Abstract: Objective The aim of this study was to explore combination of high frame rate contrast-enhanced ultrasound (H-CEUS) and ultrasound micro-flow imaging (MFI) in the differential diagnosis of benign and malignant polypoid lesions of gallbladder (PLG). Methods 122 patients with PLG were enrolled in our hospital between June 2021 and June 2024, and all underwent surgical resection for histo-pathological examination. Before operation, H-CEUS by using Mindray Resona R9S ultrasound diagnostic instrument and equipped with contrast-enhanced ultrasound software and MFI by using Philips EPIQ7 color Doppler ultrasound diagnostic instrument was conducted to record special parameters. Receiver operating characteristic curve (ROC) was drawn to evaluate diagnostic performance. Results Post-operational histo-pathological examination found malignant lesions in 33 cases(27.1%) and benign lesions in 89 cases (72.9%); gallbladder wall thickness in malignant lesions was (1.6±0.3) cm, significantly thicker than (1.2±0.2) cm in benign lesions (P<0.05), percentages of continuous gallbladder outer wall and continuous gallbladder inner wall were 18.2% and 15.2%, much lower than 85.4% and 87.6%(P<0.05) in benign lesions, while percentages of high signal enhancement and branch-like blood vessels were 75.8% and 45.5%, much greater than 34.8% and 0.0% in benign lesions, and initial enhanced time, peak time and subside time were (14.5±2.1)s, (20.1±4.7)s and (35.6±5.1)s, all significantly shorter than [(17.3±3.5)s, (24.9±5.2)s and (40.5±6.3)s, respectively, P<0.05] in benign lesions; percentages of Alder’s blood flow grade 3 and 4 were 33.3% and 45.5%, both much higher than 13.5% and 2.2%(P<0.05) in benign lesions; ROC analysis showed that the AUC was 0.909(95%CI:0.856-0.962), with sensitivity of 90.9% and specificity of 79.8%, when H-CEUS was combined with MFI parameters in differentiating benign and malignant PLG. Conclusion H-CEUS in combination with MFI examination could improve diagnostic efficacy in differentiating benign and malignant PLG, and the increased gallbladder wall thickness and discontinuity of gallbladder walls might hint the malignant PLG existence, which should manage as sooner as possbile.

Key words: Polypoid lesions of gallbladder, High frame rate contrast-enhanced ultrasound, Ultrasound micro-flow imaging, Gall bladder cancer, Diagnosis