Different actions of deferoxamine and iron on Ga-67 abscess detection in rats

The contrast-enhancing properties of iron (Fe) and deferoxamine (DFO) in abscess imaging with Ga-67 citrate were compared in rats bearing turpentine-induced abscesses. Iron administration shifted Ga-67 from plasma into tissues such as muscle and fat. As a result, the abscess-to-plasma ratio increased whereas the abscess-to-muscle ratio decreased. DFO enhanced the abscess-to-muscle and abscess-to-plasma ratios by increasing urinary Ga-67 excretion. In contrast to Fe, DFO removed abscess-bound Ga-67, thus representing a disadvantage of DFO compared with Fe. As a result, the abscess-to-plasma ratio was more effectively enhanced by Fe than by DFO. We conclude that abscess imaging with Ga-67 citrate may be improved by administration of Fe for detection of abscesses masked by blood activity, or DFO for detection of abscesses surrounded by muscle tissue.