The Diagnostic Value Of Prenatal MRI In The Placenta Accrete

Objective To compare the coincidence between the MRI diagnosis of placenta accreta with operative and pathological findings;Evaluate the value of prenatal MRI in the diagnosis and classification of placenta accreta;Analyse imaging features of prenatal MRI in patients with placenta accreta and the value of union application with multiple signs.Methods The prenatal MRI findings,clinical and pathological data of 75 patients from Jan.2015 to Oct.2017 who were highly suspected placenta previa were analyzed retrospectively.Taking the pathology results and surgical records as the golden standard of diagnosis.All patients with complete clinical data.These 75 cases were divided into two groups according to the postoperative outcomes: 30 cases without placenta accreta were taken as the control group,and the other 45 cases were taken as the placenta accreta group.The Chi-squared test was used to compared the difference between MRI findings and operation and pathology result.Use kappa identity test to evaluate the consistency between the MRI classification diagnosis with golden standard(??0.7,strong agreement,0.7>??0.4,fiar agreement,?<0.4,slight agreeement).Calculate the sensibility,specificity and accuracy of MRI classification diagnosis with placenta accreta.Use binary logistic regression to perform single factor analysis with the five signs including heterogeneous signal intensity within the placenta,the interface betwen uterus and placenta disappearing,localized eminence of womb with the partial placenta obviously thickened,increased blood vessels of the partial placental,partial bladder curtain-like projections,and the differences of MRI features between the two groups were compared.Multiple linear regression was performed to analyse placenta accreta related MRI signs.Two-sided test was used on P value,the difference was significance between two groups(P<0.05).Results There was no statistical significant diferencebetwen the MRI diagnosis and the surgical and pathology results of placenta accreta(chi-square value=0.11,P value=0.74).MRI can make typing diagnosis on placenta accretato a certain extent.The accuracy rate is highest for penetrated-type,high for implantable-type,is low for adhesive-type.Respectively according to the univariate analysis heterogeneous signal intensity within the placenta with the odds ratio(OR)value of 17.017(P=0.005),localized eminence of womb with the partial placenta obviously thickened with the odds ratio(OR)value of 6.712(P=0.049).On multivariate regression analysis,heterogeneous signal intensity within the placenta with the odds ratio(OR)value of 13.542(P=0.004),while localized eminence of womb with the partial placenta obviously thickened with the odds ratio(OR)value of 7.145(P=0.038).Conclusion MRI diagnosis was of good consistency with operative and pathological resulte for placenta accreta.MRI can make typing diagnosis on placenta accreta to a certain extent.For the five MRI signs of placenta accreta,placenta heterogeneity has high sensitivity and specificity,lower uterine segment apophysis and segmental wall thickening of placenta has good diagnosis value,it combines with placenta heterogeneity can improve the diagnostic rate.Indistinction of Placenta-uterine interface,focal abnormal increase of vessel clumps and curtain-like adhesion and nodular-like protuberance of bladder wall,for these three signs,there is no significant difference between placenta accreta group and control group.