THE VALUE OF SCINTIGRAPHIC STUDIES IN THE ASSESSMENT OF PATIENTS WITHACUTE OR CHRONIC GASTROINTESTINAL HEMORRHAGE

The scintigrams of 76 patients with gastrointestinal bleeding referred over an 8 year period have been reviewed together with their subseque nt clinical course. Twenty-five patients had either Tc-99m-sulphur col loid or Tc-99m-labelled red cell scintigraphy to localize a source of active bleeding. Fourteen patients had Tc-99m-sulphur colloid scintigr aphy, of which seven were false negatives, two were false positives an d two were true positives. Eleven patients had 12 Tc-99m-labelled red cell scintigrams, of which three were false negatives, one was a false positive and four were true positives. Fifty patients had Tc-99m-pert echnetate scintigraphy to look for ectopic gastric mucosa in Meckel's diverticula. There were 43 true negatives, two false negatives, two tr ue positives and three false positives in this group. Our results emph asize the need for caution in interpreting nuclear medicine studies in patients with blood loss from the gastrointestinal tract.