Indium-111 tropolonate leucocyte scanning in the detection of intra-abdominal abscesses.

Indium-111 leucocyte scanning is established as an accurate method for localising intra-abdominal abscesses. With the currently available cell labelling techniques there is a variable and significant delay in localisation of abscesses which is a major disadvantage in comparison with ultrasound or computed tomography. We have examined the speed and accuracy of localisation of leucocytes labelled in plasma with a new chelating agent, indium-111 tropolonate, in 90 patients with suspected intra-abdominal abscess. In 50 patients a comparison with ultrasound was made. Nineteen patients had abscesses. The sensitivity and specificity of labelled leucocytes were 95% and 99%, respectively. Comparative results for ultrasound were 60% and 83%. In nine out of 10 patients with abscesses scanned sequentially from 40 min after return of the labelled cells, activity corresponding to the abscess was already visible on the 40 min scan. These results demonstrate that indium-111 plasma labelled leucocyte scanning is both rapid and an accurate method of detecting abscesses.