To assess the diagnostic value of conventional two dimensional ultrasound and contrast-enhanced ultrasound (CEUS) for intrauterine lesions before surgery.

Fifty-five patients with intrauterine lesions who were admitted to the gynecological ultrasound department of Peking University People's Hospital from December 14, 2018 to December 10, 2020 were recruited. The malignancy of the lesions was first judged by conventional two dimensional ultrasound according to the echo, size, and blood flow signal, and then by CEUS according to the arrival time of contrast agent in the lesion area, the peak intensity, and the time of regression (contrast pattern), with the normal human uterine wall as the control. Using post endoscopic resection pathological results as the gold standard, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of conventional two dimensional ultrasound and CEUS were calculated, and the contrast patterns of malignant and benign lesion were compared.

In total, 36 patients with malignant and 19 with benign intrauterine lesions were verified by post endoscopic resection pathological examination. Using the pathological result as the golden standard, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of conventional two dimensional ultrasound were 47.3%, 63.2%, 73.7%, 70.6%, and 93.3%, respectively; the corresponding percentages for CEUS were 89.1%, 89.5%, 88.9%, 81.0%, and 94.1%. Of the six misclassified cases by conventional two dimensional ultrasound, five were correctly diagnosed by CEUS (one false positive). Regarding the 23 intrauterine lesions for which conventional two dimensional ultrasound could not predict, 20 were correctly diagnosed by CEUS, with a sensitivity of 83.3% (5/6) and specificity of 88.2% (15/17). The contrast imaging patterns of malignant intrauterine lesions were mainly characterized by early enhancement (84.2%, 16/19), high peak intensity (78.9%, 15/19), and early regression (89.5%, 17/19). Both the imaging patterns of early enhancement-high peak intensity-early regression and early enhancement-high peak intensity-synchronous regression suggested malignant lesions, and these two patterns together constituted 73.7% (14/19) of all malignant patterns. Benign lesions were mainly associated with synchronous enhancement or late enhancement (94.4%, 34/36). The pattern of late enhancement-low peak intensity-synchronous regression occurred in 13 of 36 benign intrauterine lesions.

CEUS and conventional two dimensional ultrasound are mutually complementary, and the former may make up for the deficiencies of the latter. Combined use of the two techniques can improve the accuracy of intrauterine lesion diagnosis.