Detection of focal inflammation with Tc-99m HMPAO labeled leukocytes in children.

To evaluate the applicability of Tc-99m HMPAO leukocyte scintigraphy in the assessment of focal infections in children, we retrospectively analyzed 26 studies performed between 1988 and 1992. All patients (n = 25, age range 1 month-15 years) were severely ill and suspected to have invasive bacterial infection. In each case, whole body scintigraphy was performed 2-4 hours after injection of autologous labeled leukocytes. There were 8 true positive and 14 true negative cases; specificity was 88% and sensitivity 80%. The two false negative findings were observed in patients on immunosuppressive therapy; both had fungal infections. In one case, atypical non-specific bowel accumulation of the tracer was falsely interpreted as an abscess. The other false positive finding was hip accumulation in a patient who later turned out to have Mucha-Haberman disease; transient synovitis may explain the finding. Of the eight true positive cases, six had an invasive infection focus and two had an aseptic inflammatory process. Tc-99m HMPAO leukocyte scintigraphy is a valuable method in the assessment of focal inflammation in children, including infants.