Abstract: Objective The aim of this study was to investigate the high-frequency and low-frequency ultrasound in the diagnosis of polypoid lesions of gallbladder (PLG). Methods 64 patients with PLG were enrolled in our hospital between May 2020 and April 2023, and they all underwent low-frequency and high-frequency ultrasonography and thereafter laparoscopic cholecystectomy (LC). The histo-pathological examination was routinely performed, and the diagnosis by ultrasonography was evaluated by Kappa coefficient. Results Among the 64 patients with PLG, the histopathological examination found benign lesions in 59 cases and malignant lesions in 5 cases; the ultrasonic features included the single lesion, wide substrate and lesions with blood signals in malignant lesions; the low-frequency ultrasound found malignant lesions in 9 cases (14.1) and benign lesions in 55 cases(85.9%), the high-frequency ultrasound found malignant lesions in 8 cases (12.5%) and benign lesions in 56 cases (87.5%) and the low- and high-frequency ultrasound combination diagnosed malignant lesions in 7 cases (10.9%) and benign lesions in 57 cases (89.1%), without significant differences among them (P>0.05); the sensitivity, specificity and accuracy by the high-frequency and low-frequency ultrasound combination in judging the quality of PLG were 100.0%, 96.6% and 71.4%, which had a high consistency with histopathological diagnosis (kappa=0.817). Conclusion The combination of high-frequency and low-frequency ultrasound in the diagnosis of PLG is efficacious, which might guide the clinical strategy for management of PLG.

Key words: Polypoid lesions of gallbladder, Low-frequency ultrasound, High-frequency ultrasound, Laparoscopic cholecystectomy, Histopathology, Diagnosis