Radiography

Question 1

How does radiography work?

Answer 1

1. Electromagnetic radiation ‘x-rays’ are produced by electrons colliding with a tungsten anode within the x-ray machine.
2. This beam of x-rays is then directed through the anatomy of interest onto a plate which contains film (or a digital plate).
3. Different tissues will absorb x-rays at different rates (attenuation) and hence the image produced is a result of the differential number of x-ray photons reaching the plate having passed through the tissue.
4. The plate is then processed or digitally analysed to create ‘radiograph’ itself.

Question 2

What does the quality and intensity of the beam produced by the machine depend on?

Answer 2

1. tube current (measured in milliamps mA)
2. Volatage (kV)
3. Exposure time (seconds)

Question 3

collimation

Answer 3

well collimated = square

Question 4

exposure

Answer 4

describes the amount of radiation used to generate the image.
Over exposed = too dark
under exposed = too light

Question 5

scatter

Answer 5

when putside areas of the collimated beam look exposed = can see a faint outline of the tissues outside of collimated area

Question 6

development

Answer 6

under = poor contrast areas = should be black, appear grey

Question 7

what do you need to analyse?

Answer 7

1. collimation
2. Development
3. Scatter
4. exposure