Ionizing Radiation and X- Ray Exposure

Question 1

Deterministic radiation occurs with big exposures like atomic bombs or industrial uses (rare in diagnostic imaging) What is deterministic ionizing radiation?

Answer 1

A dose that exceeds a particular threshold causing immediate damage.

Question 2

Once ionizing radiation exceeds the determination threshold, damage is _________________.

Answer 2

Inevitable (and severity increases as the dose increases)

Question 3

Two examples of local deterministic damage from radiation

Answer 3

1. Skin burns
2. Cataracts

Question 4

Sources of X-ray exposure (3)

Answer 4

1. Primary beam/ useful beam
2. Scatter
3. Leakage from tube housing (old or
   portable units)

Question 5

We are most concerned about the upward direction of scatter. What is scatter

Answer 5

Primary beam interaction with matter (body tissue) resulting in “scatter” of the primary x-ray beam

Question 6

What are three things that influence primary beam interaction (scatter)

Answer 6

1. Intensity
2. kVp
3. Structure & thickness of part being
   x-rayed

Question 7

Whats another way to refer to photons

Answer 7

Ionizing Radiation

Question 8

What is ionizing radiation

Answer 8

Radiation that causes other ions to lose electrons

Question 9

What is the exposure unit for “absorbed dose”

Answer 9

Gray (RAD)
1 Gray= 100 RADs

Question 10

What is meant by absorbed dose?

Answer 10

Energy absorbed into matter