present state of radionuclide thyroid studies

ABSTRACT

Thyroid diseases are very frequently encountered disorders by endocrinologists, and thyroid dysfunction is often suspected by almost all clinicians. The diagnosis of thyroid disease represents, therefore, a major clinical problem. The proliferation of in vitro thyroid function tests has lead to such confusion of nomenclature that many doctors do not know what they are asking for, much less the limitation of the particular investigation in question. Effective treatment of thyroid disease is relatively simple; so early diagnosis is of great asset to the clinician. Diagnosis of thyroid disease begin as in other areas of medicine, with a careful clinical history, and physical examination. A good percentage of thyroid illnesses can be correctly diagnosed on clinical grounds. The Wayne's Index was advocated to transfer clinical findings into numbers. However laboratory tests to confirm the clinical diagnosis of thyroid disease are needed,since such diagnosis often necessitates surgery or medical treatment that extends over years or throughout the patients life. Furthermore, a significant fraction of thyroid illnesses can be diagnosed only on the basis of laboratory data, and in some instances laboratory diagnosis along might be an indication to therapy in the absence of clear clinical evidence of thyroid disease. Errors in diagnosis may be contributed by any laboratory method used and when investigations are carried out in the best laboratories, values outside the normal range occur in few euthyroid people. In addition, the tests themselves are subject to limitation, which are often not appreciated by those asking for them. Laboratory tests are liable to interference by many factors unrelated to the thyroid pathology