radiological approach to biliary tract

5. A, High-resolution CT shows normal intrahepatic bile ducts (IHDs) (arrows) as linear
water-density structures accompanying the portal vein branches. B, T1-weighted MRI
after administration of gadobenate dimeglumine demonstrates IHDs (arrows) with
biliary excretion of contrast material located anterior to the portal veins.

6. Normal ERCP image shows the bile ducts, gallbladder,
and main pancreatic duct. The distal part of the common
bile duct (arrow) is not seen owing to contraction of the
sphincter of Oddi

8. echogenic fibrous tissue anterior to
the to the portal vein: triangular cord
sign
larger hepatic arterial caliber
gallbladder ghost triad
• atretic gallbladder, length less than 19 mm
• irregular or lobular contour
• lack of smooth/complete echogenic mucosal
lining with an indistinct wall

17. Choledochal cyst (C). MRCP demonstrates a
markedly dilated common bile duct (choledochal
cyst) and aberrant insertion of the common duct
into the pancreatic duct (arrow).
Choledochal cyst (C) with a small stone (arrow) on MRCP.

22. Caroli’s disease. MDCT shows cystic dilatation of the
intrahepatic bile ducts with stones (white arrows). The
black arrow indicates the so-called central dot sign.

25. Three small stones in the gallbladder and one stone in the
common bile duct, which migrated from the gallbladder

26. A small stone (arrow) in the common bile duct originated in
the gallbladder. The wall of the gallbladder is thickened and
enhanced, suggesting acute cholecystitis

28. Multiple calcified intrahepatic stones formed in the liver in
a patient with recurrent pyogenic cholangitis
Complications

30. Gallstone pancreatitis. The pancreas is enlarged and
there is a peripancreatic fluid collection. The common bile
duct (arrow) is dilated and the wall is thick. Note the tiny
stones in the gallbladder and the thickened gallbladder
wall

31. Suppurative cholangitis caused by gallbladder stone
migration into the common bile duct. Coronal CT shows
slightly dilated bile ducts with severe thickening of the
walls of the extrahepatic duct and gallbladder.

33. Common bile duct stone (arrow) containing air presenting
with the “Mercedes-Benz” sign.

34. Common bile duct stone with rim calcification (arrow)
mimicking a bull’s-eye

36. Acute suppurative cholangitis caused by a stone
originating from the gallbladder.
Suppurative cholangitis with a common bile duct stone in
a patient with recurrent pyogenic cholangitis. Note
concentric thickening of the bile duct wall with
enhancement

37. A and B, Acute suppurative cholangitis caused by carcinoma of the
common hepatic duct (arrow in B). Note the dilated bile ducts and
concentric thickening of the wall in

40. ERCP shows markedly dilated intrahepatic bile ducts with
rigidity, decreased arborization, right-angle branching,
acute tapering, and the “arrowhead” sign. The
extrahepatic duct is also dilated, with proximal narrowing
due to segmental fibrous stricture (arrows). Note the large
stones (arrowheads) in the distal common bile duct.

41. Recurrent pyogenic cholangitis. A, Cholangiogram shows
severe dilatation and acute peripheral tapering of the
intrahepatic bile ducts with the “arrowhead” sign. There
are multiple large stones in the extrahepatic duct. B, CT
shows a dilated common bile duct and stones within it.
Note the thickened wall of the common bile duct (arrows

44. Primary sclerosing cholangitis. A, ERCP shows multisegmental or diffuse narrowing and proximal
dilatation of the intra- and extrahepatic bile ducts. Peripheral ducts have a “pruned tree”
appearance. B, Contrast-enhanced CT shows diffuse thickening of the wall of the intra- and
extrahepatic bile ducts (arrows). Also note thickening of the gallbladder wall.

45. Primary sclerosing cholangitis. A, MR cholangiogram shows
innumerable foci of focal or segmental narrowing or dilatation of
the intrahepatic bile ducts, with a “beaded” appearance and
obliteration of the extrahepatic duct (arrow). B and C, CT shows
peripheral bile duct narrowing and dilatation, with scattered
segments of peripheral duct dilatation. Note obliteration of the
lumen of the extrahepatic duct due to severe thickening of the wall
(arrow in C)

47. Primary sclerosing cholangitis involving segmental intrahepatic bile ducts and
extrahepatic ducts, with thickening of the bile duct wall and intense enhancement
(arrow in B). The gallbladder wall is also thickened and enhanced.

50. Biliary hamartomas. CT shows many small cystic lesions
scattered throughout the liver parenchyma

51. Biliary hamartomas (von Meyenburg’s
complex). A, T2-weighted image shows
innumerable tiny high-signal-intensity nodules
and cystic lesions in the liver. On T1-weighted
(B) and gadolinium-enhanced (C) images, the
number of lesions is markedly decreased,
suggesting that many of the nodules are
enhanced and isoattenuating to the liver
parenchyma.

55. Biliary papillomatosis. MRI shows innumerable tiny
papillary tumors in the surface of the dilated intrahepatic
bile ducts (arrows)

62. Biliary cystadenocarcinoma. Sonogram (A), CT (B), and
MRI (C) show an oval unilocular cyst containing a solid
mass with an irregular surface. Note the punctate calcific
focus and thick irregular wall (arrows in B).

68. Peripheral cholangiocarcinoma. A, CT during the arterial
phase shows a lobulated mass with a well-enhancing
periphery and a heterogeneously enhancing center. Note
a small satellite tumor (arrow). B, CT during the delayed
phase shows the same mass, but it appears much smaller
because of gradual enhancement from the periphery.

69. MRI of peripheral cholangiocarcinoma. There is a well-
defined lobulated mass with a dimple at the surface
(arrow). The mass is of low signal intensity on the T1-
weighted image (A) and of high signal intensity on the T2-
weighted image (B). The central part is enhanced in the
equilibrium phase (C), reflecting the presence of massive
fibrosis

70. Contrast enhancement of
peripheral
cholangiocarcinoma. T1-
weighted images before
gadolinium administration
(A) and immediately (B), 5
minutes (C), and 3 hours (D)
after gadolinium injection. In
the arterial phase the
peripheral part is enhanced.
In the delayed phase the
central part is gradually
enhanced and eventually
greatly enhanced.

72. Periductal-infiltrating cholangiocarcinoma involving the intra- and extrahepatic ducts. Note the ill-defined mass
involving the right and left hepatic ducts (arrows in A) and the encircling and thickening of the extrahepatic
ducts (arrows in B), obliterating the lumen of the bile duct.

73. Combined mass-forming and periductal-infiltrating cholangiocarcinoma showing
a large ill-defined irregular mass (arrows) involving the hilum of the liver and wall
thickening along the extrahepatic duct.

77. Nodular or mass-forming cholangiocarcinoma of the distal common bile duct
(arrow) on CT (A) and cholangiogram (B).

79. Periductal-infiltrating cholangiocarcinoma. Axial (A) and
coronal (B) CT images show concentric thickening of the
common hepatic duct
It is often difficult to visualize the lesion on CT or MRI
because of the absence of distinct tumor formation; these
imaging studies may show only focal or diffuse thickening
of the bile duct.

81. Intraductal-growing cholangiocarcinoma of the
extrahepatic duct. Axial (A) and coronal (B) CT images
show a large cast like intraductal tumor (arrows). ERCP
(C) shows a large intraductal tumor with an irregular
papillary surface

83. Intraductal papillary mucinous adenocarcinoma (arrow) in
the dilated intrahepatic ducts. The extrahepatic ducts are
markedly dilated with mucin. C, Cholangiogram shows a
large amount of mucin in the extrahepatic duct (arrows).

84. Cystic intraductal papillary mucinous adenocarcinoma
containing innumerable small papillary tumors. Note
dilated intrahepatic bile ducts and communication with the
large cystic tumor
Intraductal papillary mucinous adenoma with tumor cells
lining the bile ducts but no visible mass formation. CT
shows severely dilated left intrahepatic bile ducts without
a visible mass. Liver parenchyma is virtually absent owing
to severe pressure atrophy.

86. Hilar cholangiocarcinoma, Bismuth
type IV. A and B, CT shows
concentric thickening of the wall of
the right and left hepatic ducts and
common hepatic duct. Adjacent
periductal fat and vessels are intact.
C and D, Contrast-enhanced MRIs
show concentric thickening of the
bile duct wall and enhancement.
There is no evidence of tumor
extension out of the bile duct.

87. Periductal-infiltrating hilar
cholangiocarcinoma, Bismuth type IIIA. A to
C, CT images show concentric thickening of
the right hepatic duct, common hepatic duct,
and cystic duct (short arrows) and the
common bile duct. Note the metastatic
lymph node (long arrow in B) invading the
replaced right hepatic artery from the
superior mesenteric artery. The common
hepatic artery and portal vein have not been
invaded. D, Cholangiogram shows a
cholangiocarcinoma of the common hepatic
duct and right hepatic duct