Differential diagnosis of polypoid lesions of gallbladder by superb micro-vascular imaging combined with conventional ultrasound

Objective To explore the value of superb micro-vascular imaging(SMI) combined with conventional ultrasound in differential diagnosis of polypoid lesions of gallbladder. Methods The ultrasonographic and pathological datas of 67 patients with polypoid lesions of gallbladder (of ≥1 cm) in diameter were analyzed retrospectively. According to the pathological results, the patients were divided into tumorous polyp group and non-tumorous polyp group.Conventional ultrasound, SMI and contrast-enhanced ultrasound (CEUS) were performed in all patients before operation, and the basal width, continuity of cystic wall and internal blood flow morphology of polyps were evaluated. The ROC curve was used to calculate the area under the curve and the optimum boundary value of tumorous polyps, the sensitivity and specificity of SMI combined with conventional ultrasound in the diagnosis of neoplastic polyps were calculated according to the optimal threshold. Kappa consistency test was used to analyze the consistency between microblood flow ability and CEUS shown by SMI technique. Results Of the 67 patients, 22 cases were neoplastic polyps, and 45 cases were non-neoplastic polyps.The polyps were scored quantitatively by SMI combined with conventional ultrasound (0-9 points) and the ROC curve was plotted with, area under curve 0.893(95% CI 0.792-0.994). The sensitivity, specificity and accuracy of diagnosing neoplastic polyps with score (≥4.5) were 77.3%, 93.3% and 88.1%, respectively. Compared with the score of CEUS for microblood flow display (0-4 points), the Kappa values of CDFI, SMI was 0.186, 0.688. SMI and CEUS have good consistency. Conclusions SMI combined with conventional ultrasound is helpful in differential diagnosis of polypoid lesions of gallbladder, with a high diagnostic value. SMI and CEUS have good consistency in the display of micro-blood flow. It can provide a new diagnostic basis for differential diagnosis of polypoid lesions of gallbladder. Key words: Ultrasonography; Superb micro-vascular imaging; Contrast-enhanced ultrasonography; Gallbladder diseases; Polyps