
Basics of nuclear imaging 169
measure the function associated with physiological changes in the ob
ject. In
many applications this function is measured by analysis of the changes of the
distribution of the r adioactive nuclei over time. The radioactive nuclides are
attached to various biochemical compounds which undergo physiological pro-
cesses that mimic the endogenous molecules in the subjects. We refer to thos e
as radiotracers. Based on dynamics of radiotracer molecules the properties of
endogenous molecules a re inferred. The nuclear imaging that is used to moni-
tor these changes over time will be referred to as dynamic nuclear imaging or
dynamic ...