b) Gamma camera

b) gamma camera; components - collimator, scintillator, photomultiplier tubes, computer and display; formation of image

c) diagnosis using gamma camera

gamma camera

• collimator → scintillator → light guide → photomultiplier tubes → circuits → computer

scanning process

• gamma photons travel towards the collimator

  • arrive at an angle → absorbed

  • arrive along the axis of the tubes → reach the scintillator

• gamma photon hits the scintillator

  • produces thousands of visible light photons

• visible light photons travel through the light guide into the photomultiplier tubes

• one photon is converted into a voltage signal

• voltage signals generate an image depending on the concentration of the tracer

x-ray imaging → shows anatomy

gamma imaging → shows functions and processes