Scintigraphy of the parathyroid glands with 201TI: experience with 250 operated patients.

Parathyroid scintigraphy confirmed its validity in the preoperative localization of enlarged parathyroids, showing a sensitivity of 82% in a series of 250 patients suffering from primary hyperparathyroidism and successfully operated on. The glands better visualized were in an ectopic site or they were completely or partially outside the thyroid so that they were easily visible without employing digital image subtraction. This is nevertheless necessary to visualize parathyroids in a retrothyroid site but some problems arise, related not only to movements of the patient but also to the instrumentation to perform a correct image subtraction.