Radiomics model based on MR T2WI for prenatal diagnosis and classification of placenta accreta spectrum disorders
Objective:To investigate the application value of radiomics model based on MR T2WI for prenatal predicting placenta accreta spectrum disorders(PAS)and determining the subtype of PAS.Materials and Methods:The data of 193 pregnant women with singleton pregnancies who were hospitalized for delivery in Beijing Obstetrics and Gynecology Hospital from January 2018 to January 2023 were retrospectively analyzed,including 134 cases of PAS and 59 cases of non-PAS.All pregnant women were randomly divided into training set and test set in a 2:1 ratio based on the total number of patients with the same subtype.The radiomics features were extracted from T2WI sequence,Pearson correlation coefficient and least absolute shrinkage and selection operator(LASSO)regression were used for feature screening,and the radiomics models for predicting PAS were constructed.Then,a radiomics scoring system for clinical application is constructed and trained to evaluate the subtypes of PAS,and univariate analysis and multivariate analysis are used to further analyze other potential clinical risk factors,including age,gestational age,previous gravidity,previous parity,the history of cesarean section,placental problems(placenta previa),and the history of uterine-related operations.Establish a nomogram based on the selection of clinical major risk factors.The receiver operating characteristic(ROC)curve was drawn to evaluate the predictive performance of the model,and DeLong test was used to compare the predictive efficiency of these models,the calibration curve is used to evaluate the degree of calibration of the prediction model,and the decision curve is used to evaluate the clinical value of the prediction model.Results:806 radiomics features were extracted from T2WI sequence,147 radiomics features were retained after Pearson correlation analysis,and 10 radiomics features were screened out after LASSO regression processing,and a radiomics model that is applied to scoring was established.The area under the curve(AUC)value of the radiomics model in the training set was 0.933(95%CI:0.888-0.978),the accuracy was 88.37%,the sensitivity was 88.78%,the specificity was 87.10%,the positive predictive value(PPV)was 95.60%,and the negative predictive value(NPV)was 71.05%;the AUC value in the test set was 0.914(95%CI:0.835-0.993),the accuracy was 89.06%,the sensitivity was 90.91%,the specificity was 85.00%,the PPV was 90.00%,and the NPV was 80.95%.The calibration curve and decision curve showed that the model had high performance and potential clinical application value.The radiomics scoring model has a strong ability to identify placenta percreta,the accuracy of training set and test set reached 82.95%and 89.06%,the sensitivity and NPV reached 100.00%in training set and test set,and the specificity reached 81.35%and 88.33%,respectively.In addition,this study successfully constructed a clinical-radiomics model and draws a nomogram for visualizing PAS in patients.In the training set,the AUC of the clinical-imaging model was 0.969(95%CI:0.946-0.993),in the test set,the AUC value was 0.976(95%CI:0.947-1.000).DeLong test results showed that there were significant differences in the performance of the two models(P<0.05),and the clinical-imaging model had better performance.Conclusions:The clinical-radiomics model based on the clinical major risk factors and radiomics scoring system has a good performance,and can be used as a method to predict the presence of PAS before delivery.And the radiomics scoring system has a good ability to distinguish the subtype of PAS,especially the placenta percreta.