Distance

Question 1

Distance

Answer 1

represents the length of the distance between the x-ray source to the image receptor

Question 2

The intensity of the x-ray beam is affected by changes in the ______________

Answer 2

source to image distance (SID)

Question 3

When SID is doubled, the same number of photons is spread over an area _________ the original area, and the intensity of the beam is reduced to ____________ of the original intensity

Answer 3

• four times
• one-fourth

Question 4

Beam intensity is measured in _________

Answer 4

Roentgen (R)

Question 5

Inverse square law applies to x-ray unit or radiation source. Measures:

Answer 5

• intensity of radiation source
• exposure rate

Formula:
Old I New D^2
=
New I Old D^2

Question 6

Direct square law: as SID _______, so must mAs to maintain adequate radiographic density.

Answer 6

increases

Question 7

Direct square law applies to:

Answer 7

patient and radiographic exposure

Formula:
New mAs New D^2
=
Old mAs Old D^2