Abstract
Photon-deficient areas were observed in 64 out of 884 (7.2%) bone scans performed in a general hospital over a period of 1 yr. The intrinsic causes constituted about 80% of the “cold” lesions seen; whereas extrinsic causes were responsible for the remaining 20%. Orthopedic implants were the most common source of artifactual cold lesions. The value of special views during bone scanning and care during interpretation is suggested.