Module 7

Question 1

What is a radiograph?

Answer 1

An image produced by the effect on photographic film of the
differential attenuation of a beam of radiation passing
through the body.

Question 2

Contents of Film Packet

Answer 2

• Plastic wrapper
• Outer covering
• Lead foil
• Black paper
• Film

Question 3

Intensifying Screens

Answer 3

Consist of fluorescent phosphors which emit light when
excited by x-rays which are imbedded in a plastic matrix
• Rare earth phosphors with gadolinium and lanthanum
• Yttrium (non rare earth phosphor
• Calcium tungstate (CaWO4)

Question 4

Cassettes

Answer 4

• Light tight aluminum or carbon container

* The film is sandwiched between the intensifying screens

Question 5

Film Latitude

Answer 5

• Measures a range of exposures
• Distinguish differences in optical density
• Wider film
• Greater range of densities

Question 6

Contrast

Answer 6

• Refers to density differences that result due to the type of
film used, how it was exposed and how it was produced.
• Exposing a film to produce higher film densities will
generally increase the contrast in the radiograph

Question 7

Line Focus Principle

Answer 7

• This is the principle that viewing a sloped surface at an angle reduces its
apparent size.
• In an x-ray tube the angling of the anode results in the effective focal spot
being smaller than the actual focal spot