Evolving role of magnetic resonance techniques in primary sclerosing cholangitis

Table 2 Descriptive features of primary sclerosing cholangitis on magnetic resonance imaging/ magnetic resonance cholangiopancreatography[22,30-32]

Bile duct changes

Multiple annular or short segmental strictures (1-2 mm) with slightly dilated ducts among them: “beaded” appearance

Obliteration of small peripheral ducts “pruned tree”

Periductal inflammation

Thickening of walls of large ducts

Strictures seen at bile duct bifurcation

Angles between peripheral and central bile ducts become obtuse

Exclusive involvement of extrahepatic bile duct is infrequent

Bile duct dilatations are usually subtle

Retraction of papilla

Webs, diverticula and pigmented stones

Liver parenchymal changes

Segmental or lobular atrophy with compensatory hypertrophy attributed to chronic biliary obstruction

Patchy areas of peripheral parenchymal enhancement

Caudate lobe hypertrophy1

Spherical liver shape2

Peripheral wedge-shaped areas with focal increased signal intensity on T2-weighted images3

T2-weighted hyperintensity around portal vein branches

Regional changes

Gallbladder enlargement

Enlarged regional lymph nodes

Signs of portal hypertension including splenomegaly and collateral vessels

¹Autoimmune process spares bile ducts in caudate lobe that results in compensatory hypertrophy. This feature is also seen in other cirrhotic livers because the caudate lobe has its own venous, lymphatic and biliary drainage.

²This is due to atrophy of left lateral segments and posterior segments of the right lobe.

³It remains unclear if this is caused by inflammatory or fibrotic conditions.