Nuclear medicine uses tiny, safe levels of radioactive liquid to help physicians diagnose disease. The liquid is formulated so that, after you either drink it or receive it through an IV, it goes to the part of the body being studied. Then, special cameras scan the affected area. The cameras can detect disease by registering metabolic changes that the liquid has made visible. Nuclear medicine procedures are painless, and you are exposed to no more radiation than you would receive from a traditional x-ray.