Objective To compare the application value of transabdominal ultrasonography and X-ray in assistingdiagnosis and predicting clinical outcome of neonatal necrotizing enterocolitis（NEC）.Methods Eighty NEC children wereadmitted to our hospital were selected.According to the revised Bell-NEC classification standard

they were divided into gradeⅠA

ⅠB 39 cases（group A）and higher than grade ⅡA 41 cases（group B）.Otherwise

according to the clinical outcome

the80 children were divided into good outcome group（improved after conservative treatment in internal medicine

50 cases）andpoor outcome group（operation or death

30 cases）.All the children were examined by transabdominal ultrasonography and X-ray

and the results of the two methods were compared.The manifestations of X-ray and transabdominal ultrasonography that affectedthe clinical outcome of NEC children were analyzed by Logistic regression.The receiver operating characteristic（ROC）curve wasdrawn to evaluate the predictive value of the X-ray and transabdominal ultrasonography for the poor outcome of NEC children.Results The detection rate of abdominal ultrasonography for intestinal dilatation and portal venous gas in the group B were58.54%（24/41）and 36.59%（15/41）

which were higher than those in the group A with 36.59%（15/41）and 17.07%（7/41）

there were significant differences（both P<0.05）. The detection rate of abdominal free gas

intestinal wall pneumatosis

portalvenous gas and intestinal dilatation by X-ray in the poor outcome group were 13.33%（4/30）

16.67%（5/30）

20.00%（6/30）and50.00%（15/30）

which were higher than those in the good outcome group with 2.00%（1/50）

2.00%（1/50）

2.00%（1/50）

24.00%（12/50）

there were significant differences（all P<0.05）.The detection rate of abdominal free gas

peritoneal effusion

intestinal wall thickening

intestinal dilatation by abdominal ultrasonography were 16.67%（5/30）

50.00%（15/30）

53.33%（16/30）

50.00%（15/30）

which were higher than those in the good outcome group with 2.00%（1/50）

24.00%（12/50）

24.00%（12/50）

32.00%（16/50）

there were significant differences（all P<0.05）.The results of Logistic regression analysis showed that abdominalfree gas

peritoneal effusion and intestinal wall thickening detected by abdominal ultrasonography

and intestinal dilatation andabdominal free gas detected by X-ray were the risk factors of poor clinical outcome of NEC children（all P<0.05）.ROC curveshowed that the area under the curve of transabdominal ultrasonography and X-ray plain film in predicting the poor outcome ofNEC were 0.829（95%CI:0.730～0.927）and 0.702（95%CI:0.581～0.823）

respectively

and the difference was statisticallysignificant（Z=2.036

P<0.05）.Conclusion Compared with X-ray

transabdominal ultrasonography has higher detection rate forintestinal dilatation and portal vehous gas in NEC children.It can detect the subtle changes in the intestinal tract of children withNEC

which has higer application value in early diagnosis and clinical prognosis prediction of NEC.