Technetium-99m-pyrophosphate bone scans in hyperparathyroidism.

Most patients with primary hyperparathyroidism have normal 5-hr bone-to-soft-tissue ratios for 99MTc-pyrophosphate. In contrast, all five patients with advanced secondary hyperparathyroidism in this study showed significant (p less than 0.001) increases of bone uptake. In the early period after parathyroidectomy, there was no quantitative or qualitative change in uptake. A limited decrease of bone uptake was observed only after prolonged periods of observation. In itself, parathyroid activity seems to have little direct influence on bone uptake of 99MTc-pyrophosphate.