Usefulness of contrast-enhanced ultrasonography in the differential diagnosis of polypoid gallbladder lesions

We investigated the usefulness of contrast-enhanced ultrasonography for differential diagnosis of polypoid gallbladder lesions in 60 patients, consisting of gallbladder carcinoma in 20, adenoma in 2, benign polyp in 29, and adenomyomatosis in 9, comparing contrast enhancement patterns with pathologic findings. We monitored vascular flow for 120 sec, constructing a time intensity curve (TIC) by flash-echo imaging. We compared the number of vessels and vessel diameter determined by contrast enhancement patterns and by pathologic examination. Contrast enhancement patterns were classified as linear, scattered, diffuse, or branched. When diffuse type and branched type were considered as indicative of cancer, accuracy was 84.5%, sensitivity 100%, and specificity 76.9%. In gallbladder carcinoma, the TIC rose from no contrast to early-phase contrast sooner than in other diseases. In adenocarcinoma, high-intensity values persisted at 120 sec. With an intensity of 90 or greater at 120 sec taken as indicating cancer, accuracy was 89.7%, sensitivity 89.5%, and specificity 89.7%; Vessels were significantly more numerous in diffuse type cases than in those with other patterns. Vessel diameter was greatest in the diffuse type and the branched type patterns, both differing significantly from the linear type. Ultrasonographic contrast enhancement patterns show characteristic associations with pathologic findings and serve as valuable adjuncts in the diagnosis of gallbladder diseases.