49. NUCLEAR IMAGING: ANGER CAMERA Flashcards
1
Q
- How do we obtain the functional imaging of organs during nuclear medicine?
A
- we use a large Scintillation Device
2
Q
- What did Hal Oscar Anger do in the 1950s?
A
- he developed the basic design of the Modern Nuclear
Medicine camera
3
Q
- What happens at the Camera Head in this image?
A
- this is where we find the Scintillation Crystals
- this is where we find the Photomultiplier Tubes
4
Q
- What role is the patient playing in this image?
A
- the patient is the source of the Radiation
5
Q
- What are the 4 main components of the Anger Camera?
A
- Collimator
- Camera Head
- Electronics
- Computers
6
Q
- What is the role of the Collimator?
A
- it prevents the photons from passing and reaching the
crystal - this is due to the holes and the sceptres
- these are made of lead
- this lead absorbs the photons
7
Q
- What happens when the Gamma Rays pass through the holes and the sceptres?
A
- the gamma rays are singled out to only specific
directions
8
Q
- What is the Camera Head compiled of?
A
- the Crystal
- the Photomultiplier Tubes (PMTs)
9
Q
- What do we the Computers do?
A
- they acquire images
- they process the images
10
Q
- What happens in order to produce Digital images?
A
- light photons are converted into a signal
- this is a result of the presence of the Photo Multiplier
Tubes
11
Q
- What is the Function of the Collimator?
A
- it restricts the rays from the source
- this ensures that each point in the image corresponds
to a unique point in the source
12
Q
- What are Collimators composed of?
A
- they are composed of thousands of precisely aligned
holes - these holes are depicted in a cross section
13
Q
- What do Nuclides emit?
A
- they emit Gamma Ray Photons in all directions
14
Q
- What does the Collimator allow for?
A
- it allows for only specific photons to reach the crystal
- these are the photons that travel directly along the
long axis of each hole
15
Q
- What is the usefulness of the Collimator function?
A
- we cut the photons that are not useful
- we reduce the sensitivity
- this increases the resolution
- this ensures that the image is clear
16
Q
- What happens with the photons that are emitted in any other direction?
(than the directly along the long axis)
A
- these are absorbed by the Septa
- this is found between the holes
17
Q
- Where do we place the Collimator?
A
- in front of the Crystal
18
Q
- What is the purpose of the different types of Collimators?
A
- they are designed to channel photons of different energies
19
Q
- What are the benefits of choosing the correct type of Collimator?
A
- we can either magnify the images
- or we can reduce the images
20
Q
- What other two factors can we select between when we chose a specific type of Collimator?
A
- imaging quality
- imaging speed
21
Q
- What kind of Collimator does this image represent?
A
- a Parallel Hole Collimator
- this produces a high- sensitivity
- it produces a low-resolution
22
Q
- What kind of bore does a Parallel Hole Collimator have?
A
- it has a Standard Bore
- it is designed for rectangular gamma heads to
work alongside it - it is used to image small organs
(heart / brain)
23
Q
- What affects the image quality?
A
- the size of the hole of the Collimator
24
Q
- What kind of Collimator does this image show?
A
- a Diverging Collimator
- this is used to mage objects that are larger than the
field of view of the detector - this detector has a parallel hole collimator
25
Q
- What kind of Collimator does this image show?
A
- a Converging Collimator
- this magnifies the image on the Camera face
- it has a higher resolution
- it has a higher sensitivity
26
Q
- What kind of Collimator does this image show?
A
- a Pinhole Collimator
- it has a high resolution
- it has a low sensitivity
- it magnified the organ
27
Q
- What does a smaller Collimator hole diameter result in?
A
- a higher resolution
- less noise in the image
28
Q
- What does a larger Collimator hole diameter result in?
A
- more photons passing through the Collimator
- more blur
- lower resolution
