Indium-111-labelled leucocytes in the diagnosis of abdominal abscess.

The extensive morbidity and mortality of intra-abdominal abscess is mainly due to the delay in a diagnosis. The diagnostic accuracy of 111In-labelled mixed leucocytes with gamma imaging has been investigated in 100 consecutive patients including 34 following surgery and 36 with inflammatory bowel disease. White cell scans were performed 24 h following injection of autologous 111In-labelled leucocytes and were compared with clinical outcome where abscess was only diagnosed when pus either discharged or was drained at operation. Gamma images detected 28 of the 30 abscesses with no false positives giving 93 per cent sensitivity and 100 per cent specificity. Loculi of pus were identified in 11 of the 36 patients with inflammatory bowel disease with no errors in interpretation. Inflammation was reported in 15 of the remaining 25 patients with known but not necessarily active inflammatory bowel disease. 111In-labelled leucocyte imaging provides a rapid, safe and precise method for detecting intra-abdominal abscess even in the presence of inflammatory bowel disease.