Radilogy Quizzes

Question 1

X-rays and visible light are both forms of electromagnetic radiation. Compared to visible light photons, X-rays photons have a lower what?

• energy
  -frequency
• wavelength

Answer 1

Wavelength

Question 2

In a dental X-ray tube what metal is used for the focusing cup?

Answer 2

Molybdenum

Question 3

During a dental radiograph exposure, what is the primary type of interaction happening in the patient between the X-ray photons and the outer shell electrons.

Answer 3

Compton effect

Question 4

Which of these is measured in grays?

Absorbed dose
Effective dose
Equalvent dose

Answer 4

Absorbed dose

Question 5

What type of radiation effects are we concerned about in dental radiography

Answer 5

Somatic non-deterministic

Question 6

What is the most common mechanism by which X-ray photons cause carcinogenesis

Answer 6

Indirect damage to DNA

Question 7

What model do use to estimate the risk of stochastic effect

Answer 7

LNT model.

Linear No threshold model

Question 8

If you have a panoramic radiograph taken, you are more likely to die from that than you are to winning the euro millions with 100 lottery tickets

Answer 8

True

Question 9

If a person standing 2mm from an X-ray source receives an equivalent dose of 20uSv, how many microsieverts will they receive if they stand 4m away

Answer 9

5 microsieverts

Question 10

At least how far away should you be from the X-ray source and patient when radiographing

Answer 10

1.5 metres

Question 11

You should never take routine dental radiographs of a pregnant patient in her first trimester?

True or false

Answer 11

False.

Question 12

Based on UK averages, what is the source of roughly half of our annual ionising radiation

• cosmic rays
• radon gas
• medical exposures
• injested food

Answer 12

Radon gas

Question 13

What should the ‘ focus to skin distance’ be for a dental X-ray unit ( operating >60kv)

Answer 13

200mm/20cm

Question 14

If there has been under exposure of the film what effect will this have on the image

Answer 14

Lighter image

Question 15

If the developer solution has been too warm or concentrated what effect will. It have on the image

Answer 15

It will cause a darker image

Question 16

If the developer is too old, passed its expiration date what kind of image will this result in

Answer 16

A ligher image

Question 17

If the film gets left in the solution for too ling what kind of image will this results in

Answer 17

Darker image

Question 18

If there is inadequate fixation of the film what will this result in

Answer 18

Contrast of the image will be reduced

Question 19

If the film is exposed to visible light before processing what will happen

Answer 19

Darker image

Question 20

The processed film appear greenish and browns over time what has happened here?

Answer 20

Inadequate fixation

Question 21

Which of the following can affect digital radiographs?
- exposure issues
- developing issues
- fixation issues
- washing issues
- none of the above

Answer 21

Exposure issues

Question 22

Which of the following are suitable methods of viewing film images - against a computer monitor
-against a window
- on. A light box
- towards a ceiling. Light
- all of the above

Answer 22

On the light box

Question 23

For conventional cephalogram units why is there a relatively large distance (1.5m+) between the X-ray source and the receptor?

Answer 23

To reduce asymmetrical magnification of anatomy

Question 24

In a cephalogram the X-ray beam is perpendicular to the receptor and which facial plane

Answer 24

The mid saggital plane

Question 25

In cephalograms the patient often wears lead protection to protect what

Answer 25

Thyroid gland

Question 26

Why is the cephalostat important

Answer 26

To produce reproducible images for comparison over time