Can tumefactive sludge and gallbladder polyps be differentiated from gallstones sonographically?
When sludge consolidates to form a mass, so-called tumefactive sludge, it is still typically mobile and avascular, which differentiates it from a polyp, and it does not shadow, which differentiates it from a gallstone. Gallbladder polyps can be as echogenic as are small gallstones, but they are nonmobile and do not shadow. Color Doppler flow can also sometimes be detected in a polyp.