[Application of dynamic-contrast enhanced magnetic resonance pharmacokinetic models in differential diagnosis of cellular uterine leiomyoma].

OBJECTIVE: To assess the application of the dynamic-contrast enhanced magnetic resonance imaging(DCE-MRI)pharmacokinetics models in differential diagnosis of cellular uterine leiomyoma.

METHODS: Sixty four patients with uterine leiomyoma confirmed by surgery and pathology were enrolled in the study between September 2015 and September 2016, including 30 cases of classical leiomyoma, 13 cases of cellular leiomyoma and 21 cases of degenerative leiomyoma. All patients underwent DCE-MRI before surgery. Reference region (RR) model, extended tofts (ET) model and exchange (EC) model were used to quantitatively analyze DCE-MRI data, and their differences among different pathological types of uterine leiomyoma were observed. Receiver operating characteristic (ROC) curve was used to evaluate the efficiency of the quantitative perfusion parameters in differential diagnosis of cellular uterine leiomyoma.

RESULTS: The values of Ktrans (transfer constant), Kep (efflux rate constant) in RR model, Ktrans , Kep , Vp (blood plasma volume ratio) in ET model and Ve (plasma volume ratio), Fp (plasma flow)in EC model of cellular uterine leiomyoma were higher than those of classical type( P <0.05 or P <0.01). The values of Ktrans , Kep in RR model,Ktrans ,Kep , Ve ,Vp in ET model and Ve ,Vp ,Fp in EC model of cellular uterine leiomyoma were higher than those of degenerative uterine leiomyoma( P <0.05 or P <0.01). There were no significant differences in other quantitative perfusion parameters among three types of uterine leiomyoma (all P >0.05). ROC curves revealed that the Ktrans of the ET model was more effective in diagnosing cellular uterine leiomyoma, the area under the curve (AUC) was 0.929, and the sensitivity and specificity were 92.3% and 83.7%, respectively; meanwhile, the AUCs of Fp of the EC model, Ktrans of the RR model and Kep of the ET model in diagnosis of cellular uterine leiomyoma were 0.867, 0.849 and 0.837, the sensitivities were 91.7%, 84.6% and 92.3%, and the specificities were 78.0%, 76.0% and 73.5%, respectively.

CONCLUSIONS: Three pharmacokinetics models can be used in the differentiation of cellular uterine leiomyoma from other types of uterine leiomyoma. Ktrans of the ET model has higher sensitivity and specificity in differential diagnosis of cellular uterine leiomyoma.