Thyroid gland disease diagnosis

For example, it was demonstrated by such methods that phosphorus assimilated from the soil by tomato plants tends to concentrate in the stems and certain parts of the leaves. Similarly, radioactive zinc was used to show that this element localizes in the seeds of tomatoes. The rate of absorption of iodine by the thyroid gland was established by the use of radioactive iodine this and related work did much to add to the understanding of the diagnosis and treatment of goiter. These and many similar uses of radioactive isotopes show that these substances have been of inestimable value in the study of the mechanism of chemical reactions, problems relating to plant and animal metabolism, and the diagnosis and treatment of diseases. 

Hypothyroidism and hyperthyroidism are the two primary pathological conditions that involve the thyroid glands. Laboratory testing of thyroid hormones is used to diagnose and document the presence of thyroid disease, a condition that often presents with vague and subtle symptoms. Accurate measurement of thyroid hormone concentrations is key to the proper diagnosis of thyroid gland dysfunction. 

In the patient with manifest disease, measurement of the serum T4 concentration, T3 resin uptake (or free T4), and the TSH value will confirm the diagnosis of thyrotoxicosis. If the patient is not pregnant, a 24-hour RAID should be obtained. An increased RAIU documents that the thyroid gland is inappropriately utilizing the iodine to produce more thyroid hormone at a time when the patient is thyrotoxic. 

Physical examination revealed blood pressure 180/90 mm Hg, heart rate 110/min, minimal proptosis, and an enlarged thyroid gland. Laboratory tests showed elevated thyroxine, resin uptake, radioactive iodine uptake, and antimicrosomal antibodies. A diagnosis of hyperimmune hyperthyroidism (Graves disease) was made. 

In the ontological approach to medical diagnosis, each disease is thou t of as a distinct entity. An alternative approach to the diagnostic process is the physiological approach. Disease is defined in terms of objective manifestations. For example, the disease hypertension is based on a physiological measurement Hyperthyroidism is characterized by an increased rate of accumulation of radioiodine by the thyroid gland. Different diseases may have some of the same manifestations. Examples are senile dementia of the Alzheimer type (SDAT) and idiopathic Parkinson s disease. 

The use of radioactivity in diagnosis usually involves a radiotracer, a radioactive nuclide attached to a compound or introduced into a mixture in order to track the movanent of the compound or mixture within the body. Tracers are useful in the diagnosis of disease because of two main factors (1) the sensitivity with which radioactivity can be detected, and (2) the identical chemical behavior of a radioactive nucleus and its nonradioactive counterpart. For example, the thyroid gland naturally concentrates iodine. When a patient is given small amounts of iodine-131 (a radioactive isotope of iodine), the radioactive iodine accumulates in the thyroid, just as nonradioactive iodine does. However, the radioactive iodine emits radiation, which can then be detected with great sensitivity and used to measure the rate of iodine uptake by the thyroid, and thus to image the gland. 

The only major use of iodine in the hiunan body is in the production of certain hormones by the thyroid gland, and iodine from the diet concentrates in this area of the body. Iodine-131 is used in the diagnosis and treatment of thyroid disease and has a half-life of 8 days. If a patient with thyroid disease consumes a sample of Na I containing 10 /ng of I, how long will it take for the amount of I to decrease to approximately 1/1000 of the original amount ... 

---