Radiation Biology

Question 1

Define protraction and fractionation.

Answer 1

1. protraction is when radiation dose is split up over time

2. fractionation is when radiation is delivered in doses

Question 2

Why is it preferred to do Skull images PA?

Answer 2

because ESE is higher on the side closest to the source, exposure to the eyes can be lowered if done PA

Question 3

What are the ESE for the following exams?

1. AP Abdomen
2. AP L-Spine
3. PA Chest
4. AP Axial C-Spine

Answer 3

1. 3.0 mSv
2. 3.5 mSv
3. 0.2 mSv
4. 0.8 mSv

Question 4

What is the conversion of rem to Sv?

Answer 4

100 rem = 1 Sv

Question 5

What is used to account for the differences in tissue sensitivity to ionizing radiation when determining effective dose “E”?

Answer 5

Tissue weighting factors (W1); that is it. the Radiation Weighting Factor (W2) measures radiation’s effect on tissue

Question 6

What type of radiation (scatter, primary, etc.) is leakage radiation?

Answer 6

scatter

Question 7

T/F: The least amount of scatter radiation is at a 70 degree angle from the long axis of the body.

Answer 7

false: the least amount of scatter is perpendicular to the scattering object (patient).