Exam Prep - Peter

Question 1

What is quality

Answer 1

Range of photon energies carried by the beam “penetrating power”

Question 2

What is intensity

Answer 2

Equal to the number of photons in the beam

Question 3

Factors affecting the quantity & intensity

Answer 3

Size of the tube current
Distance between the detector & target
Exposure time
Target material

Question 4

What does the size of the tube current do to quality & intensity

Answer 4

Intensity = increased

Quality = no change

Question 5

What does the distance between the detector and target do to quality & intensity

Answer 5

Intensity = decreased
Quality = no change

Question 6

What does the exposure time do to quality and intensity

Answer 6

Intensity = increased
Quality = no change

Question 7

What does the target material do to quality & intensity

Answer 7

Intensity = increased/decreased
Quality = no change

Question 8

What is the duty of a referrer

Answer 8

Health care professional entitled to request/refer for medical exposure (must have clear medical evidence to justify the reason for exposure)

Question 9

What is the duty of the operator

Answer 9

Responsible for the practical aspect (performs & optimises medical exposure)

Question 10

What is the duty of the practitioner

Answer 10

Responsible for the justification of exposure

Question 11

What are the factors should be considered when justifying a radiographic exposure

Answer 11

Objectives
Characteristics of the individual
Total potential diagnostic
Benefits / risks
Efficiency, benefits & risks of alternative methods

Question 12

Describe continuous radiation

Answer 12

Continuous X-ray spectra
Produced by breaking radiation

Electron is attracted towards a nucleus & deviated, giving off an IR photon

Question 13

Describe characteristic radiation

Answer 13

Line spectra

Electron is accelerated towards a target metal, hits an electron in the atoms shell and causes it to be ejected
Electron from a higher energy level gives off a photon & drops down an energy level top fill the space in the shell

Question 14

What is Compton scatter

Answer 14

X-ray photon interacts with an outer shell electron causing the photon to change direction

Question 15

What is photoelectric absorption

Answer 15

X-ray photon gives up all energy to eject an electron from its shell

Question 16

What is thermionic emission

Answer 16

Putting enough energy into the filament to liberate the electron

Question 17

What does Kv represent

Answer 17

Tube charge

Question 18

What does Mas represent

Answer 18

Tube current

Question 19

How many base units are there

Answer 19

7 base units

Question 20

What are derived units

Answer 20

Always contain on of the following base units: m, kg, s

Question 21

What are vector quantities

Answer 21

Quantity with direction & magnitude

Question 22

What are scalar quantities

Answer 22

Quantities with magnitude only

Question 23

What does a Kilo (k) represent

Answer 23

1000

(Multiple)

Question 24

What does a Milli (m) represent

Answer 24

0.001

(Submultiple)

Question 25

What does a micro represent

Answer 25

0.000001

Question 26

What is the atomic mass

Answer 26

Number of protons & neutrons (top number)

Question 27

What is the atomic number

Answer 27

Number of protons in the nucleus (bottom number)

Question 28

What are the electric charges for P, N & E

Answer 28

Proton = +1 Neutron = 0 Electron = -1

Question 29

What are the sources of EIR

Answer 29

X-rays (electromagnetic spectrum)

Question 30

What are the types of IR

Answer 30

X-rays Alpha particles Beta particles Gamma rays

Question 31

How are X-ray photons produced at the atomic level

Answer 31

X-ray photons a produced by accelerating electrons towards an anode target

Question 32

What is half value thickness

Answer 32

The thickness of a substance which will transmit one 1/2 of the intensity of the radiation incident upon it

Question 33

Define absorbed dose

Answer 33

The energy deposited per unit mass

Question 34

Define equivalent dose

Answer 34

A measure of the radiation dose to tissue

Question 35

Define effective dose

Answer 35

Compare the stochastic risk of non-uniform exposure to radiation

Question 36

What are grids and their uses

Answer 36

Grids are made up of strips of lead & low-attenuation material Reduce scatter - scattered photons hit the grid & are absorbed by lead strips

Question 37

What is deterministic risk

Answer 37

Have a threshold dose below which the effect will not occur

Question 38

What is stochastic risk

Answer 38

It is a chance as to wether or not the person will develop cancer