Increased 99mTc-polyphosphate muscle uptake in a patient with polymyositis: case report.

A patient with well-documented rheumatoid arthritis and polymyositis displayed abnormal muscle uptake of 99mTc-polyphosphate during routine bone scanning for occult malignancy. The regions of increased uptake corresponded to the areas of clinically active inflammatory muscle disease. On serial scans the degree of muscle labeling correlated well with both clinical and laboratory indices of disease activity.