Nuclear medicine is to physiology what radiology is to anatomy. For imaging in endocrinology an agent is chosen whose uptake or metabolism relates to the function of the particular endocrine system. The agent is radiolabelled with a g-emitting radionuclide so that, after its intravenous or oral administration, it can be detected externally and noninvasively by imaging with a g-camera. Nuclear medicine techniques may also characterise a tissue by its receptor or antigen expression in ways complementary to radiological and biochemical techniques. It allows in vivo assessment of clinical physiology and pathophysiology and is very sensitive to metabolic disorders Furthermore, stimulation and suppression techniques can be used to enhance its specificity.
