1. Gamma Camera Technology
BY M.E.THIRUMURUGAN BSC(AHS) SRMC

2. Gamma Camera
Developed by Hal Anger in 1957 therefore also called Anger camera
An electronic device that detects gamma rays emitted by radio pharmaceautical (e.g technetium 99 m) that have been introduced into body as tracers.
The position of the source of the radioactivity can be plotted and displayed on a tv monitor

4. Gamma Camera
Is a device used to image gamma radiation radioisotopes this technique is called also scintillation camera.
Gamma camera is used to view and analyse images of the human body or the distribution of the medically ingested, injected or inhaled radionuclides.
Specific Feature: scan whole body anterior and posterior view simultaneous

5. Gamma Camera

6. Gamma Camera Components
Collimator
Crystal
Photo multiplier tubes
Other circuits
Gantry

7. Gamma Camera Components
COLLIMATOR:
It is made from lead
Maintains the quality of image
Spaces between holes is called septa
Collimator constists of a series of holes in a lead plate can be used to select the direction of rays failing on the crystal
The collimator provides an interface between the patient and the scintillation crystal by allowing only those photons traveling in an appropriate direction.

8. Collimators

9. Collimators Types of collimators: A) By the accepted energy.
B) By the geometric shape.
C) By the resolution.

10. High Energy Collimator Medium Energy Collimator
Collimators
By the accepted energy
Low Energy CollimatoR
High Energy Collimator
Medium Energy Collimator

11. Converging collimator
Collimators
By the geometric shape.
Diverging collimator
Parallel-Hole
Pin-Hole Collimator
Converging collimator

12. Collimators Pin-Hole (more resolution & magnification) hip,thyroid
Parallel-Hole
Diverging
Converging

14. Crystal
Any damage to the crystal results in an inoperable scintillation camera and requires costly replacement of the crystal.
The large surface area, as well as the hygroscopic and brittle nature of the crystal, calls for constant care to avoid puncturing the housing or otherwise damaging the crystal.

15. Crystal
The chosen material for the crystal is sodium iodide with thallium.
The Na-I (Tl) crystal is stationary.
The crystal transform the gamma-ray photon > Light photon

16. Photomultiplier tube Dynode Connected to High positive volt
Photocathode

17. Photomultiplier tube
The Photocathode transform the light photon --- electron.
The PMT multiplies the electron to be a significant detected signal.

19. Other circuits
1)Pre-Amplefier
2) Amplifier

23. Advantages of Gamma Camera
The imaging time is only 1-2min
Relatively inexpensive
Cheaper than CT or MRI

24. Disadvantage of Gamma Camera
Radiation exposure
Contrast materials sometimes used might produce an allergic reaction