A nuclear imaging procedure which is performed to identify hyperparathyroidism. Sestamibi is a nuclear radiopharmaceutical which is bound to the radioactive isotope Tc99m. Tc99m-Sestamibi is taken up by both the thyroid gland and the parathyroid gland, and is also used in Nuclear Myocardial Perfusion Imaging.

An imaging test used to find overactive parathyroid glands (four pea-sized glands found on the thyroid) and breast cancer cells, and to diagnose heart disease. The patient receives an injection of a small amount of a radioactive substance called technetium which is bound to another substance called sestamibi. This substance collects in overactive glands, cancer cells, heart muscle, or other tissues and a picture is taken by a gamma camera (a special camera that detects radioactivity).