Objective:

To compare bedside ultrasonography (US) and abdominal radiography (AXR) for their ability to discriminate the need for surgical intervention in neonatal necrotising enterocolitis (NEC) and to evaluate the value of combining the two modalities.

Approach:

• Study Design: A retrospective cohort study involving 509 neonates diagnosed with NEC who underwent both AXR and bedside US within 24 hours.
• Data Analysis: Multivariable logistic regression was used to assess the predictive value of imaging signs, with model discrimination evaluated by AUC and calibration assessed by various statistical tests.

Key Findings:

• The surgical group had a lower gestational age and birth weight compared to the conservative group (both P < 0.001).
• Five signs were identified as independent predictors of surgical intervention: AXR portal venous gas (OR = 32.76, 95% CI 7.11–150.94), AXR pneumoperitoneum (OR = 11.91, 95% CI 1.81–78.58), US complex peritoneal effusion (OR = 16.94, 95% CI 3.65–78.76), US peritoneal effusion (OR = 7.53, 95% CI 4.04–14.03), and US portal venous gas (OR = 2.71, 95% CI 1.33–5.51).
• The AUCs for AXR, US, and combined models were 0.696, 0.842, and 0.862 respectively, with US and combined models showing superior discrimination compared to AXR (both P < 0.001).

Interpretation:

Bedside US was found to be superior to AXR in predicting the need for surgical intervention in neonates with NEC, while AXR provided complementary information.

Limitations:

• The study was conducted at a single center, which may limit the generalizability of the findings.
• The analysis was retrospective, which may introduce selection bias.

Conclusion:

US and AXR may serve as complementary modalities in the routine imaging work-up of NEC, with US providing superior discrimination for surgical needs.