Combining abdominal ultrasound and radiography for surgical risk stratification in necrotising enterocolitis: a prospective cohort pilot study

Objective To evaluate whether combining abdominal ultrasound with radiography improves diagnostic accuracy and surgical risk stratification in neonates with suspected necrotising enterocolitis (NEC) compared with radiography alone. Design, setting and patients Prospective cohort pilot study conducted in two tertiary neonatal intensive care units. Sixty-seven neonates with suspected NEC underwent concurrent abdominal radiography and ultrasound assessments. Imaging studies were independently reviewed by masked investigators using pre-specified criteria to classify each study as reassuring or non-reassuring. Main outcome measures The main outcome measure was the need for surgical intervention. Imaging data were analysed using unsupervised k-means clustering (k=2): logistic regression—testing associations with surgery and principal component analysis (PCA)—to identify imaging features most contributing to group separation. Results Ultrasounds were reassuring in all cases subsequently diagnosed with non-NEC, that is, feeding intolerance, whereas most radiographs in this group were non-reassuring. Clustering based on radiographs alone did not significantly discriminate surgical risk (58.8% vs 39.4%; p=0.11). Combined model (radiograph+ultrasound) produced two distinct clusters with significantly different surgical rates (78.3% vs 34.1%; OR 6.96, 95% CI 2.29 to 24.58). PCA highlighted complex ascites, absent peristalsis and abnormal bowel perfusion as key discriminating features. Conclusion Combining abdominal ultrasound with radiography improved the identification of neonates at high surgical risk from NEC, in our pilot study. A reassuring ultrasound reliably identified infants with feeding intolerance, suggesting potential to reduce unnecessary transfers and treatments. Larger multicentre studies are needed to validate these findings and inform development of a unified multimodal imaging score for NEC diagnosis.