An abscess is a pocket of infected fluid, or pus, that forms when the body tries to wall off an infection. On ultrasound, abscesses typically appear as hypoechoic or complex collections with thick, irregular walls and sometimes internal debris or gas bubbles. They can occur almost anywhere in the body, including the liver, kidney, pelvis, and soft tissues. Ultrasound is valuable for both detecting abscesses and guiding needle drainage procedures, where a needle is inserted under ultrasound guidance to remove the infected fluid.
Sonography Term