Changes

: Different [[gland]]s and [[organ]]s collect different [[compound]]s from the [[blood]] stream. A [[compound]] containing a [[radioactive]] [[isotope]] can be injected into the [[blood]] and this will accumulate in the desired [[gland]] or [[organ]]. While there the [[Unstable Isotope|unstable isotopes]] [[Radioactive Decay|decay]] and this can be detected. This can be used to create an image of that [[gland]] or [[organ]].

: [[Fluid]]s in certain [[organ]]s can become blocked. These blockages can be detected by injecting or ingesting a [[radioactive]] [[isotope]] which will accumulate at the blockage. This accumulation can then be detected as the [[Unstable Isotope|unstable isotopes]] [[Radioactive Decay|decays]] to produce [[Ionising Radiation|ionising radiation]].