Unsuspected extra-abdominal sites of infection: scintigraphic detection with indium-111-labeled leukocytes.

Scintigraphy with indium-111-labeled leukocytes (In-111-WBC) was assessed in 128 patients with suspected abdominal-pelvic abscesses. Studies were positive in 37 of 41 patients with proved abscesses, in two of two with infected aortic grafts, and in 12 of 15 with other infections; studies were negative in 63 of 70 cases without infection. The sensitivity of leukocyte scintigraphy in this series was 88%, specificity 90%, and accuracy 89%. Sixteen percent of all patients studied with In-111-WBC scintigraphy had unexpected sites of infection outside the abdomen. Of the 58 patients with proved infection, 20 (34%) had alterations in diagnostic evaluations and therapeutic regimens due to such findings.