random questions

Question 1

In an intra oral x ray set where are the x ray photons produced

Answer 1

Anode- tungsten target

Question 2

In an intra oral x ray set what is the purpose of the aluminium filter

Answer 2

to preferentially attenuate low energy x rays

Question 3

In an intra oral x ray set what is the purpose of the collimator

Answer 3

To restrict the x ray bean to a chosen area

Question 4

In an intra oral x ray set what range is the high tension voltage circuit set at

Answer 4

the 65-70 kVp range

Question 5

What does Compton scatter do

Answer 5

Reduces contrast in an image

Question 6

What is the mA current setting on an intra oral x ray set to

Answer 6

Controls the number of electrons produced at the filament

Question 7

How is the excess heat dissipated in an intra oral x ray set

Answer 7

By convection in the oil surrounding the tube

Question 8

Why is excess heat produced in an intra oral x ray set

Answer 8

Due to inefficient x ray production

Question 9

What does rectangular collimation allow for

Answer 9

1. Ensures object and receptor are in the correct relationship
2. helps align the tube to the film
3. Holds the film in the correct position
4. Reduces pt dose by around 40%

Question 10

What does the stochastic effect of ionising radiant occur as a result of

Answer 10

Chance events

Question 11

What does the paralleling intra oral technique enable

Answer 11

The beam to be centred to the film

Question 12

What shape should the collimator of an x ray beam be

Answer 12

Rectangular

Question 13

What determines the non stochastic effects of ionising radiation

Answer 13

Dose dependent

Question 14

What should the x ray beam be positioned

Answer 14

Perpendicular to the tooth and image receptor to prevent distortion

Question 15

What is the Frankfort baseline

Answer 15

A radiographic plane that extends from the external auditory meatus to the infra orbital margin

Question 16

What should be carried out prior to every exposure

Answer 16

Justification

Question 17

Who needs to justify the exposure

Answer 17

The practitioner

Question 18

Who is IRMER17 intended to protect

Answer 18

Patients

Question 19

What do the ionising radiation regulations 2017 require

Answer 19

All exposures to be restricted as far as reasonably practicable (ALARP)

Question 20

If a member of staff is pregnant what should they do

Answer 20

Inform her employer in writing if they believe they are pregnant

Question 21

What must the radiation protection supervisor have

Answer 21

Must have received appropriate training

Question 22

What is the role of the radiation protection supervisor

Answer 22

Ensure that local rules are being followed and enforced

Question 23

What is the absorbed dose for a mandibular molar radiograph

Answer 23

2 mGy

Question 24

What is Bremsstrahlung or ‘braking radiation’ a major source of

Answer 24

Photons in x ray tube

Question 25

What is the useful interaction of photons with matter when taking intra oral x rays Called

Answer 25

Photo electric absorption

Question 26

What is a diagnostic reference level (DRL)

Answer 26

It is the radiation dose which should not be normally exceeded for a standard exposure

Question 27

What should the minimum focus to skin distance of a beam collimator be

Answer 27

200mm

Question 28

At what tube potential range should intra oral radiography equipment operate at

Answer 28

60-70kV

Question 29

How effect is x ray production in a diagnostic x ray tube

Answer 29

1%

Question 30

How far away from the dental X-ray tube does the controlled area extend?

Answer 30

As defined in the local rules

Question 31

What happens in the photoelectric effect

Answer 31

The incident photon is completely absorbed

Question 32

What does the effective dose express

Answer 32

The probability of cancer incidence in a population

Question 33

What is absorbed dose

Answer 33

A measure of the energy deposited in tissue per unit mass

Question 34

Talk through the process of Bremsstrahlung (braking radiation)

Answer 34

An incident electron interacts with the nucleus releasing an x-ray photon

Question 35

What is image sharpness not affect by

Answer 35

change in kVp

Question 36

Way is patent dose not affected by

Answer 36

Using a rotating anode target

Question 37

What is dose optimisation

Answer 37

a diagnostically relevant image is obtained at the lowest dose

Question 38

What is the minimum legal filtration for a dental x ry set up

Answer 38

1.5mm Al

Question 39

What are the deterministic effects of ionising radiation

Answer 39

They have a threshold dose bellow which they do not occur

Question 40

What relationship does Stochastic radiation follow

Answer 40

are assumed to follow a linear no threshold relationship to dose

Question 41

What is the most likely radiation export to an operator

Answer 41

Compton of inelastic scattering

Question 42

Why should the x ray beam be collimated

Answer 42

limit extraneous radiation that does not play a part in the imaging process.

Question 43

What is the equivalent dose

Answer 43

absorbed dose to an organ or tissue weighted for type of radiation

Question 44

What roles does there health and safety executive have

Answer 44

1. Can prosecute a practice under the ionising radiation regulations
2. can serve enforcement notices including those which could stop work with X-rays
3. have statutory powers which allow inspectors to visit a practice unannounced
4. must have issued a registration before work with an x-ray device commences

Question 45

What is not required int eh local riles

Answer 45

An exposure chart containing both local and national diagnostic
reference levels