Imaging in Paediatric Intestinal Obstruction

1. IMAGING OF PAEDIATRIC INTESTINAL OBSTRUCTION Present by: Capt. Soe Moe Htoo PG 2nd year (Radiology)

2. Contents 1. Neonatal bowel gas pattern 2. Developmental lesions of the intestinal tract 3. Types of IO 4. Common causes of IO in neonates 5. Clinical and radiological features of common lesions 6. Conclusion 2

3. Normal neonatal bowel gas pattern Is there any abnormalities? 3

4. Normal neonatal bowel gas pattern Swallowing begins immediately after birth: • Gas in the stomach - few minutes • Entire small bowel - within 3 hours of birth • Sigmoid colon - after 8-9 hours • Disruption of this common pattern is seen in obstruction or presence of underlying illness such as brain damage, septicemia or hypoglycemia. 4

5. Developmental lesions of the neonatal GI tract 1. Attributed to embryologic maldevelopment 2. Attributed to in utero vascular (ischemic) complication 3. Functional 4. Structural and Functional Combined 5

6. 1. Attributed to embryologic maldevelopment • Esophageal atresia with or without fistula • Antro-pyloric atresia • Duodenal atresia • Midgut malrotation with peritoneal bands • Duplication or mesenteric cyst • Anorectal atresia 6

7. 2. Attributed to in utero vascular (ischemic) complication • Jejuno-ileal atresia • Colonic atresia or stenosis • Complicated meconium ileus 7

8. 3. Functional • Meconium plug syndrome and its variants • Megacystis-microcolon-intestinal hypoperistalsis 8

9. 4. Structural and Functional Combined • Hypertrophic pyloric stenosis • Midgut volvulus (complicating midgut malrotation) • Uncomplicated meconium ileus • Colonic aganglionosis 9

10. • 2 Types of intestinal obstructions: (1) Upper IO (2) Lower IO • Obstructions occurring proximal to the mid-ileum  upper intestinal obstructions. • Involving distal ileum or colon  lower intestinal obstructions 10

11. Causes of Neonatal Intestinal Obstruction High intestinal obstruction • Gastric atresia • Duodenal atresia • Duodenal stenosis (with annular pancreas) • Duodenal web • Malrotation • Jejunal atresia and stenosis Low intestinal obstruction Small bowel involving • Ileal atresia • Meconium ileus Large bowel involving • Functional immaturity of the colon • Hirschsprung disease • Colonic atresia • Anal atresia and anorectal malformation 11

12. Oesophageal Atresia • Due to abnormal division of foregut • 1 in 3000 live births • Early presentation(at birth) - drooling, vomiting, choking after feeding • Late presentation - recurrent pneumonia • Can occur with or without tracheoesophageal fistula • Most common type  Oesophageal atresia with fistula (90%) • Pure oesophageal atresia without fistula (10%) 12

13. Associations: • VACTERL anomalies 1. Vertebral anomalies 2. Anorectal malformation 3. Cardiovascular malformations (VSD, PDA, right aortic arch) 4. Tracheal anomalies 5. Esophageal fistula 6. Renal anomalies 7. Limb anomalies • Chromosomal (5-20%): Trisomy 18, 21,13 13 Oesophageal Atresia

14. Imaging features Plain radiograph • Dilated proximal oesophagus • Coiled feeding tube within the blind ending upper pouch • Gasless abdomen (indicates no distal fistula) 14 Oesophageal Atresia

15. Oesophageal atresia without fistula 15 Oesophageal Atresia

16. Hypertrophic Pyloric Stenosis • Narrowing of the opening from the stomach to the first part of duodenum • Characterized by hypertrophy of the circular muscles • 3/1000 live birth • Male: Female (4:1) • Most common cause for laparotomy before 1 year (esp. 3 weeks to 3 months) • May have positive familial history • Also occurs in adults d/t scarring from chronic peptic ulceration 16

17. 17 Pyloric Stenosis

18. Clinical Presentations • Projectile non-bilious vomiting after feeding • Stomach contractions: peristalsis across baby's upper abdomen soon after feeding, but before vomiting • Constipation • Dehydration • Hypertrophied pylorus can be palpated as an olive sized mass in the right upper quadrant 18 Pyloric Stenosis

19. Associations: • Turner syndrome • Tracheo-esophageal fistula • Esophageal atresia • Trisomy 18 19 Pyloric Stenosis

20. Imaging Features • USG is the first modality of choice • Contrast evaluation if required • Thickness of the muscle (most accurate criterion for the diagnosis) 20 Pyloric Stenosis

21. USG Method • Stomach need well distension • Antro-pyloric muscle is measured in mid-longitudinal plane. 21 Pyloric Stenosis

22. Ultrasonography • Primary imaging method • Sensitivity and specificity of approximately 100% • USG confirmed hypertrophic pyloric stenosis when: - pyloric muscle thickness (MT) > 4 mm & - pyloric channel length (CL) > 15 mm But, • Linear relationship between Pyloric MT, CL Vs Patient age • 3 mm MT (diagnostic for pyloric stenosis in younger patients) 22 Pyloric Stenosis

23. Hypertrophied muscular layer Abnormal elongation of the pyloric canal 23 Pyloric Stenosis

24. Infantile Hypertrophic Pyloric stenosis 24 Pyloric Stenosis

25. Axial oblique ultrasound shows thickened, hypoechoic muscular wall and elongated pyloric canal 25 Pyloric Stenosis

26. Pyloric Stenosis Vs Pylorospasm • Sonographic measurements in pylorospasm may overlap with pyloric stenosis. • In pylorospasm, considerable variability in measurement or image appearance with time during the study. • Sonographic double-track sign (i.e., redundant mucosa in the narrowed lumen, which creates 2 mucosal outlines) can be seen in both pylorospasm and hypertrophic pyloric stenosis. 26 Pyloric Stenosis

27. Barium examination • Performed if USG is inconclusive or gastro-oesophageal reflux is suspected. • The hypertrophied muscle mass causes: • Elongation and narrowing of pyloric canal (‘string sign’) • Bulge in the distal antrum with streak of barium pointing towards pyloric channel (‘beak sign’) • The barium may outline crowded mucosal folds as parallel lines (‘double/triple track sign’). 27 Pyloric Stenosis

28. Supine radiograph in an infant with vomiting demonstrates caterpillar sign of active gastric hyperperistalsis. 28 Pyloric Stenosis

29. Stomach shows double tracking in region of pyloric canal, indentation on base of bulb and delayed gastric emptying. 29 Pyloric Stenosis

30. Upper gastrointestinal study from a child shows the string sign 30 Pyloric Stenosis

31. Hypertrophic pyloric stenosis on an UGI exam. Lateral view from an UGI exam demonstrates elongation and narrowing of the pylorus, consistent with the string sign (arrow). 31 Pyloric Stenosis

32. Tit sign - outpouching contrast on lesser curve by distorted muscle in hypertrophic pyloric stenosis. 32 Pyloric Stenosis

33. TYPICAL UPPER GASTROINTESTINAL SERIAL IN A 2 YEARS OLD BOY WITH HYPERTROPHIC PYLORIC STENOSIS. 33 Pyloric Stenosis

34. Duodenal Atresia • 1 in 5,000-10,000 newborns • No gender predilection • one of the commonest causes of complete fetal bowel obstruction • Proximal duodenal atresia – d/t failed bowel lumen recanalization in early fetal life (late first trimester) • Distal atresia – d/t secondary of ischemic episode • 50% have history of polyhydramnios 34

35. Associations: • Trisomy 21 • VACTERL association • Malrotation • Other intestinal atresias • Annular pancreas • Biliary anomalies 35 Duodenal Atresia

36. Imaging features: • Double-bubble appearance - gas-filled distended stomach and proximal duodenum (Non-specific) • Dilatation of the duodenum is a sign of chronic obstruction • Seen in duodenal atresia, duodenal web and annular pancreas • In midgut volvulus, obstruction occurs acutely after birth, the duodenum is not usually dilated 36 Duodenal Atresia

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38. Differential diagnosis of duodenal obstruction: • Malrotation with Ladd bands and midgut volvulus - can be partial or complete obstruction. • Duodenal web - partial obstruction with small amount of distal bowel gas • Annular pancreas. • Preduodenal portal vein 38 Duodenal Atresia

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41. Duodenal atresia AXR of a newborn with bilious vomiting and abnormal antenatal ultrasound showing polyhydramnios and dilated stomach 41 Duodenal Atresia

42. Duodenal Web • Variant of duodenal stenosis • Caused by a duodenal membrane • In partial duodenal obstruction, upper GI contrast studies help to distinguish between duodenal web and malrotation with Ladd bands or midgut volvulus. 42

43. Imaging features: • Plain radiograph: dilated gas filled stomach and duodenum 'double bubble’ with small amount of distal bowel gas. • 'Windsock' or 'dimple' appearance on upper GI contrast: representing the web. 43 Duodenal Web

44. Duodenal web AXR of a newborn with bilious vomiting. 44 Duodenal Web

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46. Intestinal Malrotation, Midgut volvulus • Volvulus = Twisting • 1:6000 live births • Due to failure of complete rotation and fixation of the intestine • (Some) entire life without symptoms • 80-90%  present in the first year of life • It predispose midgut volvulus and internal hernias • Shortening and abnormal position of the mesenteric root  twist bowel and develop midgut volvulus. 46

47. • Surgical emergency and early diagnosis is vital to prevent bowel ischemia and potentially life threatening complications • C/F - Feeding intolerance and bilious vomiting 47

48. Association: • Ladd bands: abnormal fibrous peritoneal bands • Internal hernia with mesenteric defect • Cardiac isomerism 48 Malrotation

49. Imaging features: Abdominal plain film: Normal (or) Non-specific bowel gas pattern Bowel distention and cut-off sign in complete obstruction Upper GI contrast study: • Abnormal positioned Duodenojejunal junction • Corkscrew sign: proximal bowel twisted around the superior mesenteric artery represents midgut volvulus. 49 Malrotation

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56. Malrotation 5(a) markedly dilated stomach and duodenum similar to 'double bubble sign' but small amount of distal bowel gas. 5(b) Upper GI contrast study demonstrates obstruction at the duodenum (arrow) due to malrotation and the presence of a Ladd band. 5(c) AXR of another neonate presented with bilious vomiting. Bowel gas pattern is non-specific. 5(d) Upper GI contrast study demonstrates abnormal position DJ flexure over the spine and corkscrew sign (arrow head) representing malrotation with midgut volvulus. 56 Malrotation

57. Jejunal Atresia • More common than duodenal atresia • Incidence 1 in 1,000 live births • Arise form an ischemic event in utero and not infrequently involves more than one segment (50%) of jejunum 57

58. Imaging Findings: • Triple-bubble sign  Double bubble sign + Third bubble (air filled dilated jejunum) • No gas in the distal bowel Differential Diagnosis of proximal obstruction: Malrotation with midgut Volvulus • Plain film confirms complete obstruction if there is no distal gas • If there is small amount of distal gas  upper GI study (to distinguish from malrotation/ volvulus) 58 Jejunal Atresia

59. • Several dilated proximal bowel loops in the upper abdomen • No distal bowel gas indicating complete high obstruction due to Jejunal atresia • Small amount of intra-abdominal calcification (arrow) represents meconium peritonitis due to in-utero perforation secondary to the bowel obstruction Newborn with abnormal antenatal ultrasound suggesting bowel obstruction 59 Jejunal Atresia

60. Ileal atresia • In-utero ischemic event resulting in single or multiple atresias • Can associated with mesenteric defects • Usually presents within first few days after birth • Abdominal distension, bilious vomiting and failure to pass meconium • May be diagnosed on antenatal ultrasound (with polyhydramios and signs of bowel obstruction) 60

61. Imaging Findings: • Numerous dilated bowel loops (indicating a low obstruction) • Multiple air-fluid levels • Calcifications (indicating meconium peritonitis in in-utero perforation) • Microcolon and blind ending ileum on contrast enema 61 Ileal atresia

62. Differential Diagnosis of distal bowel obstruction: • Meconium ileus • Meconium plug and small left colon syndrome • Total colonic Hirschsprung disease • Colonic atresia 62 Ileal atresia

63. Ileal atresia 7(a) Plain radiograph demonstrates multiple dilated bowel loops indicating a distal obstruction 7(b) Contrast enema show a microcolon with a blind ending small distal ileum representing ileal atresia. AXR of a newborn with abdominal distension and feeding intolerance. 63 Ileal atresia

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65. Ileal atresia (a) Multiple air-fluid levels occupying the entire abdominal cavity. (b) Barium enema: numerous dilated, air-filled loops of bowel and a small, unused colon (functional microcolon). 65 Ileal atresia

66. Colonic atresia (a) Radiograph shows distended loops of bowel similar to those seen in low small bowel obstruction. (b) Barium enema: microcolon with complete obstruction to the retrograde flow of barium in the transverse portion of the colon. 66

67. Meconium ileus • Newborn bowel obstruction • Secondary to thick tenacious meconium impacted in distal ileum • Accounts for 20% of neonatal intestinal obstruction • 50% of cases are complicated with perforation • Usually managed conservatively with gastrograffin enema washout in uncomplicated intestinal obstruction 67

68. Associations: • Cystic fibrosis (almost all patients with meconium ileus have cystic fibrosis and 15% of CF patients present with meconium ileus) • Pancreatic duct stenosis/atresia • Pancreatic insufficiency 68 Meconium ileus

69. Imaging features: • 'Bubbly'/frothy appearance of intestinal contents (seen in the right lower quadrant in 50-66%). Contrast enema: • Distal small bowel impacted with filling defects (meconium pellets) • Microcolon 69 Meconium ileus

70. Meconium ileus (a) Abdominal radiograph of a neonate who failed to pass meconium, showing distended gas filled bowel loops and "soap bubble" appearance in the right lower abdomen representing the impacted meconium in the distal ileum (arrow). (b) Contrast enema examination demonstrates small-caliber colon "microcolon". Numerous filling defects in the distal ileum represent the impacted meconium pellets. Note the multiple proximal dilated loops of bowel. 70 Meconium ileus

71. Meconium ileus (a) Abdominal scout radiograph shows marked distention of the small bowel and a “soap bubble” appearance in the right side of the abdomen (arrows), a finding suggestive of mottled air and feces. (b) US image shows dilated, fluid-filled intestinal loops containing echogenic material (calcified meconium) (arrows). Associated ileal atresia was seen at surgery. 71 Meconium ileus

72. Hirschsprung disease • Most common cause of lower intestinal obstruction in neonates • 1 in 5000 live births • Male predominance (80%) • Always begins in internal anal sphincter • Extends proximally for a variable length of gut 72

73. Pathogenesis 73 Migratory failure of neural crest cells Functional obstruction Spasm of the affected segment of colon Congenital absence of colonic ganglion cells

74. Pathogenesis 74 Hirschsprung

75. Types of Hirschsprung disease: 1. Short segment disease (rectum and sigmoid) - 80% 2. Long segment disease (Rectum and sigmoid with the transition zone above the rectosigmoid) - 15-25% 3. Total colonic Hirschsprung (entire colon) - <5 % 4. Total intestinal disease - very rare 5. Ultrashort segment (only ano-rectal junction) – very rare 6. Presence of skip lesions in Hirschsprung’s disease is extremely rare 75 Hirschsprung

76. Associations: • Genitourinary anomalies (11%) • Congenital cardiac disease (6%) • Trisomy 21 (5%) 76 Hirschsprung

77. Clinical presentation • Failure to pass meconium in 1st 24 hr. of life • Abdominal distension, bilious vomiting, refusal to feed Older children present late with • Long standing history of constipation since birth • Toxic Megacolon (Fever, abdominal distension, bilious vomiting, explosive diarrhea, dehydration, shock) • Spontaneous perforation (esp. in long segment) 77 Hirschsprung

78. • Definitive diagnosis - by full thickness rectal biopsy • Contrast enema - usually demonstrates the transition zone (but can be normal in ultrashort segment disease) 78 Hirschsprung

79. Imaging features: • AXR: Multiple dilated bowel loops with lack of gas in the rectum 79 Hirschsprung

80. Barium enema • Contrast agent should be prepared with normal saline • Performed by inserting a straight tipped catheter just beyond the anal sphincter • Patient placed in lateral position • Should infused barium slowly • Rapid infusion can distend and mask the transition zone • Diagnostic feature in short segment disease is funnel shaped transition zone and reversal of the recto-sigmoid ratio. 80 Hirschsprung

81. Rectosigmoid ratio • Measurement of the diameter of the rectum divided by sigmoid colon during contrast enema. • Use in the diagnosis of Hirschsprung disease • Normal children have a rectum that is larger than the sigmoid (i.e. rectosigmoid ratio >1). • A rectosigmoid ratio (R/S) less than 1 suggests the diagnosis of short- segment Hirschsprung disease 81

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83. • Transition zone between the narrowed affected distal colon and the dilated innervated proximal colon. • Short segment: Rectum smaller than the sigmoid. Rectum in an inverted cone shape. • Long segment: Transition zone is above the recto-sigmoid junction. • Total colonic Hirschsprung: Microcolon • Normal rectum in 33% • “Saw- tooth” appearance due to irregular spasm of the affected segment • Enterocolitis: thickened and ulcerated bowel wall • 24 hr delayed films – Poor barium emptying through the colon 83 Hirschsprung

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85. Differential diagnosis of distal bowel obstruction: • Meconium ileus • Meconium plug and small left colon • Ileal atresia • Colonic atresia 85 Hirschsprung

86. Hirschsprung disease (a) AXR of a newborn who failed to pass meconium, demonstrates multiple dilated loops of bowel consistent with distal obstruction. (b)(c) Lateral and AP views of contrast enema examination of the same neonate illustrating a narrowed rectum compared to the sigmoid. The rectum shows irregular contractions. This is the classic 'inverted cone shape' rectum and 'saw-tooth’ appearance. Rectal biopsy confirmed short segment Hirschsprung disease. 86 Hirschsprung

87. Hirschsprung disease. 9(d) Dilated transverse colon with the transition zone at the splenic flexure (arrow head) corresponding to the lateral and AP barium enema contrast images (e) and (f) (curved arrow). The descending and sigmoid colon is narrowed with spasm and the rectum has a "saw-tooth appearance" due to abnormally contractions (black arrow). Biopsy confirmed long segment Hirschsprung disease. 87

88. Hirschsprung disease in a 6-month-old infant with a history of chronic constipation. Frontal (a) and lateral (b) images from a barium enema study show the proximal sigmoid colon and descending colon as greatly dilated compared with the distal colon and rectum. 88 Hirschsprung

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91. Meconium Peritonitis • Sterile chemical peritonitis • Occurs 1 in 35,000 live births • Secondary to intrauterine bowel perforation • Associated with a mortality rate of up to 60%, • When recognized early, a good clinical outcome can be achieved • Bowel content leakage causes intense inflammation and dense fibrotic tissue formation, subsequent peritoneal calcification (paracolic gutters and below the diaphragm) 91

92. Association: • Small bowel atresia • Meconium ileus • Viral infections (CMV, or HPV) 92 Meconium Peritonitis

93. Imaging features: • Punctate/linear calcifications extending throughout the abdomen (may extend into the male scrotum via a patent processus vaginalis) • Bowel loop separation (secondary to intra-peritoneal fluid) 93 Meconium Peritonitis

94. Differential diagnosis of neonatal intra-abdominal calcification: • Liver calcifications • Intra-abdominal teratoma • Congenital neuroblastoma 94 Meconium Peritonitis

95. Meconium Peritonitis Multiple small scrotal calcifications representing meconium peritonitis. More calcifications in the right upper quadrant. Intra-abdominal free air accumulating in upper central abdomen (arrow head) representing the "football sign", and free air extending into the inguinal canal (arrow). 95

96. Football sign • Seen in cases of massive pneumoperitoneum • Abdominal cavity is outlined by gas from a perforated viscus 96 Rugby ball

97. Meconium peritonitis - Linear and flocculent areas of calcification within the peritoneal cavity (arrows) - Scattered areas of calcification in the scrotum 97 Meconium Peritonitis

98. Bowel Perforation • Can be from obstruction secondary to atresia, meconium ileus and necotizing enterocolitis. • Free air collects in the non-dependent portion of the abdomen • Can seen on the supine abdominal radiograph as lucency over the central abdomen, over the liver and outlining the falciform ligament. • Lateral decubitus projection can be helpful in difficult cases, as the free air will rise to the non-dependent areas. 98

99. Pneumoperitoneum. (a) Lateral decubitus radiograph demonstrating the free air rising to the non dependent area above the liver (curved arrow). (b) Chest radiograph of a neonate showing the falciform ligament (arrow) outlined by free air and therefore becomes visible 99

100. Necrotizing Enterocolitis (NEC) • NEC is the most common gastrointestinal emergency in premature low birth weight infants • Combination of both bowel infection and ischemia • Overall mortality of 20-30%. • Most common affected site - ileum and right colon • Breast-feeding  decreased NEC incidence • Usually conservative treatment • Surgery for perforation and complications 100

101. Predisposing Factors: • Prematurity (50 - 80%) • Patent ductus arteriosus • Perinatal stress • Infection 101 NEC

102. Imaging features: • Persistent abnormally dilated bowel loops without change in position • Bowel wall thickening • Intramural gas • Portal venous gas in up to 30% • Pneumoperitoneum in perforation • Post NEC stricture resulting in obstruction 102 NEC

103. Necrotizing enterocolitis (a) Supine AXR of a premature neonate who developed severe NEC on 14th day of life, demonstrating multiple dilated bowel loop with intramural gas (pneumatosis) (arrow) and portal venous gas (branching linear lucencies in the liver extending to the periphery). (b) The same infant developed bowel obstruction several weeks after the NEC episode. (c) Contrast enema study demonstrates a focal stricture (curved arrow) with a localized perforation at the site of previous NEC (short arrow). 103

104. Intussusception • Invagination of one segment of bowel into another, leading to edema and venous congestion within the bowel wall. • Most common type - Ileocolic • Majority - under 1 year of age, with a peak incidence between 5 and 9 months • M:F (3:2) 104

105. 105 Intussusception

106. LEAD POINT • A lead point is a lesion or variation in the intestine that is trapped by peristalsis and dragged into a distal segment of the intestine, causing intussusception. • Meckel diverticulum • Polyp • Tumor • Hematoma • Vascular malformation 106 Intussusception

107. Intussusceptum (white arrow) and Intussuscipiens (black arrow) 107 Intussusception

108. Etiology 108 Intussusception

109. Etiology (Cont.) Idiopathic • Approximately 75 % of cases are idiopathic • No clear disease trigger or pathological lead point Influence of viral factors • Has a seasonal variation, with peaks coinciding with seasonal viral gastroenteritis. • 30 % experience viral illness (URTI, otitis media, flu-like symptoms) before the onset of intussusception. 109 Intussusception

110. 110 Viral infections Stimulate lymphatic tissue in the intestinal tract Hypertrophy of Peyer patches in the lymphoid-rich terminal ileum Act as a lead point for ileocolic intussusception

111. Presentation • The classic triad of symptoms: (1) intermittent colicky abdominal pain (about every 10-20 min) (2) vomiting (rapidly becoming bile-stained) (3) 'redcurrant jelly' stool • Neurological symptoms (lethargy, hypotonia or sudden alterations of consciousness) 111 Intussusception

112. Pathological process of intussusception 112 Intussusception

113. Imaging features: Plain X-ray(Abd) • Plain radiograph is normal in 25%. • Small tissue mass and crescent of air around the intussuceptum in the right abdomen. • Small bowel obstruction • Paucity of bowel gas distally • Meniscus sign: Crescent of gas within colonic lumen that outlines the apex of intussusceptum 113 Intussusception

115. Meniscus sign 115 Intussusception

117. Contrast Enema 1. Coil spring appearance: - Trapping of barium between the edematous mucosal folds of the returning limb of intussusceptum & wall of intussuscepian. 2. Meniscus sign: - Convex intraluminal mass NOTE: Barium enema is contraindicated in perforation. 117 Intussusception

118. COIL SPRING SIGN 118 Intussusception

119. Barium enema showed filling defect with crab's claw sign at the mid transverse colon 119 Intussusception

120. Ultrasound • Up to 100% accuracy for the diagnosis of intussusception • portable, noninvasive, and without radiation • Characteristic finding>>>>3- to 5-cm diameter mass, typical target or doughnut sign found just deep to the anterior abdominal wall on the right side can detect a possible pathologic lead point with higher frequency (66%) than contrast (40%) or air enema (11%) • “Target” appearance multiple concentric rings and central mesenteric fat in the transverse plane. • “Pseudo-kidney“ appearance: On longitudinal images, intussusception often shows peripheral hypoechoic bowel with central increased echoes. 120 Intussusception

121. Warning signs of necrosis on US • absence of blood flow on Doppler a thick peripheral hypoechoic rim • free intraperitoneal fluid • fluid trapped within the intussusceptum, • enlarged lymph nodes dragged with the mesentery into the intussusception 121 Intussusception

122. • Measurement of intussusception assist in differentiating between ileocolic and small bowel-small bowel intussusception • Small bowel-small bowel intussusception is smaller, typically self- limiting, and does not require intervention. • Ultrasound findings such as intussuscepted lymph nodes and interloop fluid indicate increased difficulty in an attempt at reduction 122 Intussusception

123. Target sign 123

124. • In ileocolic type, the patient should undergo reduction via air or contrast enema to prevent complications (bowel wall ischemia or necrosis, perforation, and shock) • Surgery for patients in whom reduction is unsuccessful or have contraindications to fluoroscopic reduction (e.g. free air, peritonitis, or signs of shock). 124 Intussusception

125. Non-surgical Reduction • Pneumatic or hydrostatic reduction may be performed • In both procedures, an enema tube is placed in the patient’s rectum • In pneumatic reduction, air is pumped manually through the tube into the colon, pushing the intussusceptum through the ileocecal valve. • A pressure of 120 mm Hg or less should be maintained • If the patient engages in a Valsalva maneuver, the pressure may intermittently increase • When the mass is no longer seen and air enters the distal small bowel, the reduction is considered successful. • At the end of the procedure, post reduction image must be taken. (to check +/-pneumoperitoneum) 125 Intussusception

126. • In hydrostatic reduction, water-soluble isotonic or LOCM is hung 3 feet above the table and allowed to flow freely into the colon. • When the intussusceptum reduces, contrast is seen in distal small bowel loops. • Advantages of the pneumatic technique: • Faster reduction • Decreased radiation, and • Air rather than contrast entering the peritoneal cavity (in cases of perforation) 126 Intussusception

127. Intussusception Distal SBO with a soft tissue mass in the right lower quadrant representing an ileocolic intussusception. Note the absence of gas in the colon and rectum. 127 Intussusception

128. Intussusception on ultrasound (A) Transverse and (B) longitudinal gray-scale US images - characteristic of intussusception with a target and “pseudokidney” appearance, respectively. - Lymph nodes can be seen with the intussusceptum on the transverse image (arrow) 128 Intussusception

129. CT and MRI • Are not routinely used • Intussusception found incidentally on imaging performed for another suspected diagnosis • target or doughnut sign 129 Intussusception

130. Inguinal Hernia • Herniation of the intra-abdominal structures • Due to failure of closure of processus vaginalis • Usually reducible and asymptomatic • But can be irreducible  distal bowel obstruction • 60% of hernias occur on the right side • Premature infants are at increased risk for inguinal hernia, with incidence rates of 2% in females and 7-30% in males. 130

131. Imaging features: • Low obstructive bowel pattern • Bowel gas in the scrotum or inguinal canal • Widening of the scrotal shadowing on one side 131 Inguinal Hernia

132. Inguinoscrotal hernia AXR of neonate demonstrating loops of bowel in the left inguinal region extending down to the scrotum. 132 Inguinal Hernia

133. Conclusion • Plain radiograph of a neonate provides a useful initial imaging tool to guide appropriate further imaging, conservative or surgical management. • Abnormal bowel gas pattern on plain radiography can be diagnostic of a specific bowel pathology (e.g. in case of duodenal and jejunal atresia) without further investigations required. • However, in majority of the cases contrast study will be required to reach a final diagnosis. • It is important for radiologists to have a good understanding of normal and abnormal bowel gas patterns and the potential differential diagnosis. 133

134. THANK YOU 134

Imaging in Paediatric Intestinal Obstruction

Soemoe Htoo

Imaging in Paediatric Intestinal Obstruction