ABSTRACT
Nuclear medicine consists of a range of diagnostic and therapeutic procedures that use radioisotopes. For diagnostic work it is usually necessary for the radioisotope to emit γ-rays because these can penetrate tissue and be detected outside the body, and therefore the distribution in the body can be determined. In some cases, if the diagnostic test involves measuring samples taken from a patient, it may be possible to use a β-particle emitter. For therapeutic work it is usually more desirable for the radioisotope to emit β-particles, since these have a short range in tissue and can deliver a high radiation dose to the location of the radioisotope. For example, radioiodine localizes in the thyroid gland and the dose to the local thyroid tissue can be used to treat a variety of thyroid diseases. This chapter will concentrate on the diagnostic uses of radioisotopes.
