The value of sodium pertechnetate Tc99m scans in the diagnosis of Meckel's diverticulum.

A retrospective study was conducted of our experience with sodium pertechnetate Tc99m scans for diagnosing suspected Meckel's diverticula. Seventy-seven cases scanned between 1979 and 1994 were reviewed. Eighty per cent of the group presented with bleeding per rectum, 12% with pain, and 6.5% with anaemia. Ten scans were positive with 7 true-positive and 3 false-positive. Of the 67 negative scans, 3 were false-negatives. There were six Meckel's diverticuli and four duplication cysts between the true-positive and false-negative groups. All presented with major gastrointestinal (GI) bleeding and gastric mucosa was identified on histology. The three false-positive cases had inappropriate laparotomies on the basis of scan results. The test sensitivity was 70% with a specificity of 95%, giving an overall accuracy of 92%. The Meckel's scan is a useful investigation for GI bleeding in children. Surgical intervention should be guided by the full clinical picture and the scan, rather than the scan result alone.