Value of contrast-enhanced ultrasound in diagnosis and differential diagnosis of polypoid lesions of gallbladder ≥ 1 cm.

ObjectivesTo evaluate the usefulness of Contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of Polypoid lesions of gallbladder (PLGs) ≥ 1 cm.MethodsA prospective analysis was performed on 180 patients with PLGs ≥ 1 cm. 175 cases were confirmed by pathological diagnosis and the remaining were confirmed by other imaging findings. The characteristics of lesions on conventional Ultrasonography (US) and CEUS were recorded.ResultsSignificant differences were observed in enhancement patterns between benign and malignant PLGs during both arterial (P < 0.001) and venous phases (P < 0.001). The malignant lesions typically yielded a "fast-in and fast-out" enhancement pattern. There was no significant difference in Arrival time (AT) between malignant and benign PLGs. If we consider wash-out time ≤ 40 s as a diagnostic standard for malignant lesions, the sensitivity, specificity, and accuracy were 88.24%, 85.62%, and 86.11%, respectively. Destruction of the Gallbladder (GB) wall was a particularly important indication of malignant PLGs, and the sensitivity, specificity, and accuracy were 93.33%, 92.12%, and 92.22%, respectively. The accuracy of CEUS in the diagnosis of PLGs, as well as malignant and benign lesions, was 92.22%, 92.47%, and 91.17%, respectively.ConclusionsThe "fast-in and fast-out" enhancement pattern, hyper-enhancement in comparison to the GB wall in the arterial phase, wash-out time ≤ 40 s, GB wall destruction, and hepatic parenchymal infiltration are the characteristic findings of malignant PLGs. Besides, CEUS provides a valuable reference to classify some of the benign lesions.