There are many! See the attached link to the Wikipedia article on radiopharmacology. Out of them all, I'd say my favorite pharmacological radioisotopes are 131I, 18F and 99-mTe, which are probably...
To use a radioactive isotope as a tracer, you simply introduce a compound containing it into the system you're looking at at the chosen starting point, then look for its radioactivity at the test...
They are used for C.A.T. Scans for the Dye that is used when the Scan is being done.
The dye is the "Isotopes", which alows the Tech, and the Doctor, to see the area, or
area's that are...