"Cold" lesions on bone imaging.

Photon-deficient foci or "cold" lesions were demonstrated on 99mTc-polyphosphate bone imaging in eight individuals with various malignancies and one in sickle cell crisis. The bone radiographs of five of these persons failed to show corresponding bony changes at the time of the imaging. Most of the "cold" lesions observed on bone imaging were located in the denser and tubular bones. A postulate has been advanced regarding the factors that might influence the different gamma-imaging manifestations of radiographically demonstrable lytic lesions. The cases presented herein further emphasize the importance of recognizing the existence of "cold" areas in the images of bones and the need to place these in proper perspective when interpreting scans.