Supplementary Material for: Outcome Prediction and Inter-Rater Comparison of Four Brain Magnetic Resonance Imaging Scoring Systems of Infants with Perinatal Asphyxia and Therapeutic Hypothermia

Introduction: The brain magnetic resonance imaging (MRI) result is a major predictor for the outcome of term infants with perinatal asphyxia who underwent therapeutic hypothermia. In daily practice, no uniform method is used to assess these images. Purpose: The aim of this study was to determine which MRI-score best predicts adverse outcome at 24 months of age and has the highest inter-rater reliability. Methods: Four MRI scoring systems for term infants with perinatal asphyxia were selected: Rutherford score, Trivedi score, Weeke score, and NICHD NRN score. Experienced blinded raters retrospectively evaluated the brain MR Images of 161 infants using all four scoring systems. Long-term outcome (the composite outcome death or adverse outcome, and its separate components) were routinely assessed by standardized testing at the age of 24 months. The predictive accuracy was assessed by logistic regression analyses and expressed as area under the ROC curve (AUC). The inter-rater reliability of the scores was calculated by the weighted Kappa or intraclass correlation. A sensitivity analysis using only high-quality MRI scans was performed. Results: All four MRI scoring systems demonstrated an AUC of >0.66 for the prediction of adverse outcome and ≥0.80 for the prediction of death. The inter-rater reliability analyses demonstrated the highest reliability for the Weeke and Trivedi scores. When only assessing the high-quality scans, the AUC increased further. Conclusion: All four MRI brain scores proved reliable predictors for an adverse outcome at 24 months of age. The Weeke and Trivedi score demonstrated the highest inter-rater reliability. The use of high-quality MRI further improved prediction.