Abstract
The number of false-positive gallium scans (gallium in the gastrointestinal tract) and false-negative scans (gallium not labeling abdominal inflammatory masses) can be reduced by employing subtraction techniques that accurately localize isotopically labeled organs such as liver, spleen, stomach, upper gastrointestinal tract, kidney, and bladder, using a gamma camera with an on-line computer. A gallium scan is performed first. Then without repositioning, the patient receives a Tc-99m-labeled radiopharmaceutical to label liver, spleen, gastrointestinal tract, kidney, and bladder. Software that allows one to superimpose or subtract the Tc-99m-labeled organ onto the gallium scan, thus accurately defining its borders, is described. This method is helpful in evaluating regions of the abdomen generally obscured by normal gallium uptake in organs, such as liver or spleen, and in outlining abdominal masses with no gallium uptake.
