Ultrasound Imaging of the Biliary Tract 399 GB LO RT Fig. 7. Complicated cholecystitis with gallbladder perforation (A)Longitudinal ultrasound of the gallbladder with adjacent irregularly marginated pericholecystic intrahepatic fluid (arrows). This patient presented with sep- sis 2 weeks after prostate surgery and was found to have acute cholecystitis with an adjacent liver abscess. B Longitudinal ultrasound of gallbladder containing stones shows a pericholecystic collection(arrows) containing debris. The collection abuts the free wall of the gallbladder and is not contained within the gallbladder wall (double arrow).(O) CT shows an enhancing rim around the fluid (arrows)and inflammatory edema in the adja- cent fat consistent with abscess(arrowheads).(From Rubens D. Hepatobiliary imaging and its pitfalls. Radiol Clin North Am 2004: 42: 257-78: with permission Chronic cholecystitis sign or wall-echo-shadow(WES) complex (201 (Fig. 11). The first echogenic arc of the WES com Chronic cholecystitis is defined histologically as plex is created by the near wall of the gallbladder chronic inflammation of the gallbladder wall and and the second by the gallstone. The two echoes is routinely associated with gallstones. It can gener- are discernible because they are separated by ally be differentiated from acute cholecystitis by the a thin crescent of anechoic bile in the residual gall absence of acute clinical symptoms, although it can bladder lumen. The WES complex can be mimicked be exacerbated by episodes of superimposed acute by a collapsed duodenum(Fig. 12)or, rarely, by cholecystitis. The chronic inflammation causes a porcelain gallbladder. Porcelain gallbladder is thickening and fibrosis of the gallbladder wall more common in males, is seen in conjunction and, ultimately, contraction of the gallbladder with chronic cholecystitis, and is the result of mural hich when severe can result in almost complete calcification of the gallbladder wall. It is a rare dis- obliteration of the gallbladder lumen. This order, seen in 0.06% to 0. 8% of cholecystectomy duces an US image with two brightly colored arcs specimens 2 The calcification pattern on ultra and a posterior shadow, the so-called" double arc" sound may involve the entire wall or only a portionChronic cholecystitis Chronic cholecystitis is defined histologically as chronic inflammation of the gallbladder wall and is routinely associated with gallstones. It can gener￾ally be differentiated from acute cholecystitis by the absence of acute clinical symptoms, although it can be exacerbated by episodes of superimposed acute cholecystitis. The chronic inflammation causes thickening and fibrosis of the gallbladder wall and, ultimately, contraction of the gallbladder which when severe can result in almost complete obliteration of the gallbladder lumen. This pro￾duces an US image with two brightly colored arcs and a posterior shadow, the so-called ‘‘double arc’’ sign or wall-echo-shadow (WES) complex [20] (Fig. 11). The first echogenic arc of the WES com￾plex is created by the near wall of the gallbladder and the second by the gallstone. The two echoes are discernible because they are separated by a thin crescent of anechoic bile in the residual gall￾bladder lumen. The WES complex can be mimicked by a collapsed duodenum (Fig. 12) or, rarely, by a porcelain gallbladder. Porcelain gallbladder is more common in males, is seen in conjunction with chronic cholecystitis, and is the result of mural calcification of the gallbladder wall. It is a rare dis￾order, seen in 0.06% to 0.8% of cholecystectomy specimens [2]. The calcification pattern on ultra￾sound may involve the entire wall or only a portion Fig. 7. Complicated cholecystitis with gallbladder perforation. (A) Longitudinal ultrasound of the gallbladder with adjacent irregularly marginated pericholecystic intrahepatic fluid (arrows). This patient presented with sep￾sis 2 weeks after prostate surgery and was found to have acute cholecystitis with an adjacent liver abscess. (B) Longitudinal ultrasound of gallbladder containing stones shows a pericholecystic collection (arrows) containing debris. The collection abuts the free wall of the gallbladder and is not contained within the gallbladder wall (double arrow). (C) CT shows an enhancing rim around the fluid (arrows) and inflammatory edema in the adja￾cent fat consistent with abscess (arrowheads). (From Rubens D. Hepatobiliary imaging and its pitfalls. Radiol Clin North Am 2004;42:257–78; with permission.) Ultrasound Imaging of the Biliary Tract 399