The Value Of Dynamic Contrast-enhanced MRI Parameters Of Extended Tofts And Exchange Model In The Pathological Subtype Of Uterine Leiomyoma

Objective To analyze the value of dynamic contrast-enhanced MRI(DCE-MRI)parameters of Extended Tofts and Exchange Model in differentiate the pathological pathological subtype of uterine leiomyoma.Methods and Materials Retrospectively analysis 35 cases of uterine leiomyoma confirmed by surgery and pathology from October 2015 to May 2016,all cases were underwent DCE-MRI.We prospectively measured and analyzed quantitative perfusion parameters[transfer constant(Ktrans),efflux rate constant(kep),extravascular extracellular space volume ratio(vc),blood plasma volume ratio(vp),permeability surface area product(PS),plasma flow(Fp)]by signal-input two-compartment tracer kinetic models(Extended Tofts model and Exchange model)in 35 leiomyoma cases.After the operation,the 35 cases divided into three groups about the ordinary,the cellular and the degeneration type according to the pathological classfication.To analyze the differences among the three groups about the quantitative perfiision parameters of uterine leiomyoma.LSD test was used to analyze the differences between the two groups(ordinary and cellular type,cellular and degeneration type,ordinary and degeneration type),P<0.05 has statistical significance.compared with the gold standard of pathological findings in order to draw the ROC curves to evaluate the diagnostic efficacy of different quantitative perfusion parameters.Pearson correlation analysis was also applied to observe the correlations among all equivalent parameters.Results Among three groups of the ordinary,cellular and degeneration type of uterine leiomyoma,the value of Ktrans,Kep,Vp in Extended Tofts model and Fp,Kep,Vp in Exchange model have statistical significance(P<0.05);The value of Ktrans(p<0.001),Kep(p=0.001),Vp(p=0.003)in Extended Tofts model and Kep(p=0.035)、Fp(p<0.001)in Exchange mode of cellular type are higher than the ordinary type;The value of Ktrans(p<0.001),Kepp=0.019),VP(p=0.001)in Extended Tofts model and Vp(p=0.017),Fp(p<0.001)in Exchange mode of cellular type are higher than the degeneration type;The value of Ktrans(p=0.037)in ordinary type is higher than the degeneration type.And use these quantitative perfusion parameters including Ktras,Kep,Vp in Extended Tofts model and Fp,Kep,Vp in Exchange mode to drawed ROC curves to identify the cellular leiomyoma,the area under ROC curve were 1.000、0.923、0.827、1.000、0.702、0.738 respectively.Ktrans in the extended Tofts model was correlated with PS and Fp in the Exchange model(r=0.365,P=0.034,r=0.968,P=0.000);Kep、Vp between the two kinetic models were positive correlated(r=0.454,P=0.007,r=0.479,P=0.004).,and Ve no significant correlation was seen between the two tracer kinetic models.Conclusion The value of Ktrans,KeP,Vp in Extended Tofts and Fp,Kcp,Vp in Exchange model,especially Ktrans and Fp,have a greater diagnostic efficacy in the pathological subtype of uterine leiomyoma.and Ktrans and Fp have obvious correlation.The value of Kep and Vp in Tofts Extended model have greater diagnostic efficacy than Exchange model.