Necrotizing enterocolitis - imaging findings

Summary of abdominal x ray and ultrasound findings in necrotizing enterocolitis.
From Merrow AC Jr. Diagnostic Imaging: Pediatrics. 3rd ed. Elsevier; 2017.

1. Necrotizing enterocolitis - NEC Imaging findings

2. 90% in the premature with very low birth weight, < 1500g 2-3 weeks after delivery 10% in term infants with one or more risk factors 1-3 days after delivery

3. Presentation Signs of feeding intolerance emesis increased gastric residuals bloody stool

4. Affected bowel commonly in RLQ ascending colon terminal ileum b ut can affect any segment from stomach to rectum

5. In the a cute phase l ife threatening bowel perforation  sepsis In th e ch ronic phase bowel strictures in 10-20%

6. Best imaging tools abdominal X ray - AXR ultrasound - US

7. AXR nonspecific findings suggestive findings diagnostic findings

8. AXR Nonspecific findings paucity of bowel gas

9. AXR Suggestive findings fixed dilated bowel loops on serial AXR – predictive of NEC asymmetric bowel dilation separation of bowel loops

10. AXR Diagnostic findings pneumatosis portal venous gas pneumoperitoneum

11. Pneumoperitoneum on AXR overall increased lucency of upper abdomen with liver less opaque than heart football sign – free gas outlining falciform ligament cupola sign – lucency of midline diaphragm R iegler sign – gas outlining both sides of bowel wall

12. Pneumoperitoneum on AXR cross table lateral decubitus view – crescentic lucency overlying anterior hepatic margin left lateral decubitus view – crescentic lucency overlying right hepatic margin peripheral triangles of lucency

13. US Best clues aperistaltic bowel with thick or thin wall avascular bowel wall – suggests necrosis Other complex ascites, focal fluid collections echogenic bowel wall with dirty shadowing – pneumatosis portal venous gas, pneumoperitoneum