Radiation Protection And Dosimetry Flashcards

1
Q

What units is Absorbed dose measured in, and what type of effects does it effect?

A
  • Gy (Greys)

- Absorbed dose is used to relate deterministic effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What unit is effective dose measured in, and what type of effects does it relate to?

A
  • Sv (Sieverts)

- Effective dose relates the probability of stochastic effects occurring?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What factors effect the uniformity of dose in CT?

A
  • Patient thickness

- Scan Field of View

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Automatic Tube Current Modulation?

A
  • Balances patient dose and image quality by altering the mA.
  • uses the scout scan to to calculate the changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the types of shielding in CT?

A
  1. Bismuth

2. Lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe bismuth shielding.

A
  • Used for anterior dose reduction
  • In plane shielding
  • Must be outside the SFOV for the scout scan, otherwise useless
  • Effects ATCM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe lead shielding?

A
  • Enhances perception of safety
  • Out of plane shielding
  • Must be wrapped 360 degrees around the patient
  • No effect on image quality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is over ranging?

A

In order to ensure that the entire area of interest is scanned, a scan will start slightly above the anatomy of interest and proceed below the anatomy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly