The major forms of liver abscesses (LA), classified by etiology, and are as follows: Pyogenic abscess, which is most often polymicrobial, accounts for 80% of LA cases in the United States. Amebic abscess due to Entamoeba histolytica accounts for 10% of cases. Fungal abscess, most often due to Candida species, accounts for less than 10% of cases. Furthermore Hytadid disease and Schistsomiasis can cause LA.

Biliary tract disease is the most common source of pyogenic LA. Obstruction of bile flow allows for bacterial proliferation. Biliary stone disease, obstructive malignancy affecting the biliary tree, stricture, and congenital diseases are common inciting conditions. With a biliary source, abscesses usually are multiple, unless they are associated with surgical interventions or indwelling biliary stents. In these instances, solitary lesions can be seen. Other entryways to the liver are via the portal vein (pyophlebitis) in patients with appendicitis or diverticulitis. Finally, an arterial entryway is seen in patients with osteomyelitis or endocarditis.

CT evaluation with contrast and ultrasonography remain the radiologic modalities of choice in diagnosing LA. US contrast might be helpful to evaluate the extension of the abscess and to evaluate a phlegmonic lesion undergoing change to a mature abscess. The final diagnosis of a LA is established with a ultrasound (or CT) guided puncture confirming pus.
Treatment with a combination of iv antibiotics and percutaneous drainage (needle drainage or catheter drainage) carries a high success rate.

Typically diagnostic and interventional images (ultrasound including US contrast and CT), case stories, and differential diagnoses will be presented.