(Left) Venous phase CT shows heterogeneous liver parenchyma with evidence of periportal edema , a nonspecific sign often seen in acute hepatitis, among other causes.
(Right) CT section in the same case shows subcapsular and peripheral wedge-shaped foci of hyperdensity , representing confluent fibrosis and is usually seen in advanced and more chronic liver damage. Liver biopsy showed acute and advanced liver injury due to autoimmune hepatitis (AIH).
(Left) Axial CECT of an autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) overlap shows a nodular, cirrhotic liver with signs of portal hypertension, including splenomegaly, ascites, and varices . The intrahepatic ducts are dilated with an abnormal arborization, suggestive of PSC.
(Right) Axial CECT in the same patient shows dysmorphic liver, ascites, varices, and dilated, irregular intrahepatic bile ducts typical of primary sclerosing cholangitis.
TERMINOLOGY
Abbreviations
• Autoimmune hepatitis (AIH)
Synonyms
• Chronic active hepatitis
Definitions
• Chronic hepatitis of unknown etiology characterized by hyperglobulinemia, circulating autoantibodies, and inflammatory changes on hepatic histology
IMAGING
General Features
• Best diagnostic clue
Dysmorphic liver with prominent periportal fibrosis ± signs of portal hypertension ± irregular intrahepatic ductal dilation
– Widened fissures, deep gallbladder fossa, ↑ caudate:right lobe ratio
Radiographic Findings
• AIH is not diagnosed specifically by imaging criteria
CT Findings
• CECT
Typical signs of cirrhosis + portal hypertension
Bands of fibrosis may show persistent, increased, delayed enhancement
Irregular dilation of intrahepatic ducts in autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) overlap disease
MR Findings
• Signs of cirrhosis ± portal hypertension
• MRCP is best for detecting irregular dilation of intrahepatic ducts in AIH-PSC overlap disease
Imaging Recommendations
• Best imaging tool
MR with MRCP
DIFFERENTIAL DIAGNOSIS
Primary Biliary Cirrhosis (PBC)
• Imaging and other features may simulate or coexist with AIH: AIH-PBC overlap disease
• PBC typically affects middle-aged women
• Leads to early cholestatic injury (pruritus + jaundice)
, a nonspecific sign often seen in acute hepatitis, among other causes.
, representing confluent fibrosis and is usually seen in advanced and more chronic liver damage. Liver biopsy showed acute and advanced liver injury due to autoimmune hepatitis (AIH).
. The intrahepatic ducts 
are dilated with an abnormal arborization, suggestive of PSC.
