Histologic correlation of transplant rejection diagnosed by computer-assisted sulfur colloid scan.

Sulfur colloid scanning has been suggested as a means of early detection of renal transplant rejection. Visual interpretation of increased uptake by the allograft as opposed to surrounding pelvic structures was taken to signify rejection. In an attempt to increase the accuracy of these scans we programmed a computer to do differential counts between graft and surrounding pelvis and to then calculate a ratio. Hopefully this mathematical determination of increased uptake would be more accurate. These scans were compared with simultaneously obtained biopsy material. Unfortunately, the false negative and false positive rates were too high to make sulfur colloid useful in predicting graft rejection. Finally, our data showed that an early positive scan did not predict long-term outcome as had been suggested by others.