Diagnostic Value Of MRI For Placental Implantation And Its Implantation Depth

Objective:To explore the diagnostic value of MRI in prenatal diagnosis of placenta implantation and its implantation depth,and establish a scoring system for MRI diagnosis of placenta implantation depth,quantify MRI signs,predict implantation depth,evaluate diagnostic efficacy,and improve diagnostic level.Method:The MRI and clinical data of 63 patients who were highly suspected of placenta implantation by clinical and ultrasound in our hospital before delivery were retrospectively analyzed.The MRI findings of patients with placenta implantation were analyzed with surgery and pathology as the "gold standard".Firstly,Kappa test was used to verify the consistency of MRI diagnosis results with the "gold standard".Then,by referring to relevant literature at home and abroad,9 items of MRI signs and clinical risk factors were selected to establish MRI scoring system for diagnosing placental implantation depth.The scoring value of each patient and the mean total score of the three implantation types were calculated.The ROC curve of the scoring scale was drawn by the method of least significant difference between groups.The boundary value and area under the curve were calculated,and the sensitivity and specificity of diagnosis were calculated.Results:61 of the 63 patients were confirmed to have implantable placenta,including 3 adherent placenta implantable placenta,32 implanted placenta implantable placenta and 26 penetrative placenta implantable placenta.The sensitivity of MRI for the auxiliary diagnosis of adhesion,implantable and penetrating placenta implantation were 0.666,0.879 and 0.920,respectively;The specificity was 0.983,0.893 and 0.917,respectively.The positive predictive values were 0.666,0.906 and 0.885,respectively.Negative predictive values were 0.983,0.862 and 0.943,respectively.Kappa values were 0.649,0.770 and 0.832,respectively.The mean scores of the three types of placenta accretion were adhesion(6.00±2.65)points,implantation(8.19±2.00)points and penetration(12.38±1.98)points,respectively.The scores were compared among all groups(F=37.325,P<0.05),and the differences were statistically significant.ROC curve showed that the boundary values between adhesion and implantable placenta implantation,between implantable placenta implantation and penetrating placenta implantation were 5.5 points and 9.5 points,AUC values were 0.760 and 0.947,sensitivity were 0.938 and 0.923,and specificity were 0.667 and 0.750,respectively.Conclusion:Prenatal MRI examination has a high accuracy in judging the presence of placenta implantation and its implantation depth.MRI sign score scale has a good application value in predicting the depth of placenta implantation,which will be conducive to the effective development of clinical follow-up treatment plan,and is worth promoting.