Table 1

A summary of statistical analysis of key BUS and AXR findings derived from previous meta-analyses, obtaining a range of data without further statistical analysis

Statistical significance of key bowel ultrasound findings*
BUS findingFor the diagnosis of NECEventual need for surgery or death
Sens (%)28 Spec (%)28 AXR correlateAXR Sens (%)10 AXR Spec (%)10 OR15 16
Early findings
Increased bowel perfusionNone.NSS
Simple (anechoic) ascites4592Bowel loops displaced centrally if large volume.NSS
Dilated bowelDilated bowel.3.50–3.59
Intermediate findings
Portal venous gas2794PVG.13100NSS
Pneumatosis intestinalis4891Pneumatosis.441002.01–2.23
Bowel wall thickening3167Enlarged mucosal folds.3.7–4.74
Increased bowel echogenicityNone.8.58
Late findings
Bowel wall thinning2296None.7.11–7.97
Absent peristalsis395Stationary patulous bowel loops on serial exams.8.19–10.68
Absent bowel perfusionNone.6.08–6.99
Focal fluid collections1998None.15.37–17.92
Complex (echogenic) ascitesNone.11.28
  • *Data reported are a compilation of the currently known sensitivity and specificity as reported in the referenced meta-analyses. It should be noted that not all studies included reported data on all categories. Further research is needed in this area to elucidate the most accurate data.

  • AXR, abdominal radiograph; BUS, bowel ultrasound; NEC, necrotising enterocolitis; NSS, not statistically significant; PVG, portal venous gas.