CT of intra-abdominal fluid collections

A wide variety of fluids including ascites, blood, pus, urine, bile, lymph, chyle, mucin, and cerebrospinal fluid can accumulate within the peritoneal and pelvic cavities. The location, appearance, and distribution of this fluid is governed by a number of anatomic and gravitational factors that when carefully analyzed, can help to reveal their source and etiology. Computed tomography is ideally suited to document the presence of abdominal and pelvic fluid collections; display their location and full extent; characterize the fluid and often suggest its source; and provide guidance for percutaneous diagnostic and therapeutic procedures when required.