Iodine-123 a patient in capsule form, by intravenous injection, or (less commonly due to problems involved in a spill) in a drink. (I is usually administered in a drink, due to the heavy radiation dose to local tissues which results before a capsule could dissolve). The iodine is taken up by the thyroid gland and a gamma camera is used to functional images of the thyroid for diagnosis. Quantitative measurements of the thyroid can be performed to calculate the iodine uptake (absorption) for the diagnosis of hyperthyroidism and hypothyroidism. Dosing can vary; is recommended for thyroid imaging while an uptake test
Iodine in biology Iodine in biology Iodine is an essential trace element in biological systems. It has the distinction of being the heaviest element commonly needed by living organisms as well as the second-heaviest known to be used by any form of life (only tungsten, a component of a few bacterial enzymes, has a higher atomic number and atomic weight). It is a component of biochemical pathways in organisms from all biological kingdoms, suggesting its fundamental significance throughout the evolutionary history of life. Iodine is critical to the proper functioning of the vertebrate endocrine system, and plays smaller roles in numerous other organs,