1. Radiology of the Pediatric Abdomen
Ruba Khasawneh, MD

2. Radiologic diagnosis modalities
Plain films
Barium studies
US/CT and MRI
Nuclear medicine studies

3. Modalities-Plain films
Should cover the entire abdomen from GE junction to rectum
Supine, Supine/upright and Acute abdominal series
Check lines placement
Bowel gas pattern, A/F levels
Presence of abnormal calcifications/FB or soft tissue opacities
Presence of free air, pneumatosis, ? ascites
Other

4. Modalities-US Can be performed portably No radiation
Masses , fluid collections/abscesses and ascites

5. Modalities-CT/MRI
CT : Masses, abscesses, appendicitis, acute abdomen in non-verbal patient, etc…
MRI: Masses, MRE
Risk of radiation (CT) and sedation if needed

6. Modalities-NM
Biliary atresia
GER
Meckel’s diverticulum

7. Case 1

8. Fig 1

9. Fig 2

10. Imaging Findings
Fig 1 : Multiple frontal x-rays of the chest and abdomen demonstrating enteric tube at the level of the upper thoracic region with a distended upper pouch. Note the presence of bowel gas in the abdomen. There is also collapse/consolidation of the right ULL
Fig 2: Note the presence of multiple vertebral anomalies in the lumbar region

11. Diagnosis: Esophageal atresia with TEF

12. Discussion- TEF
Incidence 1 in 3500 , Etiology not well known, faulty separation between esophagus and trachea
Esophageal atresia with distal fistula> esophageal atresia alone> TEF w/o esophageal atresia
Increased incidence with Down’s
30% born premature
Commonly associated with other anomalies: VACTERL, imperforate anus, duodenal atresia
Associated with polyhydramnios, feeding abnormalities and respiratory compromise

13. Esophageal Atresia / TE Fistula

14. Case 2

15. Fig 1

16. Fig 2

17. Imaging Findings
Multiple bowel loops seen in the right hemithorax in Fig 1 and left hemithorax in Fig 2 with hypoplasia of both lungs. Note the position of the NG tube in Fig 2 and the same findings in the corresponding fetal MR.

18. Diagnosis: Congenital diaphragmatic hernia

19. Discussion- CDH 1 in 2000-4000 live births
Patent pleuroperitoneal canal, might contain liver, spleen, stomach and bowel
M:F 2:1
L:R 9:1
Associated anomalies in 20%
Mortality related to lung hyoplasia

20. Case 3

22. HPS

23. Imaging findings
Multiple U/S images demonstrating abnormal elongation of the pyloric channel with thickening of the hypoechoic muscle layer.
Length > 16mm
Muscle thickness > 3mm

24. Diagnosis: Hypertrophic Pyloric Stenosis

25. Discussion-Hypertrophic pyloric stenosis
Incidence 3/1000, age 0-3 months
4-5 times more common in boys, 1st born
Familial: maternal > paternal
Hypertrophy of muscular channel
Projectile vomiting, non-bilious
Dehydration, weight loss
Hyperperistalsis, palpable olive Hy

27. Discussion-cont’d U/S modality of choice UGI radiation, time consuming
Pylorospasm is a pitfall!
Treatment surgical ( pyloromyotomy )/ medical in Europe

28. Normal VS. abnormal pylorus-US

30. Case 4

32. Imaging findings
Frontal x-ray of the chest and abdomen demonstrating “Double bubble sign” ; gas in the gastric fundus and in the duodenal bulb with absent gas in the rest of the abdomen.

33. Diagnosis: Duodenal atresia

34. Discussion-Duodenal atresia
Prevalence 1 in
No sex associated difference in prevalence
Defective canalization
Associated anomalies in 60%, Down’s (25%), GI, GU, CHD, VACTERL
Distal to ampulla of Vater in 80%( bilious vomiting), non-bilious vomiting if proximal

35. Case 5

38. Imaging findings
Contrast UGI study demonstrating abnormal rpositioned DJ junction lower than the duodenal bulb and to the right side of the spine. Note the corkscrew appearance of the more distal small bowel and the whirlpool sign on the US image.

39. Diagnosis: Malrotation with midgut volvulus

40. Discussion- Malrotation with midgut volvulus
First week of life
Ill infant with bilious emesis and abdominal distention
Absent normal attachments of the mesentery to the posterior abdominal wall with narrow mesenteric stalk ( which contains the SMA and SMV)
Malrotation is always present with omphalocele, gastroschisis, diaphragmatic hernia

41. Discussion-cont’d
60% associated anomalies: duodenal atresia, annular pancreas , CHD with heterotaxy, diaphragmatic hernia, imperforate anus, etc...
In older children can present with failure to thrive, recurrent abdominal pain and malabsorption.
Tx: Surgical emergency ( Ladd procedure)

42. Normal bowel rotation-UGI

43. Case 6

45. Imaging findings
Multiple distended loops of small and large bowel concerning for low bowel obstruction.
Differential diagnosis in the neonatal peroid include:
1- Imperforate anus
2- Hirshprung’s disease
3- Meconium ileus
4- Ileal atresia
5- Meconium plug syndrome

46. Differential diagnosis in the older child include:
1- Incarcerated hernia
2- Intussusception
3- Appendicitis
4- Adhesions
5- Meckel’s diverticulum

47. RULE OF THUMB
- 2or less dilated loops of bowel on abdominal x-ray indicates high bowel obstruction study from above
- 2 or more dilated loops of bowel on abdominal x-ray indicates low bowel obstruction study from below

48. Case 7

50. Imaging findings
Barium enema showing small caliber of the entire colon “microcolon” with reflux of contrast into the proximal ileum which contains multiple filling defects “inspissated meconium”. Note the multiple distended bowel loops throughout the abdomen.

51. Diagnosis: Meconium ileus vs. Ileal atresia

52. Discussion- Microcolon
No passage of normal enteric contents during development
Ileal atresia: ? Vascular accident in utero, Microcolon with no reflux of contrast into SB. Other atresias common
Meconium ileus: associated with CF, increased meconium viscosity, complications in 50% ( atresia, perforation, mec peritonitis and volvulus) ,Microcolon with inspissated meconium.

53. Case 8

58. Imaging findings
Contrast enema studies demonstrating abnormal recto-sigmoid ratio of less than 1 with transition zone seen at the rectum.
Note also the multiple dilated bowel loops throughout the abdomen consistent with low bowel obstruction.

59. Diagnosis: Hirshprung’s Disease

60. Discussion- Hirshprung’s disease
Congenital disorder/ absent ganglion cells in the myenteric plexus
Affects 1 in newborn
More common in white, M>F
Hereditary in 12.5% (typically total colonic aganglionosis)
Present with chronic constipation
Diagnosis? Barium enema, definite diagnosis is rectal biopsy

61. Case 9

65. Imaging findings
Abdominal x-ray showing a soft tissue opacity in the right upper quadrant with paucity of gas in the right side of the abdomen.
U/S images demonstrating a donut shape structure in the right lower quadrant( intussusception) containing multiple lymph nodes
Air enema study showing successful reduction of the intussusception with reflux of air into the small bowel

66. Diagnosis: Intussusception

67. Discussion- Intussusception
Invagination of bowel into itself
Ileocolic is the most common
75% < 2 years
Rare less than 3 months
Idiopathic in >95%, lymphoid hyperplasia
Pain , mass and bleeding
Tx: Reduction enema; air safer than liquid, 5% recurrent, surgery if unsuccessful

69. Case 10

72. Imaging findings
Chest and abdominal x-ray demonstrating multiple dilated bowel loops with large bilateral inguinal hernias extending into the scrotum.
Abdominal x-ray showing multiple dilated loops of bowel with small left inguinal hernia

73. Diagnosis: Incarcerated Inguinal Hernia

74. Discussion- Inguinal hernia
Most common cause of obstruction> day 4
M:F 9:1, R:L 5:1
Increased inguinal fold
Gas in the scrotum

75. Case 11

78. appy 15 y/o

79. Imaging findings
Abdominal x-ray showing multiple dilated loops of bowel with multiple air-fluid levels seen mainly in the right side of the abdomen (ileus) with appendicolith in the right lower quadrant seen in a different patient.
Ultrasound exam demonstrating a blind ending tubular structure in the RLQ which measures >6mm, is incompressible with loss of mucosal details and increased echogenicity of surrounding fat. Note also the intraluminal appendicolith.
CT scan showing distended hyperemic appendix with appendicolith and surrounding inflammatory changes and free fluid.

80. Diagnosis: Acute appenidicitis

81. Discussion- Acute appendicitis
Most common cause for emergent surgery in children
4/1000
8-9% life time risk
Presentation: periumbilical pain that moves to RLQ, N., V., anorexia and fever
Clinical diagnosis, difficult exam in the young patients, US/CT

82. Normal appendix

83. Case 12

85. Imaging findings
Large amount of free intraperitoneal air ( pneumoperitoneum) outlining the falciform ligament , note also the football sign and Rigler’s sign(air outlining both sides of the bowel ).

86. Diagnosis: Pneumoperitoneum

87. Discussion- Pneumperitoneum
Perforated viscus: Idiopathic, NEC, ulcer
Dissection from mediastinum or retroperitoneum
Post operative
Might be difficult on supine abdominal x-rays
Need horizontal beam view: cross table lateral or left lateral decubitus view

88. Intraperitoneal Air

89. Case 13

92. Imaging findings
Multiple abdominal x-rays demonstrating multiple dilated bowel loops with extensive pneumatosis intestinalis. Note also the extensive portal venous gas.

93. Diagnosis: Necrtoizing enterocolitis with pneumatosis intestinalis and portal venous gas

94. Discussion-NEC
Ischemic injury to bowel, 90% preterm/10% term( Hirshprung’s/ CHD)
Risk factors: prematurity, hypoxia, hyperosmolar feeds, stress, UAC
Hypoperfusion: sepsis, PDA and CHD
Loss of mucosal integrity
Altered enteric immunity: decreased IgA in preterm
Bacterial overgrowth, invasion
Ileocecal region most common

95. Discussion-NEC Radiology: 1- Dilated fixed bowel loops
2- Pneumatosis intestinalis: linear(subserosal), bubbly( submucosal)
3- Portal venous gas
4- Pneumoperitoneum
Complications: short bowel, stricture, fistulas.

96. Normal neonatal x-ray

97. NEC- US

98. Case 14

100. Batteries
FB Discussion
-coins are most commonly swallowed FB
-Button batteries show a characteristic double-density (2-layer) shadow.
Laterally, their edges are rounded with a step-off junction at the positive and negative terminals
Are important to identify since they may cause caustic burn injury to esophagus
If battery has remained in stomach/GI tract for more than hours, then removal is recommended (corrosion has been documented as early as 6 hours after ingestion)
-Nonradio-opaque FB: hot dog is most common, with plastic toys also commonly ingested

102. yr 4 mo rock ingestion