arteries, 2 umbilical veins

(e) No ‘normal number’ as it is common to have different combinations of umbilical arteries/veins as an anatomical variant

Answer

A

(c) 2 umbilical arteries, 1 umbilical vein

A single UA is present in less than 1 % of all births. Single UA is more common with twins and diabetic mothers, and is associated with congenital anomalies.

Question 11

Q

(GIT) A child with a subacute history of vague abdominal pain is being investigated with ultrasound. Inflammatory markers are normal and there is no clinical indication of an appendicitis. During the study, an abnormality is detected in the right iliac fossa. Which of the following sonographic features favours a duplication cyst rather than a Meckel’s diverticulum?

A. Non-compressibility

B. Teardrop shape

C. A double layered wall

D. A greater degree of irregular mucosa

E. An elongated tubular shape

Answer

A

C. A double layered wall

An inflamed Meckel’s diverticulum can be difficult to distinguish from a duplication cyst in the terminal ileum. However, a characteristic double-layered wall is seen in duplication cysts, whereas the other features are more often found in an inflamed Meckel’s diverticulum.

Question 12

Q

3) A 2-day-old, full-term baby boy is found to have a palpable abdominal mass during a routine examination. He is otherwise well. A plain abdominal radiograph demonstrates a well-defined, dense mass containing multiple calcifications in the right lower quadrant. What is the most likely diagnosis?

a. neuroblastoma

b. duplication cyst

c. meconium peritonitis

d. meconium ileus

e. Hirschsprung’s disease

Answer

A

c. meconium peritonitis

Meconium peritonitis is a chemical peritonitis that occurs in utero following perforation of bowel as a result of bowel obstruction or ischaemia. Most commonly, the perforation seals off in utero, but the extruded meconium may be palpable as an abdominal mass, or may become calcified and therefore visible on plain film as a dense calcified mass or as calcific plaques throughout the peritoneal cavity. It may also be identified on ultrasound scan as echogenic material between bowel loops with a ‘snowstorm’ appearance. In other cases, active perforation is still present at birth, and the baby presents with clinical peritonitis.
Meconium ileus may result in abdominal calcifications in the neonate, but these are intramural in location. Hirschsprung’s disease and other causes of intestinal obstruction may be associated with intraluminal calcifications in the neonate. Neuroblastoma is frequently associated with calcification, but is suprarenal in location and usually symptomatic.
Duplication cysts are not usually associated with calcification.

Question 13

Q

8) A 5-year-old, previously well girl is found to have a palpable abdominal mass. Ultrasound scan demonstrates a 5 cm cystic lesion in the right upper quadrant. The wall of the lesion has an outer hypoechoic layer and an inner echogenic layer. The remainder of the abdomen appears normal. What is the most likely diagnosis?

a. Wilms’ tumour

b. ovarian cyst

c. pancreatic pseudocyst

d. duplication cyst

e. choledochal cyst

Answer

A

d. duplication cyst

Gastrointestinal duplication cysts account for 15% of paediatric abdominal masses. They most commonly arise from the small bowel and colon and, although usually asymptomatic, those that contain ectopic gastric or pancreatic tissue may present with ulceration or haemorrhage. Contrast studies are not useful for diagnosis, as most cysts do not communicate with the bowel lumen. Ultrasound scan is the most appropriate technique and demonstrates a simple anechoic cyst with a characteristic two-layered wall, representing the inner echogenic mucosa and the outer hypoechoic muscle. These appearances are characteristic of bowel wall, and help to distinguish a duplication cyst from other cystic lesions such as ovarian cyst, which are typically thin walled. Pancreatic pseudocyst is unlikely in the absence of previous episodes of pancreatitis.

Question 14

Q

13) A newborn baby presents with coughing and choking during feeding. On examination, the baby is noted to drool excessively. Attempted passage of a feeding tube into the stomach is unsuccessful, and a chest radiograph shows the coiled feeding tube in the proximal oesophagus. An abdominal radiograph demonstrates gas within the stomach. What is the most likely diagnosis?

a. oesophageal atresia alone

b. oesophageal atresia and proximal tracheo-oesophageal fistula

c. oesophageal atresia and distal tracheo-oesophageal fistula

d. oesophageal atresia with proximal and distal tracheo-oesophageal 1fistulae

e. tracheo-oesophageal fistula without oesophageal atresia

Answer

A

c. oesophageal atresia and distal tracheo-oesophageal fistula

Oesophageal atresia is suspected when a newborn baby presents with drooling, and is confirmed on a chest radiograph by the presence of a gas-distended, proximal oesophageal pouch, or a coiled feeding tube within the pouch. Absence of gas in the abdomen on an abdominal radiograph implies oesophageal atresia either alone or with a proximal fistula. However, gas within the abdomen implies the presence of a distal tracheo-oesophageal fistula. Occasionally, there may be both proximal and distal tracheo-oesophageal fistulae, but this situation is rare, accounting for only 1% of patients, as opposed to around 80% with distal fistula alone. Oesophageal atresia and tracheo-oesophageal fistula may be part of the VACTERL association, which includes vertebral, anorectal, cardiovascular, tracheo-oesophageal fistula, renal and limb anomalies.

Question 15

Q

17) A 6-year-old girl is investigated for abdominal pain, jaundice and a palpable right upper quadrant mass. Ultrasound scan of the abdomen demonstrates a 5 cm cystic structure at the porta hepatis, which is separate from the normal gallbladder, and communicates with normal intrahepatic ducts. What is the most likely diagnosis?

a. biliary atresia

b. choledochal cyst

c. pancreatic pseudocyst

d. duodenal duplication cyst

e. pericholecystic abscess

Answer

A

b. choledochal cyst

Choledochal cyst is a congenital condition characterized by aneurysmal dilatation of the common bile duct, which in the majority of cases is associated with an anomalous junction of the common bile duct and pancreatic duct, allowing reflux of pancreatic enzymes into the common bile duct and resulting in weakening of the wall. The most common type (type I) is a localized dilatation of the common bile duct below the cystic duct. Communication with the common hepatic or intrahepatic ducts is demonstrated, and intrahepatic ducts are usually not dilated. Biliary atresia presents in the neonatal period with jaundice. Typical findings include an echogenic triangular structure at the porta, representing the atretic biliary plate, and a small or non-visualized gallbladder. Pancreatic pseudocyst and duodenal duplication cyst do not communicate with the biliary tree. A pericholecystic abscess would be unlikely in the presence of a normal gallbladder.

Question 16

Q

18) A 3-year-old boy presents with fever, skin rash and abdominal pain. On examination, he has a maculopapular rash on the extensor surfaces, erythema of the oral mucosa, palms and soles, and multiple enlarged cervical lymph nodes. He is tender in the right upper quadrant. Abdominal ultrasound scan demonstrates a markedly enlarged gallbladder with a thin wall and a positive sonographic Murphy’s sign is elicited. No gallstones are seen. What is the most likely diagnosis?

a. acute acalculous cholecystitis

b. acute gallbladder hydrops

c. choledochal cyst

d. acute calculous cholecystitis

e. emphysematous cholecystitis

Answer

A

b. acute gallbladder hydrops

Kawasaki’s syndrome is an acute multisystem vasculitis with a predilection for the coronary arteries, generally affecting children under 5 years of age. As well as skin, joint and cardiovascular manifestations, patients may develop acute hydrops of the gallbladder, probably caused by transient obstruction of the cystic duct. Ultrasound scan demonstrates a markedly enlarged and tender gallbladder with a thin wall. Acute acalculous cholecystitis may be seen in children in the high dependency or intensive care setting, especially with septicaemia and trauma, but it usually results in gallbladder wall thickening and less marked gallbladder dilatation. Choledochal cyst (aneurysmal dilatation of the common bile duct) is seen as a fusiform cyst beneath the porta hepatis separate from the gallbladder. Acute calculous cholecystitis is associated with gallstones within a thickened gallbladder wall.
Emphysematous cholecystitis usually occurs in adults over 50, and gas is seen as arc-like, high-level echoes outlining the gallbladder wall.

Question 17

Q

19) A 7-year-old boy who has recently arrived in the country from south-east Asia presents with colicky abdominal pain. Blood tests show eosinophilia. He undergoes small bowel follow-through examination, whichreveals multiple tubular filling defects in the small bowel averaging 20 cm in length, some of which contain a central, barium-filled canal. What is the most likely diagnosis?

a. ancylostomiasis (hookworm)

b. ascariasis (roundworm)

c. strongyloides infection

d. anisakiasis (herring worm disease)

e. taeniasis (tapeworm)

Answer

A

b. ascariasis (roundworm)

Ascariasis is the most common parasitic infection worldwide, predominantly affecting children aged 1–10 years.Worms mature in the small bowel and may be identified on plain films as tubular soft-tissue densities or on barium studies as linear or coiled filling defects of 15–35 cm in length. Barium ingested by the worms causes opacification of their central linear enteric canals. Patients may present with abdominal pain, appendicitis and haematemesis; occasionally, a bolus of worms may cause small bowel obstruction.
Tapeworms may also appear as linear filling defects, but are usually much longer, reaching many feet in length. In addition, tapeworms have no alimentary canal and do not ingest barium.
Hookworms measure 8–13 mm and cannot be visualized on barium studies.
Anisakiasis of the small intestine usually appears radiologically as bowel wall thickening and luminal narrowing.
Strongyloides infection may manifest as fold thickening and effacement, with a pipestem appearance of the jejunum in advanced cases.

Question 18

Q

27) What is the normal position of the duodenojejunal junction on frontal views during an upper gastrointestinal contrast examination?

a. to the left of the left pedicles of the vertebral body at the level of the duodenal bulb

b. to the left of the left pedicles below the level of the duodenal bulb

c. overlying the vertebral body at the level of the duodenal bulb

d. to the right of the right pedicles below the level of the duodenal bulb

e. to the right of the right pedicles above the level of the duodenal bulb

Answer

A

a. to the left of the left pedicles of the vertebral body at the level of the duodenal bulb

Intestinal malrotation is defined as a congenital abnormal position of the bowel within the peritoneal cavity, occurring as a result of disruption of the normal embryological process of gut rotation and fixation. It is associated with abnormal bowel fixation by mesenteric bands or lack of fixation of parts of the bowel, which may result in obstruction, volvulus and bowel necrosis. The position of the duodenojejunal junction (and by implication the ligament of Treitz) can help to identify the presence of malrotation and its type, and should be determined on every paediatric upper gastrointestinal contrast examination. The duodenojejunal junction normally lies to the left of the left-sided pedicles of the vertebral body, at the level of the duodenal bulb on frontal views.
Malrotation is associated with medial and inferior displacement of the duodenojejunal junction. Occasionally, the normal duodenojejunal junction may be displaced inferiorly by a distended stomach or dilated adjacent bowel segment, due to laxity of the peritoneal ligaments, which may mimic malrotation.

Question 19

Q

31) Regarding reduction of intussusception in children, which of these is a feature of hydrostatic reduction using barium, rather than pneumatic reduction using air?

a. lower intracolonic pressures

b. faster reduction

c. higher successful reduction rate

d. less contamination of the peritoneal cavity

e. lower radiation dose

Answer

A

a. lower intracolonic pressures

Compared with use of barium, pneumatic reduction of intussusception using air allows generation of higher intracolonic pressures, which is associated with faster and more effective reduction (70–90% success rate), and therefore less fluoroscopic time and lower radiation dose. If perforation does occur (around 1% of cases), the use of air results in smaller tears and less contamination of the peritoneal cavity. A potential complication of the pneumatic method is tension pneumoperitoneum, which may result in respiratory and haemodynamic compromise, requiring prompt needle puncture of the peritoneal cavity. Overall, pneumatic reduction is considered the optimal technique, and has replaced the use of barium in most centres. However, hydrostatic reduction with water-soluble contrast remains a viable alternative, but the contrast column needs to be elevated to a height of 150 cm to generate similar pressures.

Question 20

Q

39) A neonate with Down’s syndrome presents with persistent bilious vomiting within a few hours of birth. An abdominal radiograph demonstrates a dilated, gas-filled stomach and duodenal bulb, with a total absence of gas in the small and large bowel. What is the most likely diagnosis?

a. Hirschsprung’s disease

b. hypertrophic pyloric stenosis

c. duodenal atresia

d. duodenal duplication cyst

e. annular pancreas

Answer

A

c. duodenal atresia

Duodenal atresia is the commonest cause of congenital duodenal obstruction, and is often associated with Down’s syndrome and other congenital anomalies. Patients present soon after birth with persistent vomiting. The site of obstruction is usually distal to the ampulla of Vater, and a ‘double-bubble’ sign is seen on plain abdominal radiograph, representing gas within the duodenal bulb and stomach, but no gas is seen distally. Annular pancreas is also associated with Down’s syndrome, and may present neonatally with vomiting and the doublebubble sign, but obstruction is incomplete, with gas seen in the bowel distal to the stenosis. Hypertrophic pyloric stenosis usually presents with vomiting around 4–6 weeks of life, and a dilated duodenal bulb is not a feature. Duodenal duplication cyst may cause compression or displacement of the first and second parts of the duodenum, but rarely causes high-grade stenosis. The double-bubble sign is not a feature of Hirschsprung’s disease.

Question 21

Q

46) A 5-week-old boy presents with projectile vomiting. Examination of the abdomen is normal. He undergoes ultrasound scan of the abdomen, during which the following measurements are obtained: pyloric canal length of 18 mm, transverse pyloric diameter of 12 mm and pyloric muscle wall thickness of 3 mm. What is the most appropriate next step in management?

a. 24-hour pH probe monitoring

b. symptomatic management

c. pyloromyotomy

d. repeat ultrasound scan in 2–3 days

e. upper GI contrast examination

Answer

A

c. pyloromyotomy

Hypertrophic pyloric stenosis (HPS) is an idiopathic condition in which the circular muscle fibres of the pylorus undergo hypertrophy and hyperplasia, resulting in elongation and narrowing of the pyloric canal. Infants, often firstborn males, usually present at 4–6 weeks with projectile vomiting. If an experienced clinician can palpate an oliveshaped mass, no imaging is required. Otherwise, ultrasound scan is the imaging method of choice for diagnosis. Ultrasound findings include increased gastric peristalsis, failure of the pyloric canal to open, and elongated pylorus with thickened muscle. Pyloric canal length of >16 mm, transverse pyloric diameter of >11 mm and muscle wall thickness of >2.5 mm are indicative of HPS. The definitive treatment is pyloromyotomy.

Question 22

Q

47) A 2-day-old, full-term, male neonate presents with failure to pass meconium. A water-soluble contrast enema demonstrates a dilated sigmoid colon with a narrowed, poorly distensible rectum and a persistent corrugated appearance to the rectal mucosa. What is the most likely diagnosis?

a. colonic atresia

b. meconium ileus

c. imperforate anus

d. Hirschsprung’s disease

e. meconium plug syndrome

Answer

A

d. Hirschsprung’s disease

Hirschsprung’s disease is caused by an absence of parasympathetic ganglia in the muscle and submucosal layers of the distal colon, resulting in abnormal peristalsis and impaired evacuation of the colon. The rectum is virtually always involved, but the proximal extent of disease varies. Presentation is usually with failure to pass meconium by 48 hours. Characteristic features on contrast enema in the neonate include inversion of the rectosigmoid index (the normal neonatal rectum is of greater calibre than the sigmoid colon), tortuosity and corrugation of the narrowed aganglionic segment, and difficulty in obtaining good rectal distension. A discrete zone of transition is more commonly seen in older infants and children. Colonic atresia causes massive distension of the colon proximal to the area of stenosis, but is relatively rare. Meconium plug syndrome typically results in a dilated right and transverse colon with a transition point at the splenic flexure. Meconium ileus causes small bowel obstruction.

Question 23

Q

50) A 14-year-old girl is admitted following trauma and undergoes CT of the abdomen and pelvis. The large bowel is incidentally noted to lie on the left side of the abdomen, with the small intestine on the right. The superior mesenteric artery lies to the right of the superior mesenteric vein. What is the most likely diagnosis?

a. normal appearances

b. non-rotation

c. malrotation

d. reversed rotation

e. midgut volvulus

Answer

A

b. non-rotation

Non-rotation is an abnormality of bowel rotation in which the midgut loop returns to the peritoneal cavity without undergoing rotation. It is usually asymptomatic and is often found incidentally in older children or adults. The small bowel is located on the right side of the abdomen and the colon on the left side, and the small and large bowel have a common mesentery. The superior mesenteric vein lies to the left of the superior mesenteric artery, the reverse of the normal situation. In malrotation, the superior mesenteric vein tends to lie anterior to the superior mesenteric artery, and there is abnormal positioning of the duodenojejunal junction to the right and inferiorly, usually also with cephalad positioning of the caecum. Reversed rotation is rare, and results in the colon lying posterior to the superior mesenteric artery, with duodenum and jejunum in front of it. Midgut volvulus may complicate abnormalities of bowel rotation, resulting in torsion of the gut around the superior mesenteric artery due to a short mesenteric small bowel attachment. A clockwise ‘whirlpool’ sign may be seen on colour Doppler ultrasound scan, representing the superior mesenteric vein wrapping clockwise around the superior mesenteric artery.

Question 24

Q

57) A 6-year-old boy presents with lower gastrointestinal bleeding. He undergoes a [99mTc]-pertechnetate study, which demonstrates a small focal area of increased activity in the right lower quadrant 5 minutes after tracer injection, which increases in intensity with time paralleling the activity of the stomach. What is the most likely diagnosis?

a. Meckel’s diverticulum

b. appendicitis

c. duodenal duplication cyst

d. intussusception

e. peptic ulcer disease

Answer

A

a. Meckel’s diverticulum

Meckel’s diverticulum is a true diverticulum arising from the small bowel, usually 80–90 cm from the ileocaecal valve, representing failure of closure of the omphalomesenteric duct. Heterotopic gastric mucosa is present in 10–30% of diverticula, but is seen in 98% of those that present with bleeding. A [99mTc]-pertechnetate study demonstrates uptake in gastric mucosa within Meckel’s diverticulum, seen as a focal area of uptake, usually in the right lower quadrant with activity paralleling that of the stomach. Duodenal duplication cysts may contain heterotopic gastric mucosa, which may be a cause of a false-positive scan, but they often appear as larger areas of increased activity, and would be expected to be in the upper abdomen. Tracer uptake may be seen in inflammatory, obstructive and neoplastic conditions, including intussusception, peptic ulcer disease and appendicitis, but activity does not parallel that of the stomach.

Question 25

Q

60) A 2-year-old girl is admitted with abdominal pain and vomiting. No history of trauma is provided. On examination, she is tachycardic and has upper abdominal tenderness. Ultrasound scan of the abdomen demonstrates an echogenic intramural mass in the duodenum in keeping with an intramural haematoma. There is mild proximal dilatation of the duodenum and a small amount of free fluid within the abdomen. What is the most likely underlying cause?

a. duodenal diverticulum

b. haemophilia

c. pancreatitis

d. Henoch–Scho¨ nlein purpura

e. non-accidental injury

Answer

A

e. non-accidental injury

Duodenal intramural haematoma is usually traumatic, particularly following bicycle-handlebar accidents and lap-belt injuries. However, it isalso commonly seen in non-accidental injury, where the mechanism of injury is thought to be a blunt blow to the abdomen that compresses the duodenum against the vertebral column. Trauma to the duodenum may result in duodenal rupture, intramural tear or, most commonly, intramural haematoma. Ultrasound appearances are of an echogenic intramural mass that becomes progressively hypoechoic with maturation of the haematoma. There may be associated deformity or obstruction of the duodenum. CT may demonstrate free intraperitoneal fluid, though free air and frank perforation are uncommon. Spontaneous intramural haematoma may occur in Henoch–Scho¨ nlein purpura, but other features of the condition would be expected to be present. It may occur with anticoagulant therapy and blood dyscrasia, but haemophilia in females is extremely rare. Duodenal diverticula may cause gastrointestinal bleeding, but this is usually intraluminal rather than intramural. Duodenal intramural haematoma has been described in association with pancreatitis but is very rare.

Question 26

Q

58) A full-term baby boy born to a diabetic mother presents during the first day of life with abdominal distension and failure to pass meconium. Plain abdominal radiograph demonstrates a dilated, meconium-filled, proximal colon to the level of the splenic flexure, with an empty descending colon, sigmoid and rectum. Administration of a water-soluble enema results in passage of meconium, and the baby is discharged well 2 days later. What is the most likely diagnosis?

a. intussusception

b. Hirschsprung’s disease

c. meconium plug syndrome

d. meconium ileus

e. ileal atresia

Answer

A

c. meconium plug syndrome

Meconium plug syndrome is also known as small left colon syndrome and functional immaturity of the colon. It occurs most commonly in large infants and infants of diabetic mothers and is believed to be due to relativeimmaturity of bowel innervation. Characteristic features are of a dilated proximal colon with a calibre change at the splenic flexure and an empty descending colon. The functional obstruction is transient and usually self-limiting, and contrast enema may act as a stimulus for subsequent passage of (normal) meconium. Hirschsprung’s disease with a transition zone at the splenic flexure may mimic these findings, but the obstruction usually persists after contrast enema. Intussusception in this age group and at this site would be unusual. Meconium ileus and ileal atresia are causes of distal small bowel obstruction.

Question 27

Q

61) A 7-year-old boy is admitted with colicky abdominal pain and rectal bleeding. He is noted to have a purpuric skin rash on the extensor surfaces of his arms and legs. What are the most likely findings on CT of the abdomen?

a. multifocal bowel wall thickening

b. multiple small polyps in the colon

c. focal outpouching of the distal ileum

d. inflammatory changes at the terminal ileum

e. dilatation of the small bowel

Answer

A

a. multifocal bowel wall thickening

Henoch–Scho¨ nlein purpura is an acute systemic vasculitis that affects the skin, gastrointestinal tract, joints and kidneys. Children aged 3–10 years are predominantly affected, and may present with a purpuric rash on the extensor surfaces of the limbs, arthralgia and crampy abdominal pain with intestinal bleeding. Imaging demonstrates multifocal areas of bowel wall thickening due to intramural haemorrhage and oedema. Gastrointestinal complications include bowel infarction and perforation, as well as intussusception.

Question 28

Q

62) A 10-year-old boy is brought to accident and emergency after falling on his bike and sustaining a blunt abdominal injury by impacting the handlebars. CT shows free intraperitoneal fluid with a more focal collection of fluid at the mesenteric root. Additional findings of mesenteric stranding and focal bowel wall thickening are seen. There is diffuse homogeneous hyperattenuation of the pancreas, kidneys and bowel wall. What is the most likely underlying injury?

a. mesenteric rupture

b. bowel perforation

c. splenic rupture

d. renal contusion

e. pancreatic contusion

Answer

A

a. mesenteric rupture

The most common mechanism for traumatic mesenteric rupture is a road traffic collision, although such an injury can occur in children following any blunt abdominal trauma, with handlebar injuries and child abuse being well-recognized causes. Use of a lap belt makes children more prone to the injury. Bowel perforation, infarction and active haemorrhage are indications for immediate surgery and can be identified on CT. Most of the remaining cases are treated conservatively.
Free intraperitoneal air, extraluminal contrast or visible bowel wall defect is specific for perforation. Free fluid, haemorrhage and stranding are seen in perforation or mesenteric injury, with fluid at the root more likely to indicate the latter. Hyperattenuation of the pancreas, kidneys and bowel wall is a feature of hypoperfusion, along with small-calibre aorta and vena cava, and should not be mistaken for visceral injury.

Question 29

Q

69) Which of the following conditions is the most common underlying aetiology for intussusception in childhood?

a. viral gastroenteritis

b. Meckel’s diverticulum

c. Henoch–Scho¨ nlein purpura

d. duplication cyst

e. small bowel polyp

Answer

A

a. viral gastroenteritis

Most intussusceptions occur in childhood, usually between 6 months and 2 years of age. The vast majority are idiopathic or related to mucosal oedema and lymphoid hyperplasia following viral gastroenteritis. In the 5% of patients with a pathological lead point, causes include those listed above. Patients classically present with cramping abdominal pain, screaming episodes, ‘redcurrant jelly stools’ and a palpable abdominal mass. Most childhood intussusceptions are ileocolic. In contrast, a specific cause is identified in 80% of adult cases, and ileoileal intussceptions are more common than ileocolic.

Question 30

Q

72) An asymptomatic, 15-month-old girl is brought to the emergency department following witnessed ingestion of a hearing aid battery. A junior casualty officer asks for your advice about whether the patient requires imaging. What is the most appropriate imaging strategy?

a. reassurance that imaging is not indicated

b. patient to return for imaging if battery not passed within 48 hours

c. abdominal radiograph (and chest radiograph if abdominal radiograph negative)

d. ultrasound scan of the abdomen

e. patient to be referred straight for endoscopic removal

Answer

A

c. abdominal radiograph (and chest radiograph if abdominal radiograph negative)

Generally, in the case of ingested foreign bodies, a chest radiograph (including neck) at initial presentation is indicated. An abdominal radiograph is usually considered after 6 days only if there is doubt whether the foreign body has passed. However, if a sharp or potentially poisonous foreign body has been ingested, an abdominal radiograph is indicated at the time of presentation; a chest radiograph is indicated if the abdominal film is negative. Ingestion of disc batteries (small, coin-shaped batteries found in hearing aids, watches and calculators) may be associated with serious sequelae, particularly if the battery becomes lodged in the oesophagus, as is more likely with younger children and larger batteries. In this situation, leakage of alkaline material, and sodium hydroxide generated by electrolysis at the anode, can cause ulceration and perforation within a relatively short time. Radiography is indicated to locate the battery. If it lies within the oesophagus, emergency endoscopic removal is indicated. Batteries located beyond the oesophagus rarely require endoscopic removal, unless subsequent radiographs indicate delay in transit of the battery.

Question 31

Q

80) A 3-week-old baby boy born at full term presents with persistent jaundice. Clinical examination demonstrates hepatomegaly, and blood tests confirm hyperbilirubinaemia. He undergoes phenobarbital- augmented 99mTc-labelled IDA (iminodiacetic acid) cholescintigraphy, which demonstrates good hepatic activity within 5 minutes but no biliary clearance into the bowel on delayed images at 24 hours. What is the most likely diagnosis?

a. biliary atresia

b. neonatal hepatitis

c. cystic fibrosis

d. choledochal cyst

e. physiological jaundice

Answer

A

a. biliary atresia

Congenital biliary atresia is a destructive inflammatory process resulting in atresia of the bile ducts, which presents in neonates with persistent jaundice. Diagnosis is usually made with a combination of liver biopsy and hepatobiliary scintigraphy with a 99mTc-labelled iminodiacetic acid (IDA) analogue. Phenobarbital is given for 5 days prior to imaging to stimulate biliary secretion. Normal findings are of activity within the small bowel due to biliary excretion by 60 minutes, but in biliary atresia no biliary clearance is seen by 24 hours. Patients with non-obstructive causes of neonatal jaundice usually demonstrate biliary clearance into the bowel during the first 24 hours. Choledochal cyst usually presents in children, and cholescintigraphy may be used to confirm that the cystic structure is connected to the biliary system. The 99mTc-labelled IDA analogue will fill the cyst, and may show prolonged retention depending on the degree of obstruction. Cystic fibrosis may be associated with steatosis and biliary cirrhosis. Physiological jaundice resolves spontaneously within 2 weeks

Question 32

Q

86) A 2-year-old boy presents with jaundice, abdominal pain and precocious puberty. Ultrasound scan of the abdomen reveals a heterogeneous, hyperechoic, 10 cm mass with areas of coarse calcification in the right lobe of the liver. What is the most likely diagnosis?

a. hepatocellular carcinoma

b. hepatoblastoma

c. haemangioma

d. pyogenic abscess

e. choledochal cyst

Answer

A

b. hepatoblastoma

Hepatoblastoma is the commonest malignant liver tumour of early childhood, typically presenting before 3 years with pain, palpable mass, jaundice and weight loss, as well as precocious puberty due to hormone production. Tumours are typically large (average 10–12 cm) and appear to be heterogeneous with areas of calcification and necrosis. Metastases to the lung are common. Hepatocellular carcinoma is the second most common malignant liver tumour of children, but usually affects children over 5 years of age. Although it also commonly appears of heterogeneous echogenicity, calcifications are rare. Haemangiomas commonly appear hyperechoic on ultrasound scan and may contain calcifications, but are usually ,4 cm and are rarely seen in young children. Pyogenic abscess and choledochal cyst are typically hypoechoic lesions.

Question 33

Q

93) A 3-week-old girl presents with congestive cardiac failure and is found to have hepatomegaly on examination. Ultrasound scan of the abdomen shows an ill-defined, complex, heterogeneous, 5 cm mass in the right lobe of the liver containing multiple vascular channels on Doppler ultrasound scan. What is the most likely
diagnosis?

a. infantile haemangioendothelioma

b. hepatoblastoma

c. cavernous haemangioma

d. mesenchymal hamartoma

e. hepatocellular carcinoma

Answer

A

a. infantile haemangioendothelioma

Infantile haemangioendothelioma is the commonest benign hepatic tumour occurring in the first 6 months of life, consisting of multiple sinusoidal vascular channels with surrounding connective tissue stroma.
Patients typically present with an abdominal mass, or high-output cardiac failure secondary to arteriovenous shunting. Kasabach–Merritt syndrome (consumptive coagulopathy) is seen in 11% of patients. Typical CT features are of early peripheral enhancement and variable delayed central enhancement. Hepatoblastomas tend to occur in slightly older infants (peak 18–24 months) and congestive cardiac failure is not usually a feature. Mesenchymal hamartoma is a rare developmental liver tumour, which appears typically as a multiloculated cystic mass, but may appear solid and echogenic in infants due to innumerable microcysts.
However, these are generally hypovascular lesions. Hepatocellular carcinoma is more commonly seen in older children and adolescents. Cavernous haemangiomas are rarely seen in young children.

Question 34

Q

95) An 11-year-old boy presents with fever, vomiting and right lower quadrant pain. Ultrasound scan of the right lower quadrant demonstrates a blind-ending, compressible, fluid-filled, tubular structure measuring 4 mm in diameter, as well as enlarged mesenteric lymph nodes and several thickened loops of small bowel.
What is the most likely diagnosis?

a. acute appendicitis

b. mesenteric lymphadenitis

c. Crohn’s disease

d. Meckel’s diverticulum

e. enteric duplication cyst

Answer

A

b. mesenteric lymphadenitis

Mesenteric lymphadenitis is an inflammatory process affecting the mesenteric lymph nodes; it is most frequently caused by viral infection but also by Yersinia enterocolitica and other pathogens. It affects children and young adults, and clinically mimics acute appendicitis. Imaging findings are of enlarged mesenteric lymph nodes, and ileal and colonic wall thickening. The normal appendix must be visualized to differentiate it from acute appendicitis. Features of acute appendicitis on ultrasound scan are of a blind-ending, non-compressible, tubular, aperistaltic, fluidfilled structure measuring over 6 mm in diameter. Mesenteric lymph nodes may also be seen anterior to the right psoas muscle, but tend to be smaller and fewer than in mesenteric lymphadenitis. Thickened bowel wall may be seen on ultrasound scan in Crohn’s disease, but this would be less likely in this age group. Symptomatic Meckel’s diverticulum usually presents in younger children with gastrointestinal bleeding. Small bowel duplication cyst usually presents

Question 35

Q

100) A preterm male infant develops abdominal distension and blood-stained stools 2 days after birth. Plain abdominal radiograph shows distended and thickened bowel loops with curvilinear gas collections within the bowel wall. What is the most likely diagnosis?

a. necrotizing enterocolitis

b. Hirschsprung’s disease

c. meconium ileus

d. imperforate anus

e. viral gastroenteritis

Answer

A

a. necrotizing enterocolitis

Necrotizing enterocolitis is an acute inflammatory bowel condition seen predominantly in preterm infants. It usually presents 2–3 days after birth, with abdominal distension, vomiting and blood-stained stools. Plain film signs include distended small and large bowel, and bowel wall thickening, but the hallmark of the condition is pneumatosis intestinalis, seen in 80% of cases. This may be curvilinear (subserosal) or bubbly (submucosal) and may also be associated with portal venous gas. Hirschsprung’s disease is characterized by an aganglionic segment of distal colon, resulting in abnormal peristalsis and impaired evacuation of the colon. In this age group, it presents with failure to pass meconium, but is extremely rare in preterm infants. Meconium ileus and imperforate anus also present with failure to pass meconium. Pneumatosis intestinalis may be seen in association with mechanical obstruction resulting from these three conditions, but it is rare. It is not a feature of viral gastroenteritis.

Question 36

Q

(GIT) Which of the following may improve the detection of Meckel’s diverticulum on a [99mTc] pertechnetate study?

A. prior administration of cimetidine

B. prior administration of laxatives

C. prior administration of potassium perchlorate

D. maintenance of a full bladder

E. barium follow-through prior to study

Answer

A

A. prior administration of cimetidine

Cimetidine, a histamine H2-receptor antagonist, may be used to increase uptake of[99&hairsp;mTc] pertechnetate by inhibiting its secretion from gastric mucosa. Pentagastrinand glucagon have also been used to improve visualization, by stimulating uptake anddecreasing peristalsis respectively. Procedures such as colonoscopy and use of laxativesshould be avoided prior to the scan, as they may cause mucosal irritation. Potassiumperchlorate should not be used to block thyroid uptake, as it also blocks uptake ofpertechnetate by the gastric mucosa. The patient normally fasts for 3–4 hours and voidsprior to the study, as a full stomach or bladder may obscure an adjacent Meckel’sdiverticulum. Barium studies should be avoided for 3–4 days prior to the study, asattenuation by the barium may hamper interpretation.

Question 37

Q

1 A 3 year old presents with entral epigastric pain. Blood tests reveal a raised amylase. Which of the following is the least likely cause?

(a) Choledochal cyst

(b) Cystic fibrosis

(c) Henoch-Schonlein purpura

(d) Non-accidental injury

(e) Rubella

Answer

A

(c) Henoch-Schonlein purpura

Trauma (including NAI) is one of the leading causes of pancreatitis in the paediatric population. Other causes include cystic fibrosis, hyperlipidaemia syndromes, drugs, viral, hyperparathyroidism, hypercalcaemia, idiopathic, Pearson syndrome (mitochondrial disorder), Schwachman-Diamond syndrome, and anatomical anomaly (pancreas divisum).

Question 38

Q

13 A 2 year old boy presents with haematochezia. He is in obvious distress on examination, but the bowel sounds are normal. AXR is unremarkable, and the paediatric team suspect a Meckel’s diverticulum. Your advice is sought regarding further investigation. Which of the following would be the most sensitive radiological investigation?

(a) Barium follow-through

(b) CT

(c) MRI

(d) 99mTc-pertechnatate scintigraphy

(e) Ultrasound

Answer

A

(d) 99mTc-pertechnatate scintigraphy

Pertechnatate studies are the most sensitive test (85%), although wireless capsule endoscopy has good potential. Pertechnatate is taken up by the ectopic gastric mucosa within the Meckel’s. False +ve results include AVM, haemangioma, UC, Crohn’s, appendicitis; false -ve results occur if the diverticulum contains no gastric mucosa.

Question 39

Q

17 An 8 month old boy presents with red-currant jelly stool and abdominal distension. US confirms an intussusception and the paediatric surgeons ask you to attempt fluo’roscopic reduction. Which of the following is a contraindication to fluoroscopic reduction?

(a) Age> 12 months

(b) Evidence of small bowel obstruction

(c) Free intra-peritoneal fluid

(d) Hypovolaemic shock

(e) US demonstrates fluid in the lumen around the Intussusceptum

Answer

A

(d) Hypovolaemic shock

Hypovolaemic shock suggests ischaemic bowel, which would require surgical intervention, furthermore reduction should not be attempted in a sick infant and the patient should be appropriately resuscitated before any attempts at reduction are made. Other contraindications include pneumoperitoneum and peritonitis. The remaining options are not absolute contra-indications, but their presence reduces the chances of successful therapeutic reduction. Small bowel obstruction implies ischaemia or the presence of a tight intussusception. Free intraperitoneal fluid or fluid in the lumen surrounding the intussusceptum suggests oedema or ischaemia of the bowel. An older age (> 12 months) suggests a pathological lead point may be the aetiology, in which case resection may be necessary.

Question 40

Q

18 A supine AXR is performed on a 4 day old neonate born at 32 weeks, who is noted to have increasing abdominal distension and appears clinically unwell. Which of the following features is an indication for urgent surgery?

(a) Air in the portal vein

(b) Adynamic ileus

(c) Pneumatosis intestalis

(d) Pneumobilia

(e) Pneumoperitoneum

Answer

A

(e) Pneumoperitoneum

NEC is the commonest GI emergency in premature infants. It is an infective/ ischaemic disorder of the neonatal gut in a compromised baby secondary to hypoxia. It typically presents at 2-3 days after birth and in 90% occurs before day 10. Treatment is normally conservative, surgery may be necessary due to perforation. Compared to adult patients, air in the portal system does not have such a grave prognosis. Late complications include intestinal strictures.

Question 41

Q

21 Antenatal US shows a RUQ cystic structure. A day 3 US shows an anechoic cyst with hyperechoic inner lining and a hypoechoic outer rim, causing superior-anterior displa_cement of the 1st and 2nd portion of the duodenum without bile duct dilation. What is the most likely diagnosis?

(a) Choledochal cyst

(b) Choledochocoele

(c) Duplication cyst

(d) Mesenteric lymphangioma

(e) Pancreatic pseudocyst

Answer

A

(c) Duplication cyst

These cysts appear anechoic, displace the proximal duodenum supero-anteriorly. There is a double capsule: inner mucosa! Lining (hyperechoic) and outer rim of bowel wall (hypoechoic), this ·can be identified as the ‘muscular rim’ sign described. Choledochal cysts have 5 subtypes (type V = Caroli’s disease). All bar type Ill involve the intrahepatic bile ducts. Choledochocoeles arise from the duodenal portion of CBD, but other features support a duplication cyst. In mesenteric lymphangioma there is a single wall.

Question 42

Q

24 A 3 week old boy presents with high output cardiac failure. On examination he has a mass within the right upper quadrant. CT shows a large heterogeneous mass with central areas of low density, occupying the entire left lobe of the liver. The mass enhances peripherally in the arterial phase. What is the most likely diagnosis?

(a) Haemangioendothelioma

(b) Haemangiopericytoma

(c) Hamartoma

(d) Hepatoblastoma

(e) Hepatocellular carcinoma

Answer

A

(a) Haemangioendothelioma

Infantile haemangioendothelioma typically presents in neonates (85% are diagnosed at <j 6 months). 15% present with high output cardiac failure (AV shunts), consumption can lead to thrombocytopaenia/ DIC. Imaging characteristics are similar to adult haemangiomas. Haemangiopericytoma is a soft tissue sarcoma. Broadly speaking paediatric liver tumours present in ‘alphabetical order’ with age: haemangioendothelioma (neonates), hamartoma (15-22 months), hepatoblastoma (<3 years), and HCC (>3 years).

Question 43

Q

35 A 3 year old presents with abdominal pain and vomiting. The paediatric surgeons are concerned about possible malrotation and request a plain film in the first instance. What is the most common plain radiograph finding in malrotation?

(a) Bowel wall oedema

(b) Caecum located on left side

(c) Normal

(d) Small bowel obstruction

(e) SMA lying to right of the SMV

Answer

A

(c) Normal

The commonest plain film finding in malrotation is ‘normal appearances’, thus a ‘normal’ AXR cannot exclude malrotation. Other plain film findings of malrotation include ascites, bowel wall oedema (thumb-printing, due to SMV compression), evidence of ischaemic gut (due to SMA compression), duodenal obstruction (due to Ladd’s bands), SBO, right-sided small bowel, left-sided caecum/ colon.

Question 44

Q

37 A neonate has bile stained vomiting post feeding. The AXR shows a ‘double bubble’ sign? Which of the following conditions is the least likely underlying cause?

(a) Annular pancreas

(b) Duodenal atresia

(c) Ladd’s bands

(d) Pre-duodenal vein

(e) Pyloric stenosis

Answer

A

(e) Pyloric stenosis

The ‘double bubble’ sign describes gas within the proximal duodenum and stomach. There is often a gasless distal abdomen due to obstruction in the duodenum. Pyloric stenosis causes obstruction at the level of the pylorus. In this condition, the duodenum is usually gas-free if gas passes into the duodenum it will also freely pass more distally.

Question 45

Q

42 A pregnant mother with low α-FP, increased β-hCG and decreased unconjugated oestriol on screening is considered high risk for carrying a baby with Down’s syndrome. An 18 week anomaly US is arranged. Which of the following findings indicative of Down’s syndrome is least likely to be seen?

(a) Cystic hygroma

(b) Duodenal atresia

(c) Omphalocoele

(d) Increased nuchal thickness

(e) Short femur length

Answer

A

(b) Duodenal atresia

13-50% may not have any US-detectable anomalies. Duodenal atresia is present in 50%, but is not detected before 22 weeks. Nuchal thickness is increased in 40% to < 3 mm at 10-13 wks, 5 mm at 14- 18 wks; CHDs are present in 40%. Other US findings include hydrops, echogenic bowel, pyelectasis, hypoplasia of the 5th digit, and 11 pairs of ribs.

Question 46

Q

43 Regarding duplication cysts of the gastro-intestinal tract in neonates. Where is the commonest location?

(a) Duodenum

(b) Ileum

(c) Jejunum

(d) Oesophagus

(e) Stomach

Answer

A

(b) Ileum

15% of paediatric abdominal masses are duplication cysts, they can be found anywhere along the GI tract, commonest locations are: ileum (30-33%), oesophagus (17-20%), colon (13-20%), jejunum (10-13%), stomach (7%), pylorus (4%), duodenum (4-5%), ileocaecal junction (4%), rectum (4%).

Question 47

Q

(GIT) Regarding pancreas divisum, which of the following statements is true?

(a) The dorsal pancreas drains via the major papilla

(b) Pancreatic drainage is via the duct of Santorini

(c) The dorsal and ventral pancreas drain via the same channel

(d) The common bile duct and dorsal pancreas drain via the same channel

(e) The major papilla lies proximal to the minor papilla

Answer

A

(b) Pancreatic drainage is via the duct of Santorini

Dorsal and ventral pancreas drain separately in to the duodenum via the minor and major papillae respectively.

Question 48

Q

3 A neonate presents with vomiting, choking and drooling of secretions. An 8 Fr NG feeding tube cannot be passed into the stomach. What is the most likely diagnosis?

(a) Oesophageal agenesis with no distal oesophageal bud and no tracheal fistula

(b) Oesophageal atresia with a distal oesophageal bud, but no tracheal fistula

(c) Oesophageal atresia with a proximal tracheal fistula

(d) Oesophageal atresia with a distal tracheal fistula

(e) Oesophageal atresia with both proximal and distal tracheal fistula

Answer

A

(d) Oesophageal atresia with a distal tracheal fistula

The most common type of oesophageal atresia is that associated with a distal tracheal fistula (type C in the Gross classification, and referred to as ‘N’ shape), which accounts for 75-80% of cases. Pure atresia occurs in 10%, TOF in 10% (type E, and referred to as ‘H’ shape); other forms are rare. Oesophageal atresia with no distal oesophageal bud is very rare and is not classified within the Gross system.

Question 49

Q

7 Regarding fluoroscopically guided reduction for the treatment of intussusception in children. Which of the following is an advantage of hydrostatic barium over air reduction?

(a) It produces smaller tears if perforation occurs

(b) It is easier to confirm reduction across the ilea-caecal valve

(c) It is faster, thus less radiation dose

(d) It results in less contamination of the abdominal cavity if perforation occurs

(e) It delivers higher intracolic pressures

Answer

A

(b) It is easier to confirm reduction across the ilea-caecal valve

Fluoroscopy has the ‘rule of 3s’: 3 feet above the table (pressure 120 mmHg), a maximum of 3 attempts with 3 mins/ attempt and 3 mins between attempts. Air reduction is now used in most centres and answers (a), (c), (d) and (e) list its advantages. The only disadvantage of air reduction is confirmation of reduction across the ileo-caecal valve, especially when gas is present in the ileum. Although there is also a small risk of tension pneumoperitoneum with air reduction, any potential peritoneal ‘spill’ following perforation will be less than with barium reduction.

Question 50

Q

10 A screening antenatal US shows an abdominal wall .defect. The differential diagnosis is between gastroschisis and omphalocoele. Which additional feature confirms the diagnosis of gastrosch is?

(a) Associated herniation of the liver

(b) Central herniation into the umbilical cord

(c) Involvement of all 3 layers of the abdominal wall

(d) Multiple associated anomalies

(e) The presence of a covering membrane

Answer

A

(c) Involvement of all 3 layers of the abdominal wall

Gastroschisis is a defect involving all 3 layers of the abdominal wall, and is located to the right side of the cord in 90% of cases. There is normal insertion of the umbilical cord, and a lower incidence of associated anomalies. Omphalocoele is herniation of intra-abdominal contents into the base of the umbilical cord, any organs may herniate, but liver herniation is typical +/- bowel. Omphalocoeles have a covering membrane.

Question 51

Q

14 A 4 week old boy presents with a history of non-bilious vomiting and failure-to-thrive, but clinical examination is normal. Which of the following US features confirm the diagnosis of pyloric stenosis?

(a) Hyperechoic pyloric muscle

(b) Pyloric canal length of 13 mm

(c) Pyloric muscle wall thickness of 4 mm

(d) Reduced peristaltic waves within the antrum

(e) Transverse pyloric canal diameter of 10 mm

Answer

A

(c) Pyloric muscle wall thickness of 4 mm

Pyloric stenosis can be diagnosed clinically. US diagnostic criteria include: pyloric volume > 1.4 cm3, pyloric muscle wall thickness > 3 mm, pyloric canal length > 17 mm, pyloric transverse diameter > 13 mm when the pyloric channel is closed. In pyloric stenosis, a hypoechoic ring of hypertrophied muscle around the inner echogenic mucosa produces the ‘target sign’. Peristaltic waves are increased and hyperdynamic in an attempt to overcome the obstruction.

Question 52

Q

28 A 2 day old ex-premature boy on the neonatal unit with suspected necrotising enterocolitis has deteriorated, and the clinical team are worried about perforation. Which investigation should you recommend?

(a) Cross-table lateral AXR

(b) Erect CXR

(c) Left-side down decubitus AXR

(d) Right-side down decubitus AXR

(e) Supine AXR

Answer

A

(c) Left-side down decubitus AXR

Left-side down decubitus is the optimal view, it allows air to rise to the right lateral abdomen, which can then be seen between the liver edge and the abdominal wall; with right-side down films it is harder to detect free air due to presence of stomach/ splenic flexure. An erect CXR is likely to be impractical in a ventilated neonate. Signs on supine AXRs are often subtle (football sign, Rigler’s sign, or air around the falciform ligament). In a cross-table lateral it will be hard to differentiate free air and distended bowel (both rise centrally).

Question 53

Q

29 A neonate is noted to be jaundiced. Investigations are subsequently requested by the clinicians. Which of the following results is most supportive of the diagnosis of neonatal hepatitis over biliary atresia?

(a) Blood tests reveal a conjugated bilirubinaemia

(b) HIDA scintigraphy shows rapid hepatic tracer accumulation

(c) HIDA scintigraphy shows visualisation of tracer in bowel at 12 hours

(d) US shows no intra-hepatic duct dilatation

(e) US cannot visualise the gallbladder

Answer

A

(c) HIDA scintigraphy shows visualisation of tracer in bowel at 12 hours

Both conditions have conjugated hyperbilirubinaemia. The findings of a normal (> 1.5 cm) or enlarged gallbladder supports neonatal hepatitis, however, either finding can be present in BA as the GB can appear normal if the atresia is distal (in 20%). There is no intrahepatic duct dilatation in BA due to panductal sclerosis. In HIDA scintigraphy BA has good hepatic visualisation within 5 mins, but no excretion into the bowel, and no tracer uptake seen by 24 hours; in neonatal hepatitis there is slow and reduced uptake of the tracer by the liver, but bowel activity is seen by 24 hours.

Question 54

Q

30 Regarding enteric duplication cysts, which of the following is true?

(a) They are most commonly located in duodenum

(b) The majority communicates with the lumen

(c) There is usually calcification within the wall

(d) The majority are located on the anti-mesenteric side

(e) The capsule contains two walls

Answer

A

(e) The capsule contains two walls

Duplication cysts can be located anywhere along the GI tract, the most common location is the terminal ileum, followed by oesophagus, duodenum, colon, jejunum and stomach. They represent 15% of paediatric abdominal masses, and may be detected on antenatal US. Small bowel cysts are usually located on the mesenteric side of the bowel, oesophageal ones are typically intra-luminal. The cysts have a double capsule made of the bowel wall and mucosa, they are typically non-communicating and calcification is rare.

Question 55

Q

34 A 2 day old baby born to a diabetic mother presents with abdominal distension, never having opened the bowels. Water-soluble enema demonstrates a collapsed descending colon to the splenic flexure, with dilated proximal colon and small bowel. Following the study, copious amount of meconium are immediately passed. What is the most likely diagnosis?

(a) Hirschsprung’s disease

(b) Ileal atresia

(c) lmperforate anus (high malformation type)

(d) Meconium ileus

(e) Meconium plug syndrome

Answer

A

(e) Meconium plug syndrome

Meconium plug syndrome results from colonic inertia with subsequent inspissation of meconium. It typically presents in large babies, born to diabetic mothers, is not related to meconium ileus. Hirschsprung’s disease is the key differential diagnosis and can have similar radiological appearances. However, meconium is rarely passed following contrast examination and the given history of a diabetic mother is a leader to meconium plug syndrome.

Question 56

Q

35 What is the commonest presenting feature of a Meckel’s diverticulum?

(a) Obstruction

(b) Perforation

(c) Diverticulitis

(d) Volvulus

(e) Bleeding

Answer

A

(e) Bleeding

This is seen in over a quarter of cases. The remaining presentations are well-documented, but occur less commonly.

Question 57

Q

(GU) 47 Antenatal ultrasound at 22 weeks shows thick walled oedematous freely floating bowel loops outside the foetal abdomen. A 2 cm defect in the anterior abdominal wall is seen to the right of a normally inserted umbilical cord. Polyhydramnios but no foetal ascites is noted. No other congenital abnormality can be detected at this stage. What is the likely diagnosis?

(a) Gastroschisis

(b) Omphalocoele

(c) Limb-body wall complex

(d) Amniotic band syndrome

(e) Ectopia cordis

Answer

A

(a) Gastroschisis

This can be differentiated from omphalocoele by its location (right paraumbilical as opposed to midline), lack of covering membrane and relatively small defect size. It is also less commonly associated with other congenital defects. It is difficult to reliably diagnose this condition until at least 20 weeks gestation

Question 58

Q

50 A 2 week old baby presents with bilious vomiting. The surgical team request an upper GI Barium study looking for malrotation. Which of the following is the expected normal position of the duodenojejunal junction on the frontal view, making malrotation unlikely?

(a) Above the level of duodenal bulb, to the left of spine

(b) Above the level of duodenal bulb, to the right of spine

(c) At the level of duodenal bulb, to the right of spine

(d) Below the level of duodenal bulb, to the left of spine

(e) Below level of duodenal bulb, to right of spine

Answer

A

(a) Above the level of duodenal bulb, to the left of spine

Malrotation is the abnormal position of the bowel due to a narrow mesenteric attachment following arrest of rotation and fixation in utero. The normal DJJ is at the ligament of Treitz, to the left of the vertebral (usually L 1) pedicle at a level above or equal with the duodenal bulb on a true AP film. In malrotation, the mesentery is short, thus the DJJ does not reach the ligament of Treitz.

Question 59

Q

52 A 1 day old neonate has bile-stained vomiting. An AXR shows a dilated gas-filled stomach with air also within the duodenal bulb. No bowel gas seen distally. Which of the following is the more likely cause of these appearances?

(a) Annular pancreas

(b) Duodenal stenosis

(c) Meconium ileus

(d) Mid-gut volvulus

(e) Pyloric stenosis

Answer

A

(a) Annular pancreas

The ‘double bubble’ sign is described and implies obstruction at the level of the duodenum. Duodenal atresia (not stenosis) is thecommonest cause (30%) and is associated with Down’s. Annular pancreas is second commonest cause, others include: duodenal web/ diaphragm, pre-duodenal vein, midgut volvulus, and SMA syndrome..

Question 60

Q

65 A neonate presents at 48 hours with abdominal distension, bilious vomiting, and failure to pass meconium. The AXR shows multiple dilated loops of bowel, with a ‘soap bubble’ appearance in the RIF. Water soluble enema confirms microcolon and meconium is subsequently passed. What is the most likely underlying condition?

(a) Cystic fibrosis

(b) Duodenal atresia

(c) Hirschsprung’s disease

(d) Maternal diabetes

(e) Pancreatic duct atresia

Answer

A

(a) Cystic fibrosis

Meconium ileus is the initial presentation in 10-15% of CF neonates, but over 90% of infants presenting with meconium ileus have CF (atresia of the pancreas or pancreatic duct are other causes). The ‘soap bubble’ appearance may be seen in the RIF and represents gas mixed with meconium. A water soluble contrast enema aids diagnosis (shows an unused ‘micro’ colon) and treatment (if unsuccessful, surgery is required).

Question 61

Q

67 A 2 year old boy presents with rectal bleeding. He is not obviously in discomfort, there are no signs of obstruction and the AXR is normal. A Meckel’s diverticulum is suspected and a nuclear medicine study is arranged. Which of these pharmaceuticals should be avoided prior to image acquisition?

(a) Cimetidine

(b) Glucagon

(c) Pentagastrin

(d) Perchlorate

(e) Pertechnetate

Answer

A

(d) Perchlorate

Tc-99m pertechnetate is the radiotracer used; cimetidine, pentagastrin and glucagon have been shown to improve the sensitivity of the test. Pentagastrin enhances tracer uptake in gastric mucosa, cimetidine ‘traps’ pertechnetate within the Meckel’s, and glucagon reduces peristalsis, thus inhibits tracer washout. Potassium perchlorate given orally after the study protects the thyroid gland from accumulation of pertechnetate, however, if used prior to scanning it will block tracer uptake by gastric mucosa.

Question 62

Q

71 Regarding fluoroscopically-guided air reduction for the treatment of intussusception in a chiid. Which of the following is most likely to predict a successful outcome?

(a) 24 hour history of symptoms

(b) lntussusception seen in the sigmoid colon on US

(c) US demonstrates fluid in the lumen around the intussusceptum

(d) US shows blood flow in the intussusceptum

(e) The child is aged > 12 months

Answer

A

(d) US shows blood flow in the intussusceptum

Vascular flow is a good sign - ischaemia is unlikely. A left-sided lesion is more difficult to treat, but the majority are ileocolic (75-95%) or ileo-ileocolic (9%); colocolic lesions are very rare. A short history (< 24 hours) suggfusts there will be less oedema and the intussusception is less likely to have passed through to the left colon. An older age (> 12 months) suggests a pathological lead point may be the aetiology. lntussusception is idiopathic in 95% of paediatric cases.

Question 63

Q

75 A 4 day old boy has abdominal distension and has not opened his bowels. A contrast enema shows a narrow rectum and dilated descending colon. AXR after 24 hours shows contrast medium within the descending colon. What is the most likely diagnosis?

(a) Hirschsprung’s disease

(b) I leal atresia

(c) lmperforate anus (high malformation type)

(d) Meconium ileus

(e) Meconium plug syndrome

Answer

A

(a) Hirschsprung’s disease

Hirschsprung’s disease presents in neonates with abdominal distension and failure to pass meconium. Proximal obstruction +/- perforation can be seen on AXR. The rectum is always involved, but the proximal extent of disease varies. The normal colon will be dilated. If the transition point lies near the recto-sigmoid junction, the rectum: sigmoid diameter ratio will be less than 1 (normal is > 1 :1 ). Retention of contrast medium on a delayed 24 hours film is a classical feature, but definitive diagnosis-is-by-biopsy.

Question 64

Q

(GIT) A one-month-old baby girl with a persistent productive cough developed progressively worsening respiratory distress. She had a chest radiograph which showed clear lungs. Linear gas shadows were visible projected over the central liver. What is the most likely diagnosis?

a) Respiratory distress syndrome

b) Bronchopneumonia

c) Tracheoesophageal fistula

d) Congenital tracheobiliary fistula

e) Pulmonary emboli

Answer

A

Answer D: Congenital tracheobiliary fistula

The finding of pneumobilia is key to thinking of the diagnosis.

Answer 65

A

a. Type B

Congenital TE fistula and oesophageal atresia occur in approximately 1 in 4000 live births. They are divided into five subtypes, A to E. Type C is the most common, comprising 75% of all types and involves oesophageal atresia with a distal TE fistula. Type D involves oesophageal atresia with both proximal and distal TE fistula, and type E is a TE fistula without oesophageal atresia. Therefore types C to E do not typically present with gasless abdomen. Type B is oesophageal atresia with a proximal TE fistula; there is no communication between the trachea and the distal oesophagus, and therefore a gasless abdomen is typical. Type A is oesophageal atresia without TE fistula and therefore may also present with a gasless abdomen, but is not a listed option.

Answer 66

A

a. Prune belly syndrome

Prune belly syndrome is a non-hereditary disorder occurring in males with a triad of abdominal wall muscular hypoplasia, bilateral cryptorchidism and distended nonobstructed ureters. Other associations include malrotation of the gastro-intestinal tract, intestinal atresia, cystic renal dysplasia, vesico–ureteric reflux, pulmonary hypoplasia and cardiac anomalies (including PDA, tetralogy of Fallot and VSD).

Answer 67

A

c. Duodenal atresia

Duodenal atresia typically presents in the first few days of life with bilious vomiting, and is caused by failure of recanalisation of the duodenal lumen in the fetus. It is associated with Down’s syndrome, congenital heart disease and other gastro-intestinal disorders such as malrotation, annular pancreas and biliary atresia. The characteristic feature on abdominal X-ray is the double-bubble sign with dilatation of the stomach and duodenal cap.

Answer 68

A

c. Presence of blood flow within the intussusceptum

The following criteria are associated with a lower rate of successful enema reduction: age less than three months or greater than five years, long duration of symptoms, passage of blood per rectum, significant dehydration, obstruction of the small intestine and visualization of the dissection sign during enema therapy.

Answer 69

A

a. Pyloric muscle wall thickness of 2mm

Hypertrophic pyloric stenosis presents between four and six weeks of life with non-bilious vomiting, typically in first-born males. A palpable olive-shaped mass is a sign with reported sensitivity of up to 80%, but ultrasound is the most frequently used imaging modality. Typical ultrasound features include the target sign (central hyperechoic mucosa with surrounding hypoechoic pyloric muscle), the nipple sign (pyloric mucosa indenting the gastric antrum), pyloric canal length >16 mm, transverse pyloric diameter >13mm and pyloric muscle wall thickness >3 mm. Pyloric stenosis can be difficult to differentiate radiologically from infantile pylorospasm. Typically with pylorospasm the appearances change with time, and so if the pyloric muscle thickness is measured at less than 3mm this makes infantile pylorospasm the more likely diagnosis.

Answer 70

A

c. Presence of three lobes on the left

The neonate has heterotaxy with right atrial isomerism, which is associated with bilateral trilobed lungs, and both atrial appendages are short and broad-based. It is also usually associated with bilateral SVC and bilateral eparterial bronchus.

Answer 71

A

a. Recent barium investigation

Prior to adolescence a Tc-99m pertechnetate scan has a high pick-up rate for a Meckel’s diverticulum. This declines with increasing age as the test relies on the presence of ectopic gastric mucosa, which is less likely to be present in someone asymptomatic throughout childhood. A false negative result is most commonly due to insufficient mass of ectopic gastric mucosa within the Meckel’s diverticulum, but may also be seen with barium from recent investigation attenuating the gamma radiation, and dilution of intraluminal activity due to rapid bowel transit.

Answer 72

A

b. Meconium peritonitis

These features are typical of meconium peritonitis. This is a chemical peritonitis secondary to bowel perforation in utero. The intraperitoneal meconium characteristically calcifies within 24 hours of perforation. Other features seen on ultrasound include fetal ascites,polyhydramnios and bowel dilatation.

Answer 73

A

b. Hirschsprung’s disease

These features are typical of Hirschsprung’s disease. This is caused by absence of parasympathetic ganglion cells in the bowel wall. Meconium ileus typically shows an empty microcolon on water-soluble enema and colonic atresia shows a distal microcolon with obstruction at the point of atresia. Functional immaturity of the colon typically shows microcolon distal to the splenic flexure with an abrupt transition to mildly dilated proximal colon

Answer 74

A

a. Congenital biliary atresia

Congenital biliary atresia is the most likely diagnosis. It has a slight female preponderance and typically presents in the neonatal period. Ultrasound features include a large coarse liver with increased periportal reflectivity. Biliary dilatation is not typical. In severe neonatal hepatitis, the features on Tc-99m HIDA scan can appear similar to biliary atresia with reduced extraction and excretion. However, the more common picture is one of reduced hepatic uptake.

Answer 75

A

c. Defect situated to the right of the midline

Gastroschisis tends to be a small defect (often less than 2.5 cm in length) which occurs to the right of the midline. The herniated bowel does not have a peritoneal lining and floats freely within the amniotic fluid. Features suggesting exomphalos include the presence of other congenital anomalies, midline defect, fetal ascites, herniation of the liver, amnioperitoneal membrane covering the bowel and the defect covering a large extent of the anterior abdominal wall.

Answer 76

A

A Approximately half of all omphalocoeles are associated with other chromosomal abnormalities.

Only 5% of cases of gastroschisis are associated with other congenital anomalies.

Answer 77

A

E The TOF is usually found above the level of the carina.

Imaging is best performed in the prone position with a horizontal beam. Infants with an H-type fistula will have gas-filled bowel loops.

Answer 78

A

C Following contrast administration, there is centripetal and heterogeneous enhancement on CT.

Calcification is common and present in 50% of plain abdominal radiographs. Hepatoblastoma tends not to be multifocal; this would make hepatocellular carcinoma a more likely diagnosis.

Answer 79

A

E Transverse pyloric diameter of greater than 11 mm

Ultrasound criteria include canal length >16 mm, transverse pyloric diameter >11 mm, muscle wall thickening > 2.5 mm and increased gastric motility. A pylorus that does not open is associated with hypertrophic stenosis; however, it may also be seen in pylorospasm.

Answer 80

A

A ‘Corkscrewing’ of the duodenum and jejunum

Malrotation predisposes patients to midgut volvulus, giving rise to the ‘corkscrew’ pattern.

Answer 81

A

B A contrast enema showing pellets of meconium within the terminal

A contrast enema will demonstrate a microcolon, with reflux into the terminal ileum which should be small in calibre and demonstrate pellets of meconium. Reflux into the more proximal ileum will demonstrate a dilated

Answer 82

A

D Multiple low reflective areas with a central focus of high reflectivity in the

The typical ultrasound findings represent bile duct lakes with the portal vein seen as a central echogenic dot.

Answer 83

A

D On ultrasound, the appendix appears larger than normal in CF.

Ultrasound is a first line imaging investigation, and is very useful in picking up early stage liver cirrhosis and gallstones.

Answer 84

A

B Distal intestinal obstruction

Distal intestinal obstruction presents in 10-15% of older CF sufferers and can be potentially fatal. Treatment is with oral Gastrografin and a Gastrografin enema.

Answer 85

A

B An ultrasound finding of hypoechoic, thickened bowel wall with echogenic areas would be supportive of the clinical diagnosis.

The duodenum and jejunum are the commonest sites of involvement. However, intussusceptions tend to be located in the ileoileal region and are usually transient.

Answer 86

A

B A normal gallbladder which distends with fasting suggests an alternative diagnosis.

Eighty per cent of infants with persistent neonatal jaundice will have biliary atresia or neonatal hepatitis. Decompression of biliary atresia is important for preventing cirrhosis.

Answer 87

A

A A persistent, solitary dilated loop is an indicator of impending perforation.

Portal venous gas is seen in 10% of cases and is not always fatal. Its disappearance may indicate impending perforation.

Answer 88

A

D The risk of perforation during the procedure is around 5%.

The success rate is 60% with a perforation rate of 5%-

Answer 89

A

C The umbilical vein drains into the left portal vein.

The liver in the’newborn is less reflective than the kidney up to the age of 3—4 months. A patent umbilical vein after 2—3 weeks is not usual and is associated with portal hypertension.

Answer 90

A

C Meckel’s diverticulum

In adults, a minority of Meckel’s diverticula contain gastric mucosa and can lead to GI bleeding. The diverticulum may also become inverted and act as a ‘lead point’ for an intussusception.

Answer 91

A

D In a positive study, the activity in the Meckel’s diverticulum appears at the same time and same intensity as the gastric mucosa.

In children the majority of Meckel’s diverticula contain intestinal mucosa.

Answer 92

A

D On an enema, the aganglionic segment extends to the rectosigmoid

Skip lesions and short segment disease are unusual and a biopsy is required for definitive diagnosis. The catheter balloon should never be inflated, as this runs the risk of perforation.

Answer 93

A

B Down’s syndrome is present in 20—30% of patients with duodenal atresia.

Trisomy 21 is seen in approximately 30% of patients with duodenal atresia/stenosis and an annular pancreas.

Answer 94

A

C Pneumatic reduction has a radiation dose lower than that of barium reduction.

Studies have demonstrated that effective reduction and a lower radiation dose are achieved by using air reduction rather than barium.

Answer 95

A

D Meckel’s diverticulum

This angiographic finding is diagnostic of a Meckel’s diverticulum as it indicates that a remnant of the omphalomesenteric (vitelline) duct is present.

Answer 96

A

B Pass a nasogastric tube, then inject a small amount of air followed by a supine chest radiograph.

A nasogastric tube is a very useful tool in suspected OA, but if the tube passes into the stomach it may have entered through a fistulous connection. However, if an NG tube curls up in a proximal air-filled oesophagus, OA is highly likely.

Answer 97

A

E. Infantile haemangioendothelioma.

Also known as infantile hepatic haemangioma, infantile haemangioendothelioma is a vascular neoplasm and the most common benign hepatic tumor of infancy. It may be a solitary mass or multifocal, and most are diagnosed before the age of 1 year. The lesion itself runs a benign course, but life-threatening clinical complications may occur. These include high-output cardiac failure secondary to large arterio-venous shunts and Kasabach–Merritt syndrome of coagulopathy secondary to intratumoral platelet sequestration. On ultrasound the lesions are well-demarcated and are generally hypoechoic or of mixed echogenicity. On CT and MRI the enhancement pattern of the lesion is similar to adult haemangioma. There is intense early peripheral nodular enhancement, with centripetal progression on the later images.
Hepatoblastoma rarely occurs in the newborn but can be seen in young infants. This tumour is distinguished by a heterogeneous rather than intense centripetal enhancement pattern and markedly elevated levels of alphafetoprotein (AFP) in 90% of patients. AFP level is rarely elevated in infantile haemangioendothelioma.
Mesenchymal hamartoma of the liver, like infantile haemangioendothelioma, may also be found in the perinatal period. This benign tumour differs in imaging appearance from infantile haemangioendothelioma in that it usually appears as a multicystic, multilocular mass with enhancement of only the septa and solid portions. Less commonly, mesenchymal hamartoma may be predominantly solid, but it differs from infantile haemangioendothelioma in that it is hypovascular at dynamic contrast-enhanced imaging. Whilst metastases could occur in an infant (e.g. neuroblastoma), they would tend to be hypodense to normal liver on contrast-enhanced CT. Hepatoma is exceedingly rare in an infant and the imaging characteristics described would not be typical.

Answer 98

A

B. Longer dorsal duct draining via the minor papilla/shorter ventral duct draining via the major papilla.

Pancreas divisum is the most common congenital anomaly of the pancreatic duct and has a prevalence of 4–10% of the general population. Although it is usually asymptomatic and an incidental finding, it can lead to recurrent episodes of pancreatitis in children and adults. By definition, the dorsal and ventral ducts fail to fuse during embryological development, which results in the following features seen at MRCP: (a) a prominent dorsal pancreatic duct, which drains directly into the minor papilla, and (b) a ventral duct, which does not communicate with the dorsal duct, but joins with the distal bile duct to enter the major papilla (ampulla of Vater). Typically, the ventral duct is short and narrow, while the dorsal duct normally has a larger caliber.

Answer 99

A

D. Duodenal-jejunal corkscrew appearance on an upper GI contrast study.

In individuals with malrotation, the mesenteric attachment of the midgut, particularly the portion from the duodenal-jejunal junction to the caecum, is abnormally short. The gut is therefore prone to twist counterclockwise around the superior mesenteric artery and vein—midgut volvulus.
Options A to C are all imaging findings in malrotation, but not specifically that midgut volvulus has occurred. With regard to option E duodenal obstruction can, of course, be seen with midgut volvulus, but obstruction may also occur due to obstructive bands and there is also an increased risk of congenital duodenal anomalies in malrotation, such as duodenal atresia, stenosis, and webs. It is the finding of an abnormally located duodenal-jejunal flexure and a corkscrew appearance to the duodenum and proximal jejunum that is the most specific for malrotation complicated by midgut volvulus.

Answer 100

A

B. Diffuse fatty infiltration and fibrosis.

Pancreatic insufficiency is almost invariable in patients who have the delta F508 mutation for CF. The most commonly described imaging abnormality in patients with CF is diffuse fatty infiltration and fibrosis. While pancreatic cysts are described, their size does not usually exceed a few millimetres. Larger pancreatic cysts have only been described in a few patients and complete replacement of the pancreas by macrocysts is very unusual.

Answer 101

A

E. Duodenal web.

A duodenal web is classically associated with the ‘windsock sign’ seen on an upper GI contrast study. Over time, the web or diaphragm passively elongates as a result of continual peristalsis, to form the windsock configuration of an intraluminal duodenal diverticulum. Duodenal atresia is commonly associated with the ‘double bubble’ appearance on AXR. The atresia is most commonly just distal to the ampulla of Vater. Associated anomalies are common, such as congenital heart disease, Down’s syndrome, and malrotation. Midgut volvulus is usually a complication of malrotation. The AXR may be normal, gasless, or show signs of duodenal/high small bowel obstruction. The upper GI contrast study shows an abnormal position of the duodenal-jejunal flexure (to the right of midline) or duodenal obstruction in severe cases. More often the volvulus is intermittent, when the ‘corkscrew’ appearance is classical, due to clockwise twisting of the jejunum around the superior mesenteric artery. Annular pancreas and preduodenal portal vein are exceedingly rare. In preduodenal portal vein (persistent left vitelline vein), the portal vein lies in an abnormal position anterior to the duodenum and may cause compression. However, in this entity, the primary obstruction is more usually due to an associated obstructing duodenal lesion, such as an intraluminal membrane or web, and not to the abnormal position of the vein.

Answer 102

A

C. Neonatal hepatitis.

Physiological jaundice of the newborn usually resolves within 2 weeks and thus is unlikely to be the cause in this case. It is also unconjugated, as is jaundice secondary to hypothyroidism. Caroli’s disease (type V of the Todani choledochal cyst classification) would typically have an abnormal ultrasound, demonstrating cystic dilatation of the intrahepatic bile ducts.
The key distinction in this question is between biliary atresia and neonatal hepatitis. The question stated that the ultrasound was normal and visualization of a normal-sized gallbladder has been said to favour neonatal hepatitis. However, 20% of patients with biliary atresia may have a normal sized gallbladder, which also empties after a feed. Despite this, in the presence of a suggestive clinical picture, an absent or small gallbladder in the fasting state, a gallbladder with irregular and echogenic walls, or a large gallbladder that does not empty post feed are highly suggestive of biliary atresia. Distinction can be clarified with a HIDA scan. In early biliary atresia prior to cirrhosis, there is rapid extraction of radionuclide from the bloodstream, which persists and accumulates in the hepatic parenchyma with failure of excretion into the gut. Thus, visualization of isotope activity within the gut excludes the diagnosis of biliary atresia. In severe or late biliary atresia, hepatocyte function eventually deteriorates, resulting in sluggish tracer uptake by the hepatocytes. Patients with neonatal hepatitis often have decreased parenchymal extraction and clearance of radioisotope from the bloodstream but tracer does reach the intestines.

Answer 103

A

E. Duplication cyst.

The most common location for duplication cysts is in the terminal ileum. This is followed by oesophagus, duodenum, and stomach. Duplication cysts contain both mucosal and muscle layers. On ultrasound, the mucosa is represented by an inner echogenic line and the muscle as an outer hypoechoic layer. The cyst is usually anechoic, unless complicated by haemorrhage or infection.
Lymphangiomas, mesenteric, and omental cysts are rare. On ultrasound, they are usually anechoic, unless complicated by debris, haemorrhage, or infection. The wall is usually thin and does not have the double layer associated with duplication cysts.
Ovarian cysts arise from the pelvis and will not have the layered wall appearance of a duplication cyst.

Answer 104

A

D. Hepatoblastoma.

This is the most common primary malignant hepatic tumour in children (approximately 80%). Most cases occur below the age of 3 years. Serum alphafetoprotein is elevated in 70–90%. The imaging features are as described. Calcification is seen in approximately 50%. HCC is the next most common malignant liver tumour and has two peaks in childhood, at 2–4 years and 12–14 years. Serum alphafetoprotein is also elevated in approximately 80%. Imaging features are similar to those seen in an adult population, i.e. larger tumours are of heterogeneous echogenicity on ultrasound and on biphasic CT they show arterial enhancement with rapid washout on the portal venous phase.
Undifferentiated embryonal sarcoma (UES) is the third most common liver malignancy and is most common between the ages of 6 and 10 years. Serum alphafetoprotein levels are normal.
The imaging hallmark of this tumour is the discrepancy between its appearance on ultrasound and that on CT. Ultrasound is used to confirm the solid nature of this tumour, which typically is isoechoic or hyperechoic. On CT, UES is seen as a well-circumscribed, multiseptate, fluidattenuating lesion. Enhancement of solid-appearing septa and a pseudocapsule may be seen.
Mesenchymal hamartoma is the second most common benign hepatic lesion (to haemangioendothelioma). It is usually seen under the age of 2 years. Serum alphafetoprotein is not elevated. The typical ultrasound appearance is a multiseptate, cystic mass. Less commonly, the solid component of the lesion can be more predominant, with multiple smaller cysts giving the lesion a Swiss-cheese appearance. The usual CT finding is of a multilocular cystic mass with enhancing septa of varying thickness. Angiosarcoma is not usually seen in children, but is a rare, highly vascular and highly malignant, hepatic tumour of adults.

Answer 105

A

E. A pyloric channel length of 12 mm.

Ultrasound is the primary imaging modality used for the diagnosis of hypertrophic pyloric stenosis, although the criteria are generally applied to infants of 6 weeks and older. These include muscle thickness >3 mm, pyloric channel length >14 mm, pyloric thickness (serosa to serosa) >10 mm, failure of the pylorus to open with pyloric elongation and displacement, as well as retrograde or hyperperistaltic gastric contractions. A pyloric ratio, which is the ratio of the wall thickness to the pyloric diameter, above 0.27 is stated to be 96% sensitive for the diagnosis. The standard measurements above are not always applicable to neonates and real-time assessment to look for passage of fluid from the stomach into the duodenum becomes more important.

Answer 106

A

C. The umbilical cord inserting at the apex of the hernia.

Omphalocele is the total failure of the midgut to return to the peritoneal cavity during the tenth week of gestation. The contents may vary from a single loop of small bowel to the entire GI tract, including the liver. An omphalocele can be differentiated from a gastroschisis (rupture of the abdominal wall) because in an omphalocele, the herniated structures are covered by peritoneum and amnion, and the umbilical cord inserts at its apex. In gastroschisis, there is a normally positioned umbilicus and the hernia is through a paraumbilcal defect. Because this (probably ischaemic) rupture of the abdominal wall occurs after the bowel has returned to the peritoneal cavity, the protruding viscera are not covered in peritoneum. The contents of the hernia in gastroschisis include stomach, midgut, and occasionally portions of the urinary tract. In omphalocele, there may be associated congenital cardiac anomalies and there is also an association with Beckwith Wiedeman syndrome. There is a low incidence of additional anomalies in gastroschisis.

Answer 107

A

C. Pancreatic duct dilatation.

In cases of acute pancreatitis in children, the echogenicity of the pancreas on ultrasound is not ahelpful diagnostic feature and pancreatic enlargement is absent in 50% of the patients. The most useful diagnostic feature is dilatation of the pancreatic duct (>1.5 mm at 1–6 years of age, >1.9 mm at 7–12 years, and >2.2 mm at 13–18 years). Pancreatic ductal dilatation may also be seen in chronic pancreatitis. Pancreatic atrophy and parenchymal Calcifications are more typically associated with chronic disease.

Answer 108

A

B. Type B.

Tracheoesophageal fistulae are classed depending on the communications present between the trachea and the oesophagus. In types A–D the mid-portion of the oesophagus is absent. Type A are not truly fistulae, but consist of an absence of the mid-portion of the oesophagus. In type B the proximal oesophageal bud communicates with the trachea and in type C it is the distal bud that has a tracheal fistula. Type C is the most common subtype. Both proximal and distal buds have fistulous connections with the trachea in type D. Type E (or H type) tracheoesophageal fistulae have complete trachea and oesophagus with a fistulous connection between them resembling the letter H.

Answer 109

A

C. Water-soluble contrast enema.

This is rarely, if ever, indicated in the acute phase of necrotizing enterocolitis (NEC). It may be used for the evaluation of the presence of strictures, usually approximately 6–12 months after the acute phase of NEC.
Supine AXR is the primary method used to evaluate NEC. A ‘jumbled’ pattern may be seen secondary to bowel wall oedema, which either compresses the lumen in some areas or causes an ileus appearance in other areas. Pneumatosis may be seen, which is either ‘bubbly’ or linear. This can lead to air in the portal venous system, which does not appear to alter the morbidity or mortality.
Perforation may occur and this may be demonstrated on the supine AXR by Rigler’s sign (air on both sides of the bowel wall) or the ‘football sign’ (air outlining the falciform ligament). The left lateral decubitus and supine cross-table AXRs may both be used to detect small quantities of free air. Abdominal ultrasound may be helpful in the acute setting of NEC, as it can depict intraabdominal fluid, bowel wall thickening, assess bowel wall perfusion, and may also detect small quantities of free air and portal venous gas.

Answer 110

A

B. Gastric mucosa.

The most sensitive and specific evaluation for a Meckel’s diverticulum is a 99mTc pertectnetate scan. This is positive only if gastric mucosa is present (in approximately 20% of patients). However, ectopic gastric mucosa is present in nearly all cases of Meckel’s diverticulum that bleed, as it is the ulcerated ectopic gastric mucosa that is the source of the haemorrhage. Ectopic pancreatic and colonic mucosa can occur in a Meckel’s divericulum, but are not typically associated with haemorrhage. Ectopic thyroid tissue is not usually found in a Meckel’s diverticulum. Other complications of a Meckel’s diverticulum include obstruction (either volvulus or intussusception) and diverticulitis.

Answer 111

A

C. Lipomatous pseudohypertrophy of the pancreas.

The history is one of undiagnosed cystic fibrosis (CF), with respiratory disease and pancreatic exocrine dysfunction. Pancreatic involvement in CF initially produces inhomogenous attenuation, then low attenuation, and then complete fatty infiltration and replacement. Microcysts may develop and some of these may become small macroscopic cysts demonstrable with CT. There may be scattered calcifications. On ultrasound, there is increased diffuse echogenicity in keeping with fatty infiltration and fibrosis. CF is a major cause of pancreatic exocrine failure in childhood. Pancreatic abnormalities are seen in 85–90% of CF patients. However, the disease progresses to pancreatitis in less than 1% of CF patients. It predisposes to pancreatic cancer. Shwachman–Diamond syndrome is a rare congenital disorder characterized by pancreatic exocrine insufficiency, bone marrow dysfunction, and skeletal abnormalities. Patients usually present in infancy or early childhood with malabsorption and recurrent infections. Imaging reveals pancreatic lipomatosis.

Answer 112

A

1 Answer C: Hirschsprung disease

Hirschsprung disease is the absence of parasympathetic ganglia in the muscle and submucosal layers of the colon. It usually presents in the first six weeks of life of a full-term infant. It is very rare in preterm infants. Eighty per cent involve the rectosigmoid.

Answer 113

A

Answer D: Pyloric transverse diameter 15 mm and presence of the cervix sign

The `cervix sign’ is the indentation of muscle mass on the fluid-filled antrum in longitudinal section and is seen in pyloric stenosis. Maximal dimensions of the canal on USS are 17 mm in length, 3 mm wall thickness, 13 mm in diameter and volume of 1.4 cu cm.

Answer 114

A

Answer A: Ileocolic intussusception

This is a classic age and history for intussusceptions and the most common site type is ileocolic.

Answer 115

A

Answer C: Meckel’s diverticulum

Meckel’s diverticulum is due to persistence of the omphalomesenteric duct, which normally obliterates in utero. Fifty per cent contain ectopic mucosa, which is usually gastric but may be pancreatic or colonic. This can demonstrate technetium uptake similar to normal stomach mucosa. It is therefore very important that the entire abdomen is imaged on the camera simultaneously to demonstrate simultaneous uptake.

Answer 116

A

9 Answer D: Right paraumbilical abdominal wall defect

Answer 117

A

21 Answer B: Distal intestinal obstruction syndrome

Otherwise known as meconium ileus equivalent, distal intestinal obstruction syndrome occurs in children and adolescents with cystic fibrosis. It occurs due to impaction of inspissated stool in the distal ileum and proximal colon.

Answer 118

A

27 Answer B: Intussusception

There are many causes of false positive Tc-99m pertechnetate studies which include: ectopic gastric mucosa, enteric duplication, Barrett’s oesophagus, arteriovenous malformations, haemangiomata, hypervasculartumour, aneurysm, duodenal ulcer, ulcerative colitis, Crohn’s disease, appendicitis, intussusception, bowel obstruction and urinary tract obstruction. Ileal rotation, haemorrhage and rapid bowel transit are causes of a false negative study.

Answer 119

A

32 Answer A: Good hepatic activity within five minutes and no visualisation of bowel at six hours or 24 hours

The DISIDA nuclear scintiscan is 90-97% sensitive and 60-94% specific for biliary atresia. In addition it shows delayed clearance from the cardiac pool and increased renal excretion and bladder activity.

Answer 120

A

36 Answer C: Blood flow within the intussusceptum on colour Doppler

The `target’ sign is due to the hyperechoic mesentery of the intussusceptum surrounded by hypoechoic and hyperechoic rings of the intussuscipiens and is classic for intussusception. It is not a predictor of reducibility. Fluid inside the intussusception is associated with irreducibility and ischaemia. The absence of blood flow within the intussusceptum is suggestive of bowel necrosis

Answer 121

A

39 Answer C: Oesophageal atresia without tracheoesophageal fistula

The inability to pass a feeding NG tube is suggestive of oesophageal atresia; it is seen coiled in the oropharynx on chest radiograph. Neonates with tracheoesophageal fistulae tend to aspirate during feeding with coughing and choking.

Answer 122

A

Answer B: Duodenal atresia

Duodenal atresia is the most common cause of congenital duodenal obstruction. Twenty-five per cent of neonates with atresia have Down syndrome as in this case.

Answer 123

A

42 Answer C: Duodenal atresia

This is the most common cause of congenital duodenal obstruction. It is associated with Down’s syndrome.

Answer 124

A

57 Answer D: Haemangioendothelioma

This is the most common benign hepatic tumour seen in infants under six months old. It commonly presents with congestive heart failure due to high-output circulation. They can be solitary or multiple. Haemangioendotheliomas have a natural history of regression within 12-18 months and the initial management is medical.

Answer 125

A

Answer D: Congenital biliary atresia

It is best diagnosed with cholescintigraphy which shows good hepatic uptake but no biliary excretion. Triangular fibrous cord at porta hepatis seen on ultrasound is pathognomonic

Answer 126

A

68 Answer D: Laparotomy

These findings are consistent with necrotising enterocolitis (NEC). Congenital heart disease is a risk factor for NEC. Gas in the portal venous system can be transient and does not necessarily imply a hopeless outcome.

Answer 127

A

Answer A: Annular pancreas

Annular pancreas is a relatively common congenital anomaly wherein a ring of normal pancreatic tissue encircles the duodenum secondary to the abnormal migration of the ventral pancreas. It is associated with other congenital abnormalities in 75%; including Down syndrome. In a neonate it usually presents with duodenal obstruction and the obstruction is at D2 in 85% of cases.

Answer 128

A

69 Answer C: Supine

An abnormal position of the duodenojejunal flexure on a barium meal confirms the diagnosis of malrotation, most commonly to the right of the spine.

Answer 129

A

Answer E: Diffuse pancreatic atrophy.

Answer 130

A

1 Answer D: Pyloric transverse diameter of 20mm

Pyloric stenosis manifests itself between two and eight weeks of life and is more common in boys.
Positive findings on ultrasound include:
* pyloric muscle wall thickness >3 mm
* pyloric canal length >17 mm
* pyloric transverse diameter >13 mm
* exaggerated peristaltic waves
* delayed gastric emptying.

Answer 131

A

14 Answer B: Meconium ileus

Meconium ileus presents with small bowel obstruction secondary to meconium impacted in the distal ileum. Almost all patients with meconium ileus have cystic fibrosis. It is the earliest clinical presentation of meconium ileus (10-15% of cystic fibrosis patients present with meconium ileus).

Answer 132

A

14 Answer A: Gastric duplication cyst

This two-layered appearance is classic of gastric duplication cyst. Sixty-five per cent are in the region of the greater curvature. Most present in infancy with 75% being detected before the age of 12 years.

Answer 133

A

Answer A: Cystic fibrosis

Cystic fibrosis affects the gastrointestinal tract in the majority of patients and manifestations include: meconium plugging, meconium ileus, distal intestinal obstruction, gastro-oesophageal reflux, thickened duodenal folds, small bowel dilatation, colonic stricturing, microcolon and pneumatosis intestinalis.

Answer 134

A

17 Answer A: Tc-99m pertechnetate

Meckel’s diverticulum is a persistence of the omphalomesenteric duct and is the most common congenital abnormality of the gastrointestinal tract. Tc-99m pertechnetate is >85% sensitive and >95% specific for Meckel’s diverticulum.

Answer 135

A

24 Answer B: Hydrostatic reduction at 120 mmHg

A rule of threes usually applies: maximum three attempts for three minutes, allowing three minutes between attempts. The pressure should be approximately 120 mmHg. (The colonic bursting pressure is approximately 200 mmHg.).

Answer 136

A

a Abdomen distended by bowel gas

Answer 137

A

30 Answer B: Intestinal atresia

The description is that of gastroschisis. Gastroschisis has associated anomalies in 5 %, most of which are intestinal atresia or stenosis. Omphalocoele has a high incidence of associated anomalies including chromosomal, genito-urinary, cardiac (particularly VSD), neural tube defects, IUGR and Beckwith-Wiedemann syndrome.

Answer 138

A

31 Answer B: Free intra-abdominal air

In necrotising enterocolitis, pneumatosis intestinalis is seen in 80%. Gas in the portal vein can be seen, is frequently transient and does not imply a terrible outcome as it would in adults. Pneumoperitoneum is a poor prognostic factor and usually requires immediate surgery.

Answer 139

A

36 Answer D: Intussusception

Intussusception is the invagination of a segment of bowel (intussusceptum) into the lumen of the adjacent bowel (intussuscipiens). Ninety-five per cent of cases are idiopathic in children.

Answer 140

A

39 Answer C: Duodenojejunal junction low and in the midline

All of the above are found in malrotation. The most common findings associated with the diagnosis of malrotation are: duodenum and jejunum to the right of the spine, corkscrew duodenum and jejunum and the duodenojejunal junction low and in the midline.

Answer 141

A

43 Answer C: Fibrolamellar hepatocellular carcinoma

This is a subtype of hepatocellular carcinoma found in older children and adolescents, which is less aggressive. The central scar can calcify

Answer 142

A

46 Answer C: Pneumoperitoneum

These are all radiological findings seen in necrotising enterocolitis. This is an ischaemic bowel disease secondary to hypoxia, perinatal stress and infection. It is the most common gastrointestinal emergency in premature infants. Portal venous gas is often a transient feature.

Answer 143

A

56 Answer A: `Triangular cord’ sign in porta hepatis

This is due to fibrous tissue and is pathognomonic for biliary atresia. The other options can all be seen in both neonatal hepatitis and biliary atresia.

Answer 144

A

61 Answer A: Hereditary spherocytosis

Gallstones are rare in neonates without predisposing factors. These include: total parenteral nutrition, furosemide, short gut syndrome, obstructive congenital biliary anomaly, dehydration and haemolytic anaemia.

Answer 145

A

69 Answer A: Rectal duplication cyst

These account for 4% of all gastrointestinal tract duplications; 20% of patients develop perianal fistulae.

Answer 146

A

8 Answer C: Oesophageal atresia without tracheo-oesophageal fistula

The diagnosis is made incidentally in this instance, as the patient has not required feeding yet. Nasogastric tubes are passed routinely when the neonate is intubated. The nasogastric tube does not pass into the stomach and coils in the neck. The lack of air within the abdomen differentiates it from patients with a tracheooesophageal fistula.

Answer 147

A

9 Answer D: Appendicitis

The appendix is frequently not visualised in appendicitis due to retrocaecal position, the inability to compress the abdomen adequately or prior perforation.

Answer 148

A

13 Answer E: Fusiform cyst beneath the portal hepatis, separate from the gallbladder

The clinical and ultrasound findings are those of a choledochal cyst. This is the most common congenital lesion of the gallbladder and is a segmental dilatation of the common bile duct. It does not involve the gallbladder or cystic duct.

Answer 149

A

27 Answer B: Intussusception

Other findings on abdominal radiograph include an abdominal soft-tissue mass in the right upper quadrant, normal appearances and small bowel obstruction.

Answer 150

A

30 Answer B: Henoch-Schonlein purpura

This is a hypersensitivity-related acute small-vessel vasculitis, which often begins as an upper respiratory tract infection. It causes a proliferative glomerulonephritis with IgA deposits & can lead to renal insufficiency & rarely to end-stage renal disease.

Answer 151

A

34 Answer C: Malrotation of the ileum

The other options can all give false positive results. False negative results can be caused by a recent barium enema, irritable bowel in the right lower quadrant causing rapid transit or presence of only a small amount of ectopic gastric mucosa.

Answer 152

A

(b) Pancreas divisum

This is the most common anatomical variant of the pancreas and is due to failure of fusion of the ventral and dorsal pancreatic buds. As a result, the main dorsal pancreatic duct drains through the minor papilla while the ventral pancreatic duct with the common bile duct drains through the major papilla.

Answer 153

A

49 Answer A: Acute splenic sequestration crisis

This occurs in patients with sickle cell disease when the intrasplenic veins become obstructed leading to a sudden trapping of a large amount of blood in the spleen.

Answer 154

A

61 Answer B: Pyloric stenosis

This occurs most frequently in boys aged three to six months and presents with non-bilious vomiting.

Answer 155

A

63 Answer C: Midgut malrotation

Midgut malrotation usually presents within the first month of life with bilious vomiting. The pathognomonic finding of midgut malrotation is an abnormally positioned ligament of Treitz with the duodenojejunal junction lying to the right or below the expected normal position, shown on a barium meal. Duodenal atresia obstructs near the ampulla of Vater and results in bilious vomiting in the first 24 hours of life. Plain radiograph findings of duodenal atresia are of a `double bubble’ sign of a dilated stomach and duodenal bulb with no gas seen distally.

Answer 156

A

66 Answer C: Necrotising enterocolitis

Necrotising enterocolitis is the most common surgical emergency in neonates. Inflammation and mucosal ulceration of the bowel leads to widespread trans- mural necrosis.

Answer 157

A

68 Answer E: Passing inferiorly from the umbilicus to the pelvis then turning cranially to lie with the tip at T9

An umbilical artery catheter (UAC) should run into the pelvis via the umbilical artery to the iliac artery before turning superiorly to the aorta. An umbilical venous catheter will pass immediately superiorly. The tip of a UAC should not be positioned close to the origin of a major vessel T10-L3 due to risk of thrombosis.

Answer 158

A

70 Answer D: Rhabdomyosarcoma of the biliary tract

This a rare tumour, most commonly arising from the common bile duct. It is more common in males.

Answer 159

A

(d) Meckel’s diverticulum

The 99mTc pertechnetate scan demonstrates ectopic gastric mucosa which bleeds giving rise to symptoms.

Answer 160

A

(a) Intussusception

This is a common surgical emergency in children less than 1 year of age. Ultrasound can accurately diagnose and assess bowel viability. Hypertrophic pyloric stenosis occurs at a much younger age and does not present with bleeding per rectum. Other options are also unlikely, with the given ultrasound appearances.

Answer 161

A

(b) Ultrasound

This is the most useful investigation as it can not only accurately diagnose intussusception but also assess bowel viability and reducibility

Answer 162

A

(e) Malrotation with volvulus

Bilious vomiting in newborn infants is most likely to represent malrotation with midgut volvulus. The duodenojejunal flexure is on the right and CT or ultrasound demonstrates a ‘whirl sign’ of superior mesenteric vein and mesenteric vessels around the superior mesenteric artery.

Answer 163

A

(e) Duodenal atresia

The ‘double bubble’ sign can be seen in duodenal atresia, midgut volvulus or annular pancreas, but the absence of gas in the rest of abdomen suggests underlying duodenal atresia. Duodenal atresia is also associated with Down’s syndrome and maternal hydramnios.
Annular pancreas usually presents at a later age (if symptomatic). Midgut volvulus is seen in young infants. Some gas is seen distal to duodenum. Choledochal cyst is seen in children and young adults with biliary symptoms.

Answer 164

A

(b) Biliary atresia

Jaundice persisting beyond 1 month is usually due to biliary atresia of neonatal hepatitis. A choledochal cyst is seen in 5% of cases. These conditions have similar clinical and biochemical presentations. Ultrasound will be normal in hepatitis and biliary atresia, but no bowel activity is seen with HIDA scan on delayed images in biliary atresia.

Answer 165

A

(a) Necrotising enterocolitis

Ischaemic bowel disease secondary to hypoxia, perinatal stress and infections. The terminal ileum is commonly involved and the bowel loops show wall thickening and intramural air. Gas may be seen in the porto-venous system in the liver.

Answer 166

A

(a) Meconium ileus

Meconium ileus is almost diagnostic of cystic fibrosis and presents in neonates.
Family history of CF may be present. The abnormally thick meconium obstructs the ileum and a water soluble enema may relieve the impaction. This disorder produces the smallest of microcolons because the obstructing meconium leaves the colon unused.
Meconium plug syndrome is also known as functional immaturity of the colon. It is a temporary functional obstruction which often occurs at the splenic flexure, and is a common cause of neonatal obstruction.

Answer 167

A

(b) Meconium peritonitis

This is a sterile chemical peritonitis, secondary to perforation of bowel resulting in prenatal leak of meconium into the peritoneal cavity. This is usually secondary to bowel obstruction and perforation in utero. Meconium peritonitis usually results in intraperitoneal calcifications, which may be focal, cystic or generalised. On plain films, the primary finding is calcifications. On ultrasound there may be cysts with echogenic walls (calcifications) containing meconium. Calcifications usually disappear over months or years.

Answer 168

A

(a) Hirschsprung’s disease

This is a functional colonic obstruction characterised by an aganglionic hypertonic distal segment of bowel with associated proximal dilatation. Radiographic demonstration of the transition zone between the dilated proximal ganglionic segment bowel and the non-dilated distal aganglionic bowel is the most reliable diagnostic feature of Hirschsprung’s. Other features include a corrugated or sawtooth rectosigmoid, abnormal rectosigmoid index (normally the sigmoid should not be bigger than the rectum) and delayed evacuation of contrast medium. 38. (a) Hirschsprung’s disease
This is a functional colonic obstruction characterised by an aganglionic hypertonic distal segment of bowel with associated proximal dilatation. Radiographic demonstration of the transition zone between the dilated proximal ganglionic segment bowel and the non-dilated distal aganglionic bowel is the most reliable diagnostic feature of Hirschsprung’s. Other features include a corrugated or sawtooth rectosigmoid, abnormal rectosigmoid index (normally the sigmoid should not be bigger than the rectum) and delayed evacuation of contrast medium.

Answer 169

A

(a) Hepatoblastoma

This is the most common primary malignant hepatic tumour in children occurring before 3 years of age. There is an association with Beckwith–Wiedemann syndrome. On CT there is a heterogeneous contrast enhancement whilst on MRI, the tumour is usually heterogeneously hyperintense on T2. Hepatocellular carcinoma, metastases and hemangioendothelioma are very rare in this age group.

Answer 170

A

(c) Hypertrophic pyloric stenosis

Ultrasound is diagnostic of this condition, including an elongated pyloric canal (> 15 mm) and thick pyloric muscle (> 3 mm).

Answer 171

A

Answers:

(a) Not correct
(b) Not correct
(c) Not correct
(d) Correct
(e) Not correct

Explanation:

Hypertrophic pyloric stenosis is typically seen in first born males with peak incidence between 2 and 6 weeks of age. It is rarely seen in premature infants.
To make a diagnosis on ultrasound the pyloric canal length should be 17mm, pyloric wall thickness at least 3 mm and transverse diameter of pylorus at least 13 mm.

Answer 172

A

Answers:

(a) Correct
(b) Not correct
(c) Correct
(d) Correct
(e) Correct

Explanation:

Abdominal involvement in non-Hodgkin’s usually presents with a mass typically at ileocaecal region or intussusception causing obstruction. Splenic involvement is seen in less than 40% of cases at presentation.

Answer 173

A

Answers:

(a) Not correct
(b) Correct
(c) Correct
(d) Not correct
(e) Correct

Explanation:

The H type trachea-esophageal fistula is seen only in 10% cases. Upper esophageal atresia with a fistula between lower esophagus and trachea is the most common type (85%). Duodenal duplication cysts are usually situated along the concave border where they may cause duodenal obstruction, biliary obstruction or pancreatitis

Answer 174

A

Answers:

(a) Correct
(b) Correct
(c) Not correct
(d) Not correct
(e) Correct

Explanation:

Meckel’s diverticulum located at the antimesenteric border of the ileum. Best investigation diagnosed Meckel’s diverticulum in children is a radionuclide technetium 99 pertechnetate scan.

Answer 175

A

Answers:

(a) Not correct
(b) Not correct
(c) Correct
(d) Not correct
(e) Correct

Explanation:

Hepatoblastomas typically present as an abdominal mass in an asymptomatic child under 2 yrs of age. Hepatocellular carcinoma presents over 4 yrs of age. Both hepatoblastomas and hepatocellular carcinoma cause elevated alpha-fetoprotein levels. Hepatoblastomas are associated with hemihypertrophy and Beckwith-Wiedemann syndrome. Calcification is present in 50% cases of hepatoblastomas.

Answer 176

A

Answers:

(a) Correct
(b) Not correct
(c) Not correct
(d) Not correct
(e) Correct

Explanation:

In intussusception plain films can be normal in 50% cases with highest incidence between 3 months and 4 years of age. In children 95 % intussusception are idiopathic with no lead point.

Answer 177

A

Answers:

(a) Correct
(b) Not correct
(c) Correct
(d) Not correct
(e) Not correct

Explanation:

Double bubble sign is also seen in duodenal stenosis, annular pancreas and preduodenal portal vein. In bifid CBD insertion bowel gas may not be seen distal to atretic segment. 1/3rd of cases are associated with Down’s syndrome.

Answer 178

A

Answers:

(a) Not correct
(b) Correct
(c) Correct
(d) Correct
(e) Not correct

Explanation:

A normal DJ flexure lies to the left of spine at the same level as or more superior to the duodenal bulb. In malrotation the DJ flexure (ligament of Treitz) is abnormally positioned.
In malrotation the caecum is generally malpositioned in the right upper quadrant or in the left side of abdomen. In 20% of patients with malrotation caecum is normally positioned.

Answer 179

A

Answers:

(a) Not correct
(b) Correct
(c) Not correct
(d) Correct
(e) Not correct

Explanation:

Chronic liver disease is present in 25% of adults with cystic fibrosis and the severity increases with age. Pancreatic calcification is seen in 8% of the patient’s on radiography. MRI depicts the calcification poorly. Microgallbladder is a common finding. In patients with cystic fibrosis, the gallbladder is typically small, trabeculated, contracted and poorly functioning. It often contains echogenic bile, sludge and cholesterol gallstones

Answer 180

A

Answers:

(a) Correct
(b) Not correct
(c) Not correct
(d) Not correct
(e) Correct

Explanation:

Omphalocoele is usually associated with other anomalies in over 80% cases, with umbilical cord insertion at the apex and covered by peritoneum and amnion

Answer 181

A

Answers:

(a) Not correct
(b) Correct
(c) Not correct
(d) Not correct
(e) Correct

Explanation:

NEC is predominantly a disease of premature infants weighing less than 2 kgs. Very premature infants develop NEC until 2nd or 3rd week of life or later. Most infants however develop NEC in first few days of life. NEC is a serious neonatal disease of unknown etiology, involving predominantly the distal ileum and proximal colon characterized by mucosal or transmucosal necrosis of part of the intestine which may progress to perforation.

Answer 182

A

Answers:

(a) Correct
(b) Correct
(c) Not correct
(d) Not correct
(e) Correct

Explanation:

The pathognomonic finding of Hirchsprung disease on contrast enema is a transition zone between normal and aganglionic bowel i.e. abnormally small rectum and distal colon to a dilated normal proximal colon. However in
25% of patients transition zone is not seen which does not rule out Hirchsprung disease. In a normal patient rectum has the largest luminal diameter of the left sided colon. When rectum alone is involved the sigmoid colon has larger diameter than rectum.

Answer 183

A

Answers:

(a) Not correct
(b) Correct
(c) Not correct
(d) Correct
(e) Not correct

Explanation:

OA and TOF are associated with anomalies in the VACTERL group. OA is also associated with other atresias like duodenal atresia and imperforate anus. OA and TOF include a spectrum of anomalies involving trachea and esophagus. The most common type is N type i.e. proximal OA and distal TOF. H type is TOF without OA thus a gasless stomach is not possible.