Question

Why do we usually use isotopes emitting gamma radiations as radioactive tracers in medical science?​

Answer 1

Radioactive tracers are salts of weak radioactive isotopes (radio sodium chloride, radio-iron) used for diagnosis. Radio-sodium chloride is injected with common sodium chloride in human body. Radiation used tracers must be penetrable enough to reach the malignant tissues and cells in the human body. That's why Gamma radiations are used as radioactive tracers in medical science.​