1. Gamma Camera Technology

2. 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.

3. Gamma Camera

4. Gamma Camera Components
1-Collimators
The collimator provides an interface between the patient and the scintillation crystal by allowing only those photons traveling in an appropriate direction.

5. Collimators

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

7. High Energy Collimator Medium Energy Collimator
Collimators
By the accepted energy
Low Energy Collimator
High Energy Collimator
Medium Energy Collimator

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

9. Collimators Pin-Hole (more resolution & magnification) hip,thyroid
Parallel-Hole
Converging لتكبير الصورة وتحديد أفضل للأعضاء
Diverging للتصغير في حالة المريض البدين

11. 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.

12. Crystal The chosen material for the crystal is Na-I (Tl).
The Na-I (Tl) crystal is stationary.
The crystal transform the gamma-ray photon > Light photon

13. Photomultiplier tube Dynode Connected to High positive volt
Photocathode

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

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

16. Advantages of Gamma Camera
The imaging time is only 1-2min.
It can distinguish 2 sources about 5mm apart.

17. Types of imaging in Nuclear Medicine
Planar (Gamma Camera).
Static.
Dynamic.
Total Body.
Tomographic (SPECT).

19. Static Imaging It is the basic type of imaging.
The patient is injected before imaging.
The camera head is located at the organ of interest.
For dual head cameras two images can be acquired at the same time.
The stopping mechanism is either by Count or Time.

20. Static Imaging
The matrix size is defined according to the need from each exam starting from 64X64 up to 1024 X 1024.
The zoom is defined according to the size of the organ of interest.
Examples:
Thyroid imaging: 500 Kc acquisition count or 5 Min acquisition time with injected dose of 5 mCi
matrix= 128 X Zoom = 2 : 1

21. Static Imaging
Bone imaging: 500 Kc acquisition count or 5 Min acquisition time for each position with injected dose of 20 mCi
matrix= 512 X Zoom = 1 : 1

22. SPECT imaging What is SPECT ?
Single photon to differentiate from two annihilation photons
Generation of cross - sectional images
Images from various angular projections

23. Collectively, the different projections contents represent the basic raw data, which is then mathematically reconstructed to yield the transverse section images

24. Dual head scanner
Single head SPECT