Prediction of hemorrhage in placenta previa: Radiomics analysis of pelvic MRI images

•Prediction of intraoperative hemorrhage is still challenging in placenta previa.•Radiomics analysis has been investigated as new evaluation for medical images.•We constructed prediction models, using radiomics in MRI images of placenta.•The best model predicted hemorrhage with an accuracy of 0.70 and an AUC of 0.69.•Radiomics features based on MRI were used as effective predictive variables. Prediction of intraoperative massive hemorrhage is still challenging in placenta previa. Radiomics analysis has been investigated as a new evaluation method for analyzing medical images. We used radiomics analysis on placental magnetic resonance imaging (MRI) images to predict intraoperative hemorrhage in placenta previa. We used the sagittal MRI T2-weighted sequence in placenta previa. Using the rectangular region from the uterine os to the anterior wall, we extracted 97 radiomics features. We also collected patient demographics and blood test data as clinical variables. Combining these radiomics features and clinical variables, logistic regression models with a stepwise method were built to predict the risk of hemorrhage, defined as blood loss of > 2000 ml. We evaluated the prediction performance of the models using accuracy and area under the curve (AUC), also analyzing the important variables for the prediction by stepwise methods. We enrolled a total of 63 placenta previa cases including 30 hemorrhage cases from two institutes. The model combining clinical variables and radiomics features showed the best prediction performance with an accuracy of 0.70 and an AUC of 0.69 in the internal validation data, and accuracy of 0.41 and an AUC of 0.70 in the external validation data, compared with human experts (accuracy of 0.62). Regarding variable selection, two radiomics features. ’original_glrlm_LowGrayLevelRunEmphasis,’ and ’diagnostics_Image-original_Minimum,’ were important predictors for hemorrhage by the stepwise method. Radiomics features based on MRI could be used as effective predictive variables for hemorrhage in placenta previa. Radiomics analysis of placental imaging could lead to further analysis of quantitative variables related to obstetric diseases.