XXXX : thin-section helical CT findings.

@entity1 @entity253 @entity5 @entity3
BACKGROUND: We describe the thin-section helical computed tomographic (CT) findings of @entity253 caused by @entity3 . METHODS: Thin-section helical CT (5 mm slice thickness, 1:1 pitch, portal phase) and direct cholangiography in 50 consecutive @entity1 with @entity253 caused by metastases were reviewed retrospectively by three radiologists. The primary sites were the stomach ( n = 36), colon ( n = 12), jejunum ( n = 1), and uterus ( n = 1). The level of @entity253 was analyzed with the Bismuth classification, and the CT findings of @entity253 were classified into six types: small (<2 cm) periductal masses, large (>/=2 cm) periductal masses, extrinsic compression by a metastatic liver mass, high-attenuation intraductal mass, intrapancreatic mass, and no demonstrable lesion. RESULTS: The level of @entity253 was the hilum in 18 @entity1 (36%), the proximal common duct in 20 (40%), the distal common duct in five (10%), and the periampullary area in seven (14%). Of 18 hilar obstructions, @entity5 involvement of the secondary confluence of intrahepatic bile ducts was seen in 10 (right in six, left in one, and bilateral in three). Periductal masses were seen in 68% (small in 18, large in 16). In one @entity1 (2%), a large metastatic mass of the liver resulted in extrinsic compression and @entity253 . Lesions mimicking primary biliary or pancreatic @entity5 were seen in four, respectively. In seven, we found no obstructing lesion on CT. CONCLUSION: @entity253 in @entity1 with known primary @entity5 can show atypical patterns mimicking primary @entity5 on thin-section helical CT.
