Diagnostic values of contrast-enhanced ultrasonography in the diagnosis of endometrial lesions

Abstract

Objective To explore the characteristics and quantitative analysis results of contrast-enhanced ultrasonography (CEUS) images of different types of endometrial lesions, and analyze the values of CEUS in the diagnosis of endometrial lesions. Methods From June 1, 2016 to January 31, 2018, a total of 62 subjects with suspected endometrial lesions in the Department of Gynecology, Sichuan Integrative Medicine Hospital were enrolled into this study, aged 27-66 years. All subjects underwent transvaginal CEUS, as well as surgery or surgical curettage to obtain tissues for histo pathology. According to the endometrial histopathological results, they were divided into malignant group (n=10, endometrial cancer patients), benign group (n=41, simple endometrial hyperplasia or endometrial polyps), and control group (n=11, without endometrial lesions). The characteristics of the CEUS images were analyzed. The time-intensity curve (TIC) was used to determine the initial enhancement time, peak time, peak intensity and gradient of contrast agent in endometrium, and area under TIC curve (TIC-AUC) as the normal myometrium at the same depth as the endometrial lesion was used as a reference. The initial enhancement time of contrast agent among three groups was compared by one-way ANOVA analysis. The peak intensity, peak time, gradient and TIC-AUC among three groups were compared by Kruskal-Wallis H test. The receiver operator characteristic (ROC) curves of peak intensity and TIC-AUC for predicting the incidence of endometrial cancer were built respectively, and the area under ROC curve (ROC-AUC) was calculated. The optimal critical values of those two indicators for predicting the incidence of endometrial cancer were obtained when Youden index reaching the maximum value. And their sensitivities and specificities were calculated respectively. This study met the requirements of the World Medical Association Declaration of Helsinki revised in 2013. Clinical trials informed consent was obtained from each subject before undergoing transvaginal CEUS. Results After the injection of contrast agent through cubital vein, the characteristics of CEUS images were as follows. ①In the malignant group, the transvaginal CEUS results showed a rapid uniform or non-uniform enhancement in the early stage of endometrium. According to the different pathological types of endometrial cancer, the initial enhancement time of endometrium was significantly earlier than that of the myometrium (7 cases of adenocarcinoma endometrium) or slightly earlier than that of the myometrium (3 cases of malignant mesodermal mixed tumor or clear cell carcinoma), and the peak intensity was significantly higher than that of the myometrium (8 cases of adenocarcinoma endometrium or clear cell carcinoma) or slightly higher than that of the myometrium (2 cases of malignant mesodermal mixed tumor), and the regression times of endometrium all were later than that of the myometrium. ②Among the 41 subjects in the benign group, 9 cases were simple endometrial hyperplasia whose transvaginal CEUS results showed that the initial enhancement time of endometrium were later than that of the myometrium, and the regression time of endometrium was earlier than that of the myometrium; the early enhancement patterns of endometrium were mainly slightly enhanced. And 32 cases were endometrial polyps whose transvaginal CEUS results showed that the initial enhancement time of endometrium was slightly later than that of the myometrium, and the regression time of endometrium was earlier than that of the myometrium; the early enhancement patterns of endometrium were diverse, mainly characterized by a slightly higher nodular enhancement. ③The peak intensities of malignant group, benign group and control group were 25.1 dB (14.6-26.1 dB), 10.7 dB (7.0-15.5 dB), and 10.1 dB (7.2-15.1 dB), respectively, and TIC-AUC of malignant group, benign group and control group were 1 880.7 (734.9-2 084.2), 418.0 (240.0-718.7), and 349.8 (238.3-563.6), respectively. There were statistical differences among three groups in the peak intensity and TIC-AUC (H=6.732, 6.732; P=0.035, 0.011). But there were no statistical differences among three groups in the peak time, gradient and initial enhancement time of endometrium (P>0.05). ④Among the indicators of TIC, the ROC-AUC of peak intensity and TIC-AUC for predicting the incidence of endometrial cancer were 0.92 (95%CI: 0.78-0.97, P=0.028) and 0.96 (95%CI: 0.84-0.99, P=0.016), respectively. The optimal cut-off values of peak intensity and TIC-AUC for predicting the incidence of endometrial cancer were 16.608 dB and 767.45 respectively, and the sensitivities were 81.2% and 85.1% respectively, and the specificities were 85.8% and 87.2% respectively. Conclusions The images of endometrial lesions in transvaginal CEUS have certain characteristics. And transvaginal CEUS has certain diagnostic values in the diagnosis of endometrial malignant lesions. Key words: Endometrial neoplasms; Endometrial hyperplasia; Endometrial lesions; Endometrial polyps; Ultrasonography; Contrast media; Women