Abdominal Abscess

Collection of pus 

It can be in any organ or abdominal cavity based on the etiology.

What are the common sites of abscess?

  • Post-op
  • Subdiaphragmatic
  • Appendiceal
  • Diverticulitis
  • Pancreatitis
  • Liver abscess
  • Renal abscess
What are the useful imaging procedures in the evaluation of abdominal abscess?
  • CT abdomen is the imaging procedure of choice in evaluating patients suspected to have abdominal abscess.
  • US and CT can guide placement of drainage of abscess.
  • Plain abdomen radiographs can detect abdominal abscesses, but of low sensitivity. Extraluminal air pockets can be recognized.
What are the imaging findings of abdominal abscess?
  • Abnormal fluid collection, usually with air seen outside the lumen of the bowel.
  • Periphery may enhance with intravenous contrast material.

Image Atlas of Intra-abdominal Abscess

Post op

Subdiaphragmatic abscess post splenectomy 

  • Arrow points to multiloculated thick walled fluid collection in the left upper quadrant of the abdomen. 
  • Note absence of spleen.

Pancreatic abscess

Acute Pancreatitis

  • Diffusely enlarged pancreas with air pockets. 
  • Arrow points to body of pancreas.
  • Abscess is in tail of pancreas.

Renal abscess

  • 40 year old man with fever and diarrhea for two weeks. He has infected urine.
  • IVP shows functioning right kidney (black arrowhead).
  • No function in the left kidney.
  • Air pockets seen in the left flank (white arrowheads).

Renal abscess

CT shows a large mass in the left renal area with multiple air pockets and absence of functioning renal parenchyma.

Acute Appendicitis 

Appendiceal abscess

CT Post-contrast:

  • Arrows point to the inflammatory mass in the right lower quadrant with an air pocket indicating an abscess.
  • Mass demonstrates contrast enhancement.
  • Calcification seen within the mass probably represents an appendicolith.