| Objective: To investigate the value of contrast-enhanced ultrasound(CEUS)in the differential diagnosis for gallbladder polypoid lesions by using CEUS characteristics and time parameters.Methods:58 cases were diagnosed as polypoid lesions of gallbladder by conventional ultrasound,and then evaluated by CEUS.46 cases were confirmed by pathology and brought into this study.The items evaluated by conventional ultrasound included the number,size,basal width,surface smoothness,shape,echogenicity(compared with liver parenchyma),gallbladder wall intactness,color Doppler and spectral data(if there was any blood flow and blood flow dynamic data)of polypoid lesions.The items evaluated by CEUS included enhancement time parameters,contrast distribution characteristics,enhancement intensity,intralesional vascular architecture,wash-in and wash-out pattern and enhancement entrance mode of polypoid lesions.Finally the above-mentioned items were compared with pathological results,and were statistically analyzed.Results:1 Pathological results: Of 46 cases of gallbladder polypoid lesions,10 were neoplastic lesions,including 6 adenomas(3 adenomas associated with cholesterol polyps),4 adenocarcinomas(2 carcinomas associated with adenomas),36 were non-neoplastic lesions(22 cholesterol polyps,2 inflammatory polyps,10 adenomyomatosis,and 2 sludges).All 24 cases of polyps were accompanied with cholecystitis.2 Results of conventional B-mode ultrasound and Color Doppler Imaging: Neoplastic lesions showed regular or irregular solid masses protruding into the gallbladder cavity.Most(8 cases)had wide bases.All 4 carcinomas had wide bases.All 4 carcinomas had disrupted walls of gallbladder,whereas 6 adenomas had intacted walls.Of non-neoplastic lesions(polyps,adenomyomatosis and sludges),17 had narrow bases,19 had wide bases.Polyps usually showed nipple-like or oval masses protruding into the gallbladder cavity.Most of them(17cases)had narrow bases connecting with the walls,some of them(7cases)had wide bases.All cases of non-neoplastic group had intact walls beneath the lesions;The lesions in 10 cases of adenomyomatosis were focal or segmental,and all had wide bases.Small cysts with multiple crystalline hyperechogenicity were seen in the lesions in 4 cases of adenomyomatosis.In our study there were 2 cases of biliary sludges,without acoustic shadow,motionless.All 2 cases of sludges had wide bases.There was a statistically significant difference between noeplastic lesions and non-neoplastic lesions when the wall intactness was compared(P=0.001).And there was a statistically significant difference between noeplastic lesions and polyps(cholesterol polyp and inflammatory polyp)when the basal width was compared(P=0.019).Of neoplastic lesions in our study,8 cases showed blood flow,and 2 cases did not.34 cases of non-neoplastic lesions failed to display blood flow,and only 2 cases(cholesterol polyps)showed blood flow.There was no blood flow in adenomyomatosis and sludge cases.There was a statistically significant difference(P<0.001)between noeplastic lesions and non-neoplastic lesions when the occurrence rates of intralesional blood flows were compared.According to the maximum diameter of polypoid lesions,patients(excluding gallbladder sludge cases)were divided into two groups,the maximum diameter of the lesion ≥1.0cm(23 patients)group and that <1.0cm(21 patients)group.In the maximum diameter ≥1.0cm group,there were 7 cases(30.43%)of neoplastic lesions,including 4 carcinomas(all were ≥1.0cm).In the maximum diameter <1.0cm group,there were 3 cases(14.28%)of non-neoplastic lesions(all were adenomas).Although there was no statistically difference between these two groups,according to the proportions of neoplastic lesions in their groups,this demonstrated the tendency that maximum diameter ≥1.0cm group has higher incidence of neoplasm.3 CEUS characteristics of PLG: 44 PLG showed various degrees of enhancement,except that 2 sludges showed no any enhancement.All of 10 cases of neoplastic lesions(carcinomas and adenomas)showed heterogeneous enhancement and marked enhancement.2 of them had perfusion defect(1 was carcinoma,1 was adenoma).Most of neoplastic lesions(8 cases)presented fast wash-in and fast wash-out.5 cases of neoplastic lesions were enhanced from the center to the outer of the lesions and 5 cases from the outer to the center.Most of 34 cases of non-neoplastic lesions(polyps and adenomyomatosis)showed heterogeneous enhancement(16 cases)and marked enhancement(17 cases).Most non-neoplastic lesions(22 cases)presented fast wash-in and slow wash-out.All of 10 cases of adenomyomatosis presented fast wash-in and slow wash-out.Most of polyps(18 cases)were enhanced from the center to the outer,while all 10 cases of adenomyomatosis were enhanced from the outer to the center.2 cases in this study showed perfusion defect,1 was adenoma,1 was carcinoma.In term of intralesional microvascular architecture,of neoplastic lesions 5 presented dotted type,2 branched type,1 linear type,and 2 sinuous type(only in carcinomas).Of non-neoplastic lesions 20 presented dotted type,12 linear type,and 2 branched type.All 10 cases of adenomyomatosis presented linear type.There were statistically differences between noeplastic lesions and non-neoplastic lesions when wash-in and wash-out pattern,intralesional microvascular architecture and perfusion defect were compared(P=0.000,P=0.022,P=0.048).4 Time parameters of CEUS: The arrival time,time to peak,washout time of neoplastic lesion group were 15.19±4.31 s,26.03±6.70 s and 46.15±19.27 s respectively;The arrival time,time to peak,washout time of non-neoplastic lesion group were 15.84±7.55 s,34.32±18.51 s,84.71±27.52 s.There were statistically significant differences(P=0.036,P<0.001)when the time to peak and washout time were compared between neoplastic lesions and non-neoplastic lesions.5 In this study 3 cases were confirmed by pathology as cholesterol polyps accompanied with adenomas,and 2 cases were confirmed as adenomas accompanied with carcinomas.By observing the clips carefully we found the arrival time,time to peak and wash-out time of these lesions were different.So CEUS was helpful in identifying different pathological foci of gallbladder.6 There was no statistically significant difference for neoplatic lesions and adenomyomatosis between the diameter before and after CEUS(P >0.05).There was a statistically significant difference for polyps between the diameters before and after CEUS(P <0.05).7 Compared with final pathological diagnosis,the diagnostic sensitivity,specificity and accuracy of conventional ultrasound for GB neoplastic lesions and non-neoplastic lesions were 80%,77.78%,78.26% respectively.The diagnostic sensitivity,specificity and accuracy of CEUS for GB neoplastic lesions and non-neoplastic lesions were 100%,86.11%,89.13% respectively.The diagnostic efficiency of CEUS for GB neoplastic lesions and non-neoplastic lesions was higher than that of conventional ultrasound.Conclusion:Nature of neoplasm is related to the size of lesion.Intactness of gallbladder wall is the important indicator for differential diagnosis between neoplastic lesions and non-neoplastic lesions.Basal width is helpful for differential diagnosis between neoplastic lesions and polyps.The lesion in which blood flow is detected by CDFI has more probability of neoplastic pathology.CEUS improves the ability to clearly depict intralesional vascularity and visualize the base of lesion and gallbladder wall beneath the lesion.Arrival time,washout time,intralesional vascular architecture and wash-in-wash-out pattern play very important roles in differentiating neoplastic lesions from non-neoplastic lesions.And perfusion defect is a key feature of neoplastic lesions.Also,CEUS is helpful to identify different pathologies within gallbladder with multiple lesions.As the supplementary method of conventional sonography,CEUS has improved the diagnostic accuracy for differentiating polypoid lesions,so it is beneficial to clinical diagnosis,treatment and prognosis of PLG. |
PDF Full Text Request