[Nuclear medicine diagnosis of the thyroid]

The progress made in ultrasonography and improved in vitro tests have changed the field of application for scintigraphy of the thyroid. Thyroid scanning itself has been improved by the use of isotopes with better imaging properties and less radiation burden (99mTc, 123I) and by gamma cameras for imaging. Scintigraphy yields real topographic and functional information on the gland, in addition to which ultrasonography gives morphological data only. This holds true especially for autonomous nodular goiter with iodine deficiency. The goal of thyroid imaging is always to match the appropriate diagnostic procedure with all the clinical data available. When optimized techniques (gamma camera, on-line processor) are used thyroid scintigraphy is useful for the diagnosis, adequate therapy and follow-up of various thyroid disorders.