X-ray computed tomography (CT):
–Complex computer manipulations of data obtained from x-ray absorption by tissues of different densities.
•Soft tissue.
•Positron-emission tomography (PET):
–Radioisotopes that emit positrons are injected into blood stream.
•Collision of positron and electron result in emission of gamma rays.
–Pinpoint brain cells that are most active.
»Brain metabolism, drug distribution.
•Magnetic resonance imaging (MRI):
–Protons (H+) respond to magnetic field, which align the protons.
•Emit a radio-wave signal when stimulated.
–Brain function.