Can u scan the volume of the brain without being injected with radioactive substances ? What is the procedure called ?

Yes,an the procedure is called Prositron Emission Tomography (PET)

Explanation:Positron emission tomography is a type of nuclear medicine procedure that measures metabolic activity of the cells of body tissues. PET is actually a combination of nuclear medicine and biochemical analysis. Used mostly in patients with brain or heart conditions and cancer, PET helps to visualize the biochemical changes taking place in the body, such as the metabolism (the process by which cells change food into energy after food is digested and absorbed into the blood) of the heart muscle.

a1 = unhealthy

a2= healthy

a3= healthy