Radiogas and Radioaerosol Production, Imaging, and Dosimetry in Asthmology

Abstract

Using imaging techniques nuclear medicine studies the function of different organs and systems. When introduced in to a live organism, a radioactive chemical species with specific biological properties has a metabolic fate similar or identical to the same “cold” (nonradioactive) chemical agent. For example, the radioisotope of iodine, iodine-131 (¹³¹I), when administered orally in humans, is extracted from the intestine with the same efficiency as the cold iodine contained in food. Like dietary iodine, the radioactive ¹³¹I, after being concentrated from the blood in the thyroid and conjugated with thyroxine, also enters into the synthetic pathways of thyroid hormones. Due to these characteristics, a picomolar quantity of administered radioiodine allows “tracing” of the metabolic behavior of the total cold iodine contained in the thyroid. Therefore, it may be considered a tracer of thyroid metabolism of iodine.