Computed tomography in the diagnosis of abdominal abscess.

The CT features in 30 cases of suspected intra-abdominal abscesses are reviewed. The cases were grouped into proven (24), probable (4), and possible (2) abscess on clinical grounds, and were analyzed according to site within the abdomen. Two cases of carcinoma with fluid collections mimicking abscesses are also discussed. In the appropriate clinical context, abdominal abscess is identified on CT as a circumscribed low-density region within the abdomen. Subphrenic, hepatic, and splenic abscesses were readily recognized without contrast enhancement inthe majority of cases, although contrast enhancement consistently rendered loculation within hepatic abscesses more obvious. Aspiration and drainage under CT control were invaluable in diagnosis, permitting the identification of the causative organism in 18 cases. The precise anatomical detail provided by CT was important in achieving successful catheter placement for drainage.