Abstract: Objective To investigate the value of local brain tissue oxygen monitoring combined with multimodal magnetic resonance imaging (MRI) examination in the early diagnosis of preterm infants with brain injury. 
Methods A total of 250 preterm infants born in our hospital were selected as the research subjects. Local brain tissue oxygen monitoring and multimodal MRI were performed for all preterm infants. The results of criteria for brain injury in preterm infants examination were used as the gold standard for the diagnosis of brain injury. The consistency of local brain tissue oxygen monitoring and multimodal MRI alone and in combination in the diagnosis with the results of criteria for brain injury in preterm infants was analyzed. 
Results After local brain tissue oxygen monitoring, 250 preterm infants with brain injury were diagnosed as follows: 120 preterm infants with brain injury and 130 preterm infants without brain injury. By consistency analysis, the sensitivity, specificity, accuracy and Kappa value of local brain tissue oxygen monitoring in the diagnosis of preterm brain injury were 0.850, 0.862, 0.856, and 0.712, respectively. The diagnosis results of 250 preterm infants with brain injury were as follows: 122 preterm infants with brain injury and 128 normal preterm infants. By consistency analysis, the sensitivity, specificity, accuracy and Kappa value of multimodal MRI in the diagnosis of preterm brain injury were 0.900, 0.892, 0.896 and 0.792, respectively. By local brain tissue oxygen monitoring combined with multimodal MRI examination, the diagnosis results of 250 preterm infants with brain injury were as follows: 122 preterm infants with brain injury and 128 normal preterm infants. Through consistency analysis, the sensitivity, specificity, accuracy and Kappa value of local brain tissue oxygen monitoring combined with multimodal MRI in the diagnosis of preterm brain injury were 0.950, 0.938, 0.944, and 0.888, respectively. 
Conclusion Local brain tissue oxygen monitoring combined with multimodal MRI has good application value in early diagnosis of premature brain injury. 

Key words: infant, premature, brain injuries, local brain tissue oxygen monitoring