IMAGING IN NEONATAL GIT

1. Imaging in neonatal GIT
S. THIYAGARAJAN

2. Clinical manifestation
The most common clinical findings
• Inability to pass RT
• Vomiting
• Abdominal distension
• Failure to pass meconium/imperforate
anus
• AN detected

3. GI Causes of Vomiting
Bilious
• Infant/Child
• Intussusception
• Malrotation w/ volvulus
• Incarcerated hernia
• Neonate
• Congenital Atresia
• Meconium Ileus
• NEC
• Hirschsprung’s
Nonbilious
• Infant/Child
• Gastroenteritis
• GERD
• Hepatobiliary
• Pancreatitis
• PUD
• Gastroparesis
• Appendicitis
• Neonate
• Pyloric Stenosis

4. Esophageal Atresia &
Tracheoesophageal Fistula
• Developmental disorder
• Fault in formation and separation of
the primitive foregut into the trachea
and esophagus

5. TYPE A

6. TYPE B

7. TYPE C

8. TYPE D

9. TYPE E

10. Radiography
• Radiographic evaluation should always
include the abdomen to assess the
presence of air in the GI tract
• Blind pouch of the proximal esophagus
that is distended with air
• Type A and B - Complete absence of gas in
the stomach and intestinal tract
• Type C and D - GIT commonly appears
distended with air.

11. • The type of esophageal atresia is
confirmed by advancing a radiopaque
feeding tube through the nose to the level
of the atresia
• The tube will curl when it approaches the
blind end
• Atelectasis and pneumonia involving the
upper right lobe
• Type E (H-shaped TE fistula without
atresia) - Demonstration of the fistula,
which typically courses forward and
upward from the esophagus

12. Oesophageal
atresia

13. Esophageal Atresia and
Tracheoesophageal Fistula
• 25% associated with other GI
malformations
• Imperforate anus
• Pyloric stenosis
• Duodenal atresia
• Annular pancreas
• Less frequently, cardiac, genitourinary, and
vertebral alterations

14. Esophageal Atresia and
Tracheoesophageal Fistula
• The VACTERL complex
• Vertebral
• Anal
• Cardiac
• Tracheal
• Esophageal
• Renal
• Limb anomalies
• The best known grouping of anomalies
associated with tracheoesophageal lesions

15. VACTERL

16. Oesophageal
atresia with
absent radius -
thumb

17. Gastrointestinal duplications
• Three defining characteristics
• Have well developed coat of smooth
muscle
• Epithelial lining represents some part of
the alimentary tract
• Attached to some part of the alimentary
tract
• Part of the spectrum of mesenteric and
omental cyst

18. • Can occur anywhere along the
alimentary tract
• Duplication cysts are most often
associated with the esophagus and
jejunum/ileum

19. Esophageal duplications
• More often seen on the right side
• More common in the lower half of the
chest
• Contain gastric mucosa in 30%
• Often have associated vertebral
anomalies (neurenteric cyst)

20. Esophageal
duplications

22. HYPERTROPHIC PYLORIC
STENOSIS
• Idiopathic thickening of pyloric muscle
in infancy which creates progressive
gastric outlet obstruction
• Typically seen in 2-8 week old infants
with worsening projectile vomiting
• Incidence of - 2 per 1,000 live births

23. Radiographic Findings
• Overdistended stomach and minimal
bowel gas distally
• Stomach may be collapsed if infant has
recently vomited

25. UGI findings
• Pyloric wall thickness >10 mm
• Elongation and narrowing of pyloric canal
(2-4 cm in length)
• "Double / triple track sign"
• Crowding of mucosal folds in pyloric channel
• "String sign"
• Passing of small barium streak through pyloric
channel

26. • Twining recess = "diamond sign"
• Transient triangular tentlike cleft / niche in
midportion of pyloric canal with apex
pointing inferiorly secondary to mucosal
bulging between two separated hypertrophied
muscle bundles on the greater curvature side
within pyloric channel
• "Pyloric teat"
• Outpouching along lesser curvature due to
disruption of antral peristalsis
• "Antral beaking"
• Mass impression upon antrum with streak of
barium pointing toward pyloric channel

27. • Kirklin sign = "mushroom sign"
• Indentation of base of bulb (in 50%)
• Gastric distension with fluid
• Active gastric hyperperistalsis
• "Caterpillar sign"

28. RADIOLOGICAL SIGNS
beak
caterpillar
mush diamond
teat
track
shoulder

30. US findings
• "Target sign"
• Hypoechoic ring of hypertrophied pyloric
muscle around echogenic mucosa centrally
on cross-section
• "Cervix sign"
• Indentation of muscle mass on fluid-filled
antrum on longitudinal section
• "Antral nipple sign"
• Redundant pyloric channel mucosa
protruding into gastric antrum

31. US findings
• Thickened pylorus
Commonly accepted threshold values
• Single wall thickness of pylorus > 3 mm
• Pyloric channel length > 16 mm
• Pyloric diameter > 7 mm
• Exaggerated peristaltic waves
• Delayed gastric emptying of fluid into
duodenum
• Complications: Hypochloremic metabolic
alkalosis

32. US findings
• Pyloric volume >1.4 cm3
[maximum pyloric diameter]2 x pyloric length
4
• Most criteria independent of contracted or
relaxed state
• [Pyloric length (mm) + 3.64] x muscle thickness (mm) > 25

33. Pyloric stenosis

35. Target sign

36. Antral nipple sign
Redundant pyloric cannal mucosa
protruding into gastric antrum

37. Cervix sign
Indentation of the pylorus
into the fluid-filled antrum

38. GASTRIC VOLVULUS
• Rotation all or part of stomach > 180
degrees, ± closed-loop obstruction,
possible strangulation
• It is the rotation and not the obstruction
which defines the presence of volvulus

39. • Organoaxial volvulus: Rotation around
longitudinal axis (most common)
• Around line extending from cardia to pylorus
• Stomach twists anteriorly or posteriorly
• Antrum moves inferior to superior

40. • Mesenteroaxial volvulus: Rotation about
mesenteric axis
• Axis running across stomach right angles to
lesser & greater curves
• Rotation right to left or left to right about
gastrohepatic omentum
• Mixed volvulus
• Combination of
OAV & MAV

41. Radiography
• Abdominal plain films; patient upright
• Double air-fluid level
• Large, distended stomach; spheric viscus
displaced upward to left
• Elevation of diaphragm
• Small bowel collapsed; paucity distal gas
• Intramural emphysema gastric wall
• Chest X-ray
• Intrathoracic up-side down stomach
• Retrocardiac fluid level
• 2 air-fluid interfaces different heights
• Simultaneous fluid levels above & below
diaphragm

44. Fluoroscopic Findings
• Massively distended stomach left upper
quadrant, may extending into chest
• Inversion of stomach
• Greater curvature above lesser
• Cardia & pylorus at same level
• Downward pointing pylorus & duodenum
• May see "beaking" at point of twist
• OAV: 2 points of twist; luminal obstruction
• Contrast in stomach may not pass beyond
pylorus
• MAV: Antrum & pylorus lie above gastric
fundus

45. Organoaxial
volvulus

46. CT Findings
• Not generally performed for GV
• CT appearance may be variable
• Depends on extent of gastric herniation,
points of torsion, position of stomach
• May be linear septum within gastric lumen
(area of torsion)
• Large hiatal hernia accompanied by
partial GV
• "Pseudothrombosis" of inferior vena cava
on CT

47. Mesenteroaxial
gastric volvulus

48. DUODENUM
Duodenal Obstruction
• Complete duodenal obstruction is seen
much more frequently than congenital
gastric obstruction.
• Vomiting is usually delayed until after
the first feeding but increases
progressively thereafter

49. Radiographic Appearance of
Duodenal Obstruction
Complete obstruction
 Gasless abdomen
 Gas in stomach and prox. duodenum
 Gas distally if bifid common bile duct
Partial obstruction
 Gastric distention
 Distended small bowel
 “Double bubble”
 Scattered gas-filled bowel loops distally
 Normal if vomiting decompressed stomach and
duodenum

52. DDX Duodenal Obstruction
• Intrinsic (Often complete obstruction)
-Duodenal atresia
-Duodenal stenosis
-Duodenal web, diaphragm, or “wind sock”
• Extrinsic (Often partial obstruction)
-Malrotation with midgut volvulus
-Malrotation with Ladd’s bands
-Annular pancreas
-Preduodenal portal vein
-Hematoma

53. Duodenal atresia
• Most important cause of complete
duodenal obstruction.
• Failure of recanalization of the
duodenum between approximately the
9th and 11th weeks of gestation

55. Jejunal atresia
• Normal or near normal size colon
• Seen in jejunal and proximal ileal atresias
• Colon receives succus entericus from
remaining small bowel

56. Jejunoileal
atresia

57. JEJUNOILEAL ATRESIA

58. Ileal atresia - Contrast enema
• Microcolon (small unused colon)
• The earlier in gestation the obstruction
occurs

59. Ileal atresia

60. Small Bowel
Atresia Ba
enema

61. Rotation of Gut

62. Abnormal Gut Rotation
• Nonrotation
• When both limbs return to abdomen without further
rotation
• Small bowel on right and colon on left
• Wide mesentery – less risk of volvulus
• Gastroschisis; Omphalocele; Diaphragmatic Hernia
• Malrotation
• Duodenojejunal limb remains in nonrotation in the
right midabdomen
• Cecocolic limb in partial rotation in the midupper
abdomen fixed to abdominal wall by Ladds bands

63. Malrotation - Radiography
• X ray abdomen : less informative
• Abnormal configuration of gas in right
hypochondrium, the duodenal triangle suggests
diagnosis
• Volvulus :
• Corkscrew sign
• Tapering of beaking of the bowel in complete obstruction
• Malrotated bowel configuration
• Distal obstruction
• Closed loop syndrome features - thick walled
edematous loops with pneumatosis
• Gas less abdomen due to prolonged vomiting

66. • Upper GI series - Modality of choice
• Clearly abnormal position of
duodenum (81%)
Duodenum and Jejunum to right of spine
Corkscrew duodenum and jejunum
DJJ low and in midline
• Unusual abnormal position of
duedenum (16%)
 DJJ over right pedicle
 DJJ left of spine but low
 Duodenal redundency to right of spine
 Z shaped configuration of duodenum &
Jejunum

69. USG - Midgut volvulus
• Clockwise whirlpool sign
• Abnormal superior mesenteric vessels
• Inverted SMA/SMV relationship
• Solitary hyperdynamic pulsating SMA
• Truncated SMA
• Inapparent SMV
• Abnormal bowel
• Dilated duodenum proximal to obstruction
• Thickened wall of small bowel distal to
obstruction
• Dilated fluid filled loops of small bowel
• Ascites

70. CT
• SMV to the left of SMA in 80%
• Aplastic or hypoplastic uncinate process
of pancreas
• Chylous mesentric cyst (from interference
of lymphatic drainage)
• Midgut volvulus
• Whirlpool sign of twisted mesentary
• Bowel obstruction
• Free fluid / free gas in advanced cases

71. Whirlpool sign

72. Whirlpool sign

73. Angiography
• Barber pole sign – spiralling of SMA
• Tapering or abrupt termination of
mesentric vessels
• Mesentric vasoconstriction
• Prolonged contrast transit time
• Absent venous opacification
• Dilated tortures superior mesentric
vein.

74. INTUSSUSCEPTION
• Invagination of more proximal bowel
(the intussusceptum) into lumen of
more distal bowel (the intussuscipiens)
in a telescope-like manner
• Most common site:
• Terminal ileum/ileocecal valve
• 90% ileocolic

75. Radiography
• Soft tissue mass surrounded by a crescent
of gas
• Evidence of distal small bowel obstruction
• Absence of or decreased gas in the colon
• Pneumoperitoneum
• May be normal
• Left-side-down decubitus/prone views can be
helpful in showing lack of air-filled cecum

77. Intussusception
• Meniscus sign
Produced by the rounded apex of the
intussusceptum protruding into the column
of contrast
• Coiled spring appearance
Edematous mucosal folds of the returning
limb of the intussusceptum are outlined by
contrast material in the lumen of the colon

79. Intussusception

80. Target sign (Doughnut sign)
USG

81. Pseudokidney
sign / Hay fork
sign
USG

82. Mesenteric vessels dragged between entering and
returning wall of intussusceptum

83. Intussusception
DIFFERENTIAL DIAGNOSIS
• Normal position of sigmoid colon
• Appendicitis
• Gastroenteritis
• Ovarian pathology
• Meckel diverticulum

84. MECKEL DIVERTICULUM
• Remnant of the omphalomesenteric duct
• Bleeding (when contain ectopic gastric mucosa)
• Intussusception
• Bowel obstruction
• Perforation
• Rule of 2's :
• 2% Incidence of general population
• 2 feet of ileocecal valve
• Before age 2 years

85. Radiography
• Right lower quadrant mass
• Displacement of bowel loops,
• Obstruction
• Enteroliths
• May be normal

86. Fluoroscopic Findings
• Barium studies show indirect evidence
of mass and inflammatory changes in
adjacent bowel

87. Ultrasonographic Findings
• Heterogeneous echotexture mass in
RLQ, may mimic appendicitis
• Thick walled tubular structure or
hyperemic bowel loops in RLQ
• Inflamed Meckel diverticulum may
present as a cyst

88. CT Findings
• Findings very similar to appendicitis
• Thick walled blind ending structure near
cecum with surrounding inflammation
• If perforated may see abscess and free air
• CT is more accurate in diagnosing Meckel
diverticulum than arteriography when
presenting symptom is gastrointestinal
bleeding in pediatric patients

89. Nuclear Medicine Findings
Tc-99m pertechnetate scan
• The most specific test for Meckel diverticulum is the
Tc-99m pertechnetate scan: Accuracy -90%
• Pertechnetate accumulates in mucous cells when they
are in an acidic environment, in this case in ectopic
gastric mucosa
• The diverticulum typically does not communicate
with the bowel lumen, so the radiotracer does not
appear to move downstream in bowel unless there is
active bleeding

91. MECONIUM PLUG
SYNDROME
• Small left colon syndrome.
• Transient functional obstruction of the
newborn colon
• Common cause of distal neonatal bowel
obstruction

92. Radiography
• Multiple dilated loops of bowel
• Cannot differentiate dilated large from
small bowel loops in neonates
• Findings nonspecific, cannot
differentiate from other causes of distal
bowel

93. Contrast enema
• R/S ratio usually> 1
• Descending and sigmoid colon small in
caliber
• Abrupt zone of caliber transition in region of
splenic flexure
• Filling defects within colon
• Ascending and transverse colon increased in
caliber
• Difficult to differentiate from long segment
Hirschsprung disease
• Enema often therapeutic; passage of
meconium plugs during or just after enema

95. Small left colon syndrome
• Functional immaturity of colon
• Narrow caliber of the left colon.
• Abrupt transition at the splenic flexure.
• Multiple filling defects in the left colon
are due to meconium plugs
• These infants present at 1-2 days of age
with failure to pass meconium.

97. MECONIUM ILEUS
• Neonatal obstruction of the distal ileum
due to abnormally thick, tenacious
meconium
• Meconium becomes inspissated and
obstructs the distal ileum and is usually
a manifestation of cystic fibrosis
• Presenting illness in approximately 15%
of CF patients

98. Radiography
• Difficult to distinguish neonatal large vs. small
bowel
• Uncomplicated Type
• Multiple dilated bowel loops
• Bubbly lucencies right lower quadrant
• Few air-fluid levels (sticky meconium)
• Complicated Type
• Soft tissue mass or gas less abdomen
• ± Intrauterine perforation and peritonitis
• Curvilinear calcifications on peritoneal surface or lining
pseudocyst

99. “Bubbly"
appearance
of the
distended
intestinal
loops

100. Contrast enema
• Smallest of microcolons
• Reflux contrast into terminal ileum
• Meconium pellets in terminal ileum; not
much in colon
• Can be therapeutic in uncomplicated
type

101. Meconium ileus

102. MECONIUM PERITONITIS
• Chemical peritonitis from in utero
bowel perforation and peritoneal
leakage of sterile meconium
• At least four types are recognised:
•Fibro-adhesive
•Cystic
•Generalised
•Healed

103. Meconium
peritonitis
Soft tissue mass,
punctate or
curvilinear
calcifications,
ascites, dilated
bowel loops

105. Meconium peritonitis

106. AN - USG
• Highly echogenic linear or clumped foci
(calcifcation )
• Snowstorm appearance
• Abdominal circumference may be increased
• Associated anomalies such as dilated fetal bowel
and/or meconium pseudocysts
• Meconium pseudocyst: Heterogeneous mass
with calcified wall
• Fetal ascites and/or polyhydramnios

107. NECROTIZING
ENTEROCOLITIS
• Idiopathic enterocolitis
• VLBW premature infants
• Combination of infection and ischemia
characterized by coagulative and
hemorrhagic necrosis
• Inflammation of portions of the small
and large intestine

108. Location
• Most common right colon and terminal
ileum
• Can occur anywhere in gastrointestinal
tract

109. Radiography
• Findings range from normal to suggestive
to diagnostic
• Normal
• Suggestive findings
• Asymmetric bowel dilation
• Featureless "unfolded" bowel loops
• Separation of bowel loops
• Fixed configuration of bowel loops over serial
films

110. Necrotising
enterocolitis

111. Definitive finding:
Pneumatosis
Bubble-like
(submucosal)
or curvilinear
(serosal)
lucencies

112. Pneumatosis
intestinalis
(intramural gas)

113. Portal venous gas
Definitive finding: Portal venous gas
Branching lucencies over the liver

114. The football sign / air dome sign
• Right upper quadrant
gas
• Rigler’s (double wall)
sign
• Ligament visualization
• Inverted V sign
• Triangular air
• The cupola sign
• Football or air dome
• Scrotal air
Definitive finding: Free intraperitoneal air

115. Bell classification
• Stage I: Early or suspected NEC
• Nonspecific
• Scalloping/separation/unfolding bowel loops
• Asymmetric bowel distention
• Stage II: Definite NEC
• Pneumatosis intestinalis: Mucosal, serosal; not always
correlating with clinical symptoms/signs
• Stage III:
• Advanced disease (perforation or impending
perforation)
• PVG, free intraperitoneal air, persistent loop sign,
ascites

116. Fluoroscopic Findings
• Enema contraindicated in presumed
acute NEC
• Mucosa permeable to water-soluble
contrast and excreted into kidneys
• Stricture:
• Single or multiple
• Small bowel or colon
• Chronic complication of NEC

117. Ultrasonographic Findings
• Thickened bowel wall loops
• Increased (inflamed) or decreased
(infarcted) vascularity
• Ascites

118. Differential diagnosis
• In the correct clinical scenario the
presence of gas within bowel wall has
little differential.
•Pneumatosis coli
•Neonatal appendicitis
•Meconium ileus
•Hirschsprung disease
•Infectious enterocolitis

119. HIRSCHSPRUNG DISEASE
• Functional obstruction of the bowel due to
lack of intrinsic enteric ganglion cells
• Morphology
• Denervated colon is small, narrow, spasmodic
• Innervated more proximal bowel is dilated
• Affected portion always includes the anus and
variable length of Rectum
• Continuous disease
• No proximal without distal involvement

120. • Short segment disease : ~ 75% *
• Rectal and distal sigmoid colonic involvement only
• Long segment : ~ 15%
• Typically extends to splenic flexure / transverse colon
• Total colonic aganglionosis : 2 - 13%
• Zuezler-Wilson syndrome
• Occasional extension of aganglionosis into small
bowel
• Ultrashort segment disease
• 3 – 4 cm of internal anal sphincter only
• Controversial entity

121. Associations
• Isolated abnormality in 70% of cases
• Down syndrome : in ~ 10%
• Neurocristopathy syndromes
• Waardenburg-Shah syndrome
• Haddad syndrome
• MEN IIa
• other non-neurocristopathy syndromes
• Aarskog syndrome
• Bardet-Biedl syndrome
• Fryns syndrome
• Pallister-Hall syndrome
• Smith-Lemli-Opitz syndrome

122. Radiography
• Multiple
loops of
dilated
bowel
• Paucity of
gas in the
rectum

123. Contrast enema
• Rectum smaller than sigmoid (R/S ratio < 1)
• Transition zone from abnormally small distal to
dilated proximal colon
• Fasciculations or sawtooth appearance of mucosa of
involved colon: Spasm
• Thickened, ulcerated colon in patients with
associated colitis
• Microcolon: Total colonic disease

127. Differential diagnosis
• Functional megarectum
• Necrotising enterocolitis
• Microcolon : appears similar to long
segment / whole colon Hirschsprung
disease

128. Megacystis-microcolon-intestinal
hypoperistalsis syndrome
• The duodenum and proximal jejunum
are mildly dilated.
• Small bowel is dilated and shortened,
and the colon is a microcolon
• Abundance of ganglion cells in the
entire gastrointestinal tract.
• Megacystis and megaureters

130. ANORECTAL
MALFORMATION
• Abnormal separation of genitourinary
system from hindgut
• Spectrum; true imperforate anus (thin
membrane) to atresia distal rectum
• Classification controversial
• Anatomic: Relation of rectal pouch to
pubococcygeal line
• Surgical: Prognostic and therapeutic, "Pena“
classification

131. • Low
• Usually visible perineal orifice; stenotic or
membrane
• No GU tract communication
• Intermediate
• Usually features of high lesion
• High
• Usually rectourinary fistula in males
• Usually rectovaginal or vestibular in females
• Possible vaginal, uterine, or bladder anomalies

132. PUBOCOCCYGEAL LINE:
• Line is drawn between upper and
middle third of pubis to lower border
of S5
• Bowel ends just above this line are
termed high malformation and below
one is termed low malformation.

134. ISCHIAL LINE
• Line drawn below parallel to the
pubococcygeal line at the level of the ossified
ischial bone
• Corresponds to the most proximal level of
bulbous urethra
• Anomalies between this two lines are termed
intermediate
• If fistulas occur, they open in the bulbous
urethra in male or in to vestibule or lower part
of vagina in the female.

135. PIT LINE
• This line is parellal to the ischial line but
one to two centimetre caudal to it.
• This marks the posteroinferior part of
the bulbocavernous muscle.
• If bowel gas ended below this area
Called imperforate anal membrane or
low ARM

136. Radiography
• Distal bowel obstruction, intraluminal
calcification
• ± Gas in bladder in males, vagina in females
• Air in rectal pouch on prone cross table
lateral view: Inaccurate for level
• Bony landmark PCL
• "M" line: Horizontal to pelvis divides lower 1/3,
upper 2/3 ischium
• Low lesions appear high: Meconium-packed
pouch
• High lesions appear low: Straining, crying,
excessive distention pouch

137. ARM

138. Voiding Cystourethrogram
• Catheter into cloaca (single perineal orifice)
• Enters bladder, vagina, or colon
• Bladder findings
• Normal; vesicoureteral reflux (VUR); wall-
thickening; neurogenic bladder; fistula to rectum
• Urethral findings
• Opens to cloaca, fistula from rectum to posterior>
bulbous> penile urethra
• Vaginal findings
• Normal; rectovaginal fistula; congenital anomalies
(septate, duplicated, etc.)

139. High pressure
distalcolostography
• Several months after colostomy prior to
repair
• Key view is lateral
• Document connection to urethra,
bladder, or vagina

140. Ultrasound
• Hypoechoic rectal pouch-perineal
distance
• < 10 mm: Low lesion;
• > 10-15 mm - high or intermediate
• Reliability similar to radiography with
similar inaccuracies

141. MR Findings
• Pelvic musculature, neorectum, and anal
sphincter position/integrity
• Normal to absent levator muscle
• Normal to absent anal sphincter complex
• Muscle complex malpositioned or atrophic
• Spine
• Tethered cord, spinal dysraphism, sacral
agenesis

142. Urinary tract anomalies associated with ARM
• Renal agenesis
• Renal ectopia
• Megaureter
• HN (PUJ obstruction)
• VUR
• PUV
• Epispadias/Hypo
• Prune belly syn
• VATER anomaly

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157. Announcement!!!
GUEST LECTURE
On
By
Consultant Radiologist,
Apollo hospitals, Madurai.
Date: 12.11.2011,Saturday