Indium-111 leucocyte scintigraphy and ultrasound scanning in the detection of intra-abdominal abscesses in patients without localizing signs.

The clinical records of 45 patients with suspected intra-abdominal sepsis but without localizing abdominal signs were retrospectively reviewed. All had undergone both indium-111 leucocyte scintigraphy and real time ultrasound. Twenty-two of the 45 patients were subsequently shown to have intra-abdominal abscesses. Twenty-one patients were identified correctly by indium-111 scintigraphy (sensitivity 95%) and 10 by ultrasound (US: sensitivity 45%). There were two false positive scintiscans (specificity 91%) but no false positive US scans (specificity 100%). There was no correlation between the peripheral white cell count and the presence of absence of an abscess or the likelihood of obtaining a positive scintiscan result. Because of the excellent specificity ultrasound scanning should remain the initial investigations in this group of critically ill patients with indium-111 scintigraphy being used to clarify the US findings or in US negative patients.