What radiographic finding is characteristic of necrotizing enterocolitis on abdominal imaging?

• A. Pneumatosis intestinalis.
• B. Ground-glass liver on ultrasound.
• C. Cardiomegaly on chest X-ray.
• D. Pleural effusion.

Answer: (A)

Pneumatosis intestinalis—gas within the bowel wall—is the radiographic hallmark of necrotizing enterocolitis on abdominal imaging. This intramural gas results from mucosal injury allowing gas produced by bacteria to enter the bowel wall, producing linear or bubbly lucencies along the bowel loops on a plain radiograph. Its appearance in a neonate, especially a premature or ill infant with feeding intolerance and abdominal distension, strongly supports NEC. Additional signs like portal venous gas or, if perforation occurs, free intraperitoneal air can accompany it, but the intramural gas itself is the best single imaging clue. Other options such as a ground-glass liver pattern on ultrasound, cardiomegaly on chest X-ray, or pleural effusion are not characteristic findings for NEC.