Parathyroid imaging.

Advances in diagnostic imaging methods during the last decade have facilitated the identification of focal or diffuse parathyroid abnormalities. Major advances have included improvements in computed tomography and high-resolution ultrasonography, and the introduction of thallium-201-technetium-99m parathyroid subtraction scintigraphy. The more invasive methods of venous sampling and selective angiography have also been refined, but they have not been used as extensively because of the need for highly skilled personnel. The role of these diagnostic tools before surgery in the routine evaluation of patients with suspected primary hyperparathyroidism is unclear because a skilled surgeon should be able to achieve cures in 90% of these patients during exploratory surgery. However, most physicians would agree that, in those patients whose abnormalities go undetected during exploratory surgery of the neck, diagnostic imaging methods should be used before additional surgery is planned. Further prospective studies are needed to determine if routine localization before surgery is cost effective.