May mimic calcified or hypervascular mass on plain radiography or CT, respectively
• Treated tumor often undergoes progressive volume loss and fibrosis
May simulate focal confluent fibrosis, peripheral cholangiocarcinoma, or cirrhosis
• Consider prior resection of portions of liver
May have similar appearance to congenital absence or hypoplasia of hepatic segments
• Iatrogenic arterioportal (AP) fistula
Complication of percutaneous liver biopsy
May simulate other vascular lesions, including tumor
• Small peripheral AP shunts are common, spontaneous findings in cirrhotic liver
TOP DIFFERENTIAL DIAGNOSES
• Pyogenic abscess
• Portal venous gas with bowel infarction
• Focal confluent fibrosis
• Cholangiocarcinoma (peripheral)
• Regenerative and dysplastic nodules
• Cirrhosis
• Hepatic angiomyolipoma
• Other causes of transient hepatic attenuation (THADs) and intensity (THIDs) differences
• Congenital absence of hepatic segments
(Left) Axial CECT shows several viable enhancing liver metastases and 2 masses with gas and necrotic debris that are the result of percutaneous radiofrequency ablation.
(Right) Axial CECT shows a collection of gas but very little fluid in the cholecystectomy bed, mimicking an abscess. Note the surgical clips . This is bioabsorbable oxidized cellulose (Surgicel), which was used as a hemostatic agent to control bleeding from the operative bed during cholecystectomy.
(Left) Axial CECT shows an absence of enhancement of the left lobe with a straight line of demarcation and portal venous gas , all due to hepatic arterial ligation during attempted resection of a peripheral cholangiocarcinoma.
(Right) Axial CECT shows a metallic coil in the right hepatic artery, with a wedge-shaped collection of gas and fluid “downstream.” Needle aspiration and drainage of this collection showed an infected hepatic infarction.
TERMINOLOGY
Definitions
• Iatrogenic changes to hepatic morphology that may cause or simulate pathologic conditions
IMAGING
Imaging Recommendations
• Best imaging tool
Imaging test that shows morphology and hemodynamic characteristics of hepatic lesion
• Protocol advice
Correlate with medical records and history of prior intervention
CT Findings
• Gas collection in hepatic or perihepatic lesion
Abscess is primary concern, but also consider iatrogenic causes
Iatrogenic infarction of hepatic mass or liver parenchyma
– Sudden death of hepatic (or other) tissue releases gas, ± coexisting infection
and 2 masses with gas and necrotic debris 
that are the result of percutaneous radiofrequency ablation.
but very little fluid in the cholecystectomy bed, mimicking an abscess. Note the surgical clips 
. This is bioabsorbable oxidized cellulose (Surgicel), which was used as a hemostatic agent to control bleeding from the operative bed during cholecystectomy.
and portal venous gas 
, all due to hepatic arterial ligation during attempted resection of a peripheral cholangiocarcinoma.
in the right hepatic artery, with a wedge-shaped collection 
of gas and fluid “downstream.” Needle aspiration and drainage of this collection showed an infected hepatic infarction.
Iatrogenic infarction of hepatic mass or liver parenchyma
